[Unknown Target]

Ok, I have a theory that uses some available technology in order to create a better long-range communicae device than the radio.
My theory is that if you get two machines, M-1 and M-2, with M-1 being the sender and M-2 being the reciever, and you use light....well, let me explain that first.

        Ok, so, you're probably thinking, "Light? WTF? A giant flashlight?," and you're both right and wrong. M-1 would send a light beam to M-2, but have make it a concentrated beam, almost like a laser pointer. The "laser," will send a beam of light, precisely charged with seperate particals (Such as red, blue, purple,etc.) to M-2, which would then recieve this light as raw data. Through a program, the light would be translated into letters, which, in turn, form letters and words. So (purely as an example), if you sent a blue beam, flashed it to red, and then to orangish-purple, you might get the word "the,". The software takes the data, let's say 1=Blue, 01=Red, and 11101=Orange. The program's own code would dictate that 1=T, 01=H, and 11101 would equal E. So, the program would compile this data, which would create the code: 10111101, which would be translated as "the,".
Now, you're probably asking two things. One, how are we going to send messages to people on the other side of the Earth. Well, that's simple, we would simply bounce the light off of a reflector, such as a satalite or the atmosphere itself.
Your second question probably is, "Why is this better than radio communication?".
Well, that's also quite simple to answer; radio waves travel relatively slowly. For instance, a radio wave takes an hour's delay in reaching from here to Mars. With light, it only takes about 1/5 of a second. This means that we might finally be able to construct interstellar ships and begin our real, human, explorations of the stars.

[an0n]

Uh, no. Radio travels at light speed. The colour diferentiation ability of the receiver would limit the colours that could be used.

The only advantage that this would have would be that it'd be extremely hard to intercept.

[KillMeNow]

thats jsut a laser comincation system and yes they have those already the military uses them for secure comincations so two ships can senda  message without it being intercepted

and for normal purposes you can send them down fibre optic cables adn tahts what all super high bandwitch cables are these days

[KillMeNow]

oh and the man is right radio does travel at the speed of light and the delay to mars is about 4 mins or something i cant remember but from teh sun to earth its 8 mins

through certain things some frequncies of the electromagnictic spectrum do travel faster than others but in a vacum its all teh same and even in air and even water the speed difference itsn't that much

the electromagnic spectrum compreises everything from longwave radio, vhf, infrared,light, ultraviolet, x-ray, and gamma radiation and everything inbetween that i have forgotten

[mikhael]

Radio, like all radiant energy, travels at c. Light, being radiant energy, travels at c. X-rays travel at c. Infrared beams from your wireless remote control travel at c.

Radio is better because it doesn't require line of sight. Radio frequency radiation can curve over the horizon by bouncing it off the upper atmosphere. Light punches straight through.

[CP5670]

I think mikhael already summed up my thoughts.

[KillMeNow]

ah but anyoy can listen in to radio so it need heavy encyption if you dont want people listening in and i dont there there is any code yet that cant be broken except those weird neral net dupilcate things where only poeple the the correction computer can decode them but even taht could probally be broken in time

[CP5670]

You could just put in an insanely complex math formula that takes years to encode/decode stuff before sending or recieving the signals; it would be very hard to crack something like that.

[KillMeNow]

but if it takes that long to encode and decode then its useless lol for line of sight coms lasers are the best if you dont want people listening in

[mikhael]

Originally posted by KillMeNow
ah but anyoy can listen in to radio so it need heavy encyption if you dont want people listening in and i dont there there is any code yet that cant be broken except those weird neral net dupilcate things where only poeple the the correction computer can decode them but even taht could probally be broken in time

Anyone can listen to radio yes. That does mean it needs to be encrypted. You are, however, wrong about all codes being breakable. It is provably impossible to break a one-time-pad. Sure, you might get today's data, but what you learn today will be useless for decrypting tomorrow's data.

On the subject of symmetric neural net encryption: its no better than any other cipher. Face it: a neural net is just a state machine wired in a particular way that processes data in a particular way based on the original input stream. Basically, its a two key system (wiring is one key, original stream is the second key). Since both of these pieces of data are demonstrably unique to the cryptosystem in question, you have a two key shared-secret system. Its not even as secure/useful/flexible as a good public key system. It will take no longer to break symmetric-nueral-net systems than it will to break any other shared-secret cipher.

[mikhael]

Originally posted by KillMeNow
but if it takes that long to encode and decode then its useless lol for line of sight coms lasers are the best if you dont want people listening in

Um. No. Time to encode/decode is not a factor, generally, when using digital cryptosystems. That's what dedicated crypto hardware is for.

