Roy Lewallen wrote:

Green Egghead wrote:
. . .
Karo brand corn syrup has an interesting property.
It will rotate the linear polarization of light passing through it
by different amounts depending on the frequency.
This can easily be seen by placing a small jar of
Karo syrup between to linear polarizers and rotating
them. Different angles between the linear polarizers
will result in a different color being seen in the Karo jar. . .

Dextrose (for right) and levulose (for left) -- aka glucose and
fructose, the components of sucrose, ordinary table sugar -- are named
for the direction in which they rotate the polarization of light.

Roy Lewallen, W7EL

To make things worse, there's a d-fructose and l-fructose.

D-tagatose is the all-natural un-sugar:
http://www.jhu.edu/~jhumag/1102web/sweet.html
I think I've seen it on store shelves. I'll check it out
if it's not too expensive.

A few years ago someone discovered an efficient
way to grow crystals of a specific handedness
from solution. So I'm surprised L-tagatose hasn't
totally replaced saccharin and phenylketoneurics.
Perhaps because some diseases ()like phenylketoneuria)
are associated with certain chiral forms?

Astrobioligists have suggested using chiral tests to
determine the presense of life on other planets since,
as far as they know, all life on earth has a preference
for (or immunity against?) one handedness over the other.
This suggested to them that perhaps once life developed
on a planet it would quickly bias all life on that planet
towards one of the two forms.

More on topic, should we be testing for circular polarization
radiation exposure levels on field strength meters?

It is interesting that Faraday rotation of linear polarization
can be described in terms of circular birefringence.
I can't tell if that's an analytical more than a physical description.

I see though the Faraday Effect is used in astronomy with
oscillating pulsars but otherwise making a radio tuner in
this manner would seem to present a problem of scales.

I'm confused about this since I've seen it said the higher
frequencies of light are rotated more by Karo syrup, while
another website says the higher radio frequencies are
rotated less by the ionosphere due to the Faraday Effect
than are the lower frequencies.

If I had to guess, I would think there would be only a certain
band of radio frequencies where polarization rotation would
make a practical radio tuner. Spintronics?