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- From: loki@midway.uchicago.edu (david raoul derbes)
- Subject: Re: Are Skeptics DELUSIONAL? Do they need help to cope with reality?
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- Organization: The University of Chicago
- References: <4q27hf$nj4@tuegate.tue.nl> <4q7rdt$pe0@newsbf02.news.aol.com> <31C7CBE7.1D15@students.wisc.edu>
- Date: Sat, 22 Jun 1996 00:05:32 GMT
- Lines: 41
- Xref: news.demon.co.uk alt.paranet.ufo:54091 alt.alien.visitors:88887 sci.skeptic:73404
-
- In article <31C7CBE7.1D15@students.wisc.edu>,
- Brian Zeiler <bdzeiler@students.wisc.edu> wrote:
-
- >
- >Yes, UFO debunkers are feeble-minded morons. Here's another glaring
- >example of just how pathetic Menzel really was.
-
- Well, that is perhaps a little strong... Menzel was a very good
- scientist. However, I have a weird little true story for you.
-
- Back around 1965 (I was all of 13) a son of one of my father's colleagues,
- Skip Grulee, sent me Menzel's Guide to the Stars (a Peterson guide),
- autographed by the great man himself (Skip was at Harvard, and knew I
- was very interested in physics and astronomy.) I had just read a number
- of books on UFO's on both sides, including Menzel's skeptical one.
-
- In it, Menzel explained a green light as a meteor containing magnesium
- burning up. I spent a sizable fraction of my childhood making fireworks,
- and I know as you probably do that magnesium burns *white*, not green.
- I asked Skip to ask Menzel (his professor of astronomy) about this, and
- in the fullness of time Skip wrote back Menzel's answer: it is true that
- at sea level, Mg burns white, but in the upper atmosphere, it appears
- green. I have to say I find this a somewhat unlikely explanation. If you
- look up in the Handbook of Chem and Phys the spectral lines of Mg, sure
- enough there are green lines (several around 517 nanometers) but there
- are many *other* lines (which is why Mg appears white when it burns).
- For Rayleigh scattering to max out the green, you'd need a lot of
- scattering; and at that height, it would be (I think) very tough to
- observe the light. And presumably the color would change as the meteor
- fell, unless it burned up completely very quickly (before it changed
- altitude much.) I don't think the original sighting claimed that the
- color became more white with time, as Menzel's hypothesis would require.
- But I didn't know enough to respond to Menzel's answer at the time.
-
- I still have Menzel's autographed copy of his astronomy book...
-
- David Derbes [loki@midway.uchicago.edu]
-
- >Brian Zeiler
-
-
-