Re: Sensing light at rt angles to it direction?

From: Paul Draper (pdraper_at_yahoo.com)
Date: 09/23/04 

Date: 23 Sep 2004 10:04:16 -0700

bill.thomson@tka.co.za (Bill) wrote in message news:<4b1e845e.0409230040.4022155d@posting.google.com>...

> Thanks for the feedback.
> If I understand correctly (excluding QM for the moment) a beam of
> light (laser in vacuum) passing between two charged plates or through
> a magnetic field will not influence by these fields? I find this hard
> to fathom ? that a traveling bit of the EMS will not be influenced or
> influence these static fields in any measurable way ? given that these
> static fields constitute the primary components of the light beam?
> Surely I must be missing something?
>
> Bill

Excluding QM for the moment, this happens all the time. Waves pass
through each other *without* disrupting each other as a matter of
routine. If this were not true, a couple sitting across the dinner
table from each other would not be able to have a conversation if
there were another couple also at the table having a conversation.

If you want a demonstration, stretch a Slinky spring between you and
someone standing 8 feet away. Now, at the same time, both of you send
one pulse (shake the end once). The pulses will travel the spring,
pass through each other, and proceed unimpeded. This will be true
whether the pulses are in the same direction or opposite or
orthogonal.

PD