Re: [FRIAM] Peter Lissaman
I'm very sorry to hear of this news. As much as I found his style somewhat abrasive, he did send me some private communications that were very encouraging, and I certainly recognized his brilliant mind. Thanks for letting us know. Hugh Trenchard - Original Message - From: "Grant Holland" To: "The Friday Morning Applied Complexity Coffee Group" ; "Holland, Grant" Sent: Monday, March 12, 2012 8:10 AM Subject: [FRIAM] Peter Lissaman Friends, It is with the deepest regret that I must tell you that our friend, colleague and inspiration Peter Lissaman passed away in Santa Fe early Sunday morning. His piquant humor, brilliant insight, instrumental contributions and colorful history in science and engineering in the latter part of the twentieth century touched many of us. I'm sure he will be deeply missed in our ranks. Best regards, Grant FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] A Good Question - Should the United States join OPEC?
Thanks for responding. Of course with natural gas, the first thing comes to my
mind is "Gasland'. But I suppose if some ot those environmental issues can be
brought under control, natural gas seems like it will be a big economic driver
for a while.
- Original Message -
From: Joshua Thorp
To: The Friday Morning Applied Complexity Coffee Group
Sent: Tuesday, February 28, 2012 8:01 PM
Subject: Re: [FRIAM] A Good Question - Should the United States join OPEC?
This sounds right to me. There is a lot of finger wagging at Iran for not
having domestic capacity for petroleum refinement even though they are a crude
exporter. So I guess capacity works both ways. The other thing I know is
currently a hot topic is natural gas production. I believe the US has
increased its production quite a bit lately and is likely to have a lot more in
the future.
On Feb 28, 2012, at 8:40 PM, Hugh Trenchard wrote:
Just as a brief follow up, it seems to me one of the major factors in this
is that U.S. refining capacity has increased so that there is less need to
import refined petroleum products. I haven't researched this in any detail and
I stand to be corrected on all my assertions, but it seems to me it's not as
though there are any new sources of US domestic supply or significant increase
in technological ability to extract previously hard to obtain oil, and likely
only marginal reduction in demand. There may be some, but my thought is the
hype on this is rather misleading. Again I don't have the figures, but my
guess is that the vast majority of US crude imports likely still come from
Canada, Mexico, and other western hemisphere nations, which the U.S. refining
companies refine and re-sell as petroleum products, both for domestic use and
to export abroad.
The link below shows some of the definitions used in the petroleum/fuels
industry. From my skeptical standpoint, the hype could mislead the American
public toward a false sense of security. I suppose if it stimulates the
economy, then that's good, but if it gets people guzzling more gas, then it's
really just a fool's game.
http://www.eia.gov/dnav/pet/TblDefs/pet_move_imp_tbldef2.asp
From the link: "Petroleum products are obtained from the processing of
crude oil (including lease condensate), natural gas, and other hydrocarbon
compounds. Petroleum products include unfinished oils, liquefied petroleum
gases, pentanes plus, aviation gasoline, motor gasoline, naphtha-type jet fuel,
kerosene-type jet fuel, kerosene, distillate fuel oil, residual fuel oil,
petrochemical feedstocks, special naphthas, lubricants, waxes, petroleum coke,
asphalt, road oil, still gas, and miscellaneous products."
- Original Message -
From: Russ Abbott
To: The Friday Morning Applied Complexity Coffee Group
Cc: Hugh Trenchard
Sent: Monday, February 27, 2012 7:47 PM
Subject: Re: [FRIAM] A Good Question - Should the United States join OPEC?
We exported more petroleum products, not more oil. We are still net oil
importers.
-- Russ Abbott
_
Professor, Computer Science
California State University, Los Angeles
Google voice: 747-999-5105
Google+: https://plus.google.com/114865618166480775623/
vita: http://sites.google.com/site/russabbott/
_
On Mon, Feb 27, 2012 at 7:42 PM, Owen Densmore
wrote:
From
http://www.huffingtonpost.com/2011/05/03/us-becomes-net-exporter-o_n_857085.html
While some Americans cut back on driving as gas prices soar, the U.S.
has become a net exporter of fuel for the first time in nearly 20 years.
According to data from the Energy Department,starting last November
-- with the exception of the month of January -- the U.S. began exporting more
petroleum products than it imported.
This is not the source I got the idea from, its been in the news quite
a bit lately, this is just the first google hit I tried.
The theory is that between the recession (thus less use of fuel, both
supply side and demand), conservation/efficiency, and more recent hi-tech
oil/gas exploitation (horizontal drilling), the US consumption has dropped and
the production has increased, causing a net surplus.
It certainly is surprising.
-- Owen
On Mon, Feb 27, 2012 at 6:54 PM, Hugh Trenchard
wrote:
Where did you see that the US is now a net oil exporter? The
attachments below are 2008 and 2009, but I suspect the picture hasn't changed
much since then (US imports 75% of its oil for consumption). I believe I saw
reference to "potential exporter" in the NY Times article.
http://www.washingtonpost.com/wp-dyn/content/graphic/2008/07/26/GR2008
Re: [FRIAM] A Good Question - Should the United States join OPEC?
Just as a brief follow up, it seems to me one of the major factors in this is that U.S. refining capacity has increased so that there is less need to import refined petroleum products. I haven't researched this in any detail and I stand to be corrected on all my assertions, but it seems to me it's not as though there are any new sources of US domestic supply or significant increase in technological ability to extract previously hard to obtain oil, and likely only marginal reduction in demand. There may be some, but my thought is the hype on this is rather misleading. Again I don't have the figures, but my guess is that the vast majority of US crude imports likely still come from Canada, Mexico, and other western hemisphere nations, which the U.S. refining companies refine and re-sell as petroleum products, both for domestic use and to export abroad. The link below shows some of the definitions used in the petroleum/fuels industry. From my skeptical standpoint, the hype could mislead the American public toward a false sense of security. I suppose if it stimulates the economy, then that's good, but if it gets people guzzling more gas, then it's really just a fool's game. http://www.eia.gov/dnav/pet/TblDefs/pet_move_imp_tbldef2.asp >From the link: "Petroleum products are obtained from the processing of crude >oil (including lease condensate), natural gas, and other hydrocarbon >compounds. Petroleum products include unfinished oils, liquefied petroleum >gases, pentanes plus, aviation gasoline, motor gasoline, naphtha-type jet >fuel, kerosene-type jet fuel, kerosene, distillate fuel oil, residual fuel >oil, petrochemical feedstocks, special naphthas, lubricants, waxes, petroleum >coke, asphalt, road oil, still gas, and miscellaneous products." - Original Message - From: Russ Abbott To: The Friday Morning Applied Complexity Coffee Group Cc: Hugh Trenchard Sent: Monday, February 27, 2012 7:47 PM Subject: Re: [FRIAM] A Good Question - Should the United States join OPEC? We exported more petroleum products, not more oil. We are still net oil importers. -- Russ Abbott _ Professor, Computer Science California State University, Los Angeles Google voice: 747-999-5105 Google+: https://plus.google.com/114865618166480775623/ vita: http://sites.google.com/site/russabbott/ _ On Mon, Feb 27, 2012 at 7:42 PM, Owen Densmore wrote: From http://www.huffingtonpost.com/2011/05/03/us-becomes-net-exporter-o_n_857085.html While some Americans cut back on driving as gas prices soar, the U.S. has become a net exporter of fuel for the first time in nearly 20 years. According to data from the Energy Department,starting last November -- with the exception of the month of January -- the U.S. began exporting more petroleum products than it imported. This is not the source I got the idea from, its been in the news quite a bit lately, this is just the first google hit I tried. The theory is that between the recession (thus less use of fuel, both supply side and demand), conservation/efficiency, and more recent hi-tech oil/gas exploitation (horizontal drilling), the US consumption has dropped and the production has increased, causing a net surplus. It certainly is surprising. -- Owen On Mon, Feb 27, 2012 at 6:54 PM, Hugh Trenchard wrote: Where did you see that the US is now a net oil exporter? The attachments below are 2008 and 2009, but I suspect the picture hasn't changed much since then (US imports 75% of its oil for consumption). I believe I saw reference to "potential exporter" in the NY Times article. http://www.washingtonpost.com/wp-dyn/content/graphic/2008/07/26/GR2008072601599.html http://www.flickr.com/photos/gdsdigital/4056035804/ - Original Message - From: Owen Densmore To: Complexity Coffee Group Sent: Monday, February 27, 2012 9:14 AM Subject: [FRIAM] A Good Question - Should the United States join OPEC? Now for something completely different: http://www.nytimes.com/2012/02/26/opinion/sunday/friedman-a-good-question.html Basically whether or not the US should join OPEC now that it is a net oil exporter. Insane as it sounds, there is some reason in the discussion. -- Owen FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM App
Re: [FRIAM] A Good Question - Should the United States join OPEC?
Thanks for the clarification. It is still surprising nonetheless. - Original Message - From: Russ Abbott To: The Friday Morning Applied Complexity Coffee Group Cc: Hugh Trenchard Sent: Monday, February 27, 2012 7:47 PM Subject: Re: [FRIAM] A Good Question - Should the United States join OPEC? We exported more petroleum products, not more oil. We are still net oil importers. -- Russ Abbott _ Professor, Computer Science California State University, Los Angeles Google voice: 747-999-5105 Google+: https://plus.google.com/114865618166480775623/ vita: http://sites.google.com/site/russabbott/ _ On Mon, Feb 27, 2012 at 7:42 PM, Owen Densmore wrote: From http://www.huffingtonpost.com/2011/05/03/us-becomes-net-exporter-o_n_857085.html While some Americans cut back on driving as gas prices soar, the U.S. has become a net exporter of fuel for the first time in nearly 20 years. According to data from the Energy Department,starting last November -- with the exception of the month of January -- the U.S. began exporting more petroleum products than it imported. This is not the source I got the idea from, its been in the news quite a bit lately, this is just the first google hit I tried. The theory is that between the recession (thus less use of fuel, both supply side and demand), conservation/efficiency, and more recent hi-tech oil/gas exploitation (horizontal drilling), the US consumption has dropped and the production has increased, causing a net surplus. It certainly is surprising. -- Owen On Mon, Feb 27, 2012 at 6:54 PM, Hugh Trenchard wrote: Where did you see that the US is now a net oil exporter? The attachments below are 2008 and 2009, but I suspect the picture hasn't changed much since then (US imports 75% of its oil for consumption). I believe I saw reference to "potential exporter" in the NY Times article. http://www.washingtonpost.com/wp-dyn/content/graphic/2008/07/26/GR2008072601599.html http://www.flickr.com/photos/gdsdigital/4056035804/ - Original Message - From: Owen Densmore To: Complexity Coffee Group Sent: Monday, February 27, 2012 9:14 AM Subject: [FRIAM] A Good Question - Should the United States join OPEC? Now for something completely different: http://www.nytimes.com/2012/02/26/opinion/sunday/friedman-a-good-question.html Basically whether or not the US should join OPEC now that it is a net oil exporter. Insane as it sounds, there is some reason in the discussion. -- Owen FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] A Good Question - Should the United States join OPEC?
Where did you see that the US is now a net oil exporter? The attachments below are 2008 and 2009, but I suspect the picture hasn't changed much since then (US imports 75% of its oil for consumption). I believe I saw reference to "potential exporter" in the NY Times article. http://www.washingtonpost.com/wp-dyn/content/graphic/2008/07/26/GR2008072601599.html http://www.flickr.com/photos/gdsdigital/4056035804/ - Original Message - From: Owen Densmore To: Complexity Coffee Group Sent: Monday, February 27, 2012 9:14 AM Subject: [FRIAM] A Good Question - Should the United States join OPEC? Now for something completely different: http://www.nytimes.com/2012/02/26/opinion/sunday/friedman-a-good-question.html Basically whether or not the US should join OPEC now that it is a net oil exporter. Insane as it sounds, there is some reason in the discussion. -- Owen -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] YES
I thought that was interesting, since "beholds" took me the longest to figure out as well. It seems this is partly because the phrase "beholds with pain" is somewhat archaic and so the context was harder to see, which is largely how we sort out and make sense of the gibberish, it seems. When I figured out "beholds" I just used a basic resorting of letters methods to determine the word rather than reasoning by context. Even when I realized the word must be "beholds", I did a double take to make sense of the phrase. From: Rich Murray To: The Friday Morning Applied Complexity Coffee Group Sent: Saturday, February 11, 2012 7:31 PM Subject: Re: [FRIAM] YES beholds On Sat, Feb 11, 2012 at 7:24 PM, Nicholas Thompson wrote: Daer Gerg Sflonenend, I gesus I hvae azielrithims after all. I nveer frugeid out waht “bdelohs” wrer. Nailchos Tamshpoon From: friam-boun...@redfish.com [mailto:friam-boun...@redfish.com] On Behalf Of Greg Sonnenfeld Sent: Saturday, February 11, 2012 6:07 PM To: The Friday Morning Applied Complexity Coffee Group Subject: Re: [FRIAM] YES The fox who lnoegd for grpaes, bdelohs wtih pian The tpimetng cutelsrs wree too hgih to gian ; Gierved in his haret he fcored a clreseas slmie, And cierd , They are srahp and hlrday wotrh my wlhie . ;-) Greg Sonnenfeld “The scientists of today think deeply instead of clearly. One must be sane to think clearly, but one can think deeply and be quite insane.” -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
[FRIAM] Surf scoter formations
First off, best of the season to everyone! http://www.youtube.com/watch?v=1xKGBcAyZ3g&feature=youtu.be I captured this amazing footage yesterday. These surf scoters, a kind of duck wintering here on the west coast, show interesting clustering patterns. They align direction and increase density as they travel between feeding locations. At feeding locations they spread out and dive in various directions for food. When their feeding opportunities are exhausted in one area, they increase density again, align in a common direction, and high-tail it, so to speak, to the next good feeding area. It seems to me these alignment and density changes are clear phase transitions, and the high density clusters (when they are aligned in direction) appear to involve a wake-following/hydrodynamic mechanism to optimize travel time and energy expenditure. They generally travel at angles to each other, and not directly behind. After capturing this video yesterday on a relatively poor camera, I decided to buy a better HDD camera today and a monopod, for some better footage today. While a technical camera glitch means I have no additional footage from today, much to my chagrin, I did see some fantastic formations of a much larger flock of scoters (perhaps 1000), including an arc formation in which they fan out in a curve of one bird beside each other, perhaps acting something like a net, covering as much area as possible in search of food. I also saw tell-tale signs of a convection pattern whereby following birds, in what I surmise to be zones of lower energy expenditure, pass leading birds in zones of higher energy expenditure, creating a rotational pattern. This is the sort of convection dynamic,very apparent in bicycle pelotons, that I have so much wanted to document in natural collectives. It was unfortunate that I ended up with no additional footage today, but it looks like I will get some more opportunities, as the birds are likely to be around for a while. While there are published papers discussing scoter migratory and foraging patterns, from what I could see there are no published papers discussing in detail these fascinating clustering formations. Hugh Trenchard Victoria, BC FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] Forget not the Physics, Friam Friends!
