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Stop, Light.
parvati writes: "The New York Times is reporting that two separate research teams, both from Cambridge, MA, have managed to slow, stop, and then reconstitute light. The ability to stop and then accurately restore a beam of light has implications for quantum computing and communication in that it may provide a mechanism to store the information coded by single photons."
Lameness filter encountered. Post aborted.
la de dah dah stupid lameness filter
Based on an article that I read a couple of years ago (and nothing else, as I have no background in physics, let alone quantum phyisics) the principle of teleportation revolves around twining particles. When you have two particles, A and B, and you twine B around A, B becomes an exact opposite of A. If you them twine a third particle C around B, it becomes an exact opposite of B, hense an exact duplicate of A. In the process, though (and this is the way that I remember it, not necessarily the way it really is), A and B are effectively destroyed, leaving you only with C. By effectively destroyed, I'm assuming that they lose whatever properties they had that made them distinctly A or distinctly B. The big plus point here is that it apparently doesn't matter how far appart B and C are from each other. They could be a few feet or a few light years (though I immagine there would be problems being a few light years away).
However, the researcher interviewed in this article noted that he immagined that transporting a person by this means would be a bit like being ripped appart one particle at a time. Not the way I would want to start my vacation!
So, by inference here, I'm assuming that when the above poster said that the original would be destroyed, I don't think he meant destroyed in the sense that you destroy a rabid dog, but rather, the original would effectively disipate. Of course this all brings up the philisophical question of "am I made up of more than a bunch of random synaptic firings organized and chained in such a way as to give me personality and self?" to which I can answer a resounding and joyfull "Yes". But hey, that's the fun of Christianity.
Oh, for more on the idea of knowing that you are a copy (an idea put forth in the recent Swartzegnager [what kind of sick person gives their kid a name that hard to spell?] flick "the Sixth Day") check out the Orson Scott Card short story "Fat Farm". I think that its in the Cruel Miricles collection. There was a hardback copy of all those books put together, but I don't think its in print. I don't think the smaller books are either.
something clever
I don't think they way they did it would apply to space travel, but what about time travel? I suppose you could encase something in this gas, and achive time travel. But then again, if space and time are relavent, I guess it would be possible to travel with it... I'm not up on this subject at all, but does anybody care to post a real educated view on this?
Despite the fact that this perfect replica would be absolutely indistinguishable from you, it would only be so to anyone BUT yourself. To me, this is almost like the scientific proof of something similar to a soul.
Actually, I would think it would be quite the opposite. Most religion's concepts of a soul is something non-material/measurable/detectable, created by the "Divine Breath", and not something mankind can ever create or copy. If we can copy a person by copying its physical presence, and that copy is to all perceptions the same as the original, that would set off some serious theological alarms. Would killing the copy be murder, or just making an obscene clone fall? And how do you tell which is which? And does the copy have a soul, and if so does that mean we are just the sum of our matter or have we become Gods?
Ooh, a sarcasm detector. Oh, that's a real useful invention.
When do we get the damned spaceships?!! :)
This just serves to reinforce the position that NASA is grossly underfunded. In its heyday NASA went from having NO launch capabilities to the Apollo moon missions in 15 years.
What have we spent the last 15 years doing? Servicing the same damned shuttles and only going into low orbit on each trip. There should be a Moore's law for space technology. I think we've progressed computers far enough to keep us happy for a few years, why not concentrate on the space program?
This is where heisenbergs uncertainty principle comes in... you can't measure the transmission (read-out) without affecting the transmission. So when you have quantum communications which are eavesdropped on, _BOTH_ sides know it instantly because the quantumlink is disturbed so far for the eavesdropping where eavesdropping is defined as listening to two parties without the 2 parties _knowing_ it...
This idea was remotely touted with in a Star Trek: The Next Generation episode where Riker accidentally faces himself after a transporter fsckup.
The "duplicate" Riker (left alone on an abandoned planet for years) would be, in this scenario, the Riker that would have been "killed" (destroyed, dismantled, atomically-disassembled or whatever).
Though, being a ST:TNG episode, they instead focussed on his love affair with counsellor what's-her-name-again.
Karma karma karma karma karmeleon: it comes and goes, it comes and goes.
counsellor Troy.
Karma karma karma karma karmeleon: it comes and goes, it comes and goes.
Reading the article, I alternate between thinking that the atoms of the gas is store just information and thinking they store energy as well (the actual light). Can anyone clarify?
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Fuck the system? Nah, you might catch something.
Well, I'm pretty sure space and time are relevant.
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Fuck the system? Nah, you might catch something.
Now, there are actually teleportation devices on the Stargate series, like the Go'uld (sp?) ring teleporter thing and the Asgard's beam teleporter, which could use quantum effects, but the Stargate itself just manages to create a wormhole at both ends (That's one wormhole, with two ends.) ...witness the episode where the Stargate at the other end fell into a black hole, thus causing the non-local end of the wormhole to fall into the black hole. (Which is not really a good idea, but it was fairly funny to see them repelling down the floor towards it.)
-David T. C.
If corporations are people, aren't stockholders guilty of slavery?
From the article ...
.. I'm not sure I understand this .. if there's a way to transmit something, then there can always be someone/something in the middle that can intercept it. Anyone with any insight into this care to explain or was this a case of the reporter getting carried away?
Quantum computers could crank through certain operations vastly faster than existing machines; quantum commmunications could never be eavesdropped upon.
Could NEVER be eavesdropped on?
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Delphis
I can stop light, then send it off in a whole new direction! It's called a "mirror." I will apply at the US Patent Office, and make millions!
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"Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.
Unfortunately, the problem with this is that the probability of this happening is of course so astronomically remote that it will never happen anywhere in the expanse of the universe within whatever lifespan the universe may have.
Nitpick: that's not an entirely true statement. As long as the universe does not collapse upon itself in a Big Crunch, then the lifetime of the universe is effectively infinite. (That is not to say life itself is infinite, as at a certain point the universe becomes too cold and dead to continue to maintain life.)
One of the tenants of probability theory is that, given enough time, an event will occur. Thus, given an infinite period of time, _all_ events that are possible will eventually occur. In other words, if you wait an infinitely long time, you'll eventually teleport to the inner ring of Neptune.
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I want the first person who tries to make an artifcial black hole hauled off and shot. The second person would pray to have the fate of the first person. I am not sure if most people understand the danger of an artifical black hole.
Black holes do damage through tidal forces the smaller they are they more damaging they are to the immediate area. Also there is not way to control it. There is nothing that can hold it in one place. If you try to hold it then you feed it mass and it gets bigger. Right now with our tech if you make a black hole the world is over. The thing will eat the entire planet in fairly short order and as it undertakes simple harmonic motion through the earths core growing as it goes.
IE this is a one way death sentence. If they want to experiment with artificial black hole at least do it around the orbit of pluto. Then if we fsck up there we will have time to leave the solar system. Still not a good option but a better one.
Computer modeling for biotech drug manufacturing is HARD!
...in refrigerators. Hell, Burroughs talked about how the Martians used this to levitate their airships around a hundred years ago. There's a movie to be made: "A Princess of Mars.:
I drank what? -- Socrates
I just enter what I would if I had to register.. user aaaaa, pass aaaaa. Someone else back yonder had the courtesy to create that. =)
Bitchslapped. Neat.
> Okay, you're pulled apart and your entire > quantum makeup is sent somewhere else. What > stops you from becoming a pile of goo?
Ask Jeff Goldblum, he figured it out in "the Fly"
------ Poo-tee-weet?
So for all of the Sci-Fi authors out there, we finally have FTL Travel - We don't need to bend space, create wormholes or anything requiring any massive energy... Just open the front door and walk !!! ;-)
:-(
So would some kind soul care to explain how 'c' is a constant that is used throughout physics, but we can still slow/stop light? My physics isn't what it should be these days
Layman's terms appreciated, but not mandatory.
--
Enjoy Y2K? Roll-on Year 2037!
As others have pointed out, what's really happening here is not that photons are somehow stopped (they have zero rest mass) but that they are storing their information in the spin of the rubidium atoms. The light beam is stored with the help of a second beam used to excite the atoms.
This is analogous to a hologram, which manages to store phase information from light, using a reference beam (normally split off from the illuminating beam). This slow light is more thn just a hologram, though, because of all the extra information that is archived.
Sure, no problem. The first step is converting your garbage to light, then the light can be disposed of in the black hole.
http://www.nara.gov/exhall/charters/declaration
http://www.nara.gov/exhall/charters/declaration/d
http://www.nara.gov/exhall/char
That ratio may be different, but that ratio no longer has anything to do with the definition of pi. Curved spacetime doesn't change the fact that pi = 4*(lim(n->inf) sum(k=0..n of S(k))) where S(n) = (1+2n)^-1*(-1)^n
He may have been referring to something like this page's discussion of anisotropy in EM interactions which doesn't have to do with different velocities of light but might have been misremembered as such.
It can detect eavesdropping between Alice and her conversation partner, but it still provides no guarantee that her conversation partner is Bob; Dr. Evil can still play man-in-the-middle.
Pi is a constant in any reference frame; mathematics doesn't care how fast you're going. A geometric circle doesn't length-contract at high velocities with respect to another observer, because it isn't a physical object. A physical object in the shape of a circle might, but that has little bearing on the definition of pi, merely on one possible method of estimating it.
After the duplication event, both versions would remember having been the original. To the "original", the "duplicate" would be the "obvious duplicate", but to the true "duplicate", the "original" would be the "obvious duplicate". This further assumes that there is any way of telling which one was the "original"; suppose the technology takes one object in location A and turns it into to objects in locations B and C. Then you no longer have spatial locality from which to infer the identity of the "original".
As far as each remembering being the original, though, that's very similar to the case in which you, today, remember being the same person you were five minutes ago. Perhaps the trouble is in inferring from what seems to be a continuous chain of memories that there actually is some sort of soul or "consciousness invariant" (thanks, Greg Egan, for the term). Maybe that's the illusion from which seeming contradictions arise.
Maybe there's only one conscious entity which "time-slices" between all the sentient beings, and while "animating" each one it has memories only of always having been only that being as long as it had been alive.
