Jay

The wavelength of a VOR transmission is about 8ft long. The wavelength
of a visbile light is about 0.5 micrometer. You can fit thousands of
wavelengths inside the pupil of your eye, but you cannot fit even a
small fraction of a radio wave. For a lens to behave like a lens, its
size must be much larger than a wavelength. If it is smaller, only a
tiny fraction of a wavelength will get through. It's like trying to
squeeze a large object through a small hole. Insteading of focusing,
it simply scatters (diffracts).

If you are concerned about a VOR, consider that commercial radio and
TV stations transmit at much higher power levels. Think about that
next time you stare at a TV tower :-)




"Jay Honeck" wrote in message news:%uRYb.353608$na.522124@attbi_s04...
Okay, here's a weird one for the group: Radio waves are the same as light
waves, except they're not in the visible spectrum, right?

Here's why it matters: As we were departing from Muscatine, IA today (a
beautiful day to fly in the Midwest, BTW -- clear and warm) after a great
lunch, my gaze fell on their on-field VOR transmitter. Focusing closely on
the "Hershey's Kiss"-shaped structure (with my new glasses -- wow, what a
difference a new prescription makes!), I wondered aloud if the lens in my
eye was at that moment focusing powerful radio waves onto my retina.

Mary, a scientist with a strong physics background, was not sure if radio
waves behaved the same as light waves.

I've never heard of anyone frying their retinas by looking at a radio
transmitter, but this begs the question: Can the lens in your eye focus
radio waves?

If not, why not?