Slashdot Mirror
Stopping Light
Jon Abbott writes "NASA is reporting that physicists at Harvard University have managed to stop light altogether. The implications of this discovery are rather staggering -- quantum encryption and quantum computers might be just around the corner! " Well, I don't think this will mean any immediate changes - but it is a significant step.
Is put CowboyNeal in front of the light beam. He would stop anything.
The implications of this discovery are rather staggering - quantum encryption and quantum computers might be just around the corner!
Yeah...very, very, very slow quantum computers.
;)
-Waldo Jaquith
I was able to stop time!
But only for a second...
Good quote, too many chars. Seriously, the slashdot 120 char limit sucks!
What are the applications for pausing light? The article only spoke of applications for removing and creating light.
But what happens when light stops? It just doesn't sit there patiently for the next command, does it? I'm not a physics guy, but if light is energy, you just can't stop energy.
Colour me confused.
Karma: Excellent Birds (mostly as a result of listening to Laurie Anderson)
And here's the story from when it was news, last year.
0xB
There was an old sci-fi story about "slow glass" where people would let these light-storing windows in interesting places and then sell them.
This really sounds like a cool way of storing holographic data (which means storing a LOT of information in a small space)
this story was stopped, held, and reemitted...
-m
You catch enchiladas by picking them up behind the head and holding them underwater until they don't kick anymore -VeGas
wow... so they finally found the light switch... -Cyko
This message was brought to you by the death of 30 brain cells.
...stop that damn beam of light that hits my eyes every friggin' morning at 6:30am.
Ok this is just a point of fact: they did not stop light! They stored the information contained initially in a light wave in a new medium that they had control over, then were able to stimulate the medium to get it to re-emit.
An interesting one, although I remember /. posting the comment before. The concept really gets into gear, though, when you consider the guys who have been creating optical computers using a diamond spinning at very high speeds (they are able to perform calculations by creating minuite variations in the speed of the spinning crystal). If you can make a calculation, flash it to your new 'hard disk' (or rather, gas-light tank) and beam it out again whenever you need it, all at the speed of light and no resistance if done in a vacuum, then you get very energy-efficient, relatively easy/cheap to build computers. I don't know what their speeds would be compared to today's computers - probably lower, since electronics is quite a few generations ahead in development - but the potential is enough to be interesting.
- Jynx
A positive attitude may not solve all your problems, but it will annoy enough people to make it well worth the effort.
I'm able to stop light with my bare hands (or at least scatter and reflect it ;)
Read my keyboard review.
It was not destroyed or absorbed, but rather stored -- ready to emerge intact at the scientists' bidding.
I can just see physicists getting calling people into the lab, turning out the lights and commanding, "Let There Be LIGHT!!!" at every available opportunity
--
"Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.
They tend to call them "Red Lights" though. I wanna transporter, now.
What, me worry?
Wasn't this story just on /. a few weeks ago?
I watched C-beams glitter in the dark near the Tannhauser gate.
it lends a whole new meaning to breaking something by "letting the smoke out".
:-)
In fact, there are several stopping lights at intersections just blocks from my house!
>>Walsworth's group used warm rubidium vapors to pause their laser beam
I've noticed that occasionally somone will use warm and silent vapors to pause conversation in the elevator.
white dude
Light isnt actually stopped it is absorbed by the atoms in the medium.
So those atoms go on a higher energy state, as a result of the light they have absorbed.
When they shine another laser on the medium the atoms emit the energy they had previously absorbed, in the form of the same kind of light that came in.
After stopping light is pretty easy, it's the pausing that tuff.
Stop light? This is nothing new. We have stop lights at every major intersection.
Wasn't this done not too long ago? Using a relatively similar method?
There's an explanation of why stopping light could lead to advances in quantum computing here.
There's also some news about it here at Harvard's site. Also, there's an article here in Scientific American about this.
Didn't this all happen last year, too? Why is it just news now?
Jack Buck (1924-2002)
Darryl Kile (1968-2002)
I must have read a story like this at least 4 times in the last year. Here's an example - http://hackensackhigh.org/light.html Looks like one of the monkeys at /. was playing with his bannana
They stopped light last year. Theres even a guy whos trying to rewind light.
This is just old news, The way light was stopped before was they used extreme cold to slow light down until it stopped.
If you use Linux, please help development of Autopac
So here's an interesting thought.
We can stop and "store" light.