I can't imagine that being disprovable, though, so it's not of much use as an explanation, but it might be useful to start reasoning through the philosophical consequences of duplication of the sort you mentioned.
Does anyone else remember a cartoon short with a catchy toon they played on PBS a decade or so ago about a woman who meets a professor with a teleportation machine that turns out to copy you at the remote side of the link then kill the original? I'd love to see that again...
That's what I was saying. The original poster said "I thought Light always moved at C" and I replied "No, light moves at a MAXIMUM of C, and can move slower" - Now, stopped IS slower, right?
-- 73 de KG2V For the Children - RKBA! "You are what you do when it counts" - the Masso
As I understand it, this would make it possible to create light transistors that switch by shining light into the transistor. AFAIK, this isn't possible at the moment. Obviously, you could flip mirrors or something, but that means you have something mechanical, which defeats the purpose. Does anyone know enough about light driven transistors to verify this?
No, I don't think it can. What's been achieved here by Hau & Lukin is, as has been said in some of the other posts, more accurately described as taking a pulse of light and storing it in a gas of atoms in such a way that you can get the original pulse back out later, rather than actually stopping an individual photon in one place. That, as far as relativity says, is physically impossible; The rest frame is undefined for massless particles so it's meaningless to try to think of what one would look like if it could be stopped.
And since all that's been done here, fundamentally, is taking some energy and storing it in atoms, albeit in an extremely clever way, it has nothing to do even remotely with the way light is trapped by the warping of spacetime near a singularity. The neat applications of this work are in quantum computing and communications, as has been said, not in designer black holes. :-)
And let me add that I had the good luck to work with Lene Hau when I was an undergraduate five years ago, working on building some equipment for rubidium BEC experiments much like this. It was a great experience and I learned a lot of good experimental science from her, so I'm very pleased with her success lately, even though I ended up going off in a different direction myself so I only worked with her for the one semester.
It's not nearly as easy as you describe it, no. You probably could seperate a BEC into two smaller condensates, but I don't see any easy way to do it without breaking the entanglement between the two parts. Flattening it out could maybe be accomplished by a sufficiently perverse arrangement of electric and magnetic fields, but remember, the condensates we're talking about these days are *very* small, exist only in vaccuum chambers, and involve only a small handfull of atoms. We're not going to be manufacturing person-sized sheets of BECs any time soon. :-)
If so, then you would merely need to transport the two 'gateways' whereever you wanted and teleport between the two locations.
I'm afraid not, no. That's not how quantum entanglement works. Even though you can get instantaneous action at a distance, there's still no way to transmit information faster than light. Basically, all entanglement tells you is that when you measure thingy A, then whatever answer you get, instantly you know thingy B is in the same state. They're both spin up, or both protons, or both right-handed photons, or whatever. But you have no way of controlling *what* they both are, you just know they're the same. There's no way to take your unmeasured thingy A and force it to be spin up, which would force thingy B to be also spin up. All you can do is measure it and know that you're also getting a measurement of thingy B at the same time, no matter how far away it is. No FTL communications or transfer that we could use, alas.
Sure. Could you just mail me your ISP's IP address and root password.
Probably had the photons go across the river and drive around Boston.... they got stuck behind some double parked cars.
And in a decidedly Douglas Adams twist ("There is a theory that this has already happened") - there's (Hawking's?) thesis that the universe is merely a universe-sized quantum fluctuation.
Wait long enough, and eventually a Big Bang followed by 20-30 billion years of physics suitable for the evolution of sentient life will happen, simply by accident.
I have got a refrigerator full of data: I you open it up the data starts coming out, if you close it, it is being saved.
- In Memoriam: Jeroen de Bruin (1972-2004), bye bro
I can see it now:
"You were exceeding the speed of light in a school zone, sir."
"But I was only going 40MPH!"
"Speed of light's 38 here, sir, and 38MPH isn't just a good idea, it's the law."
--
This is not my sandwich.
You just use Heisenberg Compensator to take care of "flashing" the person.
Sheesh, you think someone around here would have seen Star Trek a couple of times. :)
Later...
KangarooBox - We make IT simple!
Then, I turned it back on, and the bulb started streaming out photons that were nearly identical to those that were there before!
That green slime had it coming.
Maybe in a few years they can stop me from getting a day star tan... stupid day star... always coming down on me...
Any ideas on how this will effect quantum cryptography?
The article didn't mention if they were able to perfectly reconstruct the photon. If they could then quantum cryptography is dead. But if that was true then heisenberg principle is also dead.
Great, so we'll go from cars that stop when they run out of gas to cars that blow up when they run out of gas.
Is that possible, according to the heisenberg uncertanty principle you can never know both the location _and_ direction of movement of a quantum particle. So how would you be able to reconstitute it without this info?
I have no
Maybe this could be engineered into a defensive weapon? Just store a super-intense pulse of laser light (expensive to produce) into this container (cheap gas cell?), and let it out at the right moment.
Only one shot though...
I know this is a stupid question, but any talk of teleportation brings it to mind:
Okay, you're pulled apart and your entire quantum makeup is sent somewhere else. What stops you from becoming a pile of goo?
Is this post not nifty? Sluggy Freelance. Worshi
Okay, what's to stop you from becoming a gigantic fly? :)
Is this post not nifty? Sluggy Freelance. Worshi
Ever read Penrose's 'The Emperor's New Mind'? It covers the teleportation duality dilemma in some depth. Even more mind-warping is what would happen if the original wasn't destroyed. Which is the real person, the one sent or the one received?
Here is the Los Alamos preprint entry.
http://xxx.lanl.gov/format/quant-ph/0012138
I have no idea who originally created this, but I always log into these NY Times articles with the username/password of slashdot2000/slasshdot200.
Just a reminder / heads-up.
Hate to be picky, but it's Counsellor Troi
Thus, given an infinite period of time, _all_ events that are possible will eventually occur. In other words, if you wait an infinitely long time, you'll eventually teleport to the inner ring of Neptune.
Unless you are destroyed by [probable_event] first.
It is this very debate that has confused me for some time. Despite the fact that this perfect replica would be absolutely indistinguishable from you, it would only be so to anyone BUT yourself. To me, this is alomst like the scientific proof of something similar to a soul. (A really weird concept for someone who does not take kindly to church)
It would be reasonable to assume that you would want the new person to be created before the old was destroyed (in order to verify any possible transfer issues). Suppose the process was stopped before the origional was destroyed. There would be 2 version of you that are indistinguishable, yet to the origional the duplicate is always the obvious duplicate. It suggests there is on some level a human perception of an individual that cannot be duplicated. Since you can't have exactly the same experiences from this point on as your duplicate, you will begin to differ (nature vs. nurture) and thus eventually be able to be distinugished... but for those first few moments after the process these differences will be at a minimum, and perhaps negligable.
Anywho, I believe the article referred to the stopping of light as if not to make it's velocity zero, but to make it's mean displacement over time zero through redirection by diffraction/reflection.
- Sig
What you say would be true about anything that was self-aware. So then you are simply equating self-awareness with (something similar to) a soul.
If there is anyone out there who is familiar with this area of research, there is something I've been wondering. Could this be used to build up a store of light (like a battery) or is it more for storing a short burst. Could you, for example, keep pouring light into this medium for a long time, to stop large amounts of it, then release it all at once?
It is possible to have quantum crypto systems where eavesdropping will always (i.e., at any desired level of security) be detected. Here's an intro article that explains this: http://www.qubit.org/intros/crypt.html
So how'd they do that, anyway? Change the colour from green to red? :)
Take life easy: one bit at a time.
easy, put some sort of detector at one end and measrure the time it takes for it to detect the light, if you know the distance and the time you can find the speed. if the detector never goes off then you can be pretty sure that the light stopped. And i never understood that thing about not being able to measure absolute zero. if you know how much energy is absorbed can's you just take that into account and find the real measurment?
There are two clarifications to be made here. First, the propogation speed of the light through some material is a property of that material. So while a given photon will travel more slowly through matter than through vacuum, it will "speed up" again when it re-enters the vacuum. Secondly, the frequency (colour) of the light does *not* change when it enters a different medium (it's wavelength does). The frequency is a fixed property of a given photon. It is directly tied to the photon energy and does not change just because it enters another medium. So, photon propogation speed does not affect the spectrum at all. The frequency shift described by the Doppler effect is due to the motion of the emitting and detecting bodies at the time the photon is generated and absorbed. That is, if you are at rest relative to the star you will measure the "standard" hydrogen spectrum. If you are moving with respect to the star the entire spectrum will be shifted slightly to higher or lower frequencies.
This isn't really a consistant way of understanding why light travels more slowly through matter than vacuum.
Light that makes it through a material has not lost any energy. If it did, it's frequency would have changed. The fact that we can pass light through material without a frequency shift at the other end, but clearly measure the increased propogation time through the material (relative to vacuum) tells us no energy has been lost by that light in the material.
Note that some fraction of the light *will* be absorbed and that energy will be lost. I'm talking about the light that made it through.
Moreover, photons don't rattle through material like pinballs richocheting off the atoms. If that were true then the final direction of the photon when it leaves the material should be essentially random and determined by the final scatter. It's hard to imagine a process by which this final scatter should preferentially point the photon in the same direction as it was travelling when it entered the material.
The most consistant description comes when you model the material (at least in the way that light "sees" it) as a general electromagnetic soup through which the photon (a self-contained electromagnetic object itself) must propogate.
The process described in the article sounds a LOT like conventional hologram creation, with the two interfering beams. It makes me wonder if they aren't just making a holographic impression on the storage gas, perhaps on the quantum level or something... I don't know. But it doesn't sound like the original light/energy that was put in is actually coming out. I look forward to the full report when it is published. This is fascinating shit!
Learn how a CPU works before you learn to program. Seriously.
I know it's a crazy thought but could this be some tech useable to make so called "beam swords," or at least "beam clubs"? =o
Don't call my crazy, that's what they called me back in the home!
The speed of light *in vacuum* is the well known c. The speed of light in a medium other than vacuum is slower by a factor of the index of refraction.
Harvard scientists say they've stopped light
Well my first thought on that one was if they have to flash a second light though the gas to 'revive' the first one....where does the second light go? How do they know that the light they think is the 'revived' light is not a variant of the second flash? I'm not a physicist, but I wish there were a BIT more details for the layman.
