(Credit: the politech mailing list)
[If you know John, you know him to be a most ardent stickler for facts. Here, John is not reporting hearsay; he's reporting about what's happened on his own server, and images he provides thereon. --jim]
At 12:34 AM +0100 3/29/03, John Walker wrote: Subject: Sniping at Snopes.com
>Almost everybody's experienced the phenomenon of encountering
>a description in news media of something they know from
>first-hand experience and discovering discrepancies that
>make them wonder about all the stories they *can't* independently
>verify.
>
>The last couple of weeks or so have been interesting at
>Fourmilab. First of all, some idiot took an image off
>Earth and Moon Viewer (a *flat map* image, mind you,
>*not* a synthetic view from above) and circulated it as
>the "last image taken from Columbia". This was picked up
>by that noted spaceflight authority Rush Limbaugh, and
>rattled around the Net for a while until it was promptly
>identified as what it was; Limbaugh removed it from his
>Web site within 24 hours.
>
>But of course, once the worms are out of the can, it's notoriously
>difficult to get them back in, especially in this brave New
>Media world. So, the image has kept popping up and being batted
>down regularly ever since.
>
>All was more or less serene with Earth and Moon Viewer until the
>war started. Apparently, some bottom-feeders got the idea
>they could watch the bombs fall and tanks roll across Iraq by
>repeatedly viewing Earth Viewer images which, of course, are
>actually generated from a static database assembled from satellite
>imagery dating from 1995-1996. It didn't help that CNN started
>broadcasting zooms into Baghdad from Keyhole's "earthviewer.com"
>site; if somebody types "earthviewer" into Google, Keyhole
>comes up number one, but guess who's number three?
>
>Anyway, the hit rate on www.fourmilab.ch, which had been hovering
>around 500,000 per day for the last two years suddenly blew the top
>off, resulting in four of the last ten days registering more than
>a million hits. When this wave first broke over the server, it was
>not pretty--CPU load, which normally runs about 2-3 on this 4 CPU
>Sun E3500, was running about 290 and all 256 Apache server processes were
>blocked waiting for rendered images, causing response time to drop
>into the minute range...which causes more re-clicks, more hits, more
>image rendering requests, greater load, longer delays...ugly.
>
>I've restricted the maximum rendered image size, added a big ugly
>red disclaimer to the results to remind folks they're looking at a
>static image, and limited the number of requests from a given site.
>This, for the moment, has brought things under control and made
>million hit days survivable. If it takes off again from *this* level,
>I think I'll just bag it and hide out in an armed compound in Switzerland.
>Damn...already did that!
>
>But let's get back to the bogus "Columbia" image. Just after I'd
>finished implementing the first round of "war emergency" fixes to
>Earth Viewer, what should happen but that image, and its provenance,
>popped up as NASA's Astronomy Picture of the Day for 2003-03-24:
>
> http://antwrp.gsfc.nasa.gov/apod/ap030324.html
>
>Well, of course, that launched another wave of hits, and another round
>of countermeasures. NASA correctly identified the image, credited the
>source, and provided appropriate links. I can't complain and, if Earth
>Viewer didn't have its back to the wall with war hits, I'd actually be
>rather flattered.
>
>Then I happened to visit the:
>
> http://www.snopes.com/
>
>urban legend site, and what should be the number 4 top search, but the
>very same "Sunset from space" picture! The hits just keep on coming.
>
>I've visited the Snopes site several times over the last few years,
>generally from links in mail and news discussions and, while there's
>nothing explicitly bogus about the site, there's something about the
>tone which I've found consistently off-putting. It's reminiscent of
>the too-smug, overly-glib style of the Skeptical Inquirer which caused me
>to let my subscription lapse in the early 80's and, perhaps, set in motion
>my
>long migration from CSICOP to Psi-perp.