So play blue-sky sci-fi author for a moment. Enormous dirigibles floating above the cloud layer, absorbing and storing light until "full", then coming to ground and offloading the light they've "mined" into solar cells (which no longer have to be laid out in flat arrays covering enormous fields) for conversion into electricity.
Hasn't that always been one of the problems, after all? There's plenty of bright, uninterrupted light available in the upper atmosphere, but the thought was always to convert it to electricity *up there* and somehow transmit the energy to ground level.
Maybe we'll just be able to mine the light.
Scary.
-- Niherlas
I'll be impressed when they can slow light down in a bose-einstein condensate, stop it, and then make it move backwards...
So it truly is vaporware!
And the people shall be oppressed, every one by another, and every one by his neighbour Isaiah 3:5
could this be used for really high density portable storage?
Would shaking the storage container make atoms discharge and ruin the whole thing?
What's worse is that he removed the end of my story submission to make room for the quip. FWIW, this is how the original story submission went:
Jon Abbott writes "NASA is reporting that physicists at Harvard University have managed to stop light altogether . The implications of this discovery are rather staggering -- quantum encryption and quantum computers might be just around the corner! <coffee-talk>Discuss.</coffee-talk>"
Slashdot's first reaction to VMware
Do you have any idea how many atoms you can fit in something the size of a CD? That's a lot of data to store MP3's on!
"Derp de derp."
stopping light can actually be used for information storage -- ie hard disks. Doing so would increase the amount of storage space incredibly (less space needed for data), reliability would go up (ie, less chance of disk failure), and data transfer speed would finally match CPU speed (no more RAID arrays, and maybe even no more I/O caching).
The One Rule Of Chess You'll Ever Need: Don't play someone who carries a kit in their bookbag.
I just don't believe they stopped the light.
For PSY - Ops, most likely for holograms to confuse and disorient enemies. Kinda like that machine the holodeck from startrek
If you use Linux, please help development of Autopac
Do the slashdot editors _even_ read the site? This is old news!
They did not (and never will) be able to slow down light. What they DID do is much like (okay, the same thing as) having a beam of light reflect between two perfectly reflective, clear and parallel mirrors. The photon that is re-emitted by an excited atom is not the same photon that entered the atom as they have differing vectors (which is a fundamental attribute of a particle).
Yeah, I guess that's almost as lame as some antiquated checkbook program on SourceForge.
You're a stupid fucking loser.
is not that it's a year old Slashdot repeat; we're used to that. The problem is that the whole "stopping light" headline that all the mainstream journalists (who should know better) carry on it is baloney.
If a photon (light) hits an atom (matter), causing it's electrons to move to a more excited energy level, I defy you to "show me the light". You can't. You can show me a really excited electron, and if you're really clever like these folks at Harvard you can even get that atom to release the exact same light with the exact same waveform, but you haven't stopped light.
It's annoying. How hard is it to say you've "trapped" light?
Slashdot Jan. 2002
Slashdot Jan. 2001
Well, that article explains the traffic problems on Mass. Ave. If they would stop messing with the traffic lights I might be able to get around.
He means that it won't mean any significant changes in how we build computers--that is, quantum comptuers are still a ways away. But it is a VERY significant step. If you read the article, they explain how they stopped a laser beam and turned it into information, stored in the up-and-down patterns of the vapor's atom's spin axes.
I mean, you don't have to be a scientist to imagine the possibilities of a vaporous hard drive, with a huge capacity, that gets written to by a laser that changes the state of the atoms within. Drool...
And the best part is no more annoying spinning noise!
c-hack.com |
There are a handful new (or at least vastly improved) technologies that will be developed and put into use in the near future that will rival the changes ushered in by the developement of the microchip. This could happen much sooner than most people think, maybe as soon as 4 or 5 years. Quantum computing will be one. It will be crude and a lot of people will look upon it the same the that the Altair or the GUI developed by Werox PARC, but advances will happen fast once things get moving. Nanotechnology will be another. Tiny machines that can clean out clogged arteries will be "neat" but this will really be useful in materials developement. Once we can custom build materials at the atomic level, things will get interesting in a hurry. Being able to stop light is something that sounds pretty obscure, but then so was a little hunk of silicon Bell Labs touted 50 some years ago. I've talked to some people who were working in the electronics industry when the transistor was first talked about. A lot of them at the time thought "Well, that's neat, but that thing will never be able to handle any serious current. Intel made a real gamble in the 70's with their little "calculator-on-a-chip", the microprocessor, that they made in the hopes of selling it to a Japanese calculator manufacturer. It will be interesting to see what comes down the road from what these people did with stopping light.