"I'm not a procrastinator, I'm temporally challenged"
What if you were destracted in the middle of reading the message?
Nucular Launch Codes: 12XH76.......
"Honey, Have you seen the cat today?"
"What? Hold on I'll be right there once I finish reading this message."
"AGHHHH!!!! Nooo I missed the message!!!!! Quick where's the recycle bin?????"
"Remember, who is the boss of you!"
> SELECT * FROM brain_cells WHERE synaptic_rate > 0
0 row returned
In the current experiment by Phillips and co-workers which is only a demonstration of the ideas and not a useful device, they can only stop about half the light pulse and it decays away inside the atomic cloud fairly quickly, so only a small fraction of the incident photons actually come out.
"but the equations are just not symmetric in space and time"
all equations are created by us to fit
the world that we know.
for example, most Newtonian physics equations
need to be updated to take into account
general relativity.
Has anyone really explained WHY time dilates?
not HOW time dilates.
anyway, getting off topic now.
cheers,
metric
disclaimer: I'm no physicist
:(
I came to the same conclusion for why
time dilation occurs.
I always get stuck at: "motion in the
direction of time".
How can you "move" in time?
moving involves time already.
cheers,
metric
I left my cool "penguin physics" sig at home.
Actually, Richard Feynman argues in QED that Heisenberg's principle was an artifact of the then-current understanding of quantum mechanics. Feynman points out that he and his colleagues had a more complete interpretation that obviated Heisenberg's calculations.
Any sufficiently well-organized community is indistinguishable from Government.
...is probably shagged then (if you can read the bits without damaging them)
let me get this straight. if i add that line to my /etc/hosts, then whenever i use my browser (which is configured to use a proxy) it will send that proxy requests with numerical ips? wow! that's fucking amazing! i didn't realise it did that! *slaps forehead*
i would like to take this opportunity to apologise for taking the bait, and responding to a comment that looked like it was written by a 12-year-old saying "you're all idiots for not using a set-up as 'leet as mine!"
it's just that some days the utter stupidty gets to me...
please, sir, could you add that line to my isp's proxy's /etc/hosts?
idiot.
wow! ontopic, witty, and containing insightful references to my comment, with well-placed bolding.
i am humbled before your magnificence. please identify yourself, coward, so i know where to send the fan mail...
oh, and btw, my goat is hairless all over. please demonstrate where i should be respectfully shoving my files. thank you.
Hollywood tought everybody that (american) cars explode on impact.
Just dont hit anything and your blackhole powered car will be fine.
You don't think a dog has any concept of time? Are you kidding me?
Last I checked, dogs sleep, get hungry, grow, get old, and die. I don't think I've met a dog who is demonstrably unaware of these phenomena.
Maybe they don't engage in English conversation about "time"; maybe they think of it as "arf" or "bark", but so what...
myselfmusic
I remember one time when I was encased in gas, but everyone else in the room travelled... or maybe I travelled to a time when there was nobody in the room.
--
As a matter of fact, I am a lawyer. But I play an actor on TV.
From the article: "the beam then left the chamber carrying nearly the same shape, intensity and other properties it had when it entered."
Umm... NEARLY?
This is very very cool, but I don't want my computer to be displaying nearly what it should, or doing math that is nearly correct. Remember the original pentium?
---
Desperation is a stinky cologne
I just finished reading Michio Kaku's book "Hyperspace". There's a chapter about einstien, and it says one of the questions that led him to his theorys of relativity was "What would a light beam look like if you could catch up with one?"
At first, he figured it would be a series of stationary waves, frozen in time. But later he figured that according to maxwell's field equations, there is no such thing as a stationary wave. And then he found you couldn't catch up with the wave if you tried!
The principle of special relativity says the speed of light is the same in all constantly moving frames. I don't know if this breaks it, probably not. But it is already known that relativity breaks down when faced with extremely large forces, like the big bang.
Isn't this the Heisenberg Uncertainty Principle? However, I am not a world class physicist, so take what I say with a proton size grain of salt. :-)
"See, we plan ahead! That way, we never have to do anything now."
How would you transport you hologram?
It is stored in a Bose-Einstein Kondensate, and even if it would not mind being moved (what i doubt, i think you need a extra damped optical table), you would still need to move a cryostate - which is no easy job, even if it is empty....
so far, it could only be used to be written and read in one place. So a rather bulky device.
Unless you can use optical fibers to transport the read-out laserbeam. Now this would be interesting, if you could maybe put this inside an optical router?
It was Maxwell...he condensed all of what was known about electricity and magnetism into those 4 (or 2, depending on your notation) equations, aptly called MAXWELL'S EQUATIONS, that govern all of electromagnetism. These equations predict very clearly the speed of an electromagnetic wave (light) in a medium based on its electric and magnetic permitivity (epsilon and mu). For a vacuum, that number is very nearly 300,000km/s. Obviously different media have different permitivities, and thus different values for c. But, that cosmic speed limit still exists...if you were IN the same media, you still wouldn't be able to go faster than light.
First, you can't refer to "slowing down" time because there isn't absolute time. If you and I move relative to each other, your time looks slower to me AND my time looks slower to you. The reason this isn't paradoxical is that we are no longer referring to the same thing. This is special relativity.
Now, the only way we get back to referring to the same thing is if we stop moving with respect to each other, which requires acceleration. ACCELERATION slows down time. This is general relativity.
Time does not exist for a photon. If you asked a photon about its trip, it wouldn't understand what you were saying because (aside from not being conscious) in the photon's frame, it is all places along its path at once (even that isn't true because "at once" refers to a time, which the photon doesn't have). Make sense? :)
I think his point is the curvature of space in GR: that in a nice flat Cartesian universe, the ratio of circumference and diameter is 3.1415927(etc); but in a curved universe (one with gravity and acceleration), that number changes. What is the ratio of circumference to diameter on the surface of a globe?
Did you think he was somehow insulting you?
And assuming that your description of events is correct, that stupid conservation of energy thingie is going to require that the photons have the required energy to create particles.
Also, thanks for the defense, but I don't think that people posting as AC pose much of a threat; their insults don't mean much if they are not upset enough to log in.
Seriously, the dielectric constant of current PC board materials has become a bit of a hinderance. Standard board etching shops have minimum features sizes of five-mil (1/1000 inch == 1 mil) lines and spaces. The cheapy places want even LARGER minimum features.
One can cheat for a while and just use a thicker substrate, but that only works until the frequency of operation approaches that of the next higher-order mode. In stripline, there is a frequency for a given board thickness at which the energy "leaks" off the trace and disperses into the board as a parallel-plate waveguide mode. Stripline circuits must work well below that frequency to ensure effecient energy guidance. Lower dielectric constant materials would allow the use of thinner substrates for a given minimum feature size and extend the useful frequency range.
Of course, it's probably all moot anyway: as the frequency of operation increases, the conductor loss starts to dominate and pretty soon your super-high-frequency transmission line becomes a very fancy electric heater. :( Nothing is free.
They don't exagerate more than anyone of us who says 'light travels slower in non-vacuum media'
As the very same phenomena appears. When we talk about the speed of light in such a medium, we deal with statistics, not with individual photons
By the way, those photons are 'not the same' when they 'get out'. Anyway, those scientists forgot to be idiots, if they claim to do such a thing, it is relevant. It might be mistaken/wrong, whatever (cold fusion anyone ?). but it is still relevant. That's what matters for the conversation here, as its correctness if far beyond our capacity to be evaluated/judged on a slashdot board (unless some very big heads enter the conversation, but I doubdt they would (I don't doubdt they exist, but I'm pretty sure there is no way they can give more than a personal opinion on this, correctness is not a matter of intuition here since long time in quantum physics)).
The claim has a very strong importance on quantic theory I believe (ability to reproduce *exactly* a photon).
For a statistical effect. (how do you understand (feel) light any other way ?), their claim to slow and stop light is very relevant, and it is not worse than when we say 'light travels slower in water than in void space'
In fact, in this case it is correct, if the claim to reproduce the original photons with great exactitude is right. (don't confuse correctness and relevance).
So if they can reproduce with great exactitude incoming photons to reproduce them at 'any time' and so on, quanticaly, they are slowing down and stopping light, as there is no way to diferentiate incoming photons from the outgoing ones. On the other hand, we are always talking about light traveling slower in one or another medium, when in fact, the photons are very affected. there are plenty of ways to diferentiate them, and in fact we use this every day to assume things on the media (absorption spectrums, etc..)
So don't be confused, the article claim isn't wronger than anyone of us in 'common talking', and in fact, for the first time (??), it might be much more correct than we are every day. (say, if the claim is verified)
Yeah, but the theorum says that everything else can't move as fast as the light. Does that mean in the medium, everything would stop? I'm not being smart, it's just my special relativity is rusty at best. Cool experiment though.
If I could think of something pithy to say, I'd put it here. No really.
Black holes do not "go nova". Nova is a process where a intermediate size star sheds its outer layers until it eventually becomes a white dwarf. Supernova is a process where large stars violently eject their outer layers and collapse into either a neutron star or, for stars with a mass greater than about 4.5, a black hole.
{RAMBLING} The trick with creating a "usefull" black hole as described above would be to give it sufficient mass, so that it had a large enough event horizon without giving it enough mass so that it swallowed everything. You would also have to be able to move the black hole, which can only be controlled by gravity, which we have no way of artificially creating. We could put a black hole in orbit around the earth, but that would be expensive to use ( $20k per kg ) and might have an adverse effect on low earth orbit satellites. Placing it in orbit near the surface of the earth might work, but you'd need keep the atmosphere away from it. So it would have to be in a large vaccuum chamber. I'm also not sure what effect the moon would have on this, because remember, the moon and the earth orbit around a common center of gravity. The black hole of sufficient mass to be useful would also orbit around this center of gravity and this may prevent you from keeping the black hole stationary relative to a particular place on the earth. So it would have to be a mobile vaccuum chamber. Hmm, maybe this black hole stuff is more trouble than it is worth.{/RAMBLING}
Remember, You are unique...just like everyone else.
