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- Path: sparky!uunet!cis.ohio-state.edu!ucbvax!dog.ee.lbl.gov!csa2.lbl.gov!sichase
- From: sichase@csa2.lbl.gov (SCOTT I CHASE)
- Newsgroups: sci.physics
- Subject: Re: Magnetic lenses
- Message-ID: <24991@dog.ee.lbl.gov>
- Date: 28 Jul 92 20:09:36 GMT
- References: <ceRLP2O00WB78ZLEYJ@andrew.cmu.edu>
- Reply-To: sichase@csa2.lbl.gov
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- Organization: Lawrence Berkeley Laboratory - Berkeley, CA, USA
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-
- In article <ceRLP2O00WB78ZLEYJ@andrew.cmu.edu>, gr1c+@andrew.cmu.edu (Greg Howard Rhodes) writes...
- >Well, as a senior undergraduate physics student, I feel that I should know
- >the answer to this, but my optics are not all they should be...(and with the
- >GREs coming up really soon, too...)
- >
- >Anyway, I just got glasses. Being able to see and all is great, but I started
- >wondering about alternatives. Now, sure there all of the contact lenses and
- >the like, and maybe even lenses designed to actually _fix_ your vision. But
- >I was thinking about something a bit more esoteric.
- >
- >Would it be possible to use a strong stationary E and/or M field to bend
- >light in such a way to mimic an eyeglass? And if it would be possible, how
- >strong would the field have to be? (and, from a consumer standpoint, how
- >small could it be made?
-
- Photons, being uncharged, are not easily affected by stationary EM fields.
- There is a nonlinear effect that is very weak and not useful for your
- purpose. So the basic answer is that it would not be possible in the
- way you describe. However...
-
- If you have ever used an image intensifier tube in a region of stray
- magnetic fields, then you have seen that the field produces a distortion
- in the output image. This is because the image is actually flying through
- the tube as electrons emitted from a surface with a low work-function.
- The final image is only reconstructed when the electrons hit the photocathode.
- If there is a stray field (at least in "first generation" tubes) the
- image is distorted. So this might provide a mechanism by which you could
- "predistort" the incoming image in such a way as to compensate for the
- distortion which your own eyes will impose before your brain gets the signal.
-
- Regards,
-
- -Scott
- --------------------
- Scott I. Chase "The question seems to be of such a character
- SICHASE@CSA2.LBL.GOV that if I should come to life after my death
- and some mathematician were to tell me that it
- had been definitely settled, I think I would
- immediately drop dead again." - Vandiver
-