Ideas? Theories? Stories? Please tell... I'm interested in this type of stuff.

Thought: All I know is that if you were invisible you'd be blind.

Theories: Maybe have a device or material that bends the light around the object. Or maybe have the image behind you show in front of you and vice versa.

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Originally posted by xenosss:
Thought: All I know is that if you were invisible you'd be blind.

Theories: Maybe have a device or material that bends the light around the object. Or maybe have the image behind you show in front of you and vice versa.

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1. please explain i find that interesting.

2. The us military has the later theory in reseach and devolpment.

CTR

The blindness issue is valid. Light needs to be intercepted to bee seen, so in order to see the eyes would be visible from behind at any angle 180��� from where you can see. But that only applies to actual transparency.

The best way to create invisbility would be with holographic technology. Invisiblity "armor" will be needed, because rigid segments will be needed. Materials will have to be composed of equal parts camera, computer chip, and emmiter. The emmiter would have to be able to aim in multiple directions and emit controlable mixtures of red green and blue.

The human eye can only determine a certian amount of physical detail, is not fantastic at subtle color detail, and has a relitivly slow scan rate. The camera segments would relay position and color data to an onboard computer, which would in turn determine which emmiter segment projects what. Computing power of that magnitude is still far off. Each emmiter will emit colord light in all possible directions, scanning faster than the human eye does. Your desk lamp flickers at about 60 times per second, but it is too quick to notice. The same will have to be done with a holographic system. Even so the system won't be perfect, but should hide a person from 20 or 30 yards on a clear day.

The other possibility is using advanced optics to "wrap" light around to where it would pass through. Again blindness would be a problem. However, an invisiblity helmet could be built to contain night vision goggles to minimize the light needed to veiw the outside world. Or IR or UV could be used because they are outside of the visible spectrum.

I messed around with simulated invisibility a bit during one of my geek brainstorms. The idea was to make a box of LCD screens, integrate pinhole camera in them and place the feed from each camera on the opposite screen. Not that workable, but fun.

The whole "light-bending" idea certainly sounds more viable from a military sense. The blindness aspect is solved by giving the soldier vision in a different spectrum not affected by the field, as was stated by Prometheus. Of course, all that goes to waste when the bad guys get IR goggles. Any practical application would have to have a pseudo-random cycling of spectrums, synced for each fellow unit. Then again, a full-spectrum camera could certainly be developed to rapidly scan all useable frequencies and programmed to build a projection of movements, numbers, etc.

It would look really fucking cool in a movie, though. Guys blinking in and out of your vision...

Feasibly there is another option as opposed to bending light waves (which really shouldn't be possible anyhow). Cancel them. It has already been prove to cancel the light of a star in order to view the planets near it. The resulets are quite spectacular. So far, it has only been proven to remove light, making an object invisible only to the person viewing the printout, but the reverse application is quite possible. I can't recall the space station that was supposed to sue this technology (if it even launched/will ever). But the msot efficiant OPTICAL invisibility wil be achieved by cancelling light waves radiating form an object. Radar is a whole nother matter. Heh. get it? "matter"? *sulks in a corner*.

Any ideas on optical fibers?

Why is bending light impossible? Glass and prisms and diamonds do it all the time. My question is: If you bent light around an object, wouldn't that bend all light and not just the visible spectrum? If not, and IR or UV vision goggles could be used to see, it's not like the enemy is going to go around wearing the goggles all the time.

I think the invisibility armor sounds like the better idea. It would be difficult to bend light around an object and having a LCD or some thinner display device seems easier.

We should do this. As Mad Scientist posters, we should figure it all out. Damn the army. We can do better than them.... sure we can...

Bending light would be feasable due to total internal refraction. (Think fibre obtics and the way that light can travel all the way through and be seen at the other end). The only problem with this is that the thinest of the thin fibre optic fibres is 1mm across. If someone could find out what the smallest possible measurement is that humans can see is, that would be helpful. If you could get a fibre that thin with for instance a magnifier half way down the fibre then becoming invisible would be very realistic.

Chunkmiester
Btw, if there are types of light that are unseeable by the human eye lets call one light "x". Why wouldn't a suit that emits light x make you invisible?

Wouldn't the suit still need to either cancel the visible lightwaves or bend the lightwaves?

If you just blasted them with non-visible light, nothing would happen.

Hey, lookit me! I'm emitting infrared radiation. You can't see me!

Bending light is perfectly possible, just not a great idea for invisibility There would just be a visible "warp". That is the major hurdle to get over. Even with cancellation there is a spot of black. We are all stuck wiht only secondhand theories too. Someone please drop a paradigm on our asses.

