Stop, Light. 254
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."
Re:Artificial Black Holes (Score:1)
Re:off topic (Score:1)
Lameness filter encountered. Post aborted.
la de dah dah stupid lameness filter
Re:light stopped? Or destroyed and re-emitted... (Score:1)
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.
Re:does this break the theory of relativity? (Score:1)
Re:light stopped? Or destroyed and re-emitted... (Score:1)
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?
SCREW QUANTUM COMPUTING! (Score:1)
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?
Re:Quantum Communications (Score:1)
Re:light stopped? Or destroyed and re-emitted... (Score:1)
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.
Re:light stopped? Or destroyed and re-emitted... (Score:1)
Karma karma karma karma karmeleon: it comes and goes, it comes and goes.
Hmm, I'm confused. (Score:1)
--
Re:Hmm, I'm confused. (Score:1)
--
Re:does this break the theory of relativity? (Score:1)
--
Re:QUANTUM TELEPORTATION POSSIBLE? (Score:1)
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.
Quantum Communications (Score:1)
Quantum computers could crank through certain operations vastly faster than existing machines; quantum commmunications could never be eavesdropped upon.
Could NEVER be eavesdropped on?
--
I found this really disturbing (Score:1)
No Biggie (Score:1)
--
Re:light stopped? Or destroyed and re-emitted... (Score:1)
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.
--
Re:Artificial Black Holes (Score:1)
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.
They've done this for years... (Score:1)
Re:Don't Forget (Score:1)
Re:QUANTUM TELEPORTATION POSSIBLE? (Score:1)
Ask Jeff Goldblum, he figured it out in "the Fly"
Walking FTL! Care to explain ? (Score:1)
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.
--
Think of it as an extended hologram (Score:1)
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.
Re:Artificial Black Holes (Score:1)
Sure, no problem. The first step is converting your garbage to light, then the light can be disposed of in the black hole.
Re:QUANTUM TELEPORTATION POSSIBLE? (Score:1)
http://www.nara.gov/exhall/charters/declaration
Re:does this break the theory of relativity? (Score:1)
Re:'BOUT THE SPEED OF LIGHT... (Score:1)
Re:No undetected eavesdropping (Score:1)
Not Stopping (Score:2)
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.
Re:light stopped? Or destroyed and re-emitted... (Score:2)
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.
Re:Holography? (Score:2)
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
Re:Artificial Black Holes (Score:2)
That could be a problem while driving your car.
Karma karma karma karma karmeleon: it comes and goes, it comes and goes.
Re:Holography? (Score:2)
Not to M.I.A. agents...
Karma karma karma karma karmeleon: it comes and goes, it comes and goes.
Re:does this break the theory of relativity? (Score:2)
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.
Re:does this break the theory of relativity? (Score:2)
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.
Re:light stopped? Or destroyed and re-emitted... (Score:2)
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.
Re:Holography? (Score:2)
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 [nasa.gov].
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).
Re:does this break the theory of relativity? (Score:2)
-David T. C.
Re:QUANTUM TELEPORTATION POSSIBLE? (Score:2)
--
Entanglement (Score:2)
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?
practical computer memory device? (Score:2)
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.
Re:light stopped? Or destroyed and re-emitted... (Score:2)
Re:Heisenberg (Score:2)
Re:Could be a weapon? (Score:2)
PRL publication information (Score:2)
http://link.aps.org/abstract/PRL/V86/P783
The official citation is Phys Rev Letters, Volume 86, p. 783 (published 29 Jan 2001).
Re:Artificial Black Holes (Score:2)
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).
--
No, it's true. (Score:2)
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...
Re:but you couldn't transport it (Score:2)
How would you transport you hologram?
Personally, I'd use a small, beeping robot.
Re:light stopped? Or destroyed and re-emitted... (Score:2)
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
Use login: cpunks password: cpunks at nytimes.com (Score:2)
-----
Re:does this break the theory of relativity? (Score:2)
Light IN a vacuum moves at a MAXIMUM of C - It CAN and does move slower, especally in other mediums.
Re:time as a fourth dimension (Score:2)
Re: (Score:2)
Correct /etc/hosts configuration (Score:2)
208.48.26.217 www.nytimes.com
Re:does this break the theory of relativity? (Score:2)
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.
Re:but you couldn't transport it (Score:2)
That was pretty much what I was trying to say.. The problem I had was that it's not too different than a black-box hard drive that stores an email and then sends it out on the internet then deletes the message.. The only difference would be that you'd garuntee it's deletion once it was sent.
However if this is fast enough, it still might have applications in the routing world.
-Michael
Re:Slow glass (Score:2)
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
Re:light stopped? Or destroyed and re-emitted... (Score:2)
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
Re:Just wondering... (Score:2)
It seems to me that the photons are not physically stopped.. In fact there is little physical difference between this and regular obsorbtion of light by matter.
The main difference seems to be that instead of giving wrought energy to the electrons / nucleus, they're exclusively affecting the spin (???). Supposedly this means that the wave-front is captured instead of just a raw packet of energy. Normally an atom obsorbs a photon, then at a later time ejects either it, or some combination of photonic energy in random directions (kind of like scattering). But what I believe is happening here is that the wave-front is reconstituted by possibily analogously gyroscopic-inertial forces (I know it's not really spin, but never truely understood it) in the exact same direction.
So basically it's no different than your common everyday sun-light off a white tee-shirt sort of event except that there's no scattering, and you can use a trigger instead of random quantum fluxuations for the retransmittion.
