Re: [OT] Power over radio is it a true thing or just a myth ?
Very off topic. On Aug 28, 2009, at 12:28 PM, Michael Tewner wrote: 88 Miles per hour? http://en.wikipedia.org/wiki/Oldsmobile_88 Geoff. -- geoffrey mendelson N3OWJ/4X1GM Jerusalem Israel geoffreymendel...@gmail.com ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: [OT] Power over radio is it a true thing or just a myth ?
On Tue, Aug 25, 2009 at 11:25 AM, Oleg Goldshmidt p...@goldshmidt.orgwrote: On Tue, Aug 25, 2009 at 10:40 AM, Gilad Ben-Yossefgi...@codefidence.com wrote: Oleg Goldshmidt wrote: Once you have satisfied yourself that N=3, you can derive R^-2 easily from flux considerations. Until, of course, the invention of the flux capacitor... http://en.wikipedia.org/wiki/DeLorean_time_machine Oh, anything is possible if you travel through space-time in a DeLorean... In particular, when you travel close to the speed of light you emit mostly in the forward direction, not isotropically... ;-) when you travel close to the speed of light 88 Miles per hour? -- Oleg Goldshmidt | o...@goldshmidt.org ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: [OT] Power over radio is it a true thing or just a myth ?
Michael Tewner wrote: Until, of course, the invention of the flux capacitor... http://en.wikipedia.org/wiki/DeLorean_time_machine Oh, anything is possible if you travel through space-time in a DeLorean... In particular, when you travel close to the speed of light you emit mostly in the forward direction, not isotropically... ;-) when you travel close to the speed of light 88 Miles per hour? Despite popular belief, the speed of light is only fixed in vacuum and scientists long acknowledged the fact that light may travels in different and lesser speeds when going through different materials, such as air, or water. 88 miles per hour, it would seem, is the speed of light as it travels through Hollywood movies. I specifically state Hollywood here, because, recent evidence show that speed traveling via a French movie for example, will be closer to 25kph, whereas in Bollywood movie it would be infinitesimally close to 88 miles per day. Interesting enough, Light travels through Israeli movies in speed close to American ones (88 mph) but, complain much more then the American counterpart when it doing so. Strangely, a love affair between an homosexual Palestinian Sumu wrestler who is in fact a Mossad agent living in Lod is also involved. And don't even get me started on the speed of Lite. Gilad :-) -- Gilad Ben-Yossef Chief Coffee Drinker CTO Codefidence Ltd. Web: http://codefidence.com Cell: +972-52-8260388 Tel: +972-8-9316883 ext. 201 Fax: +972-8-9316884 Email: gi...@codefidence.com Check out our Open Source technology and training blog - http://tuxology.net Now the world has gone to bed Darkness won't engulf my head I can see by infra-red How I hate the night. ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: [OT] Power over radio is it a true thing or just a myth ?
Please excuse me for answering a humorous post seriously. Gilad Ben-Yossef wrote: Despite popular belief, the speed of light is only fixed in vacuum and scientists long acknowledged the fact that light may travels in different and lesser speeds when going through different materials, such as air, or water. Again, not precisely accurate. While light will, indeed, travel slower through any material denser than vacuum, this is not what the term speed of light refers to. To the best of my knowledge, speed of light refers to a basic property of the universe (how fast will any change of any field propagate), and that is the property that goes into the time warping formulas (the famous c in Lorentz transformation). Just because light travels through glass at 30% less speed does not mean you have to aim 30% lower if you want to freeze time (unless, and this is something I'm not 100% clear about, YOU are traveling through glass as well). 88 miles per hour, it would seem, is the speed of light as it travels through Hollywood movies. At least that one seems pretty accurate. This also explains why pretty much anything looks different when viewed through the filters of a Holywood movie. The huge refraction coefficient acts like lens, only much more powerful. Shachar -- Shachar Shemesh Lingnu Open Source Consulting Ltd. http://www.lingnu.com ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
[OT] How many dimensions? (WAS: Power over radio)
