Chuck wrote in
:

On Sun, 9 Mar 2008 15:07:26 -0700 (PDT), K7ITM wrote:

snip


Note that, as far as I've been able to determine, Michelson did not
have a coherent light source to shine into his interferometer, but
still he saw interference patterns. Perhaps he had invented lasers

snip


It is said he used sodium vapor gas light (~589 nm). Coherent enough.

I have a wonderful old book, named "A Treatise on Optics", written sometime
in the late 1800's. I have to look it up here, Perhaps Cecil would be
interested in a pdf copy if I locate it again.

Those old boys could do an awful lot that we do today, and I was amazed at
the precise measurements that they could do with almost entirely mechanical
devices. Coherent light is not the half of it!

We are both more and less advanced than we might think.

- 73 de Mike -