As a final response to your statement, since the light isn't actually stopped, it isn't "heavier", much like the undetectible additional mass of an atom when it obsorbs photons. Beyond that, the slowing of matter makes it lighter, rather than heavier (according to the theory of relativity and the lorenz factor).
-Michael
Re:Artificial Black Holes (Score:2)
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
Re:Fundemental theory about light (Score:2)
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
NYTimes exaggerates again (Score:2)
Read the posts by zCyl and Ferzerp to see why.
Re:light stopped? Or destroyed and re-emitted... (Score:2)
Quantum repeaters (Score:2)
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.
Re:Slow glass (Score:2)
Re:Just wondering... (Score:2)
There will be some degradation, but if you put the pattern enhancers into a repeating diagnostic loop, it can save the original energy pattern for hundreds of years.
This is a good way to save yourself if you ever crash land on a Dyson Sphere. 8^D
Re:Holography? (Score:2)
Re:does this break ....PROBABLY REDUNDANT BY NOW! (Score:2)
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...)
Re:Artificial Black Holes (Score:2)
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
Re:Artificial Black Holes (Score:2)
---
Of course... (Score:2)
It is now possible to say that everyone has performed the miraculous feat of Faster-Than-Light travel!
---
Fundemental theory about light (Score:2)
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
Re:Cars of the future. (Score:2)
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.
Such material already exists; it's called thin film technology, and I really don't know much about it, but I understand it's used on the surfaces of stealth vehicles the render them almost invisible to radar.
No doubt it's way too expensive (currently) for regular automobiles, just to avoid traffic tickets.
But I say, if you feel the need for speed, put yourself on a closed race track, don't put others in danger...
--
Re:Slow glass (Score:2)
Of course, that might cause a cool quantum fishbowl effect . . . think of the sci fi applications. :)
Re:light stopped? Or destroyed and re-emitted... (Score:2)
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)
Re:Artificial Black Holes (Score:2)
I smell a new startup. Venture capital! I need venture capital!
Re:does this break ....PROBABLY REDUNDANT BY NOW! (Score:2)
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
Re:does this break the theory of relativity? (Score:2)
It does, but no-one remembered to make c final so it's a variable.
Nothing is immutable - except flux.
Slow glass (Score:2)
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 [openone.com]
Re:Walking FTL! Care to explain ? (Score:2)
--
MailOne [openone.com]
Re:A HA !! (Score:2)
Not exactly sure, but I know that it's a good way to get rid of Stay Puff Marshmelow Man.
Re:does this break the theory of relativity? (Score:2)
Re:Cool, but... (Score:2)
When you read from memory you're essentially reading through a high gain buffer which restores any signals which are almost high to a high signal or which are almost low to a low signal.
As long as there is some means to detect the appropriate value of a signal with a high enough probability of success nearly is good enough.
Re:does this break ....PROBABLY REDUNDANT BY NOW! (Score:2)
(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.
Re:Artificial Black Holes (Score:2)
Re:Just wondering... (Score:3)
Re:time as a fourth dimension (Score:3)
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
QUANTUM TELEPORTATION POSSIBLE? (Score:3)
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
time as a fourth dimension (Score:3)
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?
Re:Holography? (Score:3)
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
Re:Fundemental theory about light (Score:3)
I recommend "the elegent universe" by Tom Green. He very beautifully discrbes Einsteins relativity and multi-dimentionality in lay-terms and with lots of colorful analogies.
Essentially time can be thought of as the interval of a regular periodic event (such as a frictionless bouncing ball or pendulum.. or even a photon bouncing between two mirrors). The trick is that the event is periodic with respect to a single frame of reference. A man on a space-ship flying past you will observe a seperate period in your time-piece.
Light has a fixed velocity and is timeless in free space because it has almost no mass (there's still debate about whether it's truely massless) and thus can not "Do anything" that would be measurable (such as the position of a ball reflecting light to the observer). As the author suggested, by traveling diagonally across the foot-ball field, you're traveling in two dimensions. The hypotenus is the traveled path, and the sine or cosine is the observed path and velocity from either the point of view of time or any of the spacial dimentions. Its simple geometry.
However, when the light's wavefront interacts with neighboring atoms, they are achieving some sort of event that is non-instantaneous.. If they pass into an electron's event horizon and contribute to it's energy, that takes time. Likewise when they radiate out of the electron and continue along some new path (scattering), or reconstitute their original form (transparency).
There is massive speculation that the wave-nature of light (and all material for that matter) is such that the photon really travels all possible directions and interacts with all material proportionately (evidenced by single-photon refraction patterns). Thus the more matter nearby, the more interaction, thus the more timeable events, thus the more traveling through time, thus the less traveling through space, thus the slower apparent probagation of light through a non-vacume.
The "stop-light" above quite possibly is such a time machine for light where it travels sole-ly through time (or any of the other hypothesized micro-dimensions) until it's released. There is nothing totally radical about this, since this happens whenever a fermion captures a photon for an extended duration. The bizzarness is in the exact replication later on.
-Michael
Re:Artificial Black Holes (Score:3)
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
Holography? (Score:3)
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.
Re:light stopped? Or destroyed and re-emitted... (Score:3)
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?
Re:Don't Forget (Score:3)
Here's the article (Score:3)
Artificial Black Holes (Score:3)
Re:light stopped? Or destroyed and re-emitted... (Score:4)
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
light stopped? Or destroyed and re-emitted... (Score:4)
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
Re:light stopped? Or destroyed and re-emitted... (Score:5)