>
>The Snopes analysis of the "Columbia picture":
>
> http://www.snopes.com/photos/sunset.asp
>
>is typical of this. Unlike NASA, they did not identify the source
>(although it had been identified on newsgroups long before Snopes
>posted this article), and the Snopes commentary itself contains two
>or three factual errors, depending on how you read it, and misses three
>of the most obvious things which identify the picture as not
>taken from Columbia. Here is a copy of the comments I sent to
>Snopes:
>
> * * *
>
>The image you show on the "Sunset from Space" page:
>
> http://www.snopes.com/photos/sunset.asp
>
>was generated by the Earth and Moon Viewer on my Web site:
>
> http://www.fourmilab.ch/earthview/
>
>You can almost precisely reproduce the image shown on your page
>with the following (very long--it may need to be unwrapped)
>URL:
>
>http://www.fourmilab.ch/cgi-bin/uncgi/Earth?imgsize=320&img=learth.evif&o pt=-z&lat=36&ns=North&lon=6&ew=West&alt=72&date=1&utc=2003-04-12+19:00
>
>The image shown on your page looks like it was originally
>generated with a larger image size, then scaled to the 320x320
>pixel size shown on your page, accounting for the blurring
>which is particularly evident in the lights on the night side
>of the terminator.
>
>There are several factual inaccuracies in your discussion of this image:
>
>"...this image can't have been both 'taken by the crew on board
>the Columbia' and 'taken via satellite.'"
> Okay, this is a quibble, but as Columbia was, during its
> mission, an Earth satellite, the two statements are not, in
> fact, contradictory.
>
>"Although this images does accurately depict the landforms
>described..."
> Incorrect. This picture is a rectangular excerpt from a
> map image in a cylindrical projection. There is no
> viewpoint in orbit around the Earth from which the Earth
> would look like this. The distortion toward the poles is
> especially apparent in the shape of Iceland and the eastern
> part of Greenland toward the top. You can see the entire
> rectangular projection map with the URL:
>
>http://www.fourmilab.ch/cgi-bin/uncgi/Earth/action?opt=-p&date=1&utc=2003 -04-12+19:00
>
> Further, the field of view is ridiculously too wide to be
> seen from the altitude at which shuttles fly. The Columbia
> STS-107 mission flew at an altitude of about 150 nautical
> miles, or 278 kilometres. A horizon to horizon view from that
> altitude centred at the centre of the rectangular image you
> show may be viewed with:
>
>http://www.fourmilab.ch/cgi-bin/uncgi/Earth?imgsize=320&img=learth.evif&o pt=-l&lat=36&ns=North&lon=6&ew=West&alt=278&date=1&utc=2003-04-12+19:00
>
>"...the positioning of lighted cities to the right of the
>day-night terminator line..."
> Well, subject to the comments above, the lights may be in
> the correct positions for the *projection*, but the *shape of
> the terminator* is dead wrong for a picture which purports to
> have been taken around the start of February. Note that in the
> images above, I specified a date around mid-April when the
> terminator looks like the one in the image you show. In fact,
> an image generated with the same parameters except using the
> illumination for February 1 appears as the following URL
> displays:
>
>http://www.fourmilab.ch/cgi-bin/uncgi/Earth?imgsize=320&img=learth.evif&o pt=-z&lat=36&ns=North&lon=6&ew=West&alt=72&date=1&utc=2003-02-01+17:20
>
> Think about it--in northern hemisphere winter, the north
> pole is in constant darkness--hence the picture you show could
> not possibly represent a date during the last flight of
> Columbia.
>
> Finally, the cloudless day and night Earth image database
> used to create this rendering by the Earth and Moon Viewer on
> my site is © 1996 The Living Earth® Inc., All Rights Reserved.
> I am not affiliated with The Living Earth; they grant my site
> permission to use their database to prepare free rendered
> images in return for identifying the data source and providing
> back-links. Images created from their database by Earth and
> Moon Viewer should be re-used only with permission from The
> Living Earth (http://livingearth.com/), and with identification
> and a back link. The Living Earth routinely grants this
> permission for non-commercial use of their images.
>
> Note that when this image appeared as the NASA Astronomy
> Picture of the Day for 2003-03-24:
>
> http://antwrp.gsfc.nasa.gov/apod/ap030324.html
>
> it was identified correctly.
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