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German Physicists Claim Speed of Light Broken
Byzanthy writes "Two German physicists claim to have broken the speed of light by using 'microwave photons.' According to Einstein's special theory of relativity, it would require an infinite amount of energy to accelerate any object beyond the speed of light. However, Dr Gunter Nimtz and Dr Alfons Stahlhofen, of the University of Koblenz, say they did it by using a phenomenon known as quantum tunneling.
The pair say they have conducted an experiment in which microwave photons — energetic packets of light — traveled 'instantaneously' between a pair of prisms that had been moved up to 3ft apart." New Scientist, however, is running an article that suggests Einstein can rest easy. Aephraim Steinberg, a quantum optics expert at the University of Toronto, explains that the German physicist's results aren't necessarily wrong, they are just being interpreted incorrectly.
http://arstechnica.com/news.ars/post/20070816-fast er-than-the-speed-of-light-no-i-dont-think-so.html
Something like this was claimed a while back. Is it like this guy's experiment where although an adge of a light pulse travelled faster than light, information still could not be transmitted faster than light?
Not discrediting the achievement. This will help us clarify current theories regarding speed limits and stuffz
Cheers!
Atheist: Buddhist in a Prius
i think you're confusing quantum physics and relativity. Einsten didnt believe in, and tried to disprove, quantum physics, but i dont believe he ever questioned his own relativity theory.
"God does not play dice" is about the inherent randomness in quantum physics.
Photons do not have mass.
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From: http://imagine.gsfc.nasa.gov/docs/ask_astro/answe
The Question
(Submitted July 31, 1996)
Do photons have mass? Because the equations E=mc2, and E=hf, imply that m=hf/c2 . Is it so?
The Answer
No, photons do not have mass, but they do have momentum. The proper, general equation to use is E2 = m2c4 + p2c2 So in the case of a photon, m=0 so E = pc or p = E/c. On the other hand, for a particle with mass m at rest (i.e., p = 0), you get back the famous E = mc2.
You're thinking of the EPR Paradox.
Simplified, when you have two entangled electrons and measure the spin along an axis of the first, the second one immediately takes on the opposite spin of the first.
But you don't know what spin you are going to get by measuring the electron; because it is made of two entangled wavefunctions it's pure chance which one is going to show up. Thus, you have no control over which spin the second electron has, and thus you can't transmit any information using this phenomena.
However, you DO know the spin of the second electron, a fact that can be used. For example, you can create potentially unbreakable ciphers using Quantum Cryptography.
Indeed. Now, I won't say with certainty that this present claim is wrong... but we've seen so many "speed of light broken!" reports over the years that I'm not going to get too excited. Typically, when people think they have seen a speed-of-light violation, they are actually reporting on one of two well-established phenomena:
1. Group velocity versus speed-of-light. Basically, relativity states that no individual photon can travel faster than c. However a collection of photons interfere to form a beam or a pulse with some kind of shape. You can arrange your experiment so that the envelope of the pulse travels at some velocity (faster than light, slower than light, etc.) but the individual photons are still always traveling at exactly c.
2. Quantum instantaneousness. Two particles can be put into a quantum entanglement, such that their states depend on one another, even though they have not 'picked' a particular state yet. You can separate the two particles (even by a huge distance), collapse one particle into a state and the other particle collapses instantaneously into the corresponding state. This instantaneous effect seems to violate the light-speed rule. However because the experimenter cannot control the state which is selected upon collapse, no "information" is actually transmitted from one location to the other.
Importantly, both 1. and 2. involve emergent effects that a human may characterize as "faster than light"--but no information, and no energy, was transmitted faster than light-speed. (And, to be clear, relativity states that energy and hence information cannot travel faster than light. Emergent phenomena can travel at arbitrary speed. In fact in relativity spacetime itself can, theoretically, expand faster than light, but you still can't send signals from one location of spacetime to another at greater than c.)
From the descriptions, it really does sound that these researchers are merely committing one of those two classic fallacies (or maybe a novel combination of the two?). Now, assuming that these researchers are not novices, I find it hard to believe that they would commit such classic mistakes. So in this case it might be a subtle point to prove that relativity is not disproved, but my assumption would be that they have made a mistake somewhere.
I don't mean to dismiss these results, and new science certainly comes from violations of established science. However relativity is so well-established at this point that making the extraordinary claim "we've violated relativity" is going to require exhaustive verification.
It just goes to show that journalists have a hard time reporting science.
The Speed of Light limitation is in regards to Matter, i.e. something with Mass. A Photon does not have mass. The component is acceleration! You cannot accelerate matter faster than the speed of light. The reason being as you begin to approach the speed of light, the object in question begins to increase in mass. Thus you need increasingly more energy to propel the object. More energy, continues to increase the mass of the object.
However there is no law against objects that already travel faster than the speed of light. For example, Tachyons. Hypothetical particles that travel faster than the speed of light. However they have never been found.
So a Photon can travel faster than itself - i.e. speed of light because it has no mass. Interesting. The explanation of why it's wrong doesn't jive. The data still prove it got there faster than it should.
Theoretical Physicists have a hard time with Experimental Physicists, mainly because experimental physicists have data to backup the arguments.
Then there's Hawking: "Not only does God play dice with the universe, He sometimes throws them where you can't see them."
It's sorta like this:
:)
1. First of all, the somewhat inaccurare version Newtonian version: when you calculate the acceleration of a small body in the gravity field of another body, the small body's mass cancels itself out.
I mean, the force is: F= G * M * m / d^2
The small body's acceleration therefore is: a = F / m = G * M / d^2
You'll notice that the small body's mass isn't present at all in the acceleration, which in this case is also determining the curvature of the trajectory. Or to put it otherwise, a 1g thumb tack will fly in the exact same orbit as a thousand ton Goa'uld pyramid. As you make mass smaller and smaller, in other words take a limit when mass -> 0, well, the trajectory still stays curved.
2. Actually, in a perverse way, you are right that Newtonian mechanics should not apply to light, and they don't: if you apply Newtonian mechanics to light, the predicted deflection of light is only half the deflection actually observed. So light does act funnily in a gravity well.
Light's curvature in a gravity well is only explained right by Einstein's general relativity. There gravity is just the observed consequence of a distortion of space itself. The presence of a mass there distorts space. The usual analogy is that it's like having a horizontal rubber sheet and placing a steel ball upon it. You'll get an indentation in the sheet. The effects on other nearby bodies, or on their movement, is basically just the consequence of that distortion of space.
And so it is with light too. It's not as much that newtonian gravity pulls it, as just that it's moving through a warped piece of space.
3. Generally, don't try to apply your RL intuition and experience to relativistic or quantum phenomena, it tends to just fail spectacularly
A polar bear is a cartesian bear after a coordinate transform.