The most recent edition of Discover has an article on quantum encryption using single photons.
Basically they shoot a laser through a heavy filter, emitting only one photon. The Sender and Receiver exchange pads including what group of spins(Horizontal/Vertical, or the diag's) on each photon contains information. An Evesdropper has a 50% chance of guessing which one, and retransmiting that. The article state that on average 25% of the photons would be incorrect if your conversation was being intercepted due to wrong guesses by the snooper.
Pretty Neat - but they say it'll be at least 10 years for something that consumers can plug into a wall...
It seems the scientists didn't really stop light, but rather imprinted it onto atoms, and them by shining another laser through they could repricate the original light. Now, this is quite useful but not the same thing as stopping light alltogether. For example, this couldn't be done in a vacuum such as space just because there are no (or very few) atoms to imprint upon.
As for quantum computing this is a big step. They have basically discovered how to imprint something onto atoms, each of which could be a bit (or trit or more, depending on how they implement it) so basically you have an immense ammount of storage in a very small space. Between this and the speed of light that signals would be sent with, you would have a very fast computer with enormous ammounts of memory.
Oh, and as for portable storage, a floppy disk will be able to hold terrabytes of information.
If someone wanted to transport a highly sensitive document over the world without using a network. I could see light waves being a highly secure medium. Send 4 encrypted "bottles of light" to the destination... and have each one of the bottles be 1/4 of the information. If someone steals on of the 4 bottles... or if one of them is damaged... no message is recieved at the other end.
Granted the machinary that would pick up a half meter of light from a "bottle of light" would have to do a lot of quick calculation... unless they released it slowly... like their previous experiments to get light to move at a bicycles pace.
The nice thing about light as a storage medium is that the molocules would be infinely close in proximity of one another. If a given the burst technology existed I guess the only thing slowing this down would be the pulse rate that could be achieved from a laser source. I could imagine a line of light, no longer than a football field that contains more information than the current internet.
--Turvey
I had a flame... but she had a fire.
...And now we can accidentally bumb our head against the toilet bowl and come up with an idea of a flux capacitor...that makes time-travel possible :)
I've noticed a couple of people wondering why this discovery important. Some other people know that it is useful for quantum computing, but they don't know how it would be useful. I'll see if I can help.
The most common way qubits are stored in quantum computers is as spin, which can be thought of as angular momentum, quantum-style. The particle usually used for this task is the electron. So, now we've got the qubit stored as spin, but how do we get the different particle's spin states to interact? If we can't get them to interact, we can't do any computation, so this is a very important question.
The most successful quantum computers (those with 7 qubits) so far use Nuclear Magnetic Resonance (NMR) to make the qubits interact. This has it's problems, and would not be appropriate for a real quantum computer. So, to make a real (ie. Desktop) QC, we need something better.
This story talks about a method of turning information stored in light (as amplitude, IIRC) into spin. This sort of translation is exactly what is needed to make quantum computers work. An example QC could use a bunch of atom's as the memory system, with all of the qubits encoded as spin on the electrons orbiting the atoms. The CPU would be a bunch of optical components (beam splitters, polarizers, mirrors, etc.) that operate kind of like transistors. And the wires would just be fiber optics. Now, this is a little simplified, because it assumes we can make atomic scale optical components, but I am confident that it will happen soon.
Hope this helps some people understand why this is Stuff that matters.
Yes, I'm still a junky. Are you still a bitch?
ClockStoppers, could we?
Can they synchronize the stop LIGHTS in Harvar Square so they at least maximize the traffic flow? Jeez that burns me up each time I see it.
tone
forget about quantum computer applications - what i want to know is how long will it be before we can catch daylight, in say a chamber on my roof, and re-emit in via lamp-like gizmos in my house at night. i *really* look forward to tossing all my incandescent and florescents out the window. that'll put the "happy light" people out of business. hey! flashlights without batteries or bulbs!
Couldn't this actually mean there would be a way to crack any quantum encryption scheme? Wouldn't this mean that you could examine light without the impact of the heisenberg uncertainty principle, therefore see the attributes of the light? Then you record the quantum attributes of each photon and recreate all possible messages that could be sent by the encryption. The presumption, of course, is that with sufficiently slow photons the uncertainty principle will no longer apply.
In other news, this exciting, "light-stopper" technology will be used in filming the upcoming movie "The Matrix II".