LOS-laser comms are the best if you want to talk with someone who is within LOS. Put your target over the horizon, and all bets are off. As soon as you start going over the horizon, you introduce complexity, and thus increase the possibility of compromise.

[an0n]

the delay to mars is about 4 mins or something i cant remember but from teh sun to earth its 8 mins

I thought it was 45 mins. Thus why they couldn't do the rover by remote.

[mikhael]

The lightlag from earth to mars is variable. Anywhere from 10min to 70min, I believe.

[Unknown Target]

Well, it's time for me to defend the beast I have created

If radio travels at light speed, then how come it takes about 45 minutes (at about the fastest speed) to get to Mars, to command the old rover they (being NASA) sent up there in the early 90s.
Radio waves also weaken as it gets farther away from it's source. Light doesn't. Also, light is impossible to intercept, becuase to simply look at it means that it's been wiped clean, since you can only recieve light, you cannot stop it (however, there was one experiment that I know of that managed to stop light for about 1/100th of a second).
Oh, BTW, you can look most of this up in one of the more recent Popular Science magazines, because I got my basic idea (I'm not copy-catting, though!) from one of it's articles.


EDIT: I just read the last post again (I thought it said radio lag) and I would like to say that there is no light lag from the sun to mars, because light travels about the entire distance in about 1/100th of a second. Light is very, very fast.

EDIT AGAIN: Also, the combinations of light are nearly infinite, because, along with our visible spectrum, there is also UV rays, Gamma rays, X-Rays, etc. which the machine can be made to pick up.

[an0n]

Originally posted by mikhael
The lightlag from earth to mars is variable. Anywhere from 10min to 70min, I believe.

AH, of course. Orbital differential .

If radio travels at light speed, then how come it takes about 45 minutes (at about the fastest speed) to get to Mars

Coz it's 45 friggin light minutes away. 45*60*300,000=810,000,000km away. 0.8 Billion kilometers or 0.5 Billion miles.

there is no light lag from the sun to mars, because light travels about the entire distance in about 1/100th of a second

AAAAARRRRRRRRRRGHHHHHHHHHHHH!!!!!!

[Styxx]

Laser comm systems are not used solely by the military. I was considering, a couple of years ago, getting a laser transceiver to connect my company to the net and to clients, they're fairly common and reasonably reliable - the limitation is line of sight, and if a bird flies through the beam, it's disrupted and you have to restart the protocol. We ended up getting a dedicated physical line.

And the only thing that protect current day cryptography systems is the fact that, for now, we have no way to prove that NP problems are, or are not, "reduceable" (word in english for that?) to simple P problems, what implies that they have a complexity that rises exponentially to the size of the input value. The larger the cypher, the longer it will take to decode - but theoretically, you can decode anything (but it can take truckloads of time). You might even get lucky and get it on your first tries. There's some discussion going on right now among the cryptography community about an algorithm discovered by some guy (can't remember his name) that allows for enormous decreases on processing time for factoring algorythms (used in many current day cryptography systems) by exploiting some advantages provided by parallel processing. This might lead to further developments on the P = NP problem (not right now, though) and, if it's proved that P is in fact equal to NP, then all crypto systems will fall. And then you'll need tight beams, or secure physical lines.

[mikhael]

Originally posted by Unkown Target

EDIT: I just read the last post again (I thought it said radio lag) and I would like to say that there is no light lag from the sun to mars, because light travels about the entire distance in about 1/100th of a second. Light is very, very fast.

There is approximately 8min of light lag from the sun to the earth. Light is fast, but the universe is big.

EDIT AGAIN: Also, the combinations of light are nearly infinite, because, along with our visible spectrum, there is also UV rays, Gamma rays, X-Rays, etc. which the machine can be made to pick up.

No. Not infinite. First of all, you're limited to planck-length waves, and plank-time bursts. Then there's the whole subject of encoding data on the carrier in a useful manner.

[wEvil]

ahh....good old Max planck.

[Scorpius]

They are working on such a thing. Its called quantum Cryptography (I think) What it does is it sends one photon at a time and spins the particle in a certain direction (Vertical could mean 1 and horizontial means 0) Diagonals are impossible at the quantum level. The code is pracitally unbreakable and hard to intercept without anyone knowing because of the difficulty of determining spin without special equippment.

I read this in Discover Magazine and I probably got a lot of the facts wrong.

[wEvil]

the term "spin" is a little more ambiguous

a particle with spin 0 looks the same from all directions
a particle with spin 1 looks the same every half-turn
a particle with spin 2 looks the same only once every revolution
a particle with spin 3 only looks the same every two revolutions

or something like that...i cant remember how many spin-states there are. Either way...its about as meaningful as quark "colours" and i can't get my head around either of them because its all so weird.  I dont understand the maths behind it.