From: nedlatham@internode.on.net   
      
   Jos Bergervoet wrote:   
   > benj wrote:   
   > > Ned Latham wrote:   
   > > >   
   > > > I was thinking about parallel-sided glass blocks, and their   
   > > > fascinating demonstration of refraction of light on both   
   > > > entry and exit, and it occurred to me that I've never seen   
   > > > or heard anything about the beam itself except that it's a   
   > > > little wider on exit than on entry.   
   > > >   
   > > > So I wondered: has anyone ever looked at the exit beam in   
   > > > sufficient detail to detect a spectrum or dismiss the idea?   
   > >   
   > > Why would you assume exit beam is wider?  What if it's focusing down?   
      
   Standard high school stuff. Parallel beam demonstrating refraction.   
   Nothing more elaborate than that.   
      
   ----snip----   
      
   > > When you say looked at in great detail what do you mean "great"?   
      
   I did not say "great". I said "sufficient".   
      
   ----snip----   
      
   > > Not saying there might not be some interesting   
   > > details found but generally classic theory is usually highly in   
   > > agreement with measurements.   
      
   I am not questioning theoretical agreement with measurements. I am   
   asking whether a particular test has ever been conducted.   
      
   > The full Maxwell equations will indeed be the most usefull tool here.   
   > The description is in fact nothing else than light passing through a   
   > window (a widely spread application of parallel-sided blocks of glass.)   
      
   The question is "has anyone ever looked at the exit beam in   
   sufficient detail to detect a spectrum or dismiss the idea?".   
      
      
   [[Mod. note -- I (the moderator) am (still) unclear as to precisely   
   what experimental test you are asking about, and I suspect at least   
   some newsgroup readers may be similarly unclear.  I think our discussion   
   in the newsgroup could be far more interesting & productive if you were   
   to clarify *precisely* what sort of test you're intererested in.   
      
   For example, I don't know whether you're asking about tests involving   
   (1a) a (nearly-)monochromatic light beam incident on the glass block,   
        OR   
   (1b) a broad-spectrum light beam incident on the glass block.   
      
   And, I don't know whether you're asking about tests involving   
   (2a) checking to see if the entire exit beam is or is not monochromatic,   
        OR (the weaker test)   
   (2b) checking to see if, at each point across the width of the exit   
        beam, the light at that point is or is not monochromatic.   
      
   If you were to clarify these points, then we could address the question   
   of whether such a test has already been done & the results published,   
   and if so, what we might learn from this.   
   -- jt]]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)