Just imagine it. An agent shoots Neo with a laser pistol, and it stops in midair, allowing Keanu to easily dodge it. This will cut the special effects costs in half!
This is the four thousandth time this article has been posted here and it is still doesn't follow. Nobody is freezing photons, they're just getting them stuck in the middle of some molecules so they have to wait for another laser to be able to knock the photons loose again. Stopping photons is not the same as trapping them.
I'm a loner Dottie, a Rebel.
By the picture in the article./ images/sto plight/qubits_med.gif
http://science.nasa.gov/headlines/y2002
WTF is that supposed to represent? A bunch of frowny 1 and 0 guys mad at some happy guy who has a 1 and a 0?
God spoke to me
my @quanta;
@quanta=;
foreach $quanta (@quantum)
{
warn "DAMN! destroyed my data by reading it again!\n";
}
-- Two men say they're Jesus. One of them must be wrong. - Dire Straits
Slashdot and articles in general on the net are so misleading when it comes to anything related to physics. Where do you people come from? Leave the physics to physicist. Anyway, they didn't "stop" light. This is nothing more than a simple setup (in theory) that's based on what any grad physics student must do (time dependant pertubation theory). The light perturbs the spin 1/2 states of the Rb with off diagonal matrix elements that mix states. The polarization of the light with respect to the Rb is also very important. The physics going on here is what you could call Rabi flops. It's a simple time dependant pertubation theory problem that is exactly solvable and can be reduced to two by two subspaces. As far as the physics goes, they've done nothing all that new or exciting. The only advances they've made are perhaps technical advances in setting things up.
Also, you don't actually get to examine the photons. The information about the photons is stored in the spin state of the atoms involved in 'stopping' the light. In effect, the photons no longer exist as separate, discrete particles. And these atoms are still affected by the quantum
effects of examining them. If you examine them, you change their state, and so the state of the stored light.
We are the Music Makers, and We are the Dreamers of Dreams...
finally! light sabres are right around the corner!
Jesse Newland
Light actually stops all the time. The remarkable thing in this case was that although the laser beam was completely absorbed by the atoms, they were able to make the atoms spit it back out again. Basically it works so neatly because the atoms are so 'cold' that they never collide with each other and therefore do not cause the photons to be ejected at random times. The really remarkable discovery would be how to keep things so cold that they behave quantum-mechanically, but without having big tanks of liquid helium (and worse.)
Slashdot is so silly sometimes it makes my head hurt.
Headline: Physicists Stop Light
Slashdot: The implications for quantum computing are staggering!
Headline: Transparent Aluminum Invented
Slashdot: The implications for case mods are staggering!
Headline: Secret of Time Travel Discovered
Slashdot: Yay! We don't have to wait 2 years to see the rest of [insert name of trilogy]!
Headline: Scientists Cure Cancer
Slashdot: The implications for quantum computing are staggering!
Headline: Terrorists Nuke South Dakota
Slashdot: The implications for quantum computing are staggering!
but this phase information is quickly lost as the atoms move around in a thermal equilibrium. think about it as sky-writing. the information is written there, but as the particles move around the infomatino is quickly lost.
most of these experiments have been done with UltraCold atom clouds, and the most recent ones (presented at DAMOP last year) were done in Bose-Einstein Condensates.
due to the very short "coherence time", this phenomena is most likely not very useful for quantum computing.
the buzzwords to look for when it comes to quantum computers (i.e. the things most likely to work) are "trapped ions" and "optical lattices". i promise, one of those two will be used in the first functional quantum computer.
muerte
Is this really news, or hasn't this been done...
before?
or before?
-D
I have long thought , and am probably no the only one, that a light storage device could make for an awesome weapon.
Consider a Sphere, 2 way mirrored, on the inside, you put light in, what happens ? It bounces around, indefinatley , well as indefinatley as the quality of your reflective surface.
Now think of charging this for say months wit a high powered laser.
Only to brop and break the sphere. releasing ALL the stored light at once.
Now before you go on ranting how the reflective surface, photons etc. I know but I have wondered if there isnt a way to overcome this, this group may just have the answer.
"Launch Photon Torpedoes" may not be as far off as we think........
Sig went tro...aahemmm.....fishing........
So did the damn thing have rest mass or not?
=)
I really liked that this article was written to explain what was being done so that just about anyone would understand it. The Star Trek reference was, however, inaccurate. From this article, it sounds like they make a duplicate of Kirk using something similar to light. This is not how the transporter works.