Thank you for your illuminating observations of Friam discussions, as well as illuminations of your own depth of knowledge. Of course this is why people engage in such informal discussions as these: to learn and share ideas. Insults and denigrations do not come unexpectedly, as I am frankly unsure if there is any other way to interpret some of your comments (but please correct me I'm wrong!), and it certainly takes a certain magnitude of courage to expose one's ignorance in the face of these expectations. Now, we've all seen the various Vee formations. I had queried about in-flight rotational dynamics -- do your papers discuss these dynamics, or do you think I am mistaken that these rotational dynamics actually occur? Assuming they occur, it seems to me they have not been much studied, though I would love to be pointed to references. I have seen the Andersson and Wallander paper "Kin selection and reciprocity in flight formation?" 2004 Behavioral Ecology, Vol. 15 No. 1 (which cites one of your 1970 papers), which proposes a kin selection model for certain dynamics, which I hypothesize (yes "hypothesize") are better explained by an energy dissipation model. Certainly understanding the aerodynamic principles are important as the basis for these dynamics. But these underlying principles do not change the fact that birds and living organisms fatigue at different rates and have finite energy supplies, and if one is looking at a model for in-flight rotational dynamics, I boldy suggest that once we have a general understanding of the aerodynamical principles, the technical aerodynamics are secondary to bird fatigue rates in the various positions within the flight formation. Why would you simply dismiss the possibility of developing a model which describes certain observable collective behaviours - particularly when it is an energy dissipation model, as I like to explore, which is highly amenable to classical physics? Hugh "Modesty is not presuming others know nothing." - Original Message - From: plissa...@comcast.net To: friam@redfish.com Sent: Tuesday, March 08, 2011 12:20 PM Subject: [FRIAM] Forget not the Physics, Friam Friends! It is fun to read Friamers’ hypotheses on formation flight in birds. They are entirely unprejudiced by any knowledge of the topic. Although knowledge of a subject is counter-friamistic and takes hard work, I modestly suggest that it is helpful to understand some of the aerodynamic principles behind formation flight before hyperventilating too much.The fact is that the Biot-Savart Law teaches that the asymptotic state is really quite close, as characteristic of a semi-infinite dipole field. Consequently, aerodynamics shows that for favorable interaction flyers can utilize uneven Vees, branched Vees, small Vees, big Vees, broken Vees – and migrating birds use them all. Or look as though they do! The tip station is theoretically the most unfavorable, but better than being solo. I have published seven papers on avian flight, and read and reviewed a good few more, so don’t know very much, but I would not presume any hypothesis on really why they do it, and who does what to whom. That’s for the birds! Peter Lissaman, Da Vinci Ventures Expertise is not knowing everything, but knowing what to look for. 1454 Miracerros Loop South, Santa Fe, New Mexico 87505,USA tel:(505)983-7728 -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] Birdies do the right thing!
One problem with that, as I see it, is that a weak bird ending up in the hardest position simply cannot sustain it if the strongest bird in the easiest position pushes the pace to its sustainable maximum. At some point, sooner or later, the weak bird will fall off from exhaustion. However, if it trails off from a certain position according to some rate of diminishing strength (rather than a sudden physiological failure), it alters the dynamics of the whole group and, as I hypothesize, effectively creates other optimal positions for other birds (if not itself) - thus a rotational pattern is induced such that somewhere in the process of the changing formation, the weak bird eventually finds itself in optimal or near optimal positions by which it can recover and sustain the average speed of the group. If the rotational dynamics work along principles like this, it is not a matter that the strongest bird can always simply muscle its way into the best position - there will be a continuous rotational dynamic, particularly if the bird in the easiest position becomes isolated because all the trailing birds begin to decelerate. Basically, I'm suggesting there are principles that drive a rotational dynamic - it may be that some birds spend more time in certain positions than others, but they will not be able to remain in those positions. Hugh - Original Message - From: ERIC P. CHARLES To: Hugh Trenchard Cc: The Friday Morning Applied Complexity Coffee Group Sent: Monday, March 07, 2011 7:48 PM Subject: Re: [FRIAM] Birdies do the right thing! Alas, fundamental principles in animal behavior still tell us that animals should act selfishly. For selection to favor weakest individual willing to be in the hardest position, it only has to be the case that being in the hardest position in a group is still better than being alone. The reason we would expect the strongest individuals to be in the easiest positions is because they can move the weak individuals over. Selection should favor strong individuals who do not use their when they don't have to. The only conditions under which this arrangement should be violated is when the strongest individual gains a benefit from the weaker individual's presence. Only if this last condition is satisfied could selection favor strong individual willing to do the hardest job. Of course, if fighting is costly, this must be taken into account. Eric On Mon, Mar 7, 2011 10:00 PM, "Hugh Trenchard" wrote: I'm curious to know if there is much work showing the relative strengths of the birds and their proportionate times spent in various positions. For example, intuitively one might expect that weaker birds would actually take the easiest positions for longer durations (contrary to the ornithologist's assumptions of the day); conversely one might expect the weakest birds to be in the most difficult positions for shorter durations than the stronger birds. I imagine the rotational pattern to be counter-intuitive, at least counter-intuitive to my understanding of peloton dynamics, since a weak bird in a hard position can't simply accelerate to the easiest position at the apex - unlike a weakening cyclist in the hardest position at the front, who can simply decelerate and find a drafting position behind. From this one might imagine that flock rotation is more of a "backwards rotation" in which new effective apex positions are created farther back in the flock. These might be initiated by weaker birds behind the apex position, which due to weakening, gradually drop backward at some angle (perhaps) to its previous trajectory, and creates a new apex position for another bird (but not for the bird that started drifting back). One might imagine events in which such a drift backwards is lateral across to the opposite arm of the vee in order to avoid wing collision and/or some sort of other air instability. This might also create new or effective apex positions where a weaker bird may be able to recuperate. These adjustments behind the apex would also, one might imagine, force the bird in the previous apex position also to readjust position when the imbalance in uplift on either side begins to weaken it (if that happens). In any event, I'm just throwing out some thoughts here and I would be interested to know if there is much work on flock rotational dynamics (I haven't seen much, but I haven't done an exhaustive search). Hugh Trenchard - Original Message - From: plissa...@comcast.net To: friam@redfish.com Sent: Monday, March 07, 2011 12:59 PM Subject: [FRIAM] Birdies do the right thing! Yes, as always, Steve is correct. In my 1971 paper I included some stability calculations indicating that for a flyer moving ahead of the Vee line things became tougher, and vi
Re: [FRIAM] Birdies do the right thing!
I'm curious to know if there is much work showing the relative strengths of the birds and their proportionate times spent in various positions. For example, intuitively one might expect that weaker birds would actually take the easiest positions for longer durations (contrary to the ornithologist's assumptions of the day); conversely one might expect the weakest birds to be in the most difficult positions for shorter durations than the stronger birds. I imagine the rotational pattern to be counter-intuitive, at least counter-intuitive to my understanding of peloton dynamics, since a weak bird in a hard position can't simply accelerate to the easiest position at the apex - unlike a weakening cyclist in the hardest position at the front, who can simply decelerate and find a drafting position behind. >From this one might imagine that flock rotation is more of a "backwards >rotation" in which new effective apex positions are created farther back in >the flock. These might be initiated by weaker birds behind the apex position, >which due to weakening, gradually drop backward at some angle (perhaps) to its >previous trajectory, and creates a new apex position for another bird (but not >for the bird that started drifting back). One might imagine events in which >such a drift backwards is lateral across to the opposite arm of the vee in >order to avoid wing collision and/or some sort of other air instability. This >might also create new or effective apex positions where a weaker bird may be >able to recuperate. These adjustments behind the apex would also, one might >imagine, force the bird in the previous apex position also to readjust >position when the imbalance in uplift on either side begins to weaken it (if >that happens). In any event, I'm just throwing out some thoughts here and I would be interested to know if there is much work on flock rotational dynamics (I haven't seen much, but I haven't done an exhaustive search). Hugh Trenchard - Original Message - From: plissa...@comcast.net To: friam@redfish.com Sent: Monday, March 07, 2011 12:59 PM Subject: [FRIAM] Birdies do the right thing! Yes, as always, Steve is correct. In my 1971 paper I included some stability calculations indicating that for a flyer moving ahead of the Vee line things became tougher, and vice versa. The funny thing, as noted in that paper, was that the lead bird, at the apex of the Vee, had the easiest job. This caused a lotta comment by ornithologists who had observed that the lead position was normally assumed by the oldest and senior bird. They asked, "Why would the strongest take the easiest job?". My cynical answer was, "Twas ever thus, for Birds and Men!" Peter Lissaman, Da Vinci Ventures Expertise is not knowing everything, but knowing what to look for. 1454 Miracerros Loop South, Santa Fe, New Mexico 87505,USA tel:(505)983-7728 -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] The Best 10 Fictional Works
The Glass Bead Game, by Hermann Hesse, is a must-read for any self-respecting complexity theorist :-) Hugh - Original Message - From: "Robert J. Cordingley" To: "The Friday Morning Applied Complexity Coffee Group" Sent: Friday, October 08, 2010 12:44 PM Subject: [FRIAM] The Best 10 Fictional Works Ok, so I've decided my literary education is somewhat lacking and would like to know this group's recommendations for the "10 Best Literary Works" I should read. They have to be works of fiction and available in English and not just say of 2009 but of all time. Google searches tend to list the best of a year or be listed by one particular publisher. This is a good group to poll since you all (most) have at least some kind of scientific/technical bent. So I know the suggestions will be good ones for me! Once I have a list of all suggestions maybe I'll ask you all to vote on them. My list currently starts with Frank's recommendation today: "Blood Meridian: Or the Evening Redness in the West" by Cormac McCarthy Thanks! Robert C. FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] peloton/ leadership in flocks
Just as an update and a follow up note on the cyclist/sperm aggregations, I've
developed (and am continuing to develop) a simple computer peloton simulation
and am working through a series of experiments. Aspects of the simulation apply
to certain sperm aggregates as well (at least I will suggest this).
The plan at this point if for the the sim to involve these sets of experiments:
1. a "no drafting" set where two or more sets of agents proceed according to
their own intrinsic max sustainable speed with no capacity to match the speed
of agents of other sets;
2. a "weak drafting" set, where weaker agents can match the speeds of others if
in a certain proximity of faster agents;
3. a "strong" drafting set where agents actually seek to match speeds of others
by following behind others.
I've completed a set of experiments for number 1, which is the obvious case in
which group sorting occurs according to maximum sustainable output, and the
easiest to simulate. The others are still underway.
My aim is to demonstrate that:
a. group sorting does in fact occur according to relative differences in power
output, and that aggregates occur because their effective fitness levels are
narrowed by a "drafting" effect so their speeds are identical;
b. there is a correlation between aggregate size (ie. number of agents),
differences in relative maximum sustainable output, and the time to which group
sorting occurs.
The prediction is that the time required for group sorting to occur increases
as aggregate size increases and relative differences in max output capacities
("fitness") become smaller. In other words where agents are identically fit,
they will all stay in one group and will never sort (generally); where fitness
levels are different, they will sort rapidly. Drafting facilitates the
narrowing of fitness levels, so even if there are intrinsic differences in
output, agents will aggregate if they can draft such that they travel at the
same speed and at effectively identical output levels.
At the moment, I have in mind that sperm aggregates fall under the category of
"weak" drafting, whereby they randomly/accidently draft, but are incapable of
seeking out drafting positions as are agents in bicycle pelotons. Pelotons
exhibit strong drafting. So, under a weak drafting model, sperm sorting should
occur at some rate faster than pelotons. In a peloton, especially one in which
the entire group consists of riders of closely matched sustainable outputs
(such as a group of professional cyclists), the group will stay together to the
finish (on a uniform course). In a peloton, the primary cause of group sorting
is the occurrence of points in which drafting benefit is reduced such that
drafting no longer equalizes the entire range of output levels, such as hills,
course obstacles, and cross-winds (I have refered in the past to these as
instabilities in the system). The nature of the proximity of sperm to one
another may mean that their weak drafting results in very long sort times, such
that sort times are nearly the same as would occur under a strong drafting
situation, and that is something I can look for as well. There may be some
surprises along the way.
