Slashdot Mirror
"Time Telescope" Could Boost Fibre-Optic Communications
An anonymous reader writes "A time lens can focus a chunk of time to a point, rather like a normal lens focuses light rays. Put two time lenses together and you can create what a Cornell University team calls a 'time domain telescope' which can magnify time. They sent a 2.5 nanosecond long light pulse, encoding 24 bits of information, into their time telescope. What came out on the other side was the same 24 bit pulse, but compressed into 92 picoseconds. Squashing more information into a light pulse could help to send more information via optical fibres."
So does this mean that Verizion can set fires even faster? /I'm not bitter, I'm just stuck using Qwest DSL. Until I die. Weep.
"A time lens can focus a chunk of time to a point, rather like a normal lens focuses light rays."
no, its not LIKE a normal lens, it IS a normal lens. kind of like how "cloud computing" is the same client/ server model of decades past, a "times lens" is basically, uh, gee, a lens. but made sexy by introducing scifi fantasy terminology for the sake of grabbing attention
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
I'm used to these physics guys doing all kinds of crazy things with invisibility cloaks and such so I took the title to be a literal time lense.
After RTFA, the "time lense" is a frequency up-shifter. Still impressive, but not supernatural as I had hoped.
Not varying time but varying the speed of light over a pulse, still pretty cool but no need for the delorean yet.
Knowledge = Power
P= W/t
t=Money
Money = Work/Knowledge so the less you know the more you make
...Ben Affleck starred.
We're boned.
"A time lens can focus a chunk of time to a point,"
Since einstein we really know that space and time is the same thing, we really should just call it "squishing space", since time is really a measurement of a distribution of matter and energy, we've compressed the space (and hence the time).
"Time and space and gravitation have no separate existence from matter. ... Physical objects are not in space, but these objects are spatially extended. In this way the concept 'empty space' loses its meaning. ... Since the theory of general relativity implies the representation of physical reality by a continuous field, the concept of particles or material points cannot play a fundamental part, ... and can only appear as a limited region in space where the field strength / energy density are particularly high."--- (Albert Einstein, 1950)
Doesn't that mean they compressed the amount of time it took light to travel that distance, and therefore changed the speed of light? Or was this simply a compression of the distance between the photons?
Now all we need is Uhura to open up a channel?
.. I should know since I read them 70 picoseconds ago using my time telescope.
Moving pulses through time has been done with electronic delay lines for about 80 years now. The theory and technology are well worked out, both in the time and frequency/phase domain. A friend of mine worked out an alternate theory around 1961, which left the theorists scratching their heads--- how could there be TWO optimum but different ways of squishing pulses? But it was true.
Anyway, you don't hear much about this technology as it's not a panacea of any sort. Any information you squeeze in time is going to undergo some unavoidable phase distortion-- not anything you want a lot of. And the inverse operation at the other end adds even more distortion. Yep, no free lunch, once again.
Does this mean Slashdot can pro-actively fix dupes without anybody seeing?
Table-ized A.I.
That means communications companies will soon be able to bring us 1000+ channels of infomercials and the same sports events for just $60 more per month, while at the same time capping our broadband usage at 2GB a month.
Seven puppies were harmed during the making of this post.
So, a normal lens will compress a series of pulses into a shorter series? How, exactly? I didn't realize that normal lenses worked by exciting the atoms in a waveguide with an infrared laser.
- None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
It's shifting the frequency into a shorter wavelength, without going through a chip.
From the article:
The Cornell team made their time lenses using a silicon waveguide that can channel light. An information-carrying pulse made from a series of
small laser bursts signalling digital 1s and 0s travels through an optical fibre and into the waveguide. As it enters, it is combined with another
laser pulse from an infrared laser. The infrared pulse vibrates the atoms of the waveguide, which in turn shifts the frequencies of the
data-carrying pulse before it exits the waveguide and passes into an optical fibre beyond.
When I logged in, I was greeted with "Did you know subscribers can see articles in the future?"
...How can I hook that shit up to my DeLorean?