We have some evidence of the inner workings of transporters, but not much. They employ Heisenberg compensators, pattern buffers, phase transition coils, Biofilters, matter streams, confinement beams, and matter-energy converters, and phased matter. As for what they do, we know that you are conscious during transport (Star Trek II: The Wrath of Khan, "Realm of Fear" [TNG]), but can also be held in stasis ("Day of the Dove" [TOS], "Relics" [TNG]). Further, while in transport, you appear whole to yourself.
I hypothesize that the Annular Confinement Beam first locks onto, then disassembles the subject into phased matter, via the phase transition coils, causing it to take on a very energy-like state somewhat akin to plasma, called phased matter. The matter stream is then fed into the pattern buffer, piped through wave-guide conduits to one of the beam emitters on the hull of the starship, and then relayed to a point on the ground where the ACB reconstructs the subject.
This was taken from Transporters, Replicators and Phasing FAQ by Joshua Bell.
It's easy to stand out when the general level of competence is so low.
that this story has been posted on slashdot as reported by various publications. *sigh*
Given enough hydrogen, just about anything is possible.
Damn, it seems we're getting close to the Improbability Drive.
"That's a good name --- ground! I wonder if it will be friends with me?" Thud!
Miko O'Sullivan
nt
This was published in Nature over a year ago (25 January 2001 to be precise). This article (PDF format) is a nonspecialist introduction to this work, and this article (PDF format) is the peer-reviewed research article from Nature.
"It take 9 months to bear a child, no matter how many women you assign to the job."
The Smith family (complete with mom, dad and 2 children) is taking a 4-hour trip to Grandma's... Kid 1: Mom, are we there yet? Mom: No (Repeat 15x) Kid 2: How long's it going to be? Dad: Ok kids, if you don't keep quiet back there I'll split you up into an uncountable number of atomic particles and stow you away in your Ronald McDonald sippy cup until we get there! Kid 1: ...
Kid 2: ...
Since quantum computers aren't, strictly speaking, "digital", quantum devices aren't subject to the DMCA and CBDTPA. Anyone want to build a quantum DVD player? As a bonus, you can brute-force the title key really quickly. P.S. don't tell Sen Hollings or he'll close the loophole.
This technology has been hinted at for years in Science Fiction. You have Laser Guns which hold Laser "shots" in stasis and then release them when you pull a trigger. Rotating through several chambers, you eventually finish your magazine and require a new one... like needing more ammo. So each clip would hold X amount of laser shots.
The inclusion of Quantum Mechanics means that you could store the charge somewhere else. So you have a laser cannon/gun here, with the paired molecules being in another location, with a recharger. The recharger would be massive in order to produce the amount of energy required to produce repeated firing weapons, but the actual statis field appears to have very modest size requirements. Essentially you have a machine reloading laser bursts in a ammunition factory.
Imagine a laser handgun being powered by a nuclear reactor for example, able to release a full load at the pull of a trigger.
Their mothers TOLD them that if they kept it up, they'd go blind? Did they listen? Nooo...
["Marge, I agree with you - in theory. In theory, communism works. In theory." - Homer]
Hey! 100ms is a long time even by today's standards. Where have you been?
... not many Slashdotters killed.
[cf. Small Earthquake in Peru for the humor impaired moderators]
--
E_NOSIG
Does anyone know if this has implications for astro-physicists? I mean, could something like this happen naturally, maybe even frequently in the early stages of the universe.
Perhaps the light we're seeing from distant objects in the universe was stopped and then released again naturally.
Wouldn't this distort the measurements we rely on for calculating the age of the universe?
Read any good sonnets lately?
You might be surprised how many Slashdotters are in South Dakota.
We're going down, in a spiral to the ground
I suppose a really dark room was involved in this experiment?
Will code a sig generator for food
What do you mean, the light is just being "stored" and retransmitted. It IS stopped. The energy that makes the light is STILL THERE, stored in the atoms energy states. When you stimulate it with another beam, that releases the same energy. Also, you CANNOT make copies of quantum states, thus by definition when you "start" up the light again you are getting the ORIGINAL started up again.