If I can complete the experiments, I may seek to get the results published, or
I may aim to present them first at the 2010 AAAI Conference and seek
publication afterward. Basically the idea is to establish a model by which
predictions can be made for real aggregations, and the model should be
applicable essentially to all aggregates which move at maximum sustainable
outputs and where there is some energy saving component involved in coupled
motion. It won't apply where aggregates move at outputs significantly below max
sustainable outputs, because in those situations even the weakest agent can
keep up with the strongest (the extreme situation is where they all stand
still, or move at the equivalent of a slow walking pace). It can apply,
however, in situations where there is broad range of fitness levels and only
some agents move at maximum sustainable output, because a small increase in
output among the group causes those already at max output to be sorted "off the
back", even when many among the group are not at max output.
Vladimyr - sorry I haven't responded yet on a couple of your posts - I've
realized I need to knuckle down and really work through a simulation, and have
become focussed on that at this point. I hope to be involved in this
discussion more, however, over time.
Hugh
- Original Message -
From: Vladimyr Ivan Burachynsky
To: 'The Friday Morning Applied Complexity Coffee Group'
Sent: Saturday, April 10, 2010 10:16 AM
Subject: Re: [FRIAM] leadership in flocks
How similar to the sperm peloton and the cyclist peloton, now we have flocks
with leaders and cliques?.
If each model has a different organizing principle then why does my simple
mind think th
Re: [FRIAM] Sperm pelotons; article in Nature
Thanks, Eric. That puts it nice and succinctly. That said, I take the points
about how best to characterize "fitness" and will adjust my draft accordingly
(and I had some chuckles over the lighter responses too). I'll revise it and
re-send it sometime over the next few days (it might be old news by then, but
at least it motivates me to keep working on it!). I've just seen Vladimir
Burachynsky's post, and will respond to that momentarily too.
Hugh
- Original Message -
From: ERIC P. CHARLES
To: Nicholas Thompson
Cc: Hugh Trenchard ; Friam@redfish.com
Sent: Monday, March 29, 2010 10:13 AM
Subject: Re: [FRIAM] Sperm pelotons; article in Nature
But Nick,
Hugh's point is that we DO NOT need trait-group selection to explain the
clustering sperm. We merely need sperm to swim in the same direction, AND have
a variety of abilities. Given that alone, Hugh thinks he can prove, sperm will
cluster based on their swimming abilities (which he calls 'fitness'). Thus I
(captial 'I') declare that the real empirical question is whether or not
sperm-in-clusters are more genetically similar than Hugh's model would predict.
Only if THAT were true, would we conclude that group selection was involved, as
the authors of the Nature article have claimed. That is, the authors of the
Nature article have a flawed notion of what would happen by chance if sperm
were swimming along without 'relatedness' detectors, and hence they have a
flawed 'null hypothesis', and hence they have a flawed statistical test.
(This is all in the same sense that Schank's models have convincingly
demonstrated that the results of so-called 'menstrual synchrony' research are
exactly what you would expect due to chance. Those who think they showed
'menstrual synchrony' just have a flawed notion of what happens by chance.)
Eric
On Mon, Mar 29, 2010 12:30 PM, "Nicholas Thompson"
wrote:
Hugh,
I yield to no man in my ignorance of subject we are talking about.
However, two points:
The term "genefur" is one I use to remind myself (and anyone who happens to
be listening) that the common expression, "a gene for", (as in "a gene for
blue eyes" or "a gene for prostate cancer" is deeply problematic. I should
probably say something with more words, such as, "a gene for peletonizing,
whatever the hell that might mean." Although we know that the path from a
trait in parents to the same trait in an offspring is much more tortured than a
Dawkinsian argument requires, and that the material basis for parent-offspring
is not as "atomic" as the expression "a gene for" implies, we continue to need
a term for a unit of inheritance and "genefur" is a quietly ironic way to speak
of units of inheritance while acknowledging that that sort of speech is silly.
As I understand this discussion it has a lot to do with the
group/individual selection argument. Think of it this way. Think of a bike
race containing 20 riders from 5 teams. Let it be the case that the winning
TEAM takes down all the prize money but that it is shared unequally by members
of the team, with half taken by the winning rider, a quarter by the second
rider, and the an eighth by the 3rd rider, and the balance by the fourth, etc.
Now we have set up a conflict between group level and individual level success.
My comments on fitness are only to remind us that "fitness" in a Darwinian
conversation means winning the race by any means. In your terms, "fitness"
means using your resources to produce the maximum output. Call these
"fitnessD" and "fitnessT". One could be "fitT" all by oneself on a stationary
bike. However, as the scene in Breaking Away demonstrates, there are lots of
way to be "fitD" without being "FitT".
I wish we could engage David Sloan Wilson in this discussion, but he is too
damned busy running around the world being famous and talking about the
evolution of religion. Gawd I hate when that happens.
Nick
Nicholas S. Thompson
Emeritus Professor of Psychology and Ethology,
Clark University (nthomp...@clarku.edu)
http://home.earthlink.net/~nickthompson/naturaldesigns/
http://www.cusf.org [City University of Santa Fe]
- Original Message -
From: Hugh Trenchard
To: ERIC P. CHARLES;Nicholas Thompson
Cc: friam@redfish.com
Sent: 3/29/2010 9:42:09 AM
Subject: Re: [FRIAM] Sperm pelotons; article in Nature
Thanks Eric for taking the time to look through my post. For Nick's last
post, I am not entirely sure what a "genefur" is, although it sounds like it is
a reference to an inherent genetic trait, as you also discuss.
Re: [FRIAM] Sperm pelotons; article in Nature
Thanks Eric for taking the time to look through my post. For Nick's last post, I am not entirely sure what a "genefur" is, although it sounds like it is a reference to an inherent genetic trait, as you also discuss. Yes, I agree it will help my argument if I hone in more closely on what I mean by fitness, and I will add some description to clarify this. My useage relates to inherent physical fitness in terms of maximum power output capacity. That too needs fine-tuning because I refer to "maximum sustainable output", which is not the same as absolute maximum power output, and I would need to outline more carefully what this means. Regardless, I think there are ways of testing for the actual power-output capacities of individual sperm - I have seen references in the literature to testing procedures for this. Because I know very little about genetics, for my part I would be treading dangerously to begin describing the process in a gene-related sense (and I would not want to get into discussion about chromosomes), but to address the issue you raise (if I understand it correctly), it would be necessary to measure the power output of the sperm of individual male mice to determine the range of their output capacities and/or the sperms' average output. This is no doubt not easy, but I imagine there would be some sampling size that would provide an accurate indication of the overall output range. And certainly one would want clearly to correspond average sperm outputs and ranges with the genetic descriptions of the various mice tested, but this could be done according to a replication of the Fisher and Hoesktra procedures. It would also be necessary to determine percentages of energy savings that occur when sperm are coupled (if this does in fact occur). My model assumes that there is a difference in the average power output of individual males' sperm, whether related or unrelated or of the same species or not - a difference sufficiently significant to demonstrate that sorting occurs according to fitness (in the power-output sense) and not according to some mechanism for identifying the genetic relatedness of the sperm, as the authors of the Nature article appear to suggest. The fact that sperm aggregate indicates coupling and energy savings, which is why (in my view) the peloton model applies. In terms of chance, it seems to me Fisher and Hoekstra have taken a lot of care to establish that there is sorting beyond chance, but implicitly ascribe that sorting to some sensory/perceptual capacity of the sperm to identify related sperm. My model begins with their proven result that there is sorting beyond chance, and asks whether there is some sorting mechanism involved other than an unidentified mechanism to perceive the location of related sperm, which is intuitively problematic because (it seems) sperm do not have a sufficiently developed sensory system (i.e. eyes, ears, or other) to do this. My model provides a simpler explanation for the sorting process than the Hoekstra & Fisher explanation, because, in my model, sorting occurs according to self-organized energetic principles, and not according to a perceptual/sensory mechanism, as apparently implied by the authors. I can see how a basic computer simulation would be helpful as a starting point for making predictions according to my model, which I see is really my next step. Does anyone know how/where one could apply for some funding to resource such a simulation? I could develop it myself (and have developed at least one simulation, but it really needs to be worked through again), but it would happen a whole lot faster if I could engage someone more adept at computer modelling than me. - Original Message - From: ERIC P. CHARLES To: Nicholas Thompson Cc: Hugh Trenchard ; friam@redfish.com Sent: Saturday, March 27, 2010 2:54 PM Subject: Re: [FRIAM] Sperm pelotons; article in Nature Hugh, Very interesting model! One of my doctoral adviser's, Jeffrey Schank has demonstrated repeatedly that scientists are very bad at predicting what 'chance' looks like when trying to do experiments involving synchrony. This seems one of those situations, and the only way around it is modeling. Nick's sarcasm aside, he has a point, and it has to do with some of the flavor text surrounding your model (for geeks of the wrong variety to know what flavor text is, see: http://en.wikipedia.org/wiki/Flavor_text). If I can take a shot at identifying the problem: Rather than looking at 'fitness' as if it were a unified trait, you have created a model that needs some mutli-stage selection language (the better term escapes me at the moment). The reality is that what makes a 'fit' sperm is not necessarily what makes a 'fit' organism. To fix the flavor text of your model, you would need to ex
Re: [FRIAM] Sperm pelotons; article in Nature
e as clear as day! In any event, my aim is really to ask the question - are there energetic and coupling principles that allow sperm to end up in groups which otherwise appear to have occurred because genetically related sperm can somehow identify each other? I am really only suggesting the existence of some dynamics of the sperm aggregations that could be studied for, which don't yet appear to have been addressed. Hugh - Original Message - From: "Nicholas Thompson" To: Sent: Friday, March 26, 2010 8:04 PM Subject: Re: [FRIAM] Sperm pelotons; article in Nature This is fun to think about. Hopefully, REC will help me: Is there a paradox here. let it be the case that sperm sort themselves by fitness; let it further be the case that sperm in peletons have an advantage over sperm that dont. Isnt it now the case that sperm are no longer sorting themselves by fitness? Ok, forget that: so let be the case that "fitness" is not defined by fertization probability, but more in the sense of "physical fitness". Some of the sperm go to the gym, and some don't. Or some are more muscular than others. So let it be the case that sperm sort themselves by swimming speed. The more muscular sperm swim side by side and the less muscular sperm swim side by side. But wait a minute, other things being equal wouldnt everybody bet the peleton effect? Ok, forget THAT, too. All these models assume that everbody starts from the same starting point, right? Are they jostling at the starting gate in the prostate as they are mixed with the seminal fluid. Is there an advantage to being in the first pulsation? So f orth. Wouldnt these factors overwhelm the peleton effect? And, what about the kamakaze sperm, that stick pumps in the spokes of unrelated sperm as in that unforgettable scene in Breaking Away. Ok. Sorry. Forget the whole thing. I do so like metaphors. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] [Original Message] From: Hugh Trenchard To: The Friday Morning Applied Complexity Coffee Group Date: 3/26/2010 8:38:22 PM Subject: [FRIAM] Sperm pelotons; article in Nature On February 12, Roger Critchlow posted a reference to "sperm pelotons", which inspired me to read the Nature article and to think a bit about how principles of peloton interactions could be applied to sperm aggregations. I've outlined some thoughts below. __ DRAFT Applications of a peloton model to sperm aggregration dynamics An analysis of article: Fisher, H., Hoekstra, H. (2010) Competition drives cooperation among closely related sperm of deer mice. Nature. Vol. 463, 11 Feb 801-803 Hugh Trenchard Abstract The Nature article by Fisher and Hoekstra suggests that a mechanism exists among the sperm of certain species of mice to identify genetic relatives. The identification mechanism itself is not apparent and, based upon observations of analogous processes in bicycle pelotons, an alternative hypothesis is suggested. There are similarities between bicycle pelotons and sperm aggregations: they are both competitive dynamical systems, and there are energy savings mechanisms by which agents couple and facilitate self-organized aggregate formations. A model for the division of a peloton at critical output levels is shown and suggested as analogous to certain, but not all, sperm aggregations, and a model for the relative energy consumption of coupled and non-coupled aggregates is shown, which suggests how sub-aggregates may form that are composed of agents within a narrowed fitness range, and also why the strongest individual agents may not always reach the target objective first. This suggests that no mechanism is required for the identification of genetic relatives, but that sorting occurs according to a self-organized metabolic process whereby sperm with close fitness levels will aggregate. Sorting among sperm is hypothesized to occur at a critical output threshold, and is more likely to occur among promiscuous species than monogamous species because sperm velocity of monogamous species may not be high enough to reach the critical sorting threshold. Genetically related sperm are more likely to have closer average fitness levels, and so will naturally sort into groups composed of predominantly related sperm. Thus proposed is an alternative framework by which to analyze the data. ___ Introduction Fisher and Hoekstra (2010) provide evidence that supports the hypothesis that sperm identify related sperm, aggregate and cooperate with them and, through increased velocity when travelling in aggregations, provide an advantage to genetically related sperm in advancing one of their
[FRIAM] Sperm pelotons; article in Nature