2009/8/24 Oleg Goldshmidt p...@goldshmidt.org: I'll bite - it's OT, but too much fun to skip... ;-) 2009/8/24 Shachar Shemesh shac...@shemesh.biz: As a side note - does that prove that our universe only has three dimensions? Technically, no, though many philosophers (as opposed to physicists or mathematicians) will say it does. The number of dimensions does not follow from R^-2, but if you live in a 3D world then R^-2 follows... ;-) I have not checked every statement on http://en.wikipedia.org/wiki/Spacetime#Privileged_character_of_3.2B1_spacetime, but it does have useful pointers that I'd myself recommend. [disclosure: I *am* a physicist]. The R^-2 character of gravity is arguably even more important than radiation, but the mathematical reason is the same. If you are interested in proving that our world is 3D then probably the most important set of physical/anthropic arguments that derive N=3 from the observable universe was proposed by Ehrenfest (and Weyl: Ehrenfest concentrated on gravity and Weyl on electromagnetism) in the early 20ies - a reference is in the Wikipedia article above. For those interested in an in-depth discussion of why the Universe is what it is I recommend The Anthropic Cosmological Principle by Barrow Tipler (see the reference in the Wikipedia link) - it's big, but real fun to read, IMHO. Unfortunately, I don't have a copy and I can't recall from memory how much background it assumes. Oleg, I understood that the universe has 11 or so dimensions, and that 5 or six can even be measured. But the wikipedia article that you link to claims only 3+1. I have googled a bit but found only very technical explanations, or baby facts with no explanations. Can you sum it up for someone who is familiar with relativity, but is not a physicist? Thanks. -- Dotan Cohen http://what-is-what.com http://gibberish.co.il ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: [OT] Power over radio is it a true thing or just a myth ?
What the fuck are you doing? I did not see that movie yet... Please write spoiler and leave a few empty the next time. On יום שישי 28 אוגוסט 2009 13:17:06 Gilad Ben-Yossef wrote: Interesting enough, Light travels through Israeli movies in speed close to American ones (88 mph) but, complain much more then the American counterpart when it doing so. Strangely, a love affair between an homosexual Palestinian Sumu wrestler who is in fact a Mossad agent living in Lod is also involved. ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
RE: [OT] Power over radio is it a true thing or just a myth ?
ubergeek-mode Actually, the speed of light *in a vacuum* is the universal constant, invariant regardless of the observer's frame of reference. 'C' is so defined - the speed of light in vacuum. This is now understood to be such a basic constant that in 1983, the meter was defined in terms of the speed of light: The definition states that the meter is the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second. http://www.mel.nist.gov/div821/museum/timeline.htm Note that when a particle exceed the speed of light *in a given medium*, it gives off cerenkov radiation, analogous to a sonic boom. This is the blue glow you see in the water surrounding nuclear reactors - pretty cool. http://en.wikipedia.org/wiki/Cherenkov_radiation /ubergeek-mode Rony _ From: linux-il-boun...@cs.huji.ac.il [mailto:linux-il-boun...@cs.huji.ac.il] On Behalf Of Shachar Shemesh Sent: Friday, August 28, 2009 1:30 PM To: Gilad Ben-Yossef Cc: Linux-il@cs.huji.ac.il Subject: Re: [OT] Power over radio is it a true thing or just a myth ? Please excuse me for answering a humorous post seriously. Gilad Ben-Yossef wrote: Despite popular belief, the speed of light is only fixed in vacuum and scientists long acknowledged the fact that light may travels in different and lesser speeds when going through different materials, such as air, or water. Again, not precisely accurate. While light will, indeed, travel slower through any material denser than vacuum, this is not what the term speed of light refers to. To the best of my knowledge, speed of light refers to a basic property of the universe (how fast will any change of any field propagate), and that is the property that goes into the time warping formulas (the famous c in Lorentz transformation). Just because light travels through glass at 30% less speed does not mean you have to aim 30% lower if you want to freeze time (unless, and this is something I'm not 100% clear about, YOU are traveling through glass as well). 88 miles per hour, it would seem, is the speed of light as it travels through Hollywood movies. At least that one seems pretty accurate. This also explains why pretty much anything looks different when viewed through the filters of a Holywood movie. The huge refraction coefficient acts like lens, only much more powerful. Shachar -- Shachar Shemesh Lingnu Open Source Consulting Ltd. http://www.lingnu.com ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: [OT] How many dimensions? (WAS: Power over radio)