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Originally posted by Chunkmiester:
Bending light would be feasable due to total internal refraction. (Think fibre obtics and the way that light can travel all the way through and be seen at the other end). The only problem with this is that the thinest of the thin fibre optic fibres is 1mm across. If someone could find out what the smallest possible measurement is that humans can see is, that would be helpful. If you could get a fibre that thin with for instance a magnifier half way down the fibre then becoming invisible would be very realistic.

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I was thinking of a specialy developed crystal latice that would use internal facets reflect light to where it would pass through.

Currently the army has developed programmable camoflage that uses minicams throughtout the suit to adjust the camoflage properties of the suit. Basicly that means that the camo will roughly match what it is around. Laying half in light colored grass, and half in dark, your camo would be half light green, half dark.

Of course the tech is nowhere near the point where the average soldier will be fitted with it. Within the next 10 years it will probably become standard though.

Prometheus, and anyone else, where do you get most of your technology and science news from? I try to keep up with the newest Discover, Pop Sci and Sci Am but I never read about some of the things you mention. (like the army tech)

You guys might wanna check this out..

click

Sorry to bug in this late, but:
1) you would not necessarily be blind when invisible.
To see you need incoming light. To be invisible you need the incoming light to
continue its original path instead of being reflected. These two do not rule eachother out. The amount of light that hits your eyes
is tiny, and could be compensated for by adding light or spreading incoming light a little. As long as the little light that does reflect off your eyes is obstructed, by
using a special type of polarised glasses or
something, you will be able to see.
2) bending or cancelling out light is out of the question, that would take care of people seeing your body, but they would definately see some shady form moving against the background.
Or one would have to bend the light around the body and make sure every photon from every angle is re-emitted at the exact opposing point on the body... This is not
possible using distortion fields because of
wave interference (if one were rich enough to
create the technology).
It might be possible using optical cables,
but tiny ones at that, with amplifiers for each specific tiny cable, that in some ingenious way loop from every point on the body to points exactly opposite to that...
But that seems impossible without using computer processes to kep track of all that... And of course, for every emitter lens
we'd need a receiver lens, so the overall body coverage of such a device would still only give a max of 50% invisibility...

Then of course there is the old Philadelphia-
experiment and related invisibility stuff,
that also uses the bending of light by fields, and the account of some film that at
certail light intensities appears to render
anything wrapped in it invisible, but these
are all old stories and not confirmed...

I think you may find that you would be blind. First lets assume that you can become invisible and that light can travel straight through as if you were air. To see light goes into your eyes and basically stops at your retinas. This means that there would be a part of you visable (as the light wouldn't be able to travel through). To be entirely insvisible in which either light passes through you or around you because ALL the light is being diverted or sent straight through although you wouldn't be blind as in the common sense you would be unable to see whilst invisable. I don't think that i have explained this too well but i hope someone gets my point.

Chunkmiester

If you bend the light around yourself with properly positioned, tiny crystals (diamond would be best, since it has the highest refractive index), or grooves in a crystal plate (like a diffraction grating), so that the light went around you and came out as if it had gone straight through, then it would work. And you would have to be blind - all light is going around you, none coming in, so you wouldn't be able to see a thing. You wouldn't even be able to transmit video in... electromagnetic waves. You couldn't even see with IR goggles or whatever - it's EMR too, and so cant get through! Although it would be able to pass out, so you could still be detected. But placing the crystals or grooves would be tedious, and you'd be talking nano-technolgy.

[This message has been edited by errantminion (edited 11-06-2002).]

Getting back to optical fibers... I wanted to know if there are kinds that give like really good clarity... kinda hard to explain.

I got my gf one of those fiber optic lamps for her birthday, and when I took them out and looked through them like a telescope, everything was blurry. Now what I wanted to know is if there are fibers they sell that make the reflection clear, not blurry, or if there may be a chemical that could alter the fibers to do this. If anyone could get back to me on that, it would be greatly appreciated...

Yes, using fibers may still show some visibility, but hey it's a step in the right direction, right?

As for the philadelphia experiment and electromagnets... I have read about it many many times, but I still never understood exactly how they bent the light... could an experiment like this be done with small magnets they sell at the stores?

The theories discusses so far are sound in the physics department, but the are not in other ways.

1) Thw only way to bend light around someone or something is to use extreme amounts of gravity, crushing the person.

2) If you could find away around that(not probable) the as soon ase the light went around him he would hit near-absolute zero temperatures(-273 Kelvin). In other words, it is so cold the atoms in his body stop moving.

3) If you could get around this, the is the LAW IF CONSERVATION OF ANGULAR MOMENTUM: If the light was bend it would be almost impossiblly hard to unbend. This means that the light would not go 180 degrees around a person; it would go 360 back to the starting point being a total waste.

