Question about light, etc.

[ScatterPlot]

OK I had this thought. What if a source of light was created that could emit light. This is simple. But what if you made one whose light emitted was not only in a wave, but it's wave was in a wave with respect to time? Like when it traveled, it was visible part of the time, then infrared, or radio, etc. Could something like this be made? If so, it could be used as an "x-ray" viewer, capable of seeing through walls. X- or radio waves through the wall, visible on target, back to radio after bouncing off, going through the wall, then back to visible after the wall, showing an image? Could this be done? Sorry if there's anything blatantly wrong, just an idea that came to me, wanted to put it up before I go to bed, so I don't forget

[bleachit]

if I understand what you are saying, you would basically be trying to vary the wavelength with respect to time. I do not think it is possible to change the wavelength after the wave has left the source. interesting thought though.

[bjjb99]

No he won't, actually.

What bertmcmahan wants, judging by his post, is to have the wavelength [edit: I meant "frequency" instead of "wavelength"] of light actually shift while it is in transit. The beam of light starts out at radio frequencies, passes through a wall, and then miraculously shifts to visible frequencies once it is inside the room. It then reflects off objects in the room, miraculously shifts back to radio frequencies and passes back through the wall.

Bertmcmahan, while your concept is very interesting, I'm afraid electromagnetic radiation just doesn't work that way. You can get light to shift frequencies by causing it to interact with materials possessing rather interesting nonlinear optical properties, but those shifts are usually only a factor of two or three in frequency. The walls of buildings usually contain none of the materials required for such frequency doubling or tripling effects.

BJJB

[ScatterPlot]

Well, like I said, I haven't thought about it much, and I haven't taken any advanced classes about light and whatnot. I just thought about this one time and was like "Hey, I wonder if this will work?". Thanks for the input. Any other ideas about this?

[bleachit]

Originally posted by bjjb99


What bertmcmahan wants, judging by his post, is to have the wavelength [edit: I meant "frequency" instead of "wavelength"] of light actually shift while it is in transit.

BJJB

well if you change the frequency you change the wavelength. they are realated, the longer the wavelength, the slower the frequency. the shorter the wavelength, the faster the frequency.

[bjjb99]

Well, yes and no...

You can change wavelength without changing frequency. Shine a laser through a cup of water. The wavelength of the light in the laser beam as it travels through the water is different than it is when it travels through the air, yet the frequency remains the same. The index of refraction of the material through which light passes partially determines that light's wavelength. It also partially determines the speed of light within that material (actually, it partially determines either the phase velocity or the group velocity of a photon "packet"... it's been a while since my electricity and magnetism courses).

So, yes you are correct only so long as the light remains within a material of constant refractive index.

BJJB

[ScatterPlot]

What about magnetic fields? How much (if any) do they influence light?

[ScatterPlot]

OK I just checked some stuff really quick about light and magnets and found some stuff about light moving through a magnetized lense. This can change the polarization of light. This is kinda interesting. I wonder, and please post anything you know about this, if light could be "swirled" in something that would change it's polarization. Not swirled like in one swirl, more like a million swirls. I was thinking how much energy would it take to make the light actually have momentum enough to start spinning around on it's own after it has left the emitter? If so, could the waves be "swirled" enough that it would change the frequency any? The frequency of some lower-than-visible wavelength of light could be "charged up" to spinning very quickly, such as higher than visible, then fired through a wall or something. On the other side of the wall, the light might slow down to visible light, striking the object and then bouncing off again. On the return trip, the light might slow even further, back to below visible again and hence able to pass back through the wall and into a detector. What if the light was made to bend perpendicularly to it's axis? Seeing around corners perhaps? I would think that since the polarization of light could be changed inside some plastics and all that it could possibly be forced to do so in air. If this is so then could powerful magnetic fields aimed at light possibly turn the light in "mid-flight?" Just some stuff to think about from the mind of Bert. Probaby nothing that would work, but stuff to get the brain working. LMK what your ideas on this subject are.

[kscullin]

I believe to affect the wavelength, you have to keep refracting it. You could change the wavelength of the source by changing filters before it leaves the emitting device, but after it has left you have to focus it through different filters to change the wavelength.

I'm not sure what it would take to change it that drastically, from visible light to infra-red, etc. without diffusing it to the point where you basically don't have a single wave anymore.

[i heart my mag]

well......i believe that you're all crazy lol. this is all way over my head but very interesting to read.....bert....you thought all this up while you were going to bed???

i have a question sort of related but not really......its about light anyways.... i heard that the behaviors of light when passed through a tiny slit in a screen and projected onto another screen suggested the possibility of parallel universes. i couldnt really understand it so if anyone knows anything could you help me out? its for a school paper im doing.

well back to the topic......if you make this xray technology work......and put it into a sort of usable device to see through walls....or clothes lol......i want one!

[ScatterPlot]

LOL I didn't think of all this as I was going to bed, just some of it. I got on here and kinda started to ramble as one thing led to another, and thus my above post. Probably is completely wrong but oh well, it got me thinking! Sorry, but I don't know anything about parallel universes and stuff. When you find out, post it. I bet it'll be an interesting read :)

[i heart my mag]

will do..........hopefully for my grades' sake i can find the answers lol.......maybe someone out there in ao land knows something........?

[bleachit]

Originally posted by i heart my mag

i have a question sort of related but not really......its about light anyways.... i heard that the behaviors of light when passed through a tiny slit in a screen and projected onto another screen suggested the possibility of parallel universes.

the whole tiny slit experiments actually are evidence for the particle theory of light, if I remember correctly. basically when light was passed through multiple slits, interference patterns were created, that is there were portions on the screen the light was reflected to that were dark and some were lighted. Maybe I will go take a look in my text book later to further explain it......

[Wat]

There was a huge debate whether light was particles or a wave in the beginning of the 20th century as there were two experiments that demonstrated both.

The first was the slit experiment as mentioned earlier. You shine light through a narrow slit and shine it on a wall. If the slit is narrow enough, instead of getting a narrow light beam coming out you'd get two seperate beams coming out. As bleachit mentioned, this is due to wave interference and evidence that light was a wave.

However, if you put shiny vanes in a vacuum glass bulb and shown light on it, the vanes would spin. This is called the photoelectric effect and it demonstrats that light impacted momentum on the vanes and thus has properties of particles.

Albert Einstein was the guy who answered the question. Basically, light is both a particle and a wave. Light is massless yet it has momentum. His description of the photo electric effect won him his only Nobel prize. Nobel prizes have never been given twice in the same category before, even though einstein's work in relativity was Nobel worthy, he never got a second award.

[mikebridge]

doppler effects + gravity lensing. discuss.