Dotan Cohen wrote: Oleg, I understood that the universe has 11 or so dimensions, and that 5 or six can even be measured. But the wikipedia article that you link to claims only 3+1. I have googled a bit but found only very technical explanations, or baby facts with no explanations. Can you sum it up for someone who is familiar with relativity, but is not a physicist? Thanks. I'll do my best as another non-physicist, and then Oleg (or anyone else) can correct me where I'm wrong. In an attempt to create a grand unified theory(tm) of everything (and rejecting, with no explanation, the answer 42), some physicists have tried the big hammer(tm) approach - i.e. - hammer on the equations until they fit. This method is not to be put down, as it allowed Lorentz to phrase his Lorentz transformation even before Einstein came around and provided a relatively simple (excuse my pun) explanation for the why. In particular, the modern hammerists came up with strings theory. It is an extrapolation of existing theories, designed to encapsulate all known to be somewhat true theories about the universe (in particular, general relativity on the one hand, and quantum mechanics on the other). Strings theory does, indeed, claim that the universe has 12 dimensions. Here's the catch. Strings theory is so generic, that it fails to supply one of the basic requirements of any scientific theory. It fails to provide predictability. Any scientific theory must come with an experiment that is possible to perform (at least theoretically), with certain outcomes being agreed to mean that the theory is disproved. If a theory cannot supply such an experiment, it means that any possible outcome of any possible experiment is okay with that theory, and this means it lacks any ability to actually predict the outcome of yet unperformed experiments. Such a theory may be fine for philosophers, but is useless to scientists, and in particular, to physicists. And yet, it seems that strings theory is very far from useless. Strings theory has garnered support, and more importantly, research grants, and have occupied the time of our bests physicists around the world, with nothing concrete to show for it but the money well spent. It is trendy, and has been for quite some time now, but, at least as far as I'm concerned (and unless I am totally misunderstanding the situation, which is possible), it is not physics. People like it because of its potential, but this potential, after over a decade of research, has failed to materialize into something you can try and disprove. Shachar -- Shachar Shemesh Lingnu Open Source Consulting Ltd. http://www.lingnu.com ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: [VERY OT] Power over radio is it a true thing or just a myth ?
Michael Tewner tew...@gmail.com writes: when you travel close to the speed of light 88 Miles per hour? Michael, This is getting more and mor off-topic, but yes, exactly, 88 mph! I confess, I am a car-buff, a petrol-head, etc. I also like movies. So flame me - my /dev/null is ready. I will assume that you don't know where 88 mph comes from. If you do, sorry - maybe someone else is wondering what you are talking about. Since you mention 88 mph you must have seen Back to the Future, so you must also remember the line where Marty is shocked that Doc has built a time machine out of a DeLorean, and Doc responds that if one travels through time one might as well do it in style. DeLorean was a sports car produced in N. Ireland (sic!), with quite a cult following. Its speedometer was graded up to 85 mph (we are talking early 80ies here, it *was* fast for its time), so 88 mph in the movie is an inside joke: you *could* reach 88 mph in a DeLorean but would not *know* if or when you did. You may further speculate whether you would know when you reach the speed of light in a real time machine if you can build it. ;-) -- Oleg Goldshmidt | p...@goldshmidt.org ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
Re: [OT] How many dimensions? (WAS: Power over radio)
Shachar Shemesh shac...@shemesh.biz writes: Dotan Cohen wrote: Oleg, I understood that the universe has 11 or so dimensions, and that 5 or six can even be measured. But the wikipedia article that you link to claims only 3+1. I have googled a bit but found only very technical explanations, or baby facts with no explanations. Can you sum it up for someone who is familiar with relativity, but is not a physicist? Thanks. Ouch! We need a new list - science for Linux geeks or sth like that. Mea culpa! Essential disclaimer: I am not, nor have I ever been, a string theorist. I'll do my best as another non-physicist, and then Oleg (or anyone else) can correct me where I'm wrong. Shachar's response stripped, but *only* because anyone can find it in the archives - see below. I will not attempt to address any of the points that Shachar mentioned, but the essence of his response is quite correct. Various numbers of dimensions come from string theories, superstring theories, membrane theories, and so on. We'll call them string theories collectively. You mention 11 dimensions, there have also been theories