Re: [Science] Moon landing Hoax (fwd)

[Hugh Haskell <hhaskell@MINDSPRING.COM>]

> Hugh Haskell wrote:
> >  Interesting. And if it should happen that the reflector happened to
> >  be in the center of the face of the moon directed toward us (I don't
> >  know if this ever happens for the location of Tranquility base),
> >  would we be able to see a reflection of the Poisson spot on the moon,
> >  due to the constructive interference of the diffraction of the sun's
> >  rays around the earth?
>
> Aren't the sun's rays incoherent? Try to create diffraction or
> interference patterns using pinholes or slits with a beam of sunlight
> as the direct illuminant. I'll bet you find that this doesn't work
> nearly as well as it does with the laser in your lab as the light
> source.
>
> Have fun! :-)
>
> --MB

Are you sure? Thomas young didn't have a coherent source when he
first showed the effect in 1825 or thereabouts. And we can do an
awful lot of diffraction effects with an incandescent light at a
source. In fact if sunlight isn't coherent, then starlight isn't
either and we get spectra of stars all the time.

I guess I could accept that this isn't possible based on the distance
of the moon from the earth (approx. 1.25 light seconds) as being too
far for the sunlight to maintain the degree of coherence that is
sufficient to get spectra in the lab. I suppose that the sun's size
might make it too large to qualify as a point source which would make
it difficult to generate the interference effects necessary.

Hugh
--

Hugh Haskell
<mailto://haskell@ncssm.edu>
<mailto://hhaskell@mindspring.com>

(919) 467-7610

Let's face it. People use a Mac because they want to, Windows because they
have to..
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