"the Walsworth-Lukin team first slowed and then stopped the light in a medium that consisted of specially prepared containers of gas. In this medium, the light became fainter and fainter as it slowed and then stopped. By flashing a second light through the gas, the team could essentially revive the original beam."
Revive the original beam? Now I'm no scientist, but how exactly does one prove such a thing? Call me a skeptic, but isn't that just like taking a pair of dead batteries out of a Furby, switching one of them with a fresh battery, and saying that both of them are providing power again?
IE, if you shine a second light, and SEE a light come out, how can you say that this is a "recharged" version of the original beam?
------
Let me give you the lowdown
"
Using a distantly related but much more powerful effect, the Walsworth-Lukin team first slowed and then stopped the light in a medium that consisted of specially prepared containers of gas. In this medium, the light became fainter and fainter as it slowed and then stopped. By flashing a second light through the gas, the team could essentially revive the original beam.
"
Send light into the lasable medium (ruby/gas/whatver), the quanta are absorbed. Then stimilate (the second flash) and the quanta are released again.
I can see a fair bit of similarity, no?
My physics may be a little rusty so please correct me.
Phil
-- Real Men Don't Use Porn. -- Morality In Media Billboards
Also FatPhil on SoylentNews, id 863
It would render laser speed detection devices obsolete.
This has already done that.
--
I *invented* pants!
It would be fun to find the forest they did this in and have a bit of fun with the future owners...
___
__
Do ya feel happy-go-lucky, punk?
Actually, no. The speed of a photon is always c. However, when a photon is absorbed and reemitted (as happens a lot when you send light throug glass, gasses and any other medium), it will use more time to travel through the medium than vacum.
But the extra time used, it does not spend as a photon - it's spend as absorbed energy in the medium.
As the photon again reemerges, it's got the speed c.
- "mhrg-tap-tap-ping" - famous typewriter, 1846 AD
[http://www.famous-words.com/]
...then switching from a red laser to a yellow one is the surest way to get light to accelerate.
On norwegian television this Danish female scientist was featured doing exacly over a year ago. Its nothing new.
You can't. There can't be anything 'thinner' than vacuum, which by the way is a purely theoretical concept.
c, or 300,000 km/s is the maximum speed of light. Nothing can travel faster than it.
If you mean speeding it up after it's been stopped, I'd imagine you'd just release from the chamber of gas it's in.
For example, rubidium would normally absorb the dark red laser light used by Dr. Walsworth and his colleagues, because rubidium atoms are easily excited by the frequency of that light.
:)
But by shining a second laser, with a slightly different frequency, through the gas, the researchers rendered it transparent.
Ok, maybe I am way off here, but couldn't this leave open the possibility that at some point in the future we could use lasers to render any material anywhere transparent? Imagine shinning a special light at a building and seeing right through it (in the visible spectrum). Gee, the FBI would have tons of fun
From what I gather from the article, the light wave is dimmed (effectively destryed) and its information is stored in the gas. When a second lightray is sent through the gas, it takes on the properties on the wave.
I don't know the article you are referring to, but normally to create a black hole you have to have some pretty extreme circumstances (like the mass of a small mountain (or its equivalent in energy) packed into the volume of a hydrogen atom), this is far beyond anything possible in modern laboratories.
- Kite
`But gravity always wins.'
- Radiohead
It is also possible to measure speeds of light >C in a substance with a frequency dependant index of refraction where some wavelengths of light travel faster than C.
I've hit Karma 50 and gotten a Score:5, Troll... I win!
an object. A thin film containing the rubidium vapor could, in effect, absorb all of the in bound light. And since no reflected light is returned the object would appear extremely dark or invisible.
Could we make it a tradition that instead of useless first posts somebody create a nyt username/password just for a story and post it?
Sneakemail is to spam filters what an ounce of prevention is to a pound of cure.
1st, special relativity (which is what really pertains here) isn't really in dispute. There are very few, very radical researchers who seem to think that its false and their ideas mostly hinge on things of which there is no physical evidece, like gravity waves or such.
2nd, relativity only describes what happens, not why it happens and it accurately describes it. The GPS system had to be corrected for special relativity, particles from space can reach the surface of the earth even though their halflives would seem to forbid it. Special relativity is accurate to any percision we can measure.
When people refer to extra dimensions it is typically with reguard to string theory (a branch of particle physics), not in reguard to the tranimission of light (usually optics).
-nostradorkmus
And if you take just one cooled atom, can you take apart the beam to several places ? And more importantly, does the freezing operation preserve the quantumness of the light in the spins of the atoms ?
Now this surely must be a way to realize super-lightspeed-communications .. and distributed quantum computing .. imagine receiving your SETI parcel in a fridge brought to you by FedEx.
And remember, you read it on slashdot first :-)
I'm still trying to figure out what people mean by 'social skills' here.
You are welcome.. . That reply was fully expected :-)
I'm still trying to figure out what people mean by 'social skills' here.
It was "nearly" the same light so not exactly the same. Memory recorded in medium, new energy causes energy raise and the near perfect memory of the light to be discharged.
that's what David Brin thought, in his book "Earth" ;)
If speed is a change in distance per unit time, you'll need a different unit of measurement if you're trying to describe a change in distance *and* time per unit ... what? "ether"?
I mean... who wouldn't?? How can anyone expect to go that fast and not get pulled over?
c is the speed of light in a vacuum. The actual speed of light is entirely dependant on the material in which it is travelling.
But that doesn't necessarily mean it can't be stopped...
What's this Submit thingy do?
You mean, 'does it lose energy'?
I'm not sure, but I doubt it. It would have to radiate other quanta...
What's this Submit thingy do?
As I understand it, 'space' is a region where there is a net energy level of zero...Perhaps they were able to give it a negativie net energy level?
What's this Submit thingy do?
A 'beam' of light was the path that a photon took...It doesn't have any energy or substance of its own...
Think of it like a trail in an ion-cloud chamber.
What's this Submit thingy do?
Think of a 'beam' of light as a geometric ray. You can block the ray, making it into a line segment, or you can reflect it, changing its direction.
'light' is an amount of quanta('photons' if you prefer) whose position in the 'beam' changes with time.
What's this Submit thingy do?
That's how holographs already work...
What's this Submit thingy do?
>Yeah, but the theorum says that everything else can't move as fast as the light
No, the theorm states that nothing can travel at the speed we call c.
Something to do with rest mass...
Also, when you want to stop light, you have to make c static
Wouldn't that be a photon torpedo????
. there used to be a sig here.....
Iam am afraid I have to disagree with the first statement "Technically taking a quantum snapshot of a photon and then restarting it is ...."
True, an individual particle loses it's individuality and becomes a set of properties.
Quantum Field theory takes the view that all paraticles are destroyed and then recreated to do anything (eg. travell across a room at normal speed)
The question however cannot simply be one of "Is it the same particle?" - with this I completly agree. However, one of the key properties of light is that it travels at c: a statment equivelent with it bewing both "real" (ie not a figment of our imaginations) and massless. One of the properties associated with being a photon is always travelling at light speed.
(Before I get "jumped" on by peopel talking about other "slow light effects" such as refraction, the average speed of light can be less then c, as propogration through a medium will cause the light to be absorbed and reemitted. When light is propogating between emissions, however it still travels at c)
You cannot slow light down - this is just stopped and started light.
I can imagine this being useful, especially if they can paint a car with some sort of light deadening material. It would render laser speed detection devices obsolete. These days with radar detectors, police radar is becoming obsolete. This could do the same with the laser devices. But then the cops just might say screw it and lobby congress to install computer chips in everyone's car that automatically sends the speed to a reciever on the side of the road....
I want my rights back. I was actually using them when our government stole them after 9/11.
Not really. To use Star Trek terminology (yeah, don't shoot me cause they got it wrong), you could use it as an Optronic data stream for long range holographic transmissions.
Javascript + Nintendo DSi = DSiCade
Here is a link:
http://rd11.web.cern.ch/RD11/rkb/PH14pp/node26.htm l
"Obtuse Anger is that which is greater than Right Anger" - Lewis Carroll
As i understand, they slow it by putting it in a denser medium. So to speed it up, they would need something wich is thinner than vacuum. How would you do this?
use Bielefeld.pm
Does this say that if we manafacture a material with permitivity less than that of vaccum, then light can travel faster than the so called Cosmic limit?
I am most definitely not a physicist, but I was always under the impression that "time" does not exist -- it's a measurement that human beings have imposed on something that we don't understand. Now I know I'm getting a little metaphysical here, but does a dog have any concept of what "time" it is? I doubt they do, so can we then extend the same concept to light? How could light possibly interact with time, when time is something that we have imposed on light? Isn't it a flawed theory to begin with?
---------- You are not the contents of your sig.:-p
Imagine a Beowulf cluster of those!
There! I said it! Ha!
OK,
- B
--
http://www.bradheintz.com/
- updated
but still it have some specifications, such as frequency, which are kept with the beam.. so, with a (theorical) large amount of beams into the same container, will they be able to store 'informations'?
just a thought
-- There are two kind of sysadmins: Paranoids and Losers. (adapted from D. Bach)
will they be able to 'store' a beam of light and keep it? how much storage space will they got? :)
-- There are two kind of sysadmins: Paranoids and Losers. (adapted from D. Bach)
Boy, is Einstein gonna be pissed!!!
I'd rather be a unix freak than a freaky eunuch
Ewige Blumenkraft!
There is more about Dr. Hau's methods in an older article. A bit of the method as well, they are using Bose-Einstein condensate as the medium.
So that's how you make a light saber!!!
DO NOT SEEK THE TREASURE!!!!!!
It is funny to see a moderator (with probably no more than a high school "physical science" understanding) marking down a point in the post above from a theoretical physicist (grad school, Brown).
For a hologram, you really want to reconstruct the original light (with same phase and amplitude). If you stored the light itself and released it later, you would have a read-once hologram, of dubious usefulness.
Quoting macpeep: If photons move in both the direction of time AND in some 3D spatial direction (with the speed C), then their total speed is HIGHER than C, isn't it?
:)
you're absolutely right...C++!
--
Gosh, thanks. That must be why the other ships call me Meatfucker -- GCU Grey Area (Eccentric)
maybe I'm way off here (I'm not a physicist)but there seems to me to be sort of chicken-or-egg problem here...