The only theory to get around these three points is the open-curcuit camera on both sides of the person. But it would be encumbersome and the pecision of the human eye would easily detect the slightest movement, like the old Predator movies. The streaking would give the location away.

And yes you would be blind. THe light would never hit yor retina so it would never be seen. If it did the your eyes would be seen just as easily as you could see your environment.

If any of you have heard about the philadelphia experiment, it involves optical invisibility. Supposedly the US military tried to bend light waves using some bizarre system of magnets (though i dont know what they have to do with light waves)around a battle ship, the USS Eldrige, and it worked for a few seconds. However after that the whole story gets weird and its hard to seperate fact from fiction.

Anyway basically whether you would be physically blind or not doesnt necessarily matter. If you were in a vehicle with the correct equipment, you could "See" like they do in a submarine or a plane at night. The right types of equipment could enable you to move around in a special machine, i suppose, but as far as a person walking around invisible, i think were a little far from that scientifically.

i just had a thought about this. If you were to make a suit/machine that would absorb the visible spectrum and only give off light waves of a certain frequency, say, twice the size of a person, wouldnt it be invisble to the human eye? It might sound stupid but think about it, This is why you cant hear am radio in tunnels, because the am wave amplitude is too tall to fit into a tunnel.

quote:

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Originally posted by errantminion:
And you would have to be blind - all light is going around you, none coming in, so you wouldn't be able to see a thing. You wouldn't even be able to transmit video in... electromagnetic waves. You couldn't even see with IR goggles or whatever - it's EMR too, and so cant get through

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No material blocks the entire EM spectrum.

oldpervert, your idea would work within it's context. Unfortunatly that doesn't involve invisiblity. It is just about the same as wearing black clothing. Black clothing absorbs the entire visible spectrum, and emits heat and IR band light (which is invisible to the human eye).

True, well today i did a little research and found out that "they" (im assuming military or government funded research)are researching using optical fibers to project whats in back of object x to the front of object x to give the appearance of invisibilty.

Easy, just get a generator to create either pure light (WAAAAAAAYYY high in the top of the spectrum) or pure black light (WAAAAAAAYYY at the bottom of the spectrum). The white will reflect all, and the Black will suck in all. Either way, you will not be able to be seen.

I can't begin to describe what is wrong with that. But I'll try.

White light is a mixture of all the frequencys in the visible spectrum. This can be seen when a prisim is used to seprate out (white) sunlight.

Black light is a term used for lights that emit primarily in the ultra-violet spectrum. (incidentaly, UV light is a higher frequency than visibale light)

WAAAAAAAYYY high in the top of the spectrum is gamma rays, WAAAAAAAYYY at the bottom of the spectrum is AM radio waves.

The color white simply reflects the visible spectrum (see above). The color black absorbs the visible spectrum (black being the absence of color.

As long as something emits a different set of light waves than what would pass through that space it would be visible. Black would be fine at night, in unlit areas, but creating "pure" (I assume you ment white) light would be the same as wearing floodlights.

I know its not exactly what i ment but its what i could think of at 12 am. I ment instead of light as in true color. I dont think that works with white, but true black color steals light... Now what did i mean for what was reflective?

To lazy to read all the posts so if the idea was already posted to get pissed.

Anyone ever thought of fiber optics covered suit with a bunch of camera's placed in the right spots on both the sides showing the other side.

It would be very blury and pictures over crossing plus you got your sides all fucked up so you wouldent be tottaly invisible yet its better then nothing and if its dark and your not moving while some guy walks down a hallway you might not see you.

Someone mentioned something about streaking effect like in predator. Even if THIS level of technology could be achieved it would be very much usefull. Like Chibi said in a dark hallway you might not even be seen.

Hmmm just a thought...

The bending light thing would be kind of stupid for military purposes unless it worked both ways. Everyone is talking anout receiving light from the back and sending to to the front, but to be invisible you would have to bend the light from front to back. Otherwise you'd be totally visible if you laid down or something like that.

That sounds like an awful lot of fiber optic cables to me, if you wanted to go that way....

Or maybe I've got this all wrong. It's almost 2am......


Oh BTW... I remember hearing once that if your printer prints in 2 picoliter dots, you can see them under close examination. if it has 1 picoliter dots, you cannot tell the dots apart. Don't know if that's right, either..

Haha, I should be better informed before I speak.

YOu won't have to be blind if your invisible by an external means. REmember the movie "Hollow Man"? You would be extremely sensitive to light if your eyelids were transparent.

On th millitary thought...
Think of what would happen if you wore a suit made of an unknown material ( Let's just call it material x). NOw, some type of gas could be unleashed over the infiltration area ( gate entry, complex) by means of dropping canisters from aircraft. When the gas is inhaled, it goes straight to your eyes, blocking out the reflexion of the light from material X. It's like putting a finger before your eye so you can't see an object in front of you. Cool theory, if it could be done.

