Can the lens in your eye focus radio waves?

No.

There are many reasons for this, the most fundamental is that EM radiation (the
general term for "light of any wavelength even if it's not 'visible' light")
(EM stands for electromagnetic) reacts differently to matter depending on the
frequency ("color"). Some colors are absorbed, some are reflected, some are
transmitted. This is what makes something green, or blue, or white. In fact,
white flowers often reflect differeing amounts of UV radiation, so bees can see
a difference. This remains true throughout the entire EM spectrum. Water
absorbs IR radiation but passes visible light. Glass absorbs UV and IR,
passing visible light. If you go to your dentist and get an X-ray, the device
they focus on you passes X-rays but does not pass visible light. And so on.

As for focusing, this involves refraction, which has to do with the difference
between the speed of light in a vacuum, and the speed of light in the substance
it is passing through. (think of the matter as interfering with the light
waves as they go by, slowing them down to some extent). The amount of
refraction (if any) has to do with the frequency of the light to begin with.
"Chromatic abberation" is a defect in lenses caused by the fact that different
colors are refracted different amounts (and is the reason prisms work in the
first place). So, a lens that is designed for one wavelength will not work as
well with other wavelengths.

In the case of visible light, the wavelengths are within a factor of two of
each other. (purple, the shortest, is only half as big as red, the longest).
Radio waves are MUCH longer wavelength. Some of them can be the size of a
football field, while others are only a few inches long. That's a pretty wide
variation, and is very different from the wavelength of light (which is very
VERY tiny - much smaller than a microbe). In fact, the waves sent out by the
VOR are bigger than your eye itself. Not much chance of focusing there!

Incidentally, the wavelength is inversely proportional to the frequency. The
speed of light is about 300,000,000 meters per second. So, if you have a
wavelength of 100 mHz (close to VOR frequency), that means that 100,000,000
waves are going by every second. So, one second's worth of those waves
(traveling at the speed of light) are spread out over 300,000,000 meters.
Divide the two... 300,000,000 / 100,000,000 gives you 3 meters, or almost ten
feet. ONE wave is ten feet long! Your eye isn't focusing that worth squat!


if light is supposed to be made up of both waves and particles...


It's not. It is neither a wave nor a particle... in fact the concept of wave
and particle don't really apply to things of this nature. However, light
BEHAVES as if it were a particle sometimes, and behaves like it were a wave
other times. It never does both at once, and which it does depends on what you
are trying to observe. (yes, it depends on what you look at! weird!)

...how much does it weigh?

It weighs nothing but it has energy. Energy and mass are the same, like water
and ice are the same. When you turn on a flashlight, the flashlight does get
lighter, and all that mass is turned into energy sent out as light. The
difference is not very much, but it is there. The atom bomb works this way
too... only by harnessing nuclear rather than chemical reactions, the amount of
energy released is considerably greater.

Light does have momentum. If you shine a light on something, there is a
recoil, and it does push the illuminated object away. It just doesn't do it
very strongly. Solar sails work on this principle (to my knowledge they have
not yet been demonstrated, but they are a serious contender for unmanned
interplanetary flight). Again, it's a VERY weak force, but it is there, and
even a weak force, applied for long enough, out in space where there isn't much
resistance, can get you moving quite fast eventually.

That should get you started thinking.

Jose




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