Astronomers use spectrum-analysis to figure out the speed and constituants of bodies and regions in space (doppler-effect and all that).
But if gasses, or any matter, that these photons penetrated before reaching earth, influence the speed of these photons, what conclusions can you safely draw?
You don't know exactly what matter the light might have passed (because for now the only way to figure that out is spectral analysis)!
regards, EK
--
Gosh, thanks. That must be why the other ships call me Meatfucker -- GCU Grey Area (Eccentric)
So here I am sitting at the console to the Deep Thought and we get a programming error - light beams going everywhere. We stop the program, you know, /usr/bin/Life_the_Universe_and_ Everything.ksh, and rerun in the cool light debugger, get to the offending photon, then just tweek its parameters by adding a subtle disturbance in the eddy current of its existence. Give it the Go laser, and a new planet is instantiated. We're running again. The Mice will get a whooping maintenance bill for this.
The speed of light is set by the ISO standards people as something to do with the oscilation of electrons in some noble gas. (I'm sure someone can furnish the twiddly details) Every so often, like every few months, some scientist refines this number by a few decimal places, and so c has become the classic "variable constant".
It's one of the reasons I hate the metric system; King Edwards feet were good enough as a constant for a thousand years! How did a system started by Napoleon, that defined the earths circumference at 1 million kilometers become the basis for todays standards! :)
Jeeze, where have these guys been? Drizzt Do'Urden has been doing this since he was 12 years old.
'Same speed C but faster'
Is this a generation of new bombs? I.e. what happens if I fill the medium with an enormous amount of `light' and release it?
Excuse my ignorance.
I have a cool sig too.
Earlier people have mentioned about using it as encryption or as storage of some kind.... I know that you cannot read both the location and velocity of an electron (maybe that's irrlelevant) but is there a way to read the quantum state of the particles other than I guess shining a light at them to see what light comes out the other side... And what about just shining light at gasses like this to find out stuff about their quantum state before using light to interfere... does this serve some purpose perhaps???
--------------------------------- Born Again Bourne Again Believer: New Life, GNU/Linux Be Free!
A few years ago, one of the car manufacturers came up with the idea of a 'light engine' that would produce all the light the car needed and then pipe the light around via fiber optics where it was needed. It never caught on.
This ability to stop light opens the door to being able to store light in a container, releasing it later when needed. In 'light' of the huge amount of power that is used to produce illumination in advanced societies what kind of energy savings might be enabled by this kind of technology?
Actually, we don't even have to stop the light, if we could create an 'optic pipe' that contained the light-slowing gas in such a way that it took 12 hours or so for the light to get from one end to the other, this would create a device that 'stored' light during the day and emitted it at night. Just about the time that the last of the light got through the pipe, it would be morning again. A solar concentrator could be used to focus intense light into the pipe and the pipe could be funneled into the afore-mentioned 'light engine' idea. This strategy might be used to allow solars cells to produce light 24 hours a day...
Of course, the economics of this may make it prohibitive. I seem to remember a requirement of extremely low temperatures in relation to slowing light with cesium gases.
(Heading off to the Patent Department now...)
OK, I'm surprised nobody has asked this, because I'm sure we're all thinking: how many MP3s can you store in a beam of light?
When light is 'stopped', does it decrease in intensity after a while or can it just be stored indefinitely?
Moz.
see a Text Widget
Light for us may consist of -charged particles, flow=path of least resistance, entering sodium chamber inhibits flow, charge transferred to spin of electron shell, not adding or subtracting from that shell. Thus the light stops. Flash a laser throught this (soon to be perfect)4 demensional storage medium, the 'memorized' spin is then imparted into it, revealing what was stored. When they realized magnetically 'pumping' will restore the original beam, THAT will be soon, I hope. Are you getting all this?
I don't follow the whole black hole logic. Primordal black holes, while a pet theory of Prof Hawking have yet to be actualy proven to exist.
That nonwithstanding, I don't see how light, even slowed to a stop could create a black hole. Hmmm... let me see if I can explain. Einstein reasoned that the reason "c" was the universal speed limit was due to an increase in mass as speed increased. I.E. an object moving at light speeds will have an infinite mass, consequently, the ammount of energy needed to accelerate it TO light speeds is also infinite.
Now we reverse the logic. Partical wave duality is something we all (should) have learned in highschool. For our younger readers, this states that light behaves both as a wave form and as a partical under some conditions. Photons are interesting because they behave as both a wave and a partical and are thus exempt (through some legal technicality) from being ticketed by the physics police. So we can consider a photon to have, rather than a mass of zero, an infinitely small mass.
The difference allows the photons to behave as particals and waves. My question would be, however, do the photons retain their duality when stoped. If so, this entire rant is for naught as it would demonstrate that the duality is velocity independent.
Killfile(TGK)
No trees were killed in the creation of this post. However, many electrons were inconvenienced.
speed of light is 299,792,458 m/s. SI definition of metre is distance traveled by ligh in 1/299 792 458s
ok... as i thought, light was both wave and corpuscle (photons).
so what happens, if u stop the wave aspect of light: energy should go somewhere.. is it dissipated in the environment (the article says a new ray is needed to unleash the stored light), or is it stored in some mass modification of the photon (which appears to me as very odd).
and i didn't understand at all the stuff about quantum computing and so on. as i remember, the problem is that we can't go faster than speed light in a totally empty space (c=300 000 km.s-1). the problem for computers in then that to go faster, we have to use some quantic mechanic theory, or use the wave speed, that can be faster than speed light, because in fact it isn't speed of a corpuscle...
pfu.. i studied some physics years ago, and i think the NY Times article is a bit empty... could someone aware of what those scientists have done give the details ???
Pardon the almost assuredly redundant nature of this comment... (In "too much" of a rush to read down to 1, but feel it's important enough to say)
When light passes through glass, it is almost always absorbed and re-emitted, in other words, the original photon is converted into excited electrons, and then the excited electron('s energy) is converted into a photon that is ludicrously similar to the original. I never understood why this re-emission was at the same angle, but that's partially because I never really studied optics...
the point is, that transmission through -any- transparent surface is the destruction and recreation of light
What this break-through seems to imply is that they can hold light (relatively unchanged) for a significant period of time. I don't know the precise nature of the phenomenom, but at least it shows the theoretical possibility of optical transistors, which could quite possibly contain more information than on or off (depending on how precisely identical the new and old light are).
though, as is typical with big science news, they sorta tag on "it's for quantum computers" with positively no explanation... I don't know enough about QComputing to interpret this result as significant... *shrug*
They said they needed another light beam to release the stored one, but can they store more than one beam of light in the stored chamber? Or would putting a second beam through always restore the first? And if it is possible to store more than one, the amount of information that could be stored would be amazing. - picoears
It seems to me that they aren't slowing the light so much as absorbing it a few photons at a time as it passes through the gas, with the resulting spin states in the gas atoms retaining information about the photons. When they read it out with the second pulse they aren't getting the original photons with the same properties. I think this means that the coherence of an entangled state would be destroyed so it couldn't be used for quantum computing.
I'm guessing it has to be such as low temperature to keep the atoms/ions from moving about too much.
:)
If so could you find similar conditions in deep space? Assuming you could find a cloud of rubidium or sodium atoms, would they trap or slow any incoming photons? I guess it would only work with atoms, not molecules. Perhaps helium, but I don't know what wavelength of radiation would work.
I'm not sure that it would have any practical use or exciting properties, but a ridiculously far fatched possibility is that an intelligent gas-cloud organism could evolve in deep space, with an optical "nervous system". Now there's a ST Voyager plot if I ever heard one !
This is not a sig
It does, but no-one remembered to make c final so it's a variable.
Right. What we know as the supposed physical constant of C is actually the mean (?) value of a series of observations. I believe the "true cosmic" maximum speed of light is somewhat (fractionally, I'm sure) higher.
- Capt. D
The speed of light (c) is considered to be a barrier. This means that nothing below c can reach the speed of light and nothing moving with a speed more than c can go down to c. I was just informed about these two experiments and I must admit I wasn't surprised. I've also heard about another experiment at the MIT, in which a beam of light was speeded up to 2c and rumours about it being pattented after 5 years or so (unless someone buys or kills the researchers who dit it, of course!). Furthermore, there have been very serious indications (if not proof) that the light in space doesn't travel with the same speed in all directions, but seems to travel at a higher speed in a specific one. ...which enhances my theory...anyway...I believe that speed is only a relevant means of
understanding (up to a point) the relationship beween space and what we call "time". Neverthless, there have to b inserted many mor dimensions into the game, to get things a little more clear and the bad thing is that they can only be approaches with higher mathematics an not by observation/comprehension, cause we're only 3-4-dimensional beings.
Well, I only hope these experiments will not be burried and become the begginning of at least reconsidering some things about relativity. .-
I believe that YES, it's more likely that this experiment (2c) never took place, but it would not be surprising if it has to be kept secret, for obvous reasons, even from those who work at the same institute. I'm not trying to say anything here, just speculating. May it happened, may it did not. But even if it did, you may not know about it, even if you're working at the MIT. Or you may well be trying to cover it from public exposure (which would be the right thing to do in such a case, really). For me, such experiments, do not even come close to be the tip of the iceberg. We don't know anything about experiments that have happnened and they're trying to keep secret.
Sorry about the mess with my copy & paste!
That is, isn't the speed of light supposed to be constant? If you can slow, or "stop" light, then what happens to things like e=mc2? What about all that highschool physics mumbo jumbo about turning on the headlights of a car going at the speed of light? My head hurts, some help! :-)
Charge a rubidium gastube with photons for some hours and you got yourself a homemade photon bomb!! How much light can the rubidium gas absorb?
If you are asking if Cerenkov radiation breaks the theory of relativity, it does not. For those who don't know, Cerenkov radiation is a phoenomenon (spelling?) visible in nuclear reactors. What basically happens is the nuclear reation puts off many beta particles that have a LOT of kinetic energy. In fact, their speed exceeds the speed that light can travel underwater. This causes them to polarize the water molecules which, in their re-orientation, emit a photon. The wavelength varies with the medium, but it water the photons are in the upper-visible band with a bit of UV, creating an eerie purple-blue glow. It's quite a sight. But getting back to the presumed question, since the particles do not exceed 200,000mps, they do not exceed the speed of light in a vacuum. Therefore, from what little I understand of relativity, it seems to work out.