On February 12, Roger Critchlow posted a reference to "sperm pelotons", which inspired me to read the Nature article and to think a bit about how principles of peloton interactions could be applied to sperm aggregations. I've outlined some thoughts below. __ DRAFT Applications of a peloton model to sperm aggregration dynamics An analysis of article: Fisher, H., Hoekstra, H. (2010) Competition drives cooperation among closely related sperm of deer mice. Nature. Vol. 463, 11 Feb 801-803 Hugh Trenchard Abstract The Nature article by Fisher and Hoekstra suggests that a mechanism exists among the sperm of certain species of mice to identify genetic relatives. The identification mechanism itself is not apparent and, based upon observations of analogous processes in bicycle pelotons, an alternative hypothesis is suggested. There are similarities between bicycle pelotons and sperm aggregations: they are both competitive dynamical systems, and there are energy savings mechanisms by which agents couple and facilitate self-organized aggregate formations. A model for the division of a peloton at critical output levels is shown and suggested as analogous to certain, but not all, sperm aggregations, and a model for the relative energy consumption of coupled and non-coupled aggregates is shown, which suggests how sub-aggregates may form that are composed of agents within a narrowed fitness range, and also why the strongest individual agents may not always reach the target objective first. This suggests that no mechanism is required for the identification of genetic relatives, but that sorting occurs according to a self-organized metabolic process whereby sperm with close fitness levels will aggregate. Sorting among sperm is hypothesized to occur at a critical output threshold, and is more likely to occur among promiscuous species than monogamous species because sperm velocity of monogamous species may not be high enough to reach the critical sorting threshold. Genetically related sperm are more likely to have closer average fitness levels, and so will naturally sort into groups composed of predominantly related sperm. Thus proposed is an alternative framework by which to analyze the data. ___ Introduction Fisher and Hoekstra (2010) provide evidence that supports the hypothesis that sperm identify related sperm, aggregate and cooperate with them and, through increased velocity when travelling in aggregations, provide an advantage to genetically related sperm in advancing one of their kind to impregnate the egg. The authors report a species of mouse whose sperm exhibits "the ability to recognize sperm based on genetic relatedness and preferentially cooperate with the most closely related sperm." The question was raised: "how do sperm identify their brothers?" (FRIAM, 2010). The question reveals a problem in Fisher's and Hoekstra's analysis, and a clear mechanism for this identification process does not appear to be suggested in their article. Observations of peloton dynamics allow an alternative explanation to the cooperative aggregates that Fisher and Hoekstra (2010) have observed. Here presented, instead, is the hypothesis that any aggregation among genetically related sperm is coincidental to what is better explained by aggregates that form due to coupling among groups of sperm as a result of an energy savings effect that occurs when sperm travel closely together, an effect that is similar to drafting in a bicycle peloton. This is a self-organized process and, as such, no mechanism is required for sperm to identify genetically related sperm to adjust their positions to be near each other. This process includes a sorting of individual sperm into groups with proportionately high numbers of sperm whose swimming fitness is closest to their own. Genetically related sperm are more likely to have similar swimming fitness levels than are unrelated sperm. Hence grouping is based upon swimming fitness and not genetic relatedness, which also partially explains why aggregates are not entirely homogenous according to relatedness: genetically unrelated sperm with fitness levels near others, who may be related, will group with them. For simplicity, here this self-organized energetic process is referred to as drafting, although for sperm the energy savings mechanism is a hydrodynamic one (Lauga and Powers, 2009; Woolley et al, 2009). Similarly, the interactive dynamic between sperm that allows for this energy savings to occur is referred to as coupling. Coupling of this nature has been described as a synchronization of flagellar motion and optimal positioning of sperm-heads for friction reduction and increased sperm velocities when travelling in coupled formations as opposed to individually (Woolley, et al, 2009). Woolley et
Re: [FRIAM] Shrink Wrapped Bikes
55mph! Good, yes. But mediocre compared to current landspeed record held by friend, Sam Whittingham of Quadra Island, British Columbia. Current human powered vehicle landspeed record is 82mph, on the Varna Diablo, designed by Georgi Georgiev of Gabriola Island, not far from Quadra, and Vancouver Island where I live. Cycling the bike, not walking the walk, or talking the talk: http://en.wikipedia.org/wiki/Sam_Whittingham - Original Message - From: plissa...@comcast.net To: friam@redfish.com Sent: Wednesday, November 25, 2009 9:49 PM Subject: [FRIAM] Shrink Wrapped Bikes In the 80s we did a lotta work on that, designed, built and tested them. Didn't talk, did! The shrinkwrap is actually a shape like a vertical streamlined fin, narrow and tall, on a light stringer airframe covered with Monokote, that encloses the frame and rider. Huge benefits obtain from this. In the course of our road test work at the old Ontario Race Track we achieved human powered speeds in excess of 55 mph, and, as a delightful touch, prevailed upon a CA Highway Patrol officer to come pace us officially, and give the rider a ticket for exceeding the freeway speed limit; in those energy confused days it was 55 mph! Streamlined bikes are not much use. You need a few warm bodies to drop the fairing on you and set you up. And, of course, crosswinds are the very bugger! We had some very effective ideas for the Olympics (I worked for that committee) but, predictably they were so good that they were all banned! Peter Lissaman, Da Vinci Ventures Expertise is not knowing everything, but knowing what to look for. 1454 Miracerros Loop South, Santa Fe, New Mexico 87505,USA tel:(505)983-7728 -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] flocking windmills - bike race model
ock adjust its geometry could be a big win. A fixed installation would be tuned to the most likely wind speed and direction. -- rec -- On Wed, Nov 25, 2009 at 9:58 AM, Nicholas Thompson wrote: Hugh, Thanks for explaining this to me. I figured it was something like that. But the logic IS backwards with respect to the bike racer model. The Bike racer pod is trying to protect the lead racer from wind resistance, the wind mills are trying to pass that resistance through to ever member of the pod. We could shrink-wrap the bike-pod, and it would do its job even better. Not so the windmill pod. Right? N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Hugh Trenchard To: The Friday Morning Applied Complexity Coffee Group;nickthomp...@earthlink.net;Carl Tollander Cc: Friam@redfish.com Sent: 11/25/2009 7:15:27 AM Subject: Re: [FRIAM] flocking windmills ...that should read "rotate the position of the fans 90 degrees" (it was late and I should have been in bed). - Original Message - From: Hugh Trenchard To: nickthomp...@earthlink.net ; The Friday Morning Applied Complexity Coffee Group ; Carl Tollander Cc: Friam@redfish.com Sent: Wednesday, November 25, 2009 12:05 AM Subject: Re: [FRIAM] flocking windmills It looks to me the article addresses this. When windmills are in a conventional "face to the wind" position, they do need to be well spread out in order to catch as much wind as possible. But if you rotate the position 90 of the fans degrees so that they are spinning "sideways", they spin with greater efficiency when lined up behind each other in zones of lower air resistance. The article appears to refer to this fan position as a "vertical" rotation. The photo shows "vertically" rotating tube like structures, which are much like long fans turned on their sides. Aligning them in fish school formation evidently is the most efficient in terms of space and maximal wattage generation. That's how it all appears to me in any event. Hugh Trenchard - Original Message - From: Nicholas Thompson To: Carl Tollander Cc: Friam@redfish.com Sent: Tuesday, November 24, 2009 9:45 PM Subject: Re: [FRIAM] flocking windmills Sorry, everybody. What I meant to write was, "Wait a blithering moment!!!", suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to "feel" the "headwind"? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Carl Tollander To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 10:13:22 PM Subject: Re: [FRIAM] flocking windmills What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, "I am a wind turbine, the group has determined that it will be most efficient if you place me over there." And the humans would go do that, since the turbine family was usually right about such things. So maybe the turbines "want" some particular configuration, the friction is just one criteria. If they were a phased array antenna (in addition to being a group of wind turbines) then they would have additional criteria. C Nicholas Thompson wrote: Now what a blithering moment. Cyclists flock to reduce friction. Ditto fish, I suppose. So, turbines want less friction with the wind? Something screwy here. N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) htt
Re: [FRIAM] flocking windmills
...that should read "rotate the position of the fans 90 degrees" (it was late and I should have been in bed). - Original Message - From: Hugh Trenchard To: nickthomp...@earthlink.net ; The Friday Morning Applied Complexity Coffee Group ; Carl Tollander Cc: Friam@redfish.com Sent: Wednesday, November 25, 2009 12:05 AM Subject: Re: [FRIAM] flocking windmills It looks to me the article addresses this. When windmills are in a conventional "face to the wind" position, they do need to be well spread out in order to catch as much wind as possible. But if you rotate the position 90 of the fans degrees so that they are spinning "sideways", they spin with greater efficiency when lined up behind each other in zones of lower air resistance. The article appears to refer to this fan position as a "vertical" rotation. The photo shows "vertically" rotating tube like structures, which are much like long fans turned on their sides. Aligning them in fish school formation evidently is the most efficient in terms of space and maximal wattage generation. That's how it all appears to me in any event. Hugh Trenchard - Original Message - From: Nicholas Thompson To: Carl Tollander Cc: Friam@redfish.com Sent: Tuesday, November 24, 2009 9:45 PM Subject: Re: [FRIAM] flocking windmills Sorry, everybody. What I meant to write was, "Wait a blithering moment!!!", suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to "feel" the "headwind"? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Carl Tollander To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 10:13:22 PM Subject: Re: [FRIAM] flocking windmills What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, "I am a wind turbine, the group has determined that it will be most efficient if you place me over there." And the humans would go do that, since the turbine family was usually right about such things. So maybe the turbines "want" some particular configuration, the friction is just one criteria. If they were a phased array antenna (in addition to being a group of wind turbines) then they would have additional criteria. C Nicholas Thompson wrote: Now what a blithering moment. Cyclists flock to reduce friction. Ditto fish, I suppose. So, turbines want less friction with the wind? Something screwy here. N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Roger Critchlow To: The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 7:36:30 PM Subject: [FRIAM] flocking windmills Same power production as existing wind farms in 100th the land area. http://sciencenow.sciencemag.org/cgi/content/full/2009/1124/1 -- rec -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] flocking windmills
It looks to me the article addresses this. When windmills are in a conventional "face to the wind" position, they do need to be well spread out in order to catch as much wind as possible. But if you rotate the position 90 of the fans degrees so that they are spinning "sideways", they spin with greater efficiency when lined up behind each other in zones of lower air resistance. The article appears to refer to this fan position as a "vertical" rotation. The photo shows "vertically" rotating tube like structures, which are much like long fans turned on their sides. Aligning them in fish school formation evidently is the most efficient in terms of space and maximal wattage generation. That's how it all appears to me in any event. Hugh Trenchard - Original Message - From: Nicholas Thompson To: Carl Tollander Cc: Friam@redfish.com Sent: Tuesday, November 24, 2009 9:45 PM Subject: Re: [FRIAM] flocking windmills Sorry, everybody. What I meant to write was, "Wait a blithering moment!!!", suggesting, at least, that the metaphor between bunching up cyclists and bunching up windturbines was backwards. Don't you WANT your turbines to "feel" the "headwind"? Of course I am wrong about this, but I sure would like to understand why. Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Carl Tollander To: nickthomp...@earthlink.net;The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 10:13:22 PM Subject: Re: [FRIAM] flocking windmills What they lack is mobility - lacking some sort of mobile platform maybe they could get together and decide where the next best placement would be and tell the manufacturing and installation people. Some sort of distributed instantiation - Group orders another member, turbine shows up in the mail, speaks up, says, "I am a wind turbine, the group has determined that it will be most efficient if you place me over there." And the humans would go do that, since the turbine family was usually right about such things. So maybe the turbines "want" some particular configuration, the friction is just one criteria. If they were a phased array antenna (in addition to being a group of wind turbines) then they would have additional criteria. C Nicholas Thompson wrote: Now what a blithering moment. Cyclists flock to reduce friction. Ditto fish, I suppose. So, turbines want less friction with the wind? Something screwy here. N Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ http://www.cusf.org [City University of Santa Fe] - Original Message - From: Roger Critchlow To: The Friday Morning Applied Complexity Coffee Group Sent: 11/24/2009 7:36:30 PM Subject: [FRIAM] flocking windmills Same power production as existing wind farms in 100th the land area. http://sciencenow.sciencemag.org/cgi/content/full/2009/1124/1 -- rec -- -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] Publishing Agreements (was "More mumbo-jumbo")