As for potential uses, true quantum computers could do far more than merely let FBI thugs read your encryped email and discover you've been downloading copyrighted porn(which they knew anyway...with no job and no girlfriend, its not hard to work out)
No, "buildable" quantum computers (and no, this does NOT mean desktops. The nature of the components required I suspect will lead to most quantum computers being extremely expensive and run by a select few. Might be some kind of timesharing scheme. Remember, to store these quantum states you have to keep the parts EXTREMELY cold to minimize thermal noise from interfering. No private individual will be able to own their own liquid helium and laser cooling system unless they are very wealthy, just like private individuals cannot own spacecraft without extreme wealth)
Anyway, buildable quantum computers could finally allow for true artificial intelligence, which I believe will change the world beyond all recognition. Read The Singularity, and consider the implications of an AI being able to learn and expand at exponential rates, no longer limited by what we humans are held by.
I know you were joking, but you really can do Quantum computing with Perl
-- Will quantum computers run imaginary-time operating systems?
i hate to be a dick, but i have to agree with this guy. kind of reminds me of the reaction to the "jump to conclusions" mat in Office Space.
DUH!
Anybody can stop light with a good window blind.
http://www.scifi.com/scifiction/classics/classics_ archive/shaw/shaw1.html
Could it be the Tech of Trek is around the corner too?
...is how they release it? Anyone has clues?
They can absorb light into a container, alter the qubits (how?), and then, how do they send it off again? Opening a quvalve?
Some quEstions require quAnswers.
These bozos need to document a bit more if I'm to build one myself (ok... maybe I'm optimistic).
no text
In other news, the RIAA filed suit today against God for failing to include Digital Rights Management technology with each atom, in violation of the SSSCA, and for providing an anti-circumvention mechanism within His "Laws of Physics" prodict.
"This will destroy the music industry as we know it!" exclaimed an unnamed music industry representative, "Evil Hackers will be able to use this technology to pirate music off of even protected CD's, because they're all made of atoms!"
God was contacted for comment on these developments, but apparently prefers only to listen, and not reply.
The thing about things we don't know is we often don't know we don't know them.
Obviously everyone at Harvard should be arrested. Because they have trapped light it is obvious that they intend to use this tool to trap the light of all the fiber optic transmissions and thus spy on everyone. Furthermore it is quite obvious they plan to send all their DVDs and MP3s in this new Trapped Light Format thus aiding causing Quintillion dollars in lost revenue for the MPAA and RIAA. Someone call the National Guard these guys are really modern day entertainment media terrorists!!!
Jack Valenti
Hilary Rosen
We are closer then ever to light sabers!
How strange it is to be anything at all
Good, now I can play counter strike without the lag.
I've been doing that for years. Ever since I learned how to use the light swtich.
I can't help but wonder how this affects the Big Bang theory. This theory is based almmost solely (I'm sure that I am over simplifying here) on the basis of a consistantly observed "Red Shift" in astonomical bodies.
If all distant bodies are Red Shifting, then they must have come from a discreet place an been imparted with a great momentum, and thus a Big Bang. But this whole thing is based on Red Shift which is calculated by using a FIXED speed of light. All this research in slowing light would seem to complicate that theory to the point of unmanagability.
I think i was in the 3rd grade of humaniora (14 y.o) when my physics teacher gave me some extra homework cos I was talaking too much. I had to write a small essay on 'quantum teleportation'. I had completely no idea what it meant (neither did he, the whole idea was that the task was informative for the both of us -- he was a clever man indeed) well anyway, I started reading about it on the internet, and read that in a university in switserland (if I recall coreectly) they could teleport atoms. I found this very exhilirating, cos they also mentioned on thei rsite the applications for this, such ass mass transport, zero-time transport to other universes, super fast networks AND quantum computers. Okay my story is getting longer than I had wanted, but what I mean to say is: every day I read somewhere that quantum computers are just around the corner. Why can't they just cut the bullshit until they actually have it. This is something remakably irritating about /. (no offence to the readers/moderators/posters). Quit posting about 'they are working on '... It's kinda depressing to see all that cool stuff, and being kept reminded of it... I get kinda unrestful ;)
"The majority is always sane, Louis." -- Nessus
http://slashdot.jp
someone else has just discovered how to let light in. It is not know yet if their product's name will be contested by Microsoft Corp.
How come we have the technology for scientists to "stop" light but can't stop Cher from making more records?
Light? Where can I download this game at?