These experiments appear to be creating long-lived absorptions of the incoming light, followed by decay of the excited state by the second laser beam. In fact the article even mentions that the incoming light is effectively stored in the spin of the gas. A great leap forward for atomic gas physics, but a far cry from modifying the fundamental structure of space-time!
One of the reasons why this is exciting, is because it demonstrates large scale QM phenomena.
I would look for the body.
But you are right, for interference phenomenae to work the way they do, you need to have identical particles.
But this is important only if you want to understand how their clever trick works. (And you need to know more -- you mostly need to know electronic energy levels, what transitions are allowed, and how waves can interfere.) Understanding the importance of the result is simpler. Light has two properties: polarization and momentum. For a particular band of momentum (corresponding to the Rubidium line they are using) the polarization state is effectively recorded into the atoms of the vapor. And this is what is used in quantum encryption, "teleportation", and other newfangled ideas.
Of course, the atoms will lose this information as they collide with each other and the vessel walls, but for a thin vapor the time scale for this is over a microsecond which these days seems like an eternity.
Recording polarization may sound simple, but it's not. And this is an indirect recording... you can't look at it to tell what the state is, but the state is preserved. I do have a clumsy explanation which hopefully some readers may be able to decipher:
You know light can be linearly polarized.. horizontal is x, vertical is y, diagonals go like (x + y) and (x - y), etc. Well, if someone hands you a beam of light, you can measure the polarization of it with a sheet of polaroid. Perpendicular to the plane of polarization no light is transmitted, parallel almost all gets throught, at 45 degrees the intensity is half. So, this seems easy.
But how do you measure the direction of polarization of a single photon? The answer is: you can't. The beam of light is an ensemble of photons that are (by assumption) in the same polarization state. When we hold it diagonally, we see 50% intensity because each photon individually has a 50% chance of making it through or being blocked. When we have say 1e6 photons, we can see that 5e5 made it through and say, ah yes, we are diagonal. But if we have only one photon to go on, it either makes it through, or it doesn't. So if it makes it through, the polaroid may be aligned to the polarization, or it may be any amount off. All that we do know for sure is that it is not perpendicular.
Also, add to this an additional subtlety that coefficients describing polarization are actually complex. e.g., you can have have a polarization in the direction (x + iy) which may be circularly polarized clockwise. (x - iy) would be counterclockwise. For this light the probability of being transmitted is 50% no matter how you orient the polaroid. But I digress... The point is, quantum mechanics is a wonderful description of the world, and this new trick will be very helpful in taking advantage of quantum mechanics in engineering applications.
um. you just solved the RIAA problem.
:)
Soon, all music will be distributed this way. You will only be allowed to listen to that Madonna single once, and one time only, for each $5.00 automatically extracted from your bank account
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
The problem is that as time go on, this artificial blackhole gathers mass, and by gravitational pull, attracts more mass, until it goes nova.
That could be a problem while driving your car.
Karma karma karma karma karmeleon: it comes and goes, it comes and goes.
you would have a read-once hologram, of dubious usefulness.
Not to M.I.A. agents...
Karma karma karma karma karmeleon: it comes and goes, it comes and goes.
That makes no sense...
It was either Faraday or Maxwell... or somebody else around there which did some work which strongly indicated that c was a constant. Looking into that is on my list of things to do... this work prompted Michaelson and Morley to perform their experiments showing light moved at a constant speed in all directions.
And if you're interested in the "cosmic" speed, there were those pesky calculations involving the speed of light based on the orbits of the moons of Jupiter. This leveraged the width of the earth's orbit against Newtonian physics and the observed position of Jupiter's moons. Not horribly precise, but nothing is known to an infinate number of significant digits.
The constant 'C' is defined as the speed of light in a vacuum, as one poster here worded it so eloquently, the speed of light in different medium is due to absorption and retransmission.
But I'm only saying that 'C' is constant. I'm not saying what 'C' is. Just like PI is a constant, only known to a million or so significant digits (in an unaccelerated reference frame).
Stopping a photon is probably just some media spin.
I hate it when somebody says something irrefutable. And here I was trying to avoid somebody splitting hairs by telling me that pi was not a constant depending on your reference frame.
More precisely, the ratio of the circumference into the diameter of a circle varies in an accelerated reference frame regardless of the position, velocity or acceleration of the observer. That is an important distinction, I'm glad you pointed it out.
It would be obvious. The subject would continually complain about having his "molecules scattered about the universe," and perpetually goad his more logical, scientific colleagues with illogical references to emotion and heritage.
I can see the fnords!
Yes, and not necessarily for recording. In fact, I think it would lend itself more to spectroscopic analysis, especially at low light levels. Freeze light as it enters, integrating signal until you've collected enough to build up a useful signal to noise ratio. And the extremely high indices of refraction in the materials used would give you all the spectral resolution you ever need. Add a third dimension using holography and you have enough basis to do solid state hyperspectral imaging.
A big problem with spectroscopy and spectroradiometry is that when you get high spectral resolutions, you need insanely high signal to noise ratios, on the order of 10^3 or even 10^4, to do chemical analysis. This kind of phenomenon allows you to increase your signal without adding noise (well, beyond the inherent Poisson noise, N = S^0.5).
I can see the fnords!
Yes, and you can also get 'zero point enegery' from it, which is basically infinite energy free of charge. On the other hand, you might literally 'pop' the space-time bubble of the universe, like someone inside a balloon tunneling out of it to the low pressure outside. If you did that, the entire universe would be destroyed as the faster-then-light repressurization wave swept over it. So it's not really that great an idea. ;)
-David T. C.
If corporations are people, aren't stockholders guilty of slavery?
--
Okay, two questions...
1: (not FTL, but I'm curious)
Suppose you have a particle that has a 50% chance of changing state after time T. Actually, suppose you have two such particles, identical, entangled. (I may be talking out of my ass here- I don't know if particles can degrade like atoms do or if entanglement can work at the scale of a whole atom. IANAP.)
One particle goes on a near-lightspeed journey and comes back. The other particle doesn't. Time dialation applies. The age of the travelling particle is less than T, while the age of the particle that stayed home is greater than T.
So when you measure one of the entangled particles, is the probability that the particles have changed state higher or lower than 50%? Does it matter which one you measure? Is it even possible to send only one of the particles on a two-way trip without breaking the entanglement?
2:
Suppose you want to send one bit of information to Alpha Centauri. You need it to get there FTL. Fortunately, the Grays have a space station roughly half-way between Alpha Centauri and Earth - but slightly closer to Earth - that regularly sends out a pair of entangled particles, one to Earth and the other to Alpha Centauri, at the speed of light (or as close to it as possible).
One of these entangled particles reaches Earth. You measure either it's momentum or it's position, depending on whether you want to send a 0 bit or a 1 bit. Shortly thereafter, the other entangled particle reaches Alpha Centauri, where they attempt to measure it's position.
According to the uncertainty principle, the more you know about a particle's momentum the less you know about it's position, and vice versa. If you've measured one entangled particle's position, the good folks at Alpha Centauri should have no trouble also measuring it's position, right? On the other hand, if you've measured it's momentum, the other guys shouldn't be able to measure their particle's position, right? If it is possible for the folks at Alpha Centauri to determine whether or not the measurement was successful then they have received a bit of information from you that traveled at just under twice the speed of light. I suppose it is not possible for the folks on Alpha Centauri to determine whether or not the measurement was successful? Would they just get a measurement and be unable to determine it's accuracy?
Basically this discovery exactly remembers a
pattern of light and replicates it.
This memory device would be entirely optical
and fit into photonic computing systems.
I'd guess density would be pretty good.
The other optical memory schemes I've seen
involved continous loops, set and read.
Another is holographic alteration of material
optics.
In theory, there is already a non-zero possibility that as you read this you will be spontaneously teleported in entirety to the inner ring of Neptune. Unfortunately, the problem with this is that the probability of this happening is of course so astronomically remote that it will never happen anywhere in the expanse of the universe within whatever lifespan the universe may have. So the only way we would ever achieve teleportation of a complete human-sized object would be if we found some way to modify the quantum probability of where an individual particle's position ends up, so that we could say with certainty what the end position would be in order to keep every particle in a human together, while at the same time, keeping the human from exploding in a huge burst of particles flying in every direction. In other words, we have to find a way to violate everything we've found to be true about quantum mechanics, but keep your fingers crossed, I have hope. :)
The Phys Rev Letters paper will be available online (though isn't there yet) at:
http://link.aps.org/abstract/PRL/V86/P783
The official citation is Phys Rev Letters, Volume 86, p. 783 (published 29 Jan 2001).
Energy: time to change the picture.
gravitational pull, attracts more mass
The problem is, a black hole would need to be awfully large to have more than negligible gravitational attraction.
Black holes only have as much attraction as the mass they contain. A black hole that weighs as much as your car is going to have the same gravitational attraction as... your car. How much gravitational attraction does a skyscraper have? (Negligible.) How much gravitational attraction does an aircraft carrier have? (Negligible.)
A black hole would have to have tremendous mass to make even the slightest effect on nearby objects, and then you still have problems because black holes are incredibly dense - which means even "large" black holes are going to be incredibly small (if I remember correctly, a black hole with the mass of the Earth is about the size of a marble - how small is a black hole that only has the mass of an aircraft carrier?). How much matter it can consume is limited by the size of the black hole.
Not to mention, too, that Stephen Hawking proved that black holes do give off some radiation, and thus will shrink if they do not consume enough mass to stay stable (and if they shrink past a certain limit, they simply explode).
--
Eavesdropping by definition means a third party listening in on a conversation between two other parties.
With quantum communications, any intermediate listener would cause the signal to be modfied (or garbled) and one party would know the conversation was tapped, hence, they are no longer eavesdropping...
I seem to recall this idea being discussed in the very first Star Trek novel, "Spock Must Die". It was a very chilling concept in the context of a world where matter transporters are common.