Durrrr....

Fiber optic cables go both ways, I realize that now that I'm not half asleep. Photons don't usually collide.

A few years back I saw a show on TLC about the special foces or something. They show a brief shot of a few men in some regular looking clothing that scatered the light. They looked shadowy and slighty transparent. I dont know if anyone else saw this or if is just a delution of mine.

Camo has been a top priority in the military for a long while.

I'm sure all of these great ideas that we've disscused have already been tested and proved in various fashions. Maybe not to the exact description but within lines.

The closest thing I can say without talking out of my ass
is what the guy above me mentions.
My father was a Army Ranger. He has many times told stories of field training where they used equipment similar to what we've disscused back in mid 90's. But he said the equipment didnt make you completly invisible yet distorted.. kind of like shadowing. Your appreance assumed the attributes of was next to you. But not exactly. He said only the snipers used this equipment.

But other than that I can imagine that some elite forces used even better tech. than that.

Turn around. There is actually some governmental security agent behind you, camoflauged with Ottacon's stealth suit. WHERE's YOUR STUFF NOW MATT?!?!?!?

Sorry dudes but allthough you are of
course all right that one will not be able to see when all the light is bent around
the subject or kept from reflecting,
it is logical that such a suit would not be very usefull and I just wanted to point out
(in my last post) that a usable invisibility suit would need a one-way see-
through area at the eyes to make sure the user can still see what he's doing.
Bending the light would indeed give a sort of impression of the background, but even the best form of suit would produce morphs
and blurry effects 100 times worse than that alien in Predator...
And the camera/projection 'armor' idea is certainly
possible, but if the effect would be convincing is another matter... Anybody see that new James Bond movie? Never will it be like that!

Never say never.

Elemental is right, to make an invisibility suit you would need to take every crease, ripple and body movement into account. If you wanted to make something rigid invisible that would be more of a possibility.

Imagine however what it would look like. You would have tiny black dots of recieving lenses that would make the object appear to be a dark shadow.

Also to be considered. A life size Tv screen showing a palm tree and beach placed next to real palm trees would be obvious, even if viewed from directly in front. The reason is that it is a flat surface which makes it obvious to our binocular vision.
How could you achieve a 3D image on a flat surface to mask your stealth tank? we cant even build a 3D television yet.
to achieve a true illusion of three dimensionality every reciever would have to accept light from a near infinate series of angles and every emitter would have to take that colour pixel and emit it at at the corresponding angle.

This sounds a bit of a mission to me. perhaps achievable with a kind of fly's eye reciever emitter design of tiny hemispheres all over the object's surface. however if the minimum diameter of an optic cable is 1mm and you'd need thousands of angles on every dome to create even a semi realistic 3D illusion, the size of every dome would be way too big to create an hi res image. Equally every reciever dome would have to be just as big, generating a darker shadow.

It would be very difficult indeed to create a 3D illusion, our pupil's are at only about 2 inches apart and yet our binocular vision is effective up to about 200 m say. Thats a tiny tiny angle that our brains calculate. If it was going to look even half realistic the domes would need to be huge.

Therefore you get a comprimise scenario. Either you have a high res flat image, or a very low res one that is poorely 3 dimensional.

Either option or anything in between would look blatantly obvious to anyone up close.

The best you could hope for would be a kind of chamelion camoflage that could keep your tank well hidden about 500 m away.

Anyone agree wiv me about the flys eye idea? Seems the only semi viable option to make a 3D image.

i'm sure holographics can be usefull in achieving this 3D lighing.
Don't ask me how ill get back to you.

do we hae any technolagy that can 'suck in' light other than optic fibres?

I'll say it again, it would take a highly sophisticated crystaline matrix with internal facets to reroute all that light to exactly where it goes at the exact right angle. The problem is the light waves that would go through more than one armor peice.

In fact, it would probably work best as sort of a dome or sheild which a person be underneath, that way there is no coordination needed between components.

A while ago I read about a theory of using optical fibers to channel the light around you to the exact same spot on the other side of your body
wouldnt that be cool I would walk streight into a bank wait till someone goes into the vault walk in behing him and pocket lots of money

ok so your eyes have to be visible. who cares? really? in the middle of a fuckin war i doubt anyone will notice a pair of eyes floatin around till they get really close
next so everyone now seems to agree that there would be a blurry area where you are situated or a shadowy spot right? well id imagine that if the war you are involved in is in a jungle situation that for fightin at night this would be helpful because of the many shadows already being thrown around

oh yah if you tried the camera to screen idea on a large amount of troops on an open battlefield during the day the enemies would easily pick out the shadows. remember in this theory light is not being rerouted or absorbed but rather stopped then retransmitted.