LOL, and thanks for these responses. Yes, my current arrangement is quite loose, and being rather naive, I haven't thought it to be a problem until it occurred to me my co-hort could be off and marketing the sim without me knowing about it, possibly even to the Walt Disney corp. Lesson taken, I'd better get a clear agreement happening and/or for him to grant me a licence to the computer code. Does anyone happen to have a good form document precedent for such a licence? Hugh - Original Message - From: Miles Parker To: nickthomp...@earthlink.net ; The Friday Morning Applied Complexity Coffee Group Sent: Saturday, October 03, 2009 8:01 PM Subject: Re: [FRIAM] Publishing Agreements (was "More mumbo-jumbo") LOL. Yeah, I made it sound a lot more cut and dry then it probably actually is. Even in software there copyright can apply to L&F. There was a famous case in the 80s between Borland and umm.. Lotus (?) about the design of the spreadsheet interface. And then of course you get the fucking Walt Disney corporation involved and all bets are off. So just don't come up with some Mickey Mouse piece of code, ok Hugh? On Oct 3, 2009, at 7:52 PM, Nicholas Thompson wrote: WTFDIK, but, werent there some cases recently where somebody followed the outline and sequence of topics in another person's book and got skinned for it? Breach of ethics, only? Or did they actually have to settle? Nick Nicholas S. Thompson Emeritus Professor of Psychology and Ethology, Clark University (nthomp...@clarku.edu) http://home.earthlink.net/~nickthompson/naturaldesigns/ - Original Message - From: Miles Parker To: The Friday Morning Applied Complexity Coffee Group Sent: 10/3/2009 8:07:39 PM Subject: Re: [FRIAM] Publishing Agreements (was "More mumbo-jumbo") IANAL of course, but in general this situation is no different form one where ay someone has an idea, tells it to someone else, and that someone else writes a book about it. Ideas can't be copyrighted but software can; and implementations of ideas can be patented. (Yuck, though..) Am I right folks? By default the copyright is with the actual author, i.e. in this case the programer, unless there is some specific agreement otherwise. But that's just the default situation; if that's not what you want then you guys need to come up with an agreement that specifies that you share copyright and then make sure that the code has the appropriate notices. That should be really straightforward. On Oct 3, 2009, at 6:27 PM, Hugh Trenchard wrote: Hi Robert. I subscribe to the FRIAM listserv, and have seen your note here. I'm wondering what the law is regarding the sharing of intellectual property where one person establishes the general rules for a computer simulation and then takes those rules to a programmer who then creates a specific program based on your rules. Do you both share in the resulting simulation, or can the programmer argue the simulation is his/hers? I am in a situation where I have established the general rules for a simulation, and another fellow has created the actual sim - so am curious to know how we should go about claiming our respective intellectual property rights (hopefully they are shared). Thanks and would be grateful if you could run this by Dr Winchell. Hugh Trenchard Victoria - Original Message - From: Robert Cordingley To: The Friday Morning Applied Complexity Coffee Group Sent: Saturday, October 03, 2009 10:35 AM Subject: Re: [FRIAM] Publishing Agreements (was "More mumbo-jumbo") For those nearby, don't forget the sfComplex Meeting on Intellectual Property is next Tuesday, October 6, 2009 2:00 pm to 4:00 pm (seehttp://sfcomplex.org/wordpress/2009/09/intel_property#more-3032 for details). I can try to get Bruce to answer a few questions like these if it's too far for you. Email me your question (50 words or less) and I'll see what I can do. Thanks, Robert C ERIC P. CHARLES wrote: Interestingly, Most journals I interact with no longer have paper options for this sort of thing. All you do is click on a link that says "I agree". I have wondered how enforceable any such agreement is, and what the publisher would do if I insisted on a paper transaction in which I could do things like write in clauses. Has anyone had experience with these issues? Eric -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at
Re: [FRIAM] Publishing Agreements (was "More mumbo-jumbo")
Hi Robert. I subscribe to the FRIAM listserv, and have seen your note here. I'm wondering what the law is regarding the sharing of intellectual property where one person establishes the general rules for a computer simulation and then takes those rules to a programmer who then creates a specific program based on your rules. Do you both share in the resulting simulation, or can the programmer argue the simulation is his/hers? I am in a situation where I have established the general rules for a simulation, and another fellow has created the actual sim - so am curious to know how we should go about claiming our respective intellectual property rights (hopefully they are shared). Thanks and would be grateful if you could run this by Dr Winchell. Hugh Trenchard Victoria - Original Message - From: Robert Cordingley To: The Friday Morning Applied Complexity Coffee Group Sent: Saturday, October 03, 2009 10:35 AM Subject: Re: [FRIAM] Publishing Agreements (was "More mumbo-jumbo") For those nearby, don't forget the sfComplex Meeting on Intellectual Property is next Tuesday, October 6, 2009 2:00 pm to 4:00 pm (see http://sfcomplex.org/wordpress/2009/09/intel_property#more-3032 for details). I can try to get Bruce to answer a few questions like these if it's too far for you. Email me your question (50 words or less) and I'll see what I can do. Thanks, Robert C ERIC P. CHARLES wrote: Interestingly, Most journals I interact with no longer have paper options for this sort of thing. All you do is click on a link that says "I agree". I have wondered how enforceable any such agreement is, and what the publisher would do if I insisted on a paper transaction in which I could do things like write in clauses. Has anyone had experience with these issues? Eric -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
[FRIAM] ABMs and Plays
Having recently finished playing a role in a run of Shakespeare's Julias Caesar, the question is of particular interest to me, and one I have given some thought to in the past. As I see it, a play performance generally is constrained by the dialogue flow and whatever stage directions the playwright has written in, which represent the primary rules from which the final performance emerges. From there the directors and choreagraphers establish further rules that constrain the dynamics of the play. The actors are the components who, after being given directions and stage choreagraphy, interpret their lines and movements and deliver them a little differently every time. And where there are multiple scenes and actors, each actor need only know his or her own cues and lines, and need not know those of every other actor. In this way the final performance, while highly constrained, remains not precisely predictable and is emergent. Also, it is quite possible none of the actors has a wholistic perception of the total performance - only the audience can see that. And indeed the audience, as an external environmental factor, can have a great influence on the performance dynamics, and the total system includes the audience as one its components. Every performance is different as actors' inflections, rhythms, pacings and choreagraphed dynamics constantly shift, but each performance is highly robust with a high degree of negative feedback (the actors' recollection of the play as it has been blocked and rehearsed) which dampens any possibility that dropped lines, miscues, or interruptions (perturbations) will spiral out of control. These differences from performance to performance are what distinguish an "organic" play from re-running a video, for example, which will be precisely the same each time it is played. Under this description, the "living" play would seem to be at the farther extreme of a highly constrained system with a high number of rules with emerging patterns that are generally predictable but not precisely so, as compared to a system with few rules which give rise to plenty of unpredicted emergent patterns or functionality. Further along those lines, I would tend to think that themes such as "love in hate" are actually emergent rather than constituting additional rules from which the dynamics of the play emerge (if the latter is what you were suggesting, though it isn't entirely clear to me). It seems quite possible that Shakespeare did not indend for these themes to exist at all when he wrote his plays, and that we see them now as central to the dynamics only because the interactions of the characters and actors (and Shakespeare's genius) allow such themes to emerge. - Hugh Trenchard - Original Message - From: "Jochen Fromm" To: "The Friday Morning Applied Complexity Coffee Group" Sent: Saturday, August 22, 2009 1:06 PM Subject: [FRIAM] ABMs and Plays I am currently reading the Shakespeare biography from Peter Ackroyd. While reading this interesting work, I wondered if agent based models and plays can be considered as two extremes on one scale. In both we witness the outcome of a small number of agents or actors interacting with each other in a particular environment according to certain rules and intentions. Shakespeares' plays are basic "models" for the complexity which arises through "love in hate" (Romeo and Juliet), "hesitation in action" (Hamlet) or "striving against destiny" (Macbeth). In Shakespeares' words "Though this be madness, yet there is method in't." Is it? -J. FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] YouTube - Extreme Sheep LED Art
Nonetheless, animation or not, it would *still* be interesting to see more accelerated footage of sheep flocks in motion to look for the phenomenon I suggest will be seen and which I have observed elsewhere. HT - Original Message - From: Tom Johnson To: The Friday Morning Applied Complexity Coffee Group Sent: Saturday, March 21, 2009 9:02 PM Subject: Re: [FRIAM] YouTube - Extreme Sheep LED Art Yeah, some "fake animation." But I've seen sheep dogs do jaw-dropping things with a herd when the only command is the shepherd's long-distance whistling. Ergo, I think it may well be less than 90% animation. -t On Sat, Mar 21, 2009 at 8:30 PM, Stephen Guerin wrote: pretty cool idea even if 90% of it is fake animation. It should work as a viral ad, though, like the faked one-wing killathrill plane landing video from last year: http://www.youtube.com/watch?v=RVxe8Nm2w8I -s On Mar 20, 2009, at 5:10 PM, Tom Johnson wrote: Imagine the creator/artist trying to initially explain to the sheep ranchers what he was up to and what he wanted them to do. But I love the emergence of it all, given that the only major rule for the "sheep agents" is "Move away from the dog. Quickly." http://www.youtube.com/watch?v=D2FX9rviEhw -tj FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org -- == J. T. Johnson Institute for Analytic Journalism -- Santa Fe, NM USA www.analyticjournalism.com 505.577.6482(c)505.473.9646(h) http://www.jtjohnson.com t...@jtjohnson.com "You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete." -- Buckminster Fuller == -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] YouTube - Extreme Sheep LED Art
I agree - while I suppose I could have been "had", it looks to me like it was genuinely darn good sheepherding using mounted lights on the back of sheep and simply accelerated footage (assuming that's the part that looked the least authentic). At the least I agree it's not obvious that it is "90%" animation. - Original Message - From: "Victoria Hughes" To: "The Friday Morning Applied Complexity Coffee Group" Sent: Saturday, March 21, 2009 7:56 PM Subject: Re: [FRIAM] YouTube - Extreme Sheep LED Art A neophyte question: What indicates so clearly the fake animation? Some of it seems fabricated or heavily edited, that's clear. But what are you all seeing? Very curious about how things are made, and what reveals that. Thanks- Tory It was still a hoot and a half, however it was made. On Mar 21, 2009, at 8:30 PM, Stephen Guerin wrote: pretty cool idea even if 90% of it is fake animation. It should work as a viral ad, though, like the faked one-wing killathrill plane landing video from last year: http://www.youtube.com/watch?v=RVxe8Nm2w8I -s On Mar 20, 2009, at 5:10 PM, Tom Johnson wrote: Imagine the creator/artist trying to initially explain to the sheep ranchers what he was up to and what he wanted them to do. But I love the emergence of it all, given that the only major rule for the "sheep agents" is "Move away from the dog. Quickly." http://www.youtube.com/watch?v=D2FX9rviEhw -tj FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] YouTube - Extreme Sheep LED Art
It would have been interesting to see more of the high-speed movement of the large groups of sheep. From the very short segment in which the mass movement was shown, it looked to me there were signs of group rotation - although again we would need much more footage to confirm this. The rule of movement would be "move to the outside of the flock where there is more room to move faster/avoid collision where there is room to do so". This results in lines of sheep movement up the peripheries of the flock that are faster than movement on the inside, and so an effective backward drift in the centre and an emergent rotational pattern. There may be "eddies" or other smaller scale rotations within the flock occurring as well. This is what happens frequently in bicycle pelotons at a certain threshold of speed/power output (constituting a phase change) - riders advance up the periphery while a backward drift down the centre occurs. In pelotons there is what I call a "forward imperative", a deliberate and conscious attempt by riders to get or stay near the front of the peloton as there is strategic value in being positioned near to the front of the peloton. However, there are also, I believe, physical (self-organized, non-deliberate) reasons why peloton rotations occur, which are a combination of fatiguing riders decelerating slightly down the middle and the greater space on the periphery for fresher riders to pass. If a similar phenomenon can be seen in flock/school motion, then it strengthens the argument that the peloton rotation phenomenon is not simply a pattern that results from riders' deliberate and conscious tactical movements, but is also a function of purely self-organized processes. A similar form of rotational patterns occur in penguin huddles, but it would be interesting to confirm the pattern in other biological aggregates. Hugh Trenchard Victoria BC - Original Message - From: Tom Johnson To: fr...@redfish. com Sent: Friday, March 20, 2009 4:10 PM Subject: [FRIAM] YouTube - Extreme Sheep LED Art Imagine the creator/artist trying to initially explain to the sheep ranchers what he was up to and what he wanted them to do. But I love the emergence of it all, given that the only major rule for the "sheep agents" is "Move away from the dog. Quickly." http://www.youtube.com/watch?v=D2FX9rviEhw -tj -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
[FRIAM] Dr. Gottfried Mayer-Kress
For those who may not know, Dr. Mayer (aka Mayer-Kress), passed away on January 25 after a long battle with cancer. The complexity community loses a great contributor and pioneer in the advancement of the field. For my part, he was one of the few established scientists who took seriously my ideas regarding the self-organized complex dynamics of bicycle pelotons and offered me much mentoring and encouragement. For that I owe him a great debt of gratitude and will miss him immensely. More about him in the following links: http://www.personal.psu.edu/~gxm21/ www.comdig.org Hugh Trenchard FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
[FRIAM] Evolutionary biology and bicycle pelotons
I've been developing some ideas relating to behaviours exhibited in bicycle pelotons and their application to evolutionay biology - viewed from a resource consumption/constraint perspective. I've actually submitted a paper to a journal, but I'm not confident in it's acceptance for publication, certaintly not in it's current form, if at all. I thought I would do well to see if anyone on this list can provide any input which might help to improve it. Stephen Guerin has been kind enough to post my paper at the following link: http://www.friam.org/Trenchard-Peloton.doc Thanks for any thoughts you can provide. Hugh Trenchard FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] Complexity Science movie?
I'm not sure if these meet your criteria of a "movie", but there are countless films of bicycle road races - helicopter sweeps show pelotons in all their magnificent complexity. The rotational patterns which self-organize are the most striking. HT - Original Message - From: Louis Macovsky To: The Friday Morning Applied Complexity Coffee Group Sent: Monday, June 30, 2008 2:33 PM Subject: Re: [FRIAM] Complexity Science movie? Clockwise with John Cleese. If I recall correctly a small change in initial conditions leads to unintentional results. Lou - Original Message - From: Jen Watkins To: The Friday Morning Applied Complexity Coffee Group Sent: Monday, June 30, 2008 1:59 PM Subject: Re: [FRIAM] Complexity Science movie? Sliding Doors that Gwenyth Paltrow movie comes to mind. It is about the completely different life that would have occurred if she had not missed the train. It suggests non-linearity. Jen On Jun 30, 2008, at 2:50 PM, Joshua Thorp wrote: Can anyone think of a movie or scene in a movie that exemplifies complexity science themes, such as many interacting parts with emergent patterns, non-linear behaviors, self organizing, etc. Any thoughts? --joshua FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] Peloton analog of resource sharing system. Was: can you have 4 operating systems on one buss?