The abstract of the actual article is a little more informative, but still makes strange claims. I think they can compress a 10Ghz electrical signal into a 270GHz optical signal, with obvious ramifications in multiplexing, as you can then take 27 such signals at a time (theoretically).
The device is pretty straight forward: The light pulses become bigger on the inside than the outside.
I must have lost it in my reality distortion field.
I can think of a myriad of uses ..|||..|.||. eady using it for that.
FLR
I'll wait and see what happens.
I'm here for the experience, not the Hyperbole.
This new speed will totally revolutionize excuses for online gaming!
This reminds me of the movie Paycheck where they create a "time telescope" to see the future. I was surprised to see the post wasn't about seeing the future/past but rather the future of fiber optics. Certainly, I'm not going to complain if this eventually helps me download movies faster. Maybe at that speed, 2408 picoseconds faster is a big deal, like .1 second is a big deal to a 100m dash runner but irrelevant to a 1600m runner.
This is a complete oversell on a normal everyday phenomenon. This is a simple compression of a lightpulse, and has been done for a long time. Dispersion usually smears out a pulse, but can easily, compress the pulse. There is no "bending of time" here. Look up "Chirped pulse amplification" and also "Prism compressor", and maybe "soliton". First descibed in 1834 by John Scott Russell
don't cut it off www.mgmbill.org
Stop making shit up. Time lens? Are you fucking kidding me?
make it fancy sounding enough, and you can sell people air
read this:
http://en.wikipedia.org/wiki/Client-server
aka: cloud computing
"Client/server is a communications model. Cloud computing is a business model, a management model, a deployment model, etc... You might as well say "networking" is the real concept, and that fancy "cloud computing" is just a PHB term for "networking". Let's just call cloud "computer networking!""
so when the PHBs of the 1980s were deploying client/ server based systems, they were concerned with simply ethernet cable and routers? they weren't thinking at all about their business model, management model, or deployment model?
look, if i wave my hands fast enough, you can't see what i'm really talking about... zzz
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
It seems that they applied the "time telescope" to compress their years-long research in that one article... ... but it looks like a lot of information got lost, doesn't it?
(Like: how would that differ from already known experiences and methods?)
...and he got modded up. "News for Nerds" used to mean the kind of nerds that were like Lisa Simpson and Martin Prince. Now the typical Slashdot nerd is more likely to be the Milhouse van Houten kind of nerd.
What happens when you take four Time Lenses and align them to be 90 degree angles to each other?
ONE MAN KNOWS THE TRUTH!
I was under the impression optical data transmission for backbone lines was not limited by the transmission speed of the fiber, but rather the switching ability of both ends of the line to process/re-route the packets. This doesn't seem like something that would help with that. Yeah we can increase bandwith by 2.7X, but can we handle the optical->electronic processing at the other end? Split the line and add more devices I suppose?
And no, I don't have a link to a white paper handy.
If I read the article correctly, all they are doing is compressing the data on the storage medium (the carrier wave) so they can fit more on it.
Hmm, maybe I should throw out this explanation using some basic ideas.
If your car is 12' long and travels at 100mph, think of that as the standard.
Now what this guy has done is figured out a way to make your car 3' long (while still holding the exact same stuff) and it still only travels at 100mph.
He calls it a "time telescope" because if you paint a finish line on the road, the shorter car arrives at the finish line at the exact same time as the longer car, but it takes it less time to completely cross it because it's shorter...
Yeah, I'm thinking he's an #@&*$ also.
To be nice, maybe it's just somebody with the heart of a marketing weasel trying to make their relatively boring (but potentially important) creation sound exciting...
mm now what would macGyver do with this if he only had a few sharks and some lasers?
Let's make a time machine with this technology already! :o
I could be very wrong but wouldn't shifting the frequency increase the latency of the signal since the original wavefront will be delayed to allow for the compression to happen? Maybe it wouldn't be a great shift (and so not really matter) but I was curious. Anyone with expertise in field care to comment?
"Why, Johnny Ringo. You look like somebody just walked over your grave." Doc Holliday, Tombstone.
...and he got modded up.
