Re: PHOTO-3D digest 1306

[P3D Jim Record [RHR Software] <jrecord@xxxxxxxxxxx>]

> 
> The lads at work still insist that light is planar and travels in waves and so
> circular polarisation ((anti)Clockwise) is impossible..... Help..
> 
> Marcus ?8^)
> 
Light is a transverse wave, which means that whatever wiggles (in this case
the electric and magnetic fields) does so at right angles to the direction
of motion. Visualize a horizontal sine wave and a vertical wave offset by
a quarter cycle; the resultant will be a corkscrew. Leading and lagging
produce clockwise and counter-clockwise, but I forget which is which.

Tell the lads at work to look at a good physics text.
> 
> The lads at work still insist that light is planar and travels in waves and so
> circular polarisation ((anti)Clockwise) is impossible..... Help..
> 
> Marcus ?8^)
> 
> Light is a transverse wave, which means that whatever wiggles (in this case
> the electric and magnetic fields) does so at right angles to the direction
> of motion. Visualize a horizontal sine wave and a vertical wave offset by
> a quarter cycle; the resultant will be a corkscrew. Leading and lagging
> produce clockwise and counter-clockwise, but I forget which is which.

Actually just think about either the electric or the magnetic field. If
two polarized electromagnetic waves are generated with one polarized 45
degrees from the other, then the result is a circularly polarized wave.
By adjusting the polarization you can get right-circular or left circular.

This is done for radio, or microwave, using two antennas fed with signals
that are shifted in phase, or with an antenna with a spiral wire.

-- 
Jim Record
RHR Software                 Icometrics - for image analysis
http://www.rhrsoft.com/ico
(303) 467-2936
(303) 467-2936 (fax)


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