(Phil henshaw) "What kind of information might indicate the approach of common resource limits? How would that be different from evidence that other users are breaking their agreements? As independent users of natural resources tend to have less information about, or interest in, each other's particular needs than, say, cyclists in a peloton, how would they begin to renegotiate their common habits when circumstances require it?" Here is a short essay that looks at Phil's questions of resource consumption from the perspective of a peloton analog. It doesn't seek to answer the questions, but rather proposes a model in which to analyze them. It may be rather simplistic against the backdrop of sophisticated economic theory, but as a very real system, I suggest the dynamics of pelotons may provide insight into them. The scope of my essay may also be overly broad, and in that respect, incomplete, but my hope is that there are a few kernels that may assist Phil's analysis, or are at the very least, interesting. Information exchange, resource consumption and sharing in bicycle pelotons: a model for analyzing competitive systems Hugh Trenchard Bicycle racing is by definition competitive, and involves strategies for the cooperative distribution and exploitation of individual and collective resources. Individual resources exist in the form of energy available for consumption within a rider's body, either in the form of glucose stored in rider's livers and muscles, or body fats, and the physiological mechanisms which allow riders to expend that energy. Rate of individual resource consumption may be reduced by drafting, which occurs when riders are positioned in zones of lower air pressure, either directly behind others riders', or at angles to the wind direction. Riders in drafting positions reduce energy expenditure by as much as 30 - 40% over a rider in front at 40km/hr, depending on positioning within the peloton (Hagberg and McCole, 1990). Reduction of energy expenditure in drafting positions is also a collective, or shared resource. It is a collective resource when riders in competitive situations either cooperate or exploit this resource to maximally reduce their own individual resource expenditure or the expenditure of allies. Allies may be team-mates, but are also frequently competitors from different teams who cooperate when a peloton has split into groups, thereby temporarily becoming allies to achieve specific objectives, before again becoming competitors. The relative and continuous balance between cooperation and exploitation occurs most notably when a peloton has split into groups of two or more, and the objective of group(s) ahead is to remain ahead of following groups, while the reverse objective exists for groups behind, which is to reintegrate groups ahead. In situations like these, free-riders, quite literally, are prevalent, repleat with a number of modes of punishment. A more detailed account of that, however, is beyond the scope of this discussion. In the course of their resource consumption, the information cyclists receive or generate is largely visual. There is also vocal information, and, at the highest levels there is nearly always communication exchanged between riders within the peloton and sources outside the peloton (coaches or "director sportifs"), via radio contact - an advancement in racing tactics that has developed and been allowed in races for roughly 20 years now. Generally riders have limited global information due to obstructed viewing (i.e. blocked by riders surrounding them) and primarily receive only local information about the riders immediately surrounding them. One reason (albeit a secondary reason) for advancing or falling back within a peloton is to gather information about the positions of competitors. Some of this information may be relayed verbally through information links within the peloton (other cyclists), or riders acquire the information by visual observation, or through radio contact. The information riders seek is primarily threefold: 1 competitor positioning 2 apparent rider resource consumption 3 course constraints 1. Competitor positioning This is determined by a. local observation of riders in immediate 360 degree visual field, where course topography is flat b. partial or complete global observations of peloton where elevation and course configuration allow visual information to be obtained from higher or lateral vantage points (e.g. if a cyclist is near the rear of a descending peloton on an open road, the rider has a clear view of cyclists' positions ahead); c. positional information may also be gleaned by implication, namely if a cyclist is at the front, he or she knows all her competitors are behind, and will see them if they try to pass. Similarly, but more anxiety causing, if a cyclist is at the back,
Re: [FRIAM] can you have 4 operating systems on one buss?
I might as well throw this example into the fray, which may cover a few of your bases, Phil, though I'll happily stand corrected if they are not on target. The only complex system I can claim any sort of slightly-more-than-superficial understanding is that of bicycle pelotons. As I've mentioned in previous posts, a bicycle peloton is a group of cyclists who ride within drafting range of each other (except for the riders facing the wind), who thereby reduce their energy output by drafting. A peloton is a very good example of resource optimization, since it easily demonstrated that a peloton can travel faster and farther than an individual cyclist on his or her own. In high-level bicycle races, the range between the riders' ability is fairly narrow (I've compiled some figures which show the range to be about 17 percent). The range is narrowed further by drafting, and I've also compiled figures which show that the range is narrowed to an average of about 4% between first and last place finishers in pelotons (as compared to 17% between first and last place finishers in individual time trials, which is where the first figure of 17% above comes from), and there are frequent race situations where an entire peloton finishes with the same finishing time. In any event, if I understand your original inquiry, a peloton is a good example of the kinds of self-organized resource sharing you are talking about. When cyclists set off at the beginning of a race, there is a period when the speeds are low enough when they have no need to draft one another to feel comfortable in any position in the peloton and are not expending energy close to maximum capacity. However, as speeds increase, a transition occurs (I argue this is a true phase transition) whereby resource sharing becomes necessary as cyclists are either in drafting positions or at the front (most are drafting). In this phase, a balancing occurs between energy expenditure and optimal position within the peloton. Because it is a competitive situation, it is better to be positioned as close to the front as possible. As this is a continuous imperative, rotational movements occur within the peloton, where riders are moving up and down the peloton, or are caught in "eddies" whereby they advance for relatively short distances within the peloton, before begin shifted backward again, and then attempt to move forward again. These movements occur while riders attempt to use as little energy as possible to advance. So, where there are riders who shift to the outside of the pack (facing the wind by doing so), other riders will follow in their draft. This results in a pattern whereby riders advance up the sides for relatively long stretches, while riders drop back within the peloton, and while within the peloton there are these smaller-scale eddies. Another phase transition occurs when the pace shifts up beyond another threshold, whereby the speeds are too high for there to be continuous rotational movement within the peloton, and the peloton stretches into a single line. This phase, while easily observable, is a precurser to a final transition where the peloton begins to splinter: individual riders fall off the back, or separations occur in the line of riders which following riders cannot bridge, and the peloton splinters. This last phase is an example of the transition to "conflict" which you were referring to, if I understand it correctly. In this situation, every rider is either in direct competition with the each other, or small groups form which cooperate internally, but each of which are also in direct conflict as chasing groups want to reintegrate groups ahead, while groups ahead want to stay ahead of those behind. Does this sound a bit like the kind of resource sharing states you were talking about? Hugh Trenchard - Original Message - From: "Phil Henshaw" <[EMAIL PROTECTED]> To: "'The Friday Morning Applied Complexity Coffee Group'" Cc: "'Diegert, Carl F'" <[EMAIL PROTECTED]> Sent: Saturday, March 29, 2008 9:02 AM Subject: Re: [FRIAM] can you have 4 operating systems on one buss? > Marcus, > I think the boundary conditions of the problem include both the variable > of > system design and control, and that of the independent behaviors of the > users. The question is what each of those contributes. With computer > networks you can't do without both, of course, but you can consider what > the > options are for each independent of the other. Then both may learn to > make > a combined system work better. > > You say " ...resources can be managed by a secure executive process that > divides up the work fairly. Systems that don't do this are non-critical > systems." That is generally true for computer networks. Pl
Re: [FRIAM] patent puzzle
Hi Phil. I work as a paralegal in constitutional/administrative law for the Attorney General of British Columbia in Canada. While our laws are going to be substantially different from what goes on in the States, up here the PTO board would be an administrative tribunal whose decisions are subject to judicial review by the courts. Here, administrative tribunals must adhere to certain principles of natural justice (ie. administrative fairness) and one of the enumerated grounds for such fairness is for an administrative body to give adequate reasons for its decisions. On Canadian principles, your PTO sounds like it will have violated that, and probably other grounds of administrative fairness. Such decisions can be reviewed by the courts (which apply more rigorous standards of appeal etc than admin tribunals). But that's applying our law. Sounds like legal advice is in order. There ought to be a whole slough of lawyers in patent/copyright law eager to litigate, and will probably provide an initial consultation for free. Hugh Trenchard - Original Message - From: "Phil Henshaw" <[EMAIL PROTECTED]> To: "'The Friday Morning Applied Complexity Coffee Group'" Sent: Thursday, March 06, 2008 3:46 PM Subject: [FRIAM] patent puzzle Might there be anyone who knows what to do with a PTO appeals board decision to not say why they're reversing a previous appeals board decision, and saying they wouldn't believe the claim even if they saw the clear evidence of it? Phil Henshaw .·´ ¯ `·. ~~~ 680 Ft. Washington Ave NY NY 10040 tel: 212-795-4844 e-mail: [EMAIL PROTECTED] explorations: www.synapse9.com -- "it's not finding what people say interesting, but finding what's interesting in what they say" -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] Flocking
Absolutely fantastic! A lot of synchronized trajectories, and possibly some oscillation patterns between higher and lower density formations. One almost wonders if there is communication occurring at a holistic level, between groups as complete units. It seems there is collision avoidance between some of the groups, which might be indicative of group communication, although it is hard to tell. But there is also a lot of integration between groups which might counter the possibility of collision avoidance on a group level. Just a few thoughts. Hugh Trenchard - Original Message - From: Robert Cordingley To: The Friday Morning Applied Complexity Coffee Group Sent: Friday, January 19, 2007 2:19 PM Subject: Re: [FRIAM] Flocking Really impressive. A while ago my daily commute took me out past the rice fields south of Houston. Once a year we would see migrating 'rice birds' in a 'contiguous' tube-like flock stretching from one horizon to another while rising above the hedge rows. (But that was before digital cameras.) The flock might drift from side to side but the birds just kept on coming and coming and coming. These flocks too showed a sharp boundary between relatively evenly spaced birds to none. What's the story behind boundary effects/observations I wonder. Douglas Roberts wrote: I know you FRIAM'ers are fond of flocking behavior: http://video.google.com/videoplay?docid=8761390434094738310&pr=goog-sl -- Doug Roberts, RTI International [EMAIL PROTECTED] [EMAIL PROTECTED] 505-455-7333 - Office 505-670-8195 - Cell FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org -- FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
[FRIAM] fun and sandpiles
Thanks, Phil, and I definitely agree that sandpile phenomena and play phenomena are not mutually exclusive in the domain of complexity. I think I was only trying to emphasize the point that I started my thread with a view to specific pattern formations of frigatebirds which result from some specific rules of interaction. At the risk of misinterpretation here (and no disrespect intended, if I am misinterpreting), an argument was presented, it seemed, that there are no reasons for certain behaviours other than that they are the result of having fun, but the argument was made in the context of animals that were not necessarily in the pattern formations I was looking at. It may very well be that it is fun for frigatebirds to be in these formations, but there are, I think, still physical reasons why they choose those formations - and not other ones - related to the way in which they couple due to the energy savings that certain formations allow (I hypothesize). Coming back to cyclists who interact, it is certainly satisfying when a drafting cyclist finds the "sweetspot" in the draft zone, where maximal drafting benefit is experienced. It also fun and satisfying to be part of the peloton experience, to have engaged in a series of interactions with other cyclists that result in emergent pattern formation. Even so, the pattern formations can be traced primarily to physical coupling between cyclists, namely the drafting benefit, collision avoidance and forward motion. Bicycle racing, is of course, a sport, so it also involves strategies and directives from leaders, but you can remove those and there will still be certain types of patterns which will arise by the basic rules I've noted (I've simulated some by computer, although the results are still a bit controversial). In any event, I certainly agree that there is a broad scale of complexity, since most types of interactions result in some sort of emergent phenomena. I think, though, that it becomes increasingly difficult to identify even what the emergent phenomena are when looking at complex interactions that involve a multitude of factors and rules of interaction, let alone isolate what the principles of interaction are that lead to the emergent phenomena. What is the emergent phenomena of birds that are playing, in apparently random configurations? I'm not suggesting there are any, they're just difficult to see, that's all. - Original Message - From: "Phil Henshaw" <[EMAIL PROTECTED]> To: "'The Friday Morning Applied Complexity Coffee Group'" Sent: Thursday, January 11, 2007 6:34 PM Subject: Re: [FRIAM] Will Rogers and Animal Behavior I for one don't think emergent systems study requires choosing between 'sand piles' and animals having 'fun'. Playful experimentation is one of the all time best natural systems for discovering natural structures it seems to me, just a higher level version of jumping potential wells like some grain of sand seems bound to have done at a critical point to get a slide going. The range of complex system phenomena is tremendous. One thing that helps me is that there seem to be various scales you can arrange the entire spectrum on, complexity of self-regulation for example. Thermostats and sand piles are on the simple side and animal acrobatics on the high side. You don't necessarily have to assign a number to things to have a useful scale, of course, just have a way to order things and make note of uncertainties. That's what the paleontologists do with all their species branching diagrams (clad notation). For those who like numbers, though, there's the rudimentary numerical development scale, the number of doublings a system performs in its development. Humans and the world economy thus far are about 30 doublings, for example. Yep, kind of an interestingly compressed scale! Phil Henshaw .·´ ¯ `·. ~~~ 680 Ft. Washington Ave NY NY 10040 tel: 212-795-4844 e-mail: [EMAIL PROTECTED] explorations: www.synapse9.com > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Hugh Trenchard > Sent: Wednesday, January 10, 2007 8:05 PM > To: The Friday Morning Applied Complexity Coffee Group > Subject: Re: [FRIAM] Will Rogers and Animal Behavior > > > I for one am rarely afraid to ask questions, stupid or > otherwise, when my > curiosity is piqued. > > Do the ravens in Sante Fe align in vee formations when they roll off > chandelles? If they do, then regardless of whether they are > having fun, it > is an interesting pattern formation which causes one to ask > reasonably why > they choose such a formation. Do they do it for the sheer > pleasure of the > esthetics of the vee form
Re: [FRIAM] Will Rogers and Animal Behavior
I for one am rarely afraid to ask questions, stupid or otherwise, when my curiosity is piqued. Do the ravens in Sante Fe align in vee formations when they roll off chandelles? If they do, then regardless of whether they are having fun, it is an interesting pattern formation which causes one to ask reasonably why they choose such a formation. Do they do it for the sheer pleasure of the esthetics of the vee formation? This would, it seems, entail some "fun" of the formation, although I doubt I would find many people who would argue that is the fun they derive. So then why is it fun that they should align in those formations? I myself wouldn't claim to subscribe to a behaviourist school, unless you can generalize the term to include analysis of the emergence of physical patterns among collectives. Pattern formation within sandpiles is more akin to my specific interests than the behaviour of individual animals. That is always interesting too, but it isn't the focus of my inquiry here. Hugh Trenchard - Original Message - From: "Peter Lissaman" <[EMAIL PROTECTED]> To: Sent: Wednesday, January 10, 2007 1:05 PM Subject: [FRIAM] Will Rogers and Animal Behavior > When he was given a brief description of the learned theories of Dr. > Freud, > and told that they accounted for all human behavior, Will Rogers stated > that: "he found it real interesting, but reckoned that in Oklahoma, folks > mainly did things jes' acause they felt like it". I gave a paper at AIAA > annual meeting in Reno earlier this week on birds extracting energy from > turbulence. There's a lot in it for the birdies, with their low flight > speeds, superb sensing and rapid response. Ravens in Santa Fe are > marvellous aerobats in the turbulence rolling off the Sangres. But why? > When you see them rolling off perfect chandelles, as with dolphins surfing > and gamboling in the bow wave, you have to admit that they're "jes' havin' > fun", contrary to these gloomy animal "behavioristos" who claim animals do > everything for a reason. > > Peter Lissaman, Da Vinci Ventures > > Expertise is not knowing everything, but knowing what to look for. > > 1454 Miracerros Loop South, Santa Fe, New Mexico 87505 > TEL: (505) 983-7728FAX: (505) 983-1694 > > > > > > FRIAM Applied Complexity Group listserv > Meets Fridays 9a-11:30 at cafe at St. John's College > lectures, archives, unsubscribe, maps at http://www.friam.org FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
