Re: [ATM] Not quite immaculate

[Jarvis Krumbein <jkoptic@juno.com>]

Vladimir, it's not necessary to use interferometry to demonstrate this. 
We used to apply a finger tip to heat the surface of a mirror under test,
either plate or pyrex, for a minute and the resultant bump could always
be easily seen with the Foucault test.  This was a good way to
demonstrate the sensitivity of the test.

Jarvis Krumbein 


On Wed, 7 Nov 2007 10:12:08 +0100 "Vladimir Galogaza"
<vladimir.galogaza1@zg.t-com.hr> writes:
> You can have bad narrow spot by holding the mirror at this spot, or 
> keeping 
> your
> finger at it causing local heating and consequently swelling of  the 
> surface 
> at this spot.
> Subsequent figuring will polish off this spot and you will end with
> kind of hole at this place. This is not pure imagination because it 
> was
> excellently documented by Dale Eason. He showed  how local heating
> of the surface by finger touch can be demonstrated 
> interferometricaly.
 
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