I haven't read the book in about 20 years, but a lot of the philosophy behind your topic is discussed in it, since the story revolves around a transporter accident.
Rick "Putting Plastic Pointy Ears Back in the Drawer Now" Gutleber
You are in a maze of twisty little passages, all alike.
No need to actually register yourself into their spam machinery.
-----
nuclear iraq bioweapon encryption cocaine korea terrorist
No,
Light IN a vacuum moves at a MAXIMUM of C - It CAN and does move slower, especally in other mediums.
-- 73 de KG2V For the Children - RKBA! "You are what you do when it counts" - the Masso
I forgot to mention one thing.. If photons move in both the direction of time AND in some 3D spatial direction (with the speed C), then their total speed is HIGHER than C, isn't it?
Comment removed based on user account deletion
208.48.26.217 www.nytimes.com
Actually, that's not true. The speed of light in a vacuum is exactly 299,792,458 metres per second by decree.
Unfortunately nobody remembered to make the length of a metre final.
sub f{($f)=@_;print"$f(q{$f});";}f(q{sub f{($f)=@_;print"$f(q{$f});";}f});
Anyway, my REAL point: what about heisenberg's uncertainty principle? As the photon slows shouldn't it's position become more and more indeterminable? And when it stops, how do they know where it is?
Except that we're not dealing with a single photon, but a sea of photons. The only times we've ever been able to monitor single photons is when they've collided with a photo-cell. We could say, yup, there it was at that moment in time in that exact place, but good luck finding that particular photon ever again.
-Michael
-Michael
Well, first of all this is speculation into the realm of sci-fi.. We have no technology even close to what it might take, so all we can do is look at new discoveries and contemplate the possibilities.
In this case for example.. What we seem to have is the ability to "capture" the quantum states (mainly the wave-front) of a volley of photons inside the spins of gaseous atoms. Essentially this sounds like taking a picture of the macro-scopic cloud of light, then reanimating it. Well, to my mind that's a building block towards teleportation of any type. In this case it's really only a time-shifting. But the fact that the information was reproduced amid the regular quantum fluxuations is astounding enough for my imagination to go active.
In my comment, I even went so far as to discount amplification of the information signal (which essentially rules out almost any form of analysis, which would include information dessimation that would otherwise violate Hisenburg's principle). The "signal" in my mind was such a photographic plate as this gaseous stop-light. That this concept could ever be applied to anything other than light is pure speculation - albeit a fun one.
-Michael
-Michael
Untrue. Electrons don't have event horizons -- classically speaking, they're "naked singularities"
The key being classically speaking. I tend to champion string theory which suggests that there are no such point-like singularies. Among other things, it gets rid of the paradoxes when combining gravitational relativity to quantum physics. My Information comes from "The Elegant Universe" by Tom Green. So take that as you will.
I believe that how they capture photons in the first place.
No, it's definitely not a gravitational effect..
Never mentioned gravity. Einstein showed that all forces are indistinguishable, and string theory suggests that at the right temperature and pressure, they are litterally the same force.
Each force that is attractive to another paticle has an event horizon, provided that repulsive forces do not counter it. Gravity is obvious, but charge is the same, assuming they are attractive. Likewise with the nuclear force (at least the strong one; I don't really understand the weak nuclear force, though it's been tied into electro-magnetism).
As for a lack of ability to escape the event horizon. There is already a strong belief that quantum particles radiate away from the horizon through quantum fluxuation (black-body radiation). On a smaller scale, the fluxuations are significantly more likely to have a profound affect.
String theory doesn't really say much on this topic, so I'm really just speaking out of my hat.
Actually, string theory suggests that there fundamentally aren't such things as particles, just strings.
Particle does not necessarily denote shape.. Singularity would be the correct term for classical quantum particles.
Additionally, there are branches of string theory that suggest the existence of multi-dimensional undulating blobs. I believe M-theory takes care of all of this, so a multi-dimensional vibrating particle would probably be the best generic description.
From the book, mass was really just a side effect that is completely cancelled out in the case of bosons. Whether they're initially massless or massive is just a frame of reference; duals like the wound and unwound string.
-Michael
-Michael
The book is by Brian Greene, not Tom Greene.
Perhaps I should qualify, from memory, and then specify when I'm leaving the book as a source of reference.
You seem to have gotten some mistake impressions from Greene's book, though
Well, the event-horizon stuff isn't in the book; that's for sure. (At least not for anything other than classical black-holes).
But I don't think that really distorts the content too much (assuming that I'm wrong, which I'm not convinced that I am).
-Michael
-Michael
This is another case of the NYTimes screwing up the technical details and making something have totally different implications than one it sounds like. They are NOT stopping light AT ALL IN ANY WAY. I like the NYTimes, but the BBC reports this tech stuff better. They are not stopping light, just copying it's parameters into the gas, then recalling them.
Read the posts by zCyl and Ferzerp to see why.
in saying it's a snapshot, i mean, information of the light is stored and new light is emitted from that information. The article states that the light exitting the device does not have the exact same characteristics of the light entering. So, it is changed.
One of the practical problems with quantum encryption is that the receiver must receive the same photons that were sent by the transmitter, or the message will be undecipherable. No repeaters can be used. (Repeaters are used to maintain the strength of optical signals over long distances.)
If the beam could be reconstructed with a higher intensity than the original beam, but the same properties (spin etc.), stop-light chambers could be used as repeaters for quantum-encrypted signals.
So they use the glass in the wall of a bathroom to make a nice calm peacfull setting. What hapens when they house is sold? or 20 years in the future you get to watch some guy take a leak.
These people looked deep into my soul and assigned me a number based on the order in which I joined.
The speed of light in a medium is inversely proportional to the refractive index of the medium. The refractive index of air is about 1.0008, of water is 1.33, of quartz is 1.54, and diamond is 2.42. When light crosses a boundary between media with different refractive indices the path changes (Snell's Law).
As far as relativity is concerned, this doesn't cause any problems. Relativity only says you can't go faster than the speed of light in vacuo. As others above have pointed out, Cerenkov radiation is emitted when particles exceed the speed of light in a medium - those particles are not exceeding the speed of light in vacuo. Relativistic mass gain is due to velocity, not acceleration (review those Lorenz transforms). A (relatively) easy way to think of this is to view the Lorenz transforms as mathematically compressing Newton's mechanics so that what Newton would have called an infinite velocity is instead perceived as the speed of light. Think of taking the straight line from velocity = acceleration * time (Newton's model) and bending it so that it approaches the vertical speed of light line asymptotically (special relativity). Some extremely counterintuitive things occur, but they have actually been observationally verified. (Now I'm rambling, too, so I'll stop...)
"Bite me, it's fun!" - Crowe T. Robot
From my understanding of that work it was not intended to actually create black holes, but by slowing light down enough you could create a vortex in the material that would suck the slow moving light in, in the same way as a black hole.
This would allow lots of interesting studies of the effects, and would be a lot safer (read: less terminal) than actually creating a black hole.
This was from a New Scientist article relating to the same research.
Lots Of Love
Bill
I just hate it when my car goes critical, and there ain't a service station for miles around....
---
Good judgment comes from experience.
Experience comes from bad judgment.
You know what this means.
It is now possible to say that everyone has performed the miraculous feat of Faster-Than-Light travel!
---
Good judgment comes from experience.
Experience comes from bad judgment.
But uhh yeah, like has been said, velocity is a measure involving time. My stupid way of thinking is velocity measures the change of everything else, xyz, in fixed positions of time. So would moving in time measure (eg) zyt, in fixed positions of x?
Head hurting...
Good thread btw, I'd mod it up if I could
Of course, that might cause a cool quantum fishbowl effect . . . think of the sci fi applications. :)
funny munging
Correct me if I am wrong, but are they not, in essense, just taking a snapshot of a photon and then recreating it?
According to the Heisenberg Principle, that's not possible. If they had 'taken a snapshot' that would have serious ramifications for the way we perceive the world... (insert beethoven's 5th)
Hmmm. Artificial black holes, eh? Would make nice portable garbage disposals, wouldn't they? So, assuming black holes exist in all sizes, you just create a "quantum" black hole, then put it in a mason jar large enough to be just beyond the hole's event horizon. And with the intense radiation from the hole's perimeter, you could also attach a steam turbine and power your car or PC off it.
I smell a new startup. Venture capital! I need venture capital!
Correct so far.
This means that when moving from a medium into one in which the speed of light is slower than the first, the lightwaves/photons (whatever) need to release some energy, (As energy=hf, and f=speed of light/wavelength [sorry, couldn't find lambda sign]so there would be a difference in energy after going into a "slower" medium) which is given off as, I believe, flashes of visible light (yes?, no? maybe? I'm unsure)[Also, then how does light speed up going into faster media? Does it? What accelerates it if it does? Anyone?)
When moving into a denser medium (as in one with a higher index of refraction so it slows down the light travelling through it), it's wavelength is also shortened. It's frequency, however remains the same. Since f=v/wavelength, and v and wavelength are both reduced by the same factor (to do with the ratios (ratii??) of the refractive indices of the two media), then f remains constant.
Another way to see this is to think about the light wave as it enters the medium. Imagine the peaks and troughs of the wave as they cross the boundary. For each peak entering, there must be a corresponding peak leaving, hence the frequency remains constant.
When light enters a medium in which it can travel faster, the inverse happens. This still doesn't break any rules about faster then c, unless you go from a vacuum, to something less dense, but I guess that ain't possible.
As far as flashes being observed, these are simply due to the fact that as the light crosses a boundary between two substances with differing refactive indices, some reflection occurs. This reduces the intensity of the light, but does not affect the frequency. This leads on to things such as antireflective coatings, where you go through intermediate layers to 'soften' the effect of reflections, to things such as impedence matching in wires (hence why some people spend money on 'matched' cables for AV systems, trying to improve quality by reducing reflections along the cables).
Or something like this.
Banni
It does, but no-one remembered to make c final so it's a variable.
Nothing is immutable - except flux.
This reminds me of the "slow glass" stories. For the uninitiated: Slow glass is just like regular glass but the thicker it is, the longer it takes for light to pass through. So for a 1 inch thick piece it may take, say, 20 years. They put the glass out in the forest for 20 years, then install it in a house. Now the inhabitants have a 20 year forest scene streaming in the window. Other stories put the glass to other uses.