Re: [FRIAM] frigatebirds - short video
Thanks. The only complex group dynamic I can claim any special knowledge of is a bicycle peloton, and if I apply the "dropping in" effect and the "shaking out" effect, I recognize that a bicycle peloton is both a socialized phenomena and a purely self-organized one. It is also a good example of a dynamic that is both leader-driven and self-organized. An example of "dropping in" occurs when a lone rider sees a peloton of riders ahead, speeds up to catch the group because he knows for a fact that he will save energy by riding with the group. That's a socialized response, because he has learned or been taught that there is energy savings in a group through drafting. Once he is part of the group, the main physical parameters are energy savings by drafting and collision avoidance. Both of these result in continuous positional adjustments within the peloton. A combined physical/social pattern to result is positional rotation within the peloton - physical because riders at the front sometimes become so fatigued that fresh riders behind simply ride past the fatiguing riders, who can then drop into drafting positions to recover; socialized because riders are also taught to trade positions. If we think of the source of the emergent patterns as a ratio of physical to social behaviour, then as riders at the front of the peloton approach their phsysiological thresholds, the ratio of physical/social increases. That is, their fatigue is likely to force a reduction in output so they can recover, while fresher riders behind maintain speed and pass the fatiguing riders. In other words, any speed or power output increases that intitially led to these physiological thresholds may have been leader induced, but once cyclists approach thresholds, then the pure limits of physiology and physics take over. There are many nuances to this analysis of pelotons, but before I get too profuse here, my main point is that your suggestion of a "dropping in" and "shaking out analysis" is very helpful, and I agree there is a lot to be learned from it. By the way - in addition to this discussion, were there any comments on my second main observation in Mexico - the "cab sifting" effect in traffic? Hugh Trenchard - Original Message - From: "Phil Henshaw" <[EMAIL PROTECTED]> To: "'The Friday Morning Applied Complexity Coffee Group'" Sent: Wednesday, January 10, 2007 3:50 AM Subject: Re: [FRIAM] frigatebirds - short video Oh yes! It's an important reservation that "they could very well not be aware of the global pattern they are forming, just as in a much larger flock, birds will [may] only be aware of their immediate neighbours." In evo. bio. the phrase is that "A is random with respect to B". It is quite common for things produced by one mechanism are instrumental to another mechanism which develops quite independently. Most natural systems develop from 'found objects', as it were. Now it's possible in a case like this that the social behavior which makes a bird discover the energy saving groove of 'V' formation flight is partly evolved and recorded in their DNA. Relying on that, though, is like throwing darts at a black hole in my way of thinking, your dart just disappears because it only identifies an assumption. I don't see how in this case, but sometimes you can identify a larger property, like if you saw birds 'dropping in' on a forming 'V' rather than 'shaking out' into the 'V' form. Watching the details of how things happen is often very helpful. Phil Henshaw .·´ ¯ `·. ~~~ 680 Ft. Washington Ave NY NY 10040 tel: 212-795-4844 e-mail: [EMAIL PROTECTED] explorations: www.synapse9.com > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Hugh Trenchard > Sent: Wednesday, January 10, 2007 2:04 AM > To: The Friday Morning Applied Complexity Coffee Group > Subject: Re: [FRIAM] frigatebirds - short video > > > > Phil, > > Thanks for the follow up. As Dr. Lissaman says in a > subsequent post, that > clip by itself may say nothing, but it's only an indication > of the type of > formations I was referring to, namely a complete vee > formation without > flapping that I observed (while gliding, and in relatively stationery > positions - ie. not moving across the sky at high speed), but > not shown in > that short video. The "phase change" I referred to would > have involved > several frigate birds in the formation like the two shown > next to each other > in the video. > > By the way, I would say that there may be forms of coupling > that go on when > tw
Re: [FRIAM] frigatebirds - short video
Phil, Thanks for the follow up. As Dr. Lissaman says in a subsequent post, that clip by itself may say nothing, but it's only an indication of the type of formations I was referring to, namely a complete vee formation without flapping that I observed (while gliding, and in relatively stationery positions - ie. not moving across the sky at high speed), but not shown in that short video. The "phase change" I referred to would have involved several frigate birds in the formation like the two shown next to each other in the video. By the way, I would say that there may be forms of coupling that go on when two lions on the savannah walk side-by-side. For example their gaits may be synchronized or phase-locked. It would be interesting to see what emergent patterns might arise if you put one hundred globally coupled in that fashion, side-by-side and set them all walking. My thought on the leadership question is that the frigatebirds wouldn't undergo a "phase change" unless there was some energy reduction benefit for them to do so. This would be an evolutionary development and in my mind would apply across species. But as you or someone pointed out, there are ways to confirm that, as I certainly can't state that as a fact. There may be elements of leadership involved, but in my mind any emergent formations are more likely to result from local physical rules, although I can imagine some emergent patterns could arise from a combination of leadership and local physical rules, and there probably are plenty of examples of that. In terms of "physically feeling the vee formation effect", I would argue that they can certainly feel the reduction in energy output required in the most efficient positions, and perhaps are aware of the positions of other birds in their field of view and perhaps have seen other Vees off in the distance, but they end up in their formations because they learned, originally by accident at some stage in their evolutionary development, that there was smaller energy output in certain positions. My point is they could very well not be aware of the global pattern they are forming, just as in a much larger flock, birds will only be aware of their immediate neighbours. >From my experience as a bicycle racer, it's obvious that cyclists can feel the physiological benefits of certain formations, but in a large peloton, the cyclists may easily not be aware of certain pattern formations, which become observable only from the air and upon a closer analysis of their global movements. I agree that we are largely guessing when determining the underlying mechanisms for certain behaviours, but if we can find similar behaviours among different groups, and can identify mechanisms underlying one group, then it is some evidence similar mechanisms apply to the other groups. Not proof obviously, but it is *some* evidence, and it is certainly cause for closer investigation for the curious minded. - Original Message - From: "Phil Henshaw" <[EMAIL PROTECTED]> To: "'The Friday Morning Applied Complexity Coffee Group'" Sent: Tuesday, January 09, 2007 4:55 AM Subject: Re: [FRIAM] frigatebirds - short video That video is very nice for putting it into context. There's an appearance, for that 10 seconds, that one pair are flying together in locked position and another is in the group mixing positions. Is that what you first meant by the first two parts of "often hover and glide for several minutes at a time without flapping and that they tend to glide in disordered configurations until they spontaneously undergo a phase change"? I was also hoping I could get you to clarify a comment you made about my suggestion that some communities might have more 'leadership' (i.e. social structure). You said "As we all know, self-organized phenomena arise without leaders to guide the emergent patterns - I can't think of why it would be any different for frigatebirds." I would be surprised if you thought self-organization in sand piles and communities of intelligent species happened the same way. Peter described how the birds would be able to physically feel the 'V' formation effect, and I was essentially suggesting that some communities may have stronger group awareness into which that would fit. For much of the instrumental mechanisms of natural system behaviors like these we're left wildly guessing, of course. I just try to balance the shakiness of my foundations for it with my confidence in the conclusions, always looking for the strong foundation of the behavior's particular growth dynamic as an anchor. Phil Henshaw .·´ ¯ `·. ~~~ 680 Ft. Washington Ave NY NY 10040 tel: 212-795-4844 e-mail: [EMAIL PROTECTED] explorations: www.
Re: [FRIAM] Mechanics of Formation Flight
My thanks as well for the clear and educational presentation. If I understand correctly (which I very well may not be), then essentially all the birds, including the one at the front reach an equipartition of power output, although it sounds like possibly there is maximal drag reductions in the front three positions at the apex (depending how closely abreast the two following the leader are), and the least for the birds at the back of the vee. Getting to one of the front three positions would require a short term high power output burst by a trailing bird, which might explain why the weakest ones end up in the worst positions, since the strongest ones are able to make the short term bursts required to get into the best positions. In any event, your notes certainly require me to rethink some things, but I should clarify that my own discussions have been about the underlying principle of energy savings among coupled agents which allows for the emergence of complex dynamics among the system as a whole. Being a "forest for the trees" exercise, the details of the aerodynamics affect my analysis only to a small extent, although it certainly helps that I understand them. I also realize now I need to be careful about using the term "drafting" when types of energy savings dynamics other than drafting may be happening. Perhaps it is more accurate to refer to the principle as "energy savings by coupling". Regardless, there are still universal complex dynamics that occur - for example, if there is a rotation dynamic within a vee formation, then that is a dynamic shared among rotating penguin huddles and rotating bicycle pelotons. In any event, thanks again for the very useful and helpful outline. Hugh Trenchard - Original Message - From: Peter Lissaman To: friam@redfish.com Sent: Sunday, January 07, 2007 4:59 PM Subject: [FRIAM] Mechanics of Formation Flight MECHANICS OF FORMATION FLIGHT -- PETER LISSAMAN Here are some actual facts, which folks may wish to use for discussion - on t'other hand maybe they just prefer their own opinions! Doesn't matter to anyone who just wants to ramble on a fascinating subject. I am designing flight systems to use turbulent energy, in test flight right now, so, unfortunately, gotta stick to Newton's Laws!. 1. A lifting wing develops one half its induced wash AHEAD of it. Yeah, folks, before the air has even met the wing. It's a continuous fluid, remember! The balance of the induced wash due to the trailing system develops downstream of the wing and is reaches its asymptotic value about 3 spans downstream. Within the span of the wing this induced flow is downwash, more or less spanwise uniform; outboard it is upwards, very intense just beyond the tip and attenuating rapidly as one moves away from the wing. 2. If another wing system is positioned outboard of the wing, it experiences a strong upwash, that will greatly reduce its power requirements. This effect is mutual, and its integrated intensity depends only on the tip separation as a fraction of span. 3. Consider three identical wings, line abreast, call them Left (L) Center (C) and Right (R). In this configuration the wing R experience a favorable upwash due to C and L, but the L contribution is fairly small. So it has a certain saving in its induced drag. But the wing C experiences the full upwash effect from both L, R and consequentially C has approximately double the saving. Good news for C! 4. If the wings L, R get pissed off at all that hard work, and drift downstream, they will experience stronger upwash due to the trailing system of C, but their influence on C will be attenuated, so they will experience larger savings at the expense of C. If they drift very far downstream, then they will have no influence on C, but L, R will still experience the induced flows of C so that ALL the saving will now be transferred to R , L. In the vernacular, C doesn't even know the wingmen are there, far astern, but they can see C's fully developed wake lying right between them! There is a configuration providing equipartition which defines the Vee angle of this little "Vic". 4. This mechanism continues for flights with larger numbers of wings. The calculations indicate, as so often in aerodynamics, that infinity is not far away, and reached very soon, so that large flights are advantageous but with diminishing returns. 5. The stability mechanism (we have the math, but it's too much for here) is that if a formation were in echelon (a single skewed line) then the front bird would have a hard time, and he'd drift downstream. His wingman would then be leading and think, "Jesus, I'm in front now! No way". And he'd drift downstream. This would proceed until you had about three or four birds in one file of
Re: [FRIAM] frigatebirds - short video
http://ibc.hbw.com/ibc/phtml/votacio.phtml?idVideo=3621&tipus=1 Here is a link to a short video which provides a small inkling of the "drafting" behaviour or frigatebirds. It isn't a long enough video to know if the alignment there was more than accidental, nor does it show more than two in alignment, but it's a start. Thanks for the suggestion about contacting bird-watchers in frigatebird territory for a work-around, I'll look into it. Hugh - Original Message - From: "Phil Henshaw" <[EMAIL PROTECTED]> To: "'The Friday Morning Applied Complexity Coffee Group'" Sent: Saturday, January 06, 2007 9:28 PM Subject: Re: [FRIAM] observations of complex phenomena while in Mexico I'll be glad to see what further patterns you find. Just to clarify, my suggestion was not just that the two colonies were different, but that the variation in local colony behavior might be as great as the variation in local environments where colonies are found. If you were to make observations randomly across the range of the species you'd get a better sense of what behaviors are universal and what are local. What you'd want is a work-around, of course, that would be a little less work. Perhaps you could try getting a list of bird watchers in the frigatebird range and randomly calling them to see what they have to say. As to the generality of a "drafting principle", there is at least one major example of it I've given a good bit of study, the formation and evolution of air currents. If you want an example of the vast creativity of local physical processes you might do well to give them a little look. Do all the modeling you like and none of it will produce the degree of intricate and inventive complexity you find in the pathway negotiations taking place around any even mildly warm body like, for example, the one sitting in front of your computer screen right now! Phil Henshaw .·´ ¯ `·. ~~~ 680 Ft. Washington Ave NY NY 10040 tel: 212-795-4844 e-mail: [EMAIL PROTECTED] explorations: www.synapse9.com > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of Hugh Trenchard > Sent: Saturday, January 06, 2007 7:16 PM > To: The Friday Morning Applied Complexity Coffee Group > Subject: Re: [FRIAM] observations of complex phenomena while in Mexico > > > Thanks for all your comments. Next time I'm in Mexico, I will > definitely do > my best to get some video footage. My recollection of what I > saw in October > 2005 in Mazatlan is that the various yaws and compensations > were easy to > see, as you say. I can't remember how long the formations > were stable - > perhaps generally less than a minute, before the formation > would break down > (but I'm really just guessing) - but they were long enough to see the > dynamics involved. And after the formations broke down, they > would often > reform again fairly soon. > > Regarding Phil's comment that the Mazatlan colonies were > possibly just > different from the Cancun colonies I will need to investigate that. > (Frank - I was in Cancun over Christmas, by the way and the > migration habits > might be a factor involved in when and why they engage in vee > formation - > something else to investigate). It seems, though, it is > unlikely that a > single colony in Mazatlan would have developed the vee > formation capacity > completely independently of a colony in Cancun, especially > when the distance > between them is not really that great when we think in terms of bird > migratory habits. So far, I still think the wind conditions > are more likely > what prevented vee formation in Cancun, but of course I will > need a bit more > evidence to support that. > > Also, Phil, I would argue that strong leadership is not a > factor in vee > formations. As we all know, self-organized phenomena arise > without leaders > to guide the emergent patterns - I can't think of why it would be any > different for frigatebirds. The formations must self-organize > from some > principle of interaction - in the case of organisms that save > energy by > drafting, it is the coupling between them that occurs because > there is a > physiological or energetic advantage to their coupling (ie. to their > drafting). > > It could be that frigatebird vee formations are simply > derived from their > inherent natural behaviours and have no basis in any > underlying physical > principles, but given the advantages conferred upon other > types of organisms > that engage in drafting dynamics and formations, it seems > reasonable to ask > if there is there is a p
Re: [FRIAM] Friam Digest, Vol 43, Issue 6 Formation Flight
Thank you for the interesting article - this listserv is proving to be a
wonderful resource! Thanks also for clarifying that energy savings in bird
flight formations involve different aerodynamics than drafting, which is an
important difference from my perspective. The key for me is still the
energy savings due to some positional zone where output is reduced, although
I may have call any universal phenomena in this respect something other than
a "drafting principle", which is what I was suggesting in my original note
on the subject.