"News for Nerds" used to mean the kind of nerds that were like Lisa Simpson and Martin Prince. Now the typical Slashdot nerd is more likely to be the Milhouse van Houten kind of nerd.
Whoah whoah whoah! To be fair, Milhouse declared himself he wasn't a nerd, because "nerds are smart".
Where's my goddamn flying car???
MOAR INTERNETS!
I've been compressing my documents by shrinking all the fonts for ages.
Perhaps, rather than trolling, you could explain exactly what the problem with his statement is? It seems to me like what he said is true.
OMFG, that is the BEST Simpsons analogy EVER.
*rotflmao*
Do daemons dream of electric sleep()?
This means I can watch all six Star Wars Episodes in less than ten minutes.
Todos mis movimientos están friamente calculados
IANAP but based on reading temporal magnifier article the conclusion is that this is cool stuff that is intentionally being massively distorted by New Scientist in a UFO-craze way. Totally turns me off that mag now.
The paper is relatively readable even if you are not a physicist. Basically there is nothing spooky going on as New Scientist would say. The researchers developed a way to greatly stretch a short signal to a long one, is all.
The problem as stated in the Nature abstract, is that the science of photonics delivers such super-high speed signals that electronics are not fast enough to cope, you'd need a computer built of optical circuits. So this is a hybrid photonic and electronic circuit that delivers the next level of sophistication in enabling people to handle high speed signals.
Older ways of analyzing brief signals are limited to signals of low bandwidth, or they only work on repetitive ones, or they are hard to read out quickly. For example you could take a short signal and spread parts of it across several different detectors in space, but that isn't very good.
The researchers used a totally different approach. In information communications science it appears there is an equivalence between the way a signal can disperse diffracts in space and how it disperses in time. One method called four wave mixing (FWM) can be used to stretch out the signal in time.
The scientists at Cornell used FWM but introduced a non-linear process that stretches the signal much more. The process is not just linear, it is quadratic so you can get exponential amounts of stretching.
They call this device a a time lens, as it operates in the time domain, the way a normal optical lens works in the spatial domain. It even has a similar quality they call its focal length. The "lens" can "magnify" (stretch) a very short signal into something long enough that it can be analyzed.
It also can be used in reverse to "shrink" (compress) a signal in time similarly. For example as a demonstration they created a sequence of pulses each 33 picoseconds in length and then compressed each pulse in the sequence to only 4.5 picoseconds in length using their time lens as a compressor.
The lens can be set at different magnification factors, and the maximum they achieved so far is a world record, 520 times magnification. It is very cool and the idea of usign an optical paradigm in the time domain to create a circuit that is a "time lens" seems to be a very powerful technique that will generate a lot of further advances and applications.
I believe it is possible, but you have to know exactly what is going to happen in the future.
The only analogy I can think of:
The lens is like b-frames in mpeg4 encoding, it allows time to be compressed once time is over but you can't compress the future.
This is an interesting idea, but they note that you will need to decompress the stream at the other end. This means that unless you can multiplex the light and have multiple compressed streams sharing the same channel, you won't see any performance improvement. You are still limited to transmitting/receiving at a fixed rate; its just that the bits take a shorter time to transit the pipe.
Are there any losses that are proportional to the time a light pulse spends in a fiber? I'm pretty sure its just related to distance.
Mon chien, il n'a pas du nez. Comment scent-il? TrÃs mauvais!
I've just got to work out how to plug my time-lense into my VideoRecorder. :(
So they've discovered WinZip for laser pulses? That's what this sounds like to me... 2.5 nanosecond / 24 bit laser pulse goes in, 92 picosecond / 24 bit laser pulse comes out, with the same information encoded. It's lossless compression, basically.
Yes, the Time Tunnel project has begun!
...and he got modded up.
"News for Nerds" used to mean the kind of nerds that were like Lisa Simpson and Martin Prince. Now the typical Slashdot nerd is more likely to be the Milhouse van Houten kind of nerd.
Whoah whoah whoah! To be fair, Milhouse declared himself he wasn't a nerd, because "nerds are smart".
I think this was the GP's main premise...
I don't know any of those people.