Anyway, my REAL point: what about heisenberg's uncertainty principle? As the photon slows shouldn't it's position become more and more indeterminable? And when it stops, how do they know where it is?
--
MailOne
Non-meta-modded "Overrated" mods are killing Slashdot
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Cerenkov radiation, I think
First off, c is the speed of light in a vacuum, and light travels at differents speeds in different media. This means that when moving from a medium into one in which the speed of light is slower than the first, the lightwaves/photons (whatever) need to release some energy, (As energy=hf, and f=speed of light/wavelength [sorry, couldn't find lambda sign]so there would be a difference in energy after going into a "slower" medium) which is given off as, I believe, flashes of visible light (yes?, no? maybe? I'm unsure)[Also, then how does light speed up going into faster media? Does it? What accelerates it if it does? Anyone?)
(mmmm, a bit offtopic, aren't i?)
Relativity (or some part of it anyway) means, at least for this case, that nothing can travel faster than the speed of light in that medium. And most massive objects (like ships) cant come anywhere near close. Please, correct me if i am wrong, but as an object (not light) accelerates toward fairly fast speeds (or velocities, if you prefer, but I just want the scalar) it gets more and more massive, and hence acceleration gets harder and harder (a=F/m)
Very much out of my depth here, considering only formal education in physics so far is high school level, but does the above have anything at all to do with the wave behaviour of non-light particles? I mean, how can an object gain mass due to acceleration, unless looking at kinetic mass (?) being calculated by energy and velocity, energy being calculated by that formula given above.
Please correct me, i am rambling. May as well mod me down now.
Why yes, all my base are belong to you.
How did you guess?
So what would happen if you dropped your black hole? Would it careen through the planet, slowly gathering mass until it got big enough to do some real damage?
Except that relativistic velocities are not simply additive... v_net != v_1 + v_2. Rather, v_net = (v_1 + v_2) / (1 + v_1*v_2/c^2). That way, even if v_1 = v_2 = c, the equation becomes v_net = (c + c) / (1 + c*c/c^2) = 2c/2 = c. At speeds that are not a significant fraction of c, the equation gives v_net \approx v_1 + v_2, as the denominator is approximately 1 (well, 1 + epsilon, which as we all know, is 1).
Your flaw is trying to add things with dissimilar units... when you consider time as a fourth dimension, you are really doing calculations with ct (a length), not t (a time). That way, you can express the distance through spacetime as ds^2 = (ct)^2 - r^2 (or r^2 - (ct)^2, depending on which metric you use).
Eric
Eric
Would it be possible to create a huge bose-einstein condensate, break it in half and flatten it out?
If so, then you would merely need to transport the two 'gateways' whereever you wanted and teleport between the two locations.
The theory being that when you walk into one of the portals, your entire quantum makeup would be absorbed and transmitted to the other portal because of quantum entanglement.
Anyone think this would work? How would you stimulate the portal to 'release' your energy?/ declaration.html
http://www.nara.gov/exhall/charters/declaration
http://www.nara.gov/exhall/charters/declaration/d
http://www.nara.gov/exhall/char
Think about a football field that is 100 meters from end to end. Now think of a guy that runs in a straight line from one end to the other, along the sidelines. If he runs 10 meters per second, it takes him 10 seconds to run the entire length of the field. Now make the guy run from one corner to the other. He still runs at 10 meters per second, but it will take him more than 10 seconds to reach the other end. By spending some of his motion in the width-direction of the field, his motion in the direction of the length of the field becomes slower.
Think for a moment that time works just like a spatial dimension. You have a specific absolute speed in a specific direction.. time. When you start moving to some spatial dimension (one of the three traditional ones), your motion in the direction of time becomes slower because you are no longer fully "commited" in that direction.
Now think about photons. They move with ALL of their speed in some spatial dimension. Does this mean that photons stand still in time? If you slow down light, does this mean that time actually starts ticking for them? Could it be that the fading of the light has something to do with the fact that time runs for them? If they are in an absolute vacuum, light doesn't fade because time stands still, no matter how far you shine the light. Introduce "dust" and it slows down and fades.
I'm sure my theory is very flawed but I'm not exactly sure at what point. I mean time DOES slow down when you move, but am I looking at this the wrong way?
I wonder if this could also be used for holography
:) At first glance, I can concieve of doing with this as people have hypothized about quantum computers.. Send encryption keys that can only be read once down a fiber line, etc. The stumbling block I see here is that only the gas medium holds this property.. Transmittion down the fiber is still subject to existing hackability. But perhaps a short-distance "secure" channel of gas could be used?
:)
Better yet, it could be used for read-once messages. Albeit bulky and not as cool as flash-paper, or exploding sun-glasses.
Maybe not..
-Michael
-Michael
Even an electron has an event horizon, when the radius is small enough.. I believe that how they capture photons in the first place. Isamov's black-body radiation probably explains how the photons escape.
Light travels at different speeds in different mediums (due to permiability and permittivity values), so in a very slow probagation medium, it's possible that quntum particles get a boost in the sizes of their event horizons.
Of course this has little to do with the capture of other _atoms_ which is what initiates the common concept of a massive black hole.
It might be possible to pack so much energy into a quark that it's event horizon could capture another fermion. But of course it would be so "hot" that it would break through just about anything.
In theory, you could boost a particle with enough photons simultaneously that it becomes another particle (along the lines of string theory). It's the same basic idea of atom-smashers. If you were to find a big enough quantum particle, then it would have rest energy sufficient to maintain a suitible event-horizon withtout being too hot. Unfortunately the only way we currently know to give a particle enough energy is through larger and more expensive colliders.
Perhaps a focused "stop-light" could provide enough simultaneous photonic energy that the target quantum particles will rematerialize into something larger just long enough to collect neighboring particles in a mini-black hole.. Don't worry though, the most likely result will be a decay of that macro-particle in short order.
Quantum physics doesn't lend much room for ultra-massive particles. BUT, string theory suggests that all particles are inherently massive (a plank-mass - the wieght of a grain of salt) and that through vibration of 11 different dimentions their apparent mass is reduced in several discrete levels.
My idea is this. Take a massive spherical chamber filled with high a temperature gas that will act as this light-trajectory-storage medium. Shine bright light radially inward with the "store" light turned on... The light at the center will be dimmed and ultimately too low an intensity to wreck havoc. Then after sufficient time and energy is stored in this huge volume of now super-highly energetic particles. Trigger the light's release. Since the wave-front is stored, it should reproduce the original direction of the light and thus flash the center with energies approaching if not exceeding atom-smashers.
The high temperature gas will help obsorbe any reactions that might occur since their expansion should be minimized.
-Michael
-Michael
Obligatory no log in link
However, I wonder if this could also be used for holography: freeze the interference pattern into the material, and read it out later, reconstructing the image. In theory, since the material could record the interference pattern in three dimensions rather than two (like a photographic plate), this might allow for more detailed holograms.
www.eFax.com are spammers
That is the key concept that is poorly conveyed within the Times article. It's obvious that even good science reporting is not necessarily understandable by the masses without the teaching genius of a Sagan or the like.
This brings up an interesting topic, the subject of many late-night, coffee-fueled debates around here: If you could teleport a human through some means, would this property of "no-unique-identity" actually allow you to create an EXACT COPY of the teleported human (who is unaware that he/she/it is even a copy), while, in fact, you KILLED the original? How would you detect this?
What'dya mean there's no BLINK tag!?
Yes, you're right. Just found the Discover article, which does indeed say that the lab-grown black holes wouldn't be the real thing. They would instead be "a small and completely safe vortex of cold atoms" that would let researchers study the effects of black holes.
I've heard that this capability might allow scientists to create artificial black holes. Apparently if you can slow light down enough, you might be able to create a situation in which a singularity comes into existence. I wish I had more information on this-- I think I read it in Discover a few months back. I have no idea if this discovery would make such a thing possible. Anyone with more information? I'm obviously fairly ignorant in this area, but the article I read seemed to take the possibility seriously enough.
In order to reproduce your inner-most quantum states (e.g. the electrical synapses currently coursing through your system), you'd have to flash every particle some-how. Whenever you detect a particle, you disturb it significantly.
It seems to me that the only way you could teleport would be to 'flash' the host, then radiate their profile. It _might_ be possible to analyze the profile so as to reproduce multiple targets. But my belief is that the discretization of this profile information would render it useless. Additionally, analog amps / splitters could quite possibly introduce disturbences which would defore the target.
I still don't think teleportation will ever be practical for life-forms, but it might work for the simple transport of raw minerals (with pure substances). Perhaps, for example, you could energize the minned metal on the moon into a super-plasmic or photonic state which could be tunnelled. Alternatively the wave-properties in cooled matter might be of more use - Instead of super-heating, perhaps super-cooling is what is necessary. Course in either manner, the atomic structure is disrupted, so the usefulness is minimized.
Heck it would be useful just to condence matter to alleviate gravitational weight for greater space-transport.
Oh well, fun to brain-storm.
-Michael
-Michael
From reading the article, it sounds to me like the light is being destroyed and then new *nearly* (from the article it says it's not the same) identical light is emitted. While interesting, this phenomena is no where near as much of a breakthrough as if they had actually stopped light.
:)
Correct me if I am wrong, but are they not, in essense, just taking a snapshot of a photon and then recreating it?
I would go in to some of the implications of actually stopping light (instantaneous communications, etc), but it is too early in the morning for my mind to work that deeply
Technically, taking a quantum snapshot of a photon and then recreating it is the same thing as stopping it and restarting it. When we get down to such a level, we sacrifice the idea that a particle has an individual identity, and instead only acknowledge the existence of a set of properties for the particle. If the experiment simply resulted in light of the same frequency being emitted, then this would still be interesting as a means of optical storage, but by no means would it be as interesting from a theoretical perspective. What makes it interesting is that the imprint of the light is stored in the quantum spin states of the gas atoms, which means there is a theoretical possibility (which can't be determined too well from a nytimes article) that all the "uncertainty information" inherent in the photon is preserved across the restart. That would make this a true stopping and restarting of a photon.