Have you made, or do you know of any studies that involve the dynamics of
frigatebirds? As I was noting, it appears to me that they align in vee
formations while gliding in relatively stationery positions. I was
suggesting this constitutes another type of "drafting", where the agents do
not create the air flow by moving through it, but attempt to remain as
motionless as possible in the face of air that is already moving (ie.
sufficiently high winds). If they are not flapping their wings, then does
this vee formation involve different aerodynamics from that of moving
pelicans or geese or others?
Also, would you agree that fundamentally a similar phenomenon is occurring
as that which happens in penguin huddles - where penguins reduce heat loss
by close formations?
In terms of the reason why stronger birds may take up easier positions in a
flight formation, I can actually offer a possible explanation on that. It's
based on my own observations of energy savings in bicycle pelotons (group of
cyclists riding together), and a equation I've developed with Gottfried
Mayer-Kress (formula not yet published though):
PDR = (Pa - Pb / Pa) / D
PDR is peloton disintegration ratio
Pa is maximum power output of lead rider
Pb is max power output of drafting rider
D is energy savings due to drafting expressed as a percentage
Pa - Pb / Pa gives a percentage output difference
So for example, rider A can put out a max of 450w at 40km/h when riding
solo, while rider B may be capable of a max of 330w for a max speed of
30km/h when riding solo. But by drafting behind A, rider B can go 40km/h,
the same speed as A, while both are proceeding at their maximum outputs (B
saves 27 percent (Hagberg & McCole)). However, if rider C is capable of say
470w for 41km/h, rider B would not be able to keep up.
Applying this to birds, depending on how much stronger a lead bird is than a
following bird and how much energy is actually saved by following, it's
possible that stronger birds are actually so strong that even the energy
savings by flying in the zone of greatest savings is not enough to keep up
(PDR would be > 1, using my equation).
So, what ends of happening is the strong birds ruin the flight formation -
so they end up with the luxury of sitting in, because they haven't learned
how to adjust their speed properly when they are the front to prevent
following birds from also hitting maximum and fatiguing too quickly.
Just as a note, my primary interest is with the dynamics of bicycle
pelotons - I do not hold any special expertise, but am an amateur scientist,
as it were. I've made a number of observations of peloton dynamics, and am
still working on getting material published in the area.
Hugh Trenchard
- Original Message -
From: "Peter Lissaman" <[EMAIL PROTECTED]>
To:
Sent: Saturday, January 06, 2007 9:47 PM
Subject: Re: [FRIAM] Friam Digest, Vol 43, Issue 6 Formation Flight
> In connections with the comments about FORMATION FLIGHT
>
>
> FORMATION FLIGHT by PETER LISSAMAN
>
> The formation flight of birds has long been of interest to natural
> scientists. Leonardo da Vinci discussed this in 1504, as did Lord
> Rayleigh
> in 1889. The Vee formation produces significant energy saving. There is
> no debate about this. It has been established unequivocally
> theoretically,
> measured in flight tests with aircraft, and also, indirectly, in the
> remotely monitored pulse rate of formations of our feathered friends,
> actually Brown Pelicans. The mathematics is complicated. It relates to
> the
> flows induced by the vortex wake behind a lifting wing. Outboard of the
> wing a large upwash is induced, proportional to the circulation on the
> wing, and the wing man ("bird"?), if he tucks up tight on the tip, is
> flying in a strong upwash, with big drag savings. That's all there is to
> it! But, Ah, the Details! As Leonardo said "God is in the Details"! It
> would be boring to go into those mathematics, except to say that the
> procedure is considered well-understood and correct, but a helluva mess!
> The birdies jus' do it, and could care less!
>
> The first paper I know of that treated the topic mathematically (and
> brilliantly) was Wieselsberger in ZFM, 1914; an
Re: [FRIAM] observations of complex phenomena while in Mexico
Thanks for all your comments. Next time I'm in Mexico, I will definitely do my best to get some video footage. My recollection of what I saw in October 2005 in Mazatlan is that the various yaws and compensations were easy to see, as you say. I can't remember how long the formations were stable - perhaps generally less than a minute, before the formation would break down (but I'm really just guessing) - but they were long enough to see the dynamics involved. And after the formations broke down, they would often reform again fairly soon. Regarding Phil's comment that the Mazatlan colonies were possibly just different from the Cancun colonies I will need to investigate that. (Frank - I was in Cancun over Christmas, by the way and the migration habits might be a factor involved in when and why they engage in vee formation - something else to investigate). It seems, though, it is unlikely that a single colony in Mazatlan would have developed the vee formation capacity completely independently of a colony in Cancun, especially when the distance between them is not really that great when we think in terms of bird migratory habits. So far, I still think the wind conditions are more likely what prevented vee formation in Cancun, but of course I will need a bit more evidence to support that. Also, Phil, I would argue that strong leadership is not a factor in vee formations. As we all know, self-organized phenomena arise without leaders to guide the emergent patterns - I can't think of why it would be any different for frigatebirds. The formations must self-organize from some principle of interaction - in the case of organisms that save energy by drafting, it is the coupling between them that occurs because there is a physiological or energetic advantage to their coupling (ie. to their drafting). It could be that frigatebird vee formations are simply derived from their inherent natural behaviours and have no basis in any underlying physical principles, but given the advantages conferred upon other types of organisms that engage in drafting dynamics and formations, it seems reasonable to ask if there is there is a physical principle underlying the formations. Nonetheless, what this all suggests to me that it is an area ripe for further study, and that very little work has been done to establish the universality of the "drafting principle" as I am calling it. I actually think it applies in a lot of other situations as well, from trail formation to aspects of economics, but that's little more than a gut feeling at this point. But I suppose, at the very least, until I can get some good footage of frigatebird formations and some wind speed measurements, we can only speculate as to what is happening with them. I'm not sure when I'll be in Mexico next, but I'll keep everyone posted as to what I see. If anyone else is going, please keep an eye out for the frigatebirds! Pelicans also fly in vees too, but they are more like geese, I think - they fly past at fairly high speed. On the note about the decline of traveling geese, I really can't speculate. I live on the west coast of Canada in British Columbia and I still see vee formations going in all directions. But perhaps global warming is a factor in the distances they need to fly now - maybe they can stay farther north all year round. Hugh Trenchard - Original Message - From: "Carl Tollander" <[EMAIL PROTECTED]> To: "The Friday Morning Applied Complexity Coffee Group" Sent: Friday, January 05, 2007 10:16 PM Subject: Re: [FRIAM] observations of complex phenomena while in Mexico > Curious. I was wondering if, since the frigatebirds are aligning into > formations without > flapping, if it would be easier to perceive if there were differences in > the "yaw" of the > bird wing or body relative to its position in the formation. If so, > several hypotheses > about aerodynamics on formation might be arise. If, for example, there > was a pronounced > yaw to the right on the right side of the V due purely to the drafting > aerodynamics of the > V (this is just an example) then the bird in its local frame might be > adjusting its position > relative to the bird in front, which would be somewhat to the left of > where it "should" be, > (given the local aerodynamic properties of the surrounding air > (temperature, pressure, wind speed, etc) > so the bird would work harder to adjust its position so that the bird in > front would be > more in the expected position. At some point the energy advantage gained > by remaining > in the V formation would be lost, and the V would not be supportable. > > Frigatebirds are relatively large, so the idea here is that any drafting > effect would not occur > uniformly on any given bird in a V formation, p
[FRIAM] observations of complex phenomena while in Mexico
I am a lurker on this listserv and find many of the discussions here interesting and valuable. Recently I was in Mexico and noticed a couple of interesting complex phenomena I thought I would share with this group. The first relates to frigatebird formations and ties in with observations of these birds I made last year. Last year, when in Mazatlan, I noticed that frigatebirds often hover and glide for several minutes at a time without flapping and that they tend to glide in disorderd configurations until they spontaneously undergo a phase change (it seems to me) when they align in vee formations - still gliding nonetheless. These are fantastic sights to see, since the birds seem to hang in the air in these vee formations without passing across the sky at the relatively high speeds of geese, for example. This year, in Cancun, I noticed frigatebirds gliding in disordered configurations and, waiting patiently for the phase change, I was disappointed when these changes did not occur. I wondered if I was imagining the alignments I saw last year in Mazatlan, but fairly certain I wasn't, I speculate why the phase changes did not occur among the birds I saw in Cancun. Firstly it's possible the frigatebird colonies on the Caribbean side of Mexico simply don't undergo these formations, being a slightly different sub-species or what have you. Perhaps, but I hypothesize that the wind speeds are the primary factor in determining whether formation phase changes occur. In Mazatlan last year in late Sept/early October, the wind speeds were low, I recall. In Cancun, wind speeds were significantly higher. I suggest that gliding in vee formations can only occur between a certain range of wind speed - if wind speed is too low, the birds cannot glide at all; if too high, they can glide, but they cannot align in vee formations. The critical range allows frigate birds to draft when gliding behind another while maintaining position, but above the range the drafting effect is too high and the birds get "sucked" through - or tend to fall, it looked to me - the low pressure areas and cannot hold their positions. Drafting ordinarily has the effect of saving energy (a la cyclists in a peloton), but if birds are gliding and already saving substantial energy by not flapping their wings, I wondered whether any significant energy savings benefit can be derived by aligning in vee formations while gliding. At first I thought not, but gliding inevitably requires some energy - small muscle coordination and positional adjustments - not as costly as flapping wings, but some energy is required. When frigatebirds form vees, I hypothesize there is in fact significant energy savings for those birds in drafting positions - small muscle contractions for positional adjustments may be reduced, and birds in these formations will expend less energy. They would not, I suggest, align in these ways if it were not for some energy savings benefit. Because frigatebirds do not generate the higher air pressure behind which to draft, such as geese do, or cyclists do, or fish in water do by propelling themselves through the medium (air or water), I suggest this form of energy savings constitutes a third type of "drafting". The other is energy reduction by huddling, such as penguins undergo. So I suggest three types of drafting occurrences: I Occurs when system components generate effective air or liquid pressure as they propel themselves through the medium; eg. cyclist pelotons, fish schools, geese in vees; II Occurs when system components remain stationery and air or liquid pressure is generated externally; eg frigatebirds in vees while gliding and remaining more or less positionally stable, and possibly some types of fish (here I suggest this may occur in fish swimming upstream, such as salmon, which may hold themselves in a stationery position against the flow of the water - I haven't specifically observed any interesting drafting formations as a result, although I have watched salmon swim upstream and speculate drafting formations do occur) III Occurs when system components remain stationery and environment temperature drops; eg. penguin huddles Type I exhibit phase changes from disordered states to ordered states and back again through hysteresis loops. For cyclists, when peloton speeds are higher than a critical speed/drafting threshold, disorder in the peloton occurs. In a peloton, density is generally higher at low speeds and density decreases as speeds increase. At a relatively high threshold speed, a peloton loses cohesiveness entirely. To resume cohesion, peloton speeds must fall to a lower threshold to resume cohesive formations (I've observed and documented this). The loop is clockwise (speed on Y axis, density/order on X) , but is the inverse of vehicle traffic hysteresis, for example, where density increases as speed decrease