The article mentions experiment from 1999 where light was slowed to the "bicycle speed". This was accomplished by shining light trough "Bose-Einstein" condensate. Bosons are particles with integer spin (e.g. photons). In 1924 it was predicted that an ensemble of bosons could, under certain conditions, undergo a phase transition. This is analogue to vapor condensation or crystallization of liquid. In order to create Bose-Einstein condensate it is necessary to achieve temperatures less than one millionth of a degree above absolute zero. First successful experiment was performed in 1995 utilizing laser cooling. One of the properties of BE condensate is that the light propagates trough it with speed that is 20-million-fold slower than a speed of light in vacuum.
h tm l,
The article is not very informative about actual physics involved in the newest experiment. However there is a nice description at: http://www.aip.org/physnews/update/521-1.html.
Also there is a an interesting site about Bose-Einstain condensation at
http://www.colorado.edu/physics/2000/bec/index.
with some nifty Java applets
Am I the only one interested in seeing what light looks like when it's stopped? What about when it's passing at the speed of a bicycle in a dark or foggy room?
What really chaps my hide about this story is all the discussion of destrution of light. You *CAN'T* Destroy light (well unless maybe you hit it with an antiparticle) you merely transform the photon into another form of energy, such as say exciting an electron, or heating the black asphault as described in the article. No one creates or destroies light, they just convert photons from one form of energy to another.
What if it is just turtles all the way down?
The Palestinian-Israeli conflict will be resolved, global warming reversed, and world hunger ended. I am definitely staggered.
(having one of those days when these sorts of breakthroughs seem ever so slightly irrelevant to the future of life on Earth - could you tell?)
Next they reduced the intensity of the signal laser until the polariton was 100% atomic. There were no photons left inside the chamber.
There were no photons, people. They didn't stop light. Halted light would mean there are photons in there, moving at exactly zero meters per second. There were no photons left.
That that is is that that that that is not is not.
Now I can dance around naked and sacrifice goats whenever I want!
One step closer to a working light saber. Thank you Harvard!
Blearf. Blearf, I say.
now I can blue screen XP at
any speed up to and including the speed of
light.
Yes not only did they stop light they made it go backwards!
PLease don't post a stroy on mirrors now!
We don't want Disney or the RIAA to get any ideas.
wow... this is the THIRD time i've seen an article about this on slashdot....
Am I the only one who thinks it's strange that while we get told about all these fantastic things that can be done which weren't possible a year ago, people still say convincingly that "you can't get the state from the system without leaving finger prints" ?
I'm sure we can't today. And I'm equally sure that someone is going to figure out a way to touch the system so insignificantly that the "reading" cannot be measured.
Like when reading from a hard-drive: Of course the head will alter the state of the platter when passing by - it's just so insignificant that it doesn't matter, and it would probably be hard to measure if anybody tried.
While this is fascinating and all, I just don't buy into the "can't cheat with this one". Many years ago, everyone agreed that you couldn't split an aton - which was natural, because "the atom" itself was a relatively new idea in itself at that time.
I find it hard to believe that the progress stops here.
I have a time machine in my bedroom. I have only been able to go forward in time 8-12 hours at a time. I lie down on it and poof, it is 8-12 hours later.
Setting his threshold to 5, Sparky eliminated most of the trolls on /.
... on New Year's Day. Millions of hungover people will thank them for stopping that godawful light ...
How is this done...
Xon Xoff or by hardware flow control...?
Exactly. You know, this has been going on forever; I hit an atom with a photon, and it becomes excited to a higher energy level. Then when it re-emits the photon, it is of the same frequency as before. Though like this story, it's not the same photon; but it has the same properties as the one that was absorbed. But hey, more media coverages means more grants in this "industry". I see where they're coming from with this one...
"The weak are always anxious for justice and equality. The strong pay no heed to either." - Aristotle
Faster than light that is.
Geesh - Never thought I'd break any land-speed records. Now if I could only go faster than sound now...
( Somebody had to do it ).
There's a gorilla from Manilla whose a fella that stinks of vanilla and has salmonella.
The city of Boston is suffering a complete blackout. All traffic lights are dead, completly stopping traffic in the area.
It's "its", not "it's"!!!!!!!!!!!!!11
-joe
Since fiber optics are much "harder" to listen in on I bet the NSA is going to eat this invention up left and right.
Now what is important is speeding it up. That is the basis for most sci-fi drives and possibly real space drives in the future.
--"God may not play dice with the universe, but I vill" Einstien in the movie 'I.Q.'
I like replies better than Karma, even if they are flames, because that tells me I got someone thinking.