predicting 10, 26, 119 (or at least a hundred and something, I don't recall the details, and there have been quite a few of those), or whatever. These are mathematical theories that start from various symmetry considerations, and usually operate on mathematical constructs, be it 1-dimensional strings or multi-dimensional surfaces (membranes, or branes for short). Observable phenomena, e.g., particles, are particular resonances or eigenstates corresponding to oscillations of those strings or membranes, similar to different musical notes corresponding to particular resonant states of a guitar or a violin or a piano string. This is where strings and membranes get their names from - they must be oscillating lines or surfaces to produce particles we can observe. Now, if a string or a membrane oscillates the oscillation has some energy and, by relativity, this energy can be related to the mass of the corresponding particle. Now you do the math to fit the observations. E.g., a photon, that travels with the speed of light, must be massless. It turns out that this can happen only if the string/membrane/whatever world has so many dimensions (the value of so many depends on the theory, it may be 11, or 26, or sth else). How do these theories reconcile the 10/11/26/115/etc. dimensions with the observed 3+1 of the macro world? They devised a notion that the extra dimensions are compactified, i.e., in the other dimensions the world is so small that it cannot be measured, at least not at attainable energies (and at the required energies it is not clear to me if any theory predicts that Heisenberg's uncertainty principle can be overcome). Now, as Shachar wrote, this is all mathematics. To become physics, these theories must make predictions that can be empirically verified. Physics, unlike philosophy, is an empirical science. Unfortunately, the zillion and a half of various string theories predict observable effects at energies that are many orders of magnitude higher than anything modern particle accelerators can produce. In fact, the preferred method (beyond arguments related to mathematical elegance) of picking most promising theories out of the multitude is based on the minimal energy at which the theory predicts an observable effect. Mind you, they pick the theory that predicts an effect at the lowest energy as promising *not* because they think chances are it will be correct, but because it will be the first to check if and when they get enough billions or trillions to build an accelerator that is 100 times more powerful than the current most powerful one. This is part of the reason why these guys are so keen to build more and more powerful colliders. So, to sum up, as far as physics, the empirical science, knows there are 3 spatial and 1 temporal dimensions. There are a zillion and a half complicated mathematical theories of various degrees of elegance that predict various number of dimensions (there is indeed a subclass that predicts 11), the extra dimensions must be compactified in order not to spook the imaginative (or not[1]) non-mathematicians. None of these theories makes any prediction that is practically verifiable at the current level of experimental technology. If and when the relevant experiments are performed either (some of) the theories will be rejected or we'll find out that the Universe is more fascinating than we thought. Until then you are welcome to retell your favourite version of theory vs. practice witticism. Now, if you'll excuse me, I have plans for tonight that are restricted to 3+1 dimensions. ;-) [1] Gauss said of one of his former students, He became a poet, he didn't have enough imagination to become a mathematician. -- Oleg Goldshmidt | p...@goldshmidt.org ___ Linux-il mailing list Linux-il@cs.huji.ac.il
Re: ext2 partition on G1 Android
Some things that come to mind: 1) Is your ext2 partition your 2nd partition? When loading, Android relies on the order of the partition not their type. 2) Is the partition formatted? The boot might fail if it can't mount the partition. If you have adb installed, an 'adb logcat' will probably show you what's going on even if the phone doesn't complete the boot. Gadi eliyahu cohen wrote: I'm trying to setup apps2sd on a G1. I can resize the fat32 partition without a problem, but whenever I add an ext2 partition to the SD card, the phone wont come up after a reboot. I've tried partitioning with fdisk, gparted, and sdsplit (as per http://code.google.com/p/android-roms/wiki/Fat_Ext2_Partition). Any ideas what could be wrong? -- Gadi Cohen aka Kinslayer dra...@wastelands.net www.wastelands.net Freelance admin/coding/design HABONIM DROR linux/fantasy enthusiast KeyID 0x93F26EF5: 256A 1FC7 AA2B 6A8F 1D9B 6A5A 4403 F34B 93F2 6EF5 ___ Linux-il mailing list Linux-il@cs.huji.ac.il http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il