I know very little about "quantum mechanics"; but it seems to me that this would bring us closer to building a cloaking device of some sort. If you think about it, cloaking is nothing but the bending of light around an object - and it seems to me that if you can pause light and store it in matter; then you can move that matter around to the other side and re-emit it(?)
On the other hand, perhaps not, since it took two lasers and a lot of work to make this experiment happen.. I dunno.
Wasn't the military trying to look into cloaking recently? I think I remember reading that.
You can run but you can't hide, except, apparently, along the Afghan-Pakistani border.
Actually, quantum energy states are ... er ... stopped !
Doesn't matter anyway though because such equations only apply to particles with mass. Since light travels at the speed of light, it cannot have momentum or mass.
Einstein was a pretty smart guy...
int func(int a);
func((b += 3, b));
Said it better than I could...
Always curious why people post good stuff AC.
int func(int a);
func((b += 3, b));
Did you hear about backprop based neural networks? Those based on descrete Lagrange formula. Generalize the formula to fileds, like optical fields and you get a best quantum computer you can imgagine today - the one, which can use adaptive fuzzy logic for self-organization and self-training. Don't you find this idea new? Hmm... I worked with such project back in 1991 in last days of Soviet Union. Who knows who would dictate the world which technologies should be exported or not if communists would not blow up the whole thing.
Applying this slowed light trick, we can now get an OC48 to cap at 56K. I'll bet Ameritech is hard at work trying to accomplish this at this very moment. Just think, it'll be like the good old ARPA net days in no time.
Or I keep the collector and switch it off after an hour letting all the photons to continue on their way towards the terrorist de jour.
So when do we get slow glass?
Headline: Terrorists Nuke South Dakota
Slashdot: The implications for case mods are staggering!
-
- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
This is really old news and not even "technology." Following the examples in California and this ENRON thing, it's clear that stopping light isn't so much a technical marvel as it is poor management.
Trapping light and then releasing it later on? When I was a kid, I had a plastic toy dinosaur that would soak up light and then glow in the dark. Big deal.
:-)
Its too bad that we're probably the worst thing that has ever happened to the planet, because as a species we do some really amazing things.
When you sit down and thing about it, the fact that we take something like electrons, and shove them through a wire to create light, you have to wonder who came up wit this stuff.
Our physisists can stop light, but we're still using fossil feuls to power our cars.
Many of you said that this result is not revolutionary because it is just recording and retransmitting information which has been around for a long time. I am a quantum physicist and would like to offer some clarification in order to better see the difference.
The keyword here is "quantum" information. Light (or any other particle or anything for that matter) carries a set of physical information (speed, position, energy, angular momentum, etc.). Heisengberg's rule however tells us that there is no way to measure all this information at the same time with arbitrary precision. Measuring one characteristics basically destroys the information about something else, therefore recording and retransmitting is always confined to a subset of the physical quantities.
For those who know some physics: for example you can measure the x-component of the angular momentum but the very measurement loses _all_ information about the y-component of the angular momentum. The x-component of the retransmitted light's angular momentum might be identical to the original one's but the y-component necessarily differs.
Therefore the challenge in stopping light is the following: you want to confine the information carried by light to a small region of space _without_ actually detecting that information. This is what has been achieved in these experiments: when one retransmits the light previously captured, it will carry the same quantum properties as the original incoming light.
And this is definitely something very new.
Tamas
Now I really can say that I work at the speed of light!
I am anarch of all I survey.
i can just imagine them now.. all lit up like tron
[insert witty comment here]
There is a really anoying streetlight right in front of my bedroomwindow. I could really use this technology !!! Wait a minute... I CAN stop light it's called a curtain. Nothing to see here, move along.
in this system, I wonder why. At least if I got these calcs right.
Light at 186,000 mi/sec, then the 2 mile beam is about 1.07^-5 seconds. Running a system at 10 gigahrtz (10 billion bits/sec) you get 5.34^4 bits per mile.
The 2 mile beam was stored in 10 cm so you get 1.08^5 bits in 10 cm or 1.08^4 bits cm. With 8 bits to a byte you get 1.35^3 bytes/cm
Yielding 1.3Kb/cm.
I would bet my 80gig hard drive does better.
I must be missing something here.
Gizmos Gagets For Ninjas
i havent yet read the article, will do after this, but my first thoughts are that if they have stopped light altogether, or at least slowed it almost infintismally, they would have had to have slowed down time to achieve it...
or
if they have managed to somehow slow down light, have they also accidentally slowed down time? my 2c. now i will go read.
Dont ask me...Im just the bass player.