Slashdot Mirror
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.
What are they going to do to fix it?
I read Slashdot for the headlines, because the headlines, unlike the articles, are usually original and never duplicated
186,000 miles per second, it's not just a good idea, it's the law.
What, me worry?
How am I supposed to welcome our new microwave-photon overlords if they've already arrived?
Information on how to break the light barrier has been around for ages.
End of lesson. You may press the button.
http://arstechnica.com/news.ars/post/20070816-fast er-than-the-speed-of-light-no-i-dont-think-so.html
Doesn't quantum changing of spin happen faster than light would travel between two points? Does teleportation actually breaking speed of light? Otherwise why would it be called teleportation if it's just moving things (really) fast?
Wasn't it done with photons? I mean, who cares if you accelerate light, we've seen that before in gases.
The time barrier's been broken, so where's that damn warp drive?
Two German physicists claim to have broken the speed of light by using 'microwave photons.'
Microwave?...I mean, this is Slashdot, shouldn't that be a quantum-nano-buckyball sort of arrangement?
they did it by using a phenomenon known as quantum tunneling
Oh...OK, my bad, I was getting worried there for a minute.
A goal is a dream with a deadline
I brought enough for everyone.
-tyfighter
"Microwave photons" are neither "light", nor "energetic".
Photons with a frequency in the microwave region are thousands of times less energetic than the least energetic light photon. Basic Plank's equation, E = hv, you see.
And Einstein need not worry, his basic theory or Relativity covers the fuzzy concept of "simultaneity" and "instanteinity" quite thoroughly.
Guys come out confusing group velocity with the speed of light, from the very first equation I am beginning to suspect that it is the case. I have read the paper, and must question their conclusion as their setup is not entirely clear. This said, everybody loves surprises. Yes, IAAP.
At least, going by TFA, I should be instantaneously like the 8th post AND the first post! w00t!!
Anyway, I'm not all that convinced that the speed of light would require infinite energy to be broken. According to E=MC2 and all the special relativity and all that crabopple, just to travel AT the speed of light requires almost all the energy in the universe and the mass of the object increases to nearly the same amount of mass in the universe (purely from memory and I'm not a scientist/physicist/quantum physicist/lawyer). If such is the case, or something relatively similar to what I just said, then how does a photon, WHICH HAS VOLUME AND MASS, travel at the speed of light without having the same mass/energy as the whole of the universe?
If someone can explain that to me, I'd very much like to hear it.
Halitosis - (n.) Halle Berry's Camel Toe.
Am I mistaken, or is it the old group velocity vs. velocity error again? One thinks it's about time the quantum physicists learn basic wave mechanics, especially as various scientists have made similarly incorrect faster-than-light claims several times now.
Einstein died thinking his theory was the "dumbest thing since ...". I'm not sure what exactly, actually, but it had something to do with God.
I do remember his "God does not play dice" statement.
But he spent the last 30 or so years of his life trying to disprove relativity, because he thought it wrong. So actually he probably would be glad someone finally succeeds.
You have to walk the plank.
"Waste not one watt!" - CZ
But if it had broken the speed of light, it should have arrived BEFORE it left. Unless Einstein just happens to be wrong...
but who knows. Atoms are weird. I wouldn't be surprised if it turns out that when they travel at the speed of light they generate dancing-banana particles which can be explained by a peice of paper and a crayon.
Those using pirated Tinysoft signatures(TM) are a real threat to society and should all be thrown in jail.
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'm glad there was a post today to tell me the speed of light isn't broken. I need a reminder every once in a while.
How many German physicists does it take to change a broken speed of light? Answers below:
c++;
Hold on a second here... They say that they've exceeded the speed of light with (drumroll please) Photons! But, wait a minute, isn't that light? However fast those photons were going, *is* the speed of light. It's just that they've discovered that all the rest of the photons in the universe just really aren't giving it their all.
(by the way, this is a joke. I know what they mean, it just seems funny to me.)
Pound! Bang! Bin! Bash! is this a shell script or a Batman comic?
With this new discovery the Germans have made an incredible jump in technological advancement, so Europe prepare for World War III :)
On a more serious note, wasn't it part of the theory that when you travel faster than lightspeed you travel into the future or past? So if they did succeded in surpassing lightspeed how would they be able to tell? (and how are they able to tell anyways?)
We shall call this new Technology:
Way to go Anywhere Really Phast
Or WARP
Light is light, no matter the frequency. I think when you say "light", you're trying to refer to light in the visible part of the spectrum.
The summary does however call photons "energetic packets of light" when I think they're trying to say "packets of energy".
The effect they measured is not new. As they described correctly, the waves are evanescent modes. The thing about these modes is that they do not possess a velocity with a real number value; the index of refraction is effectively imaginary. Imaginary in the sense that you need to consider the square root of a negative number. The imaginary velocity means the modes decay away from the surface (of the prism in this case). But if you have another prism close enough, it can pick up some of the evanescent mode and convert it back to real propagating light (which travels at real light speed).
Since imaginary speed waves die out over long distances, for which we do need "faster than light" speed, we will not be able to use this effect.
Photons do not have mass.
r s/960731.html
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.
"Aephraim Steinberg, a quantum optics expert at the University of Toronto ..."
Blame CANADA!
From the press statement:
And there you have it - The McKenzie Brothers' explanation... Beer DOES affect relativity, in a relative sort of way. I guess.
I was actually a little disappointed to see it debunked. I guess hot green alien women will have to wait.
does anyone know how these scientists measured time for this experiment? what sort of equipment do you use to measure picoseconds
And now I turn off my microwave photon gun set to "drippy irony".
RS
Shoes for Industry. Shoes for the Dead.
On an advancedphysics.org board in 2005 Fernanda summed it up nicely:
"yeah, I'm done with this thread and will order any admin here to close all threads Michael opens regarding photons having mass, weight, size or whatever the heck wacky proposal he has."
I thought that something travelling at exactly the speed of light required infinite amounts of energy. No-one said anything about more than the speed of light.
Check out what happens when X-Rays pass the speed of "light" in water. check out Cherenkov radiation. Irregularwebcomic has a good explanation http://www.irregularwebcomic.net/1636.html
B.
Every experiment which ends in a big bang is a good experiment.
Zephram Cochran called. He's not buying it.
OK, so now when I put my cold food in the nukerwave, it'll be heated up and done before I press start?
They broke it because of Global Warming... the whole world is out of whack... we need a new science... w/ proven results... ...results that are quantifiable... solid... not subject to "misinterpretation" ... non of this crap that we've gotten so far... what has science given us already... geesh.
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.
While I'm sure there will be the prerequisite warp drive/time travel jokes about this, I think the most interesting aspect lies in potential applications to communications and computing. The potential of quantum computers is already quite impressive, but imagine coupling that with the ability to design a system without concern about the physical proximity of some components. Imagine being able to build a planetary computer capable of answering the question of life the universe and .... everything! Planetary should be big enough for that, right?
To the making of books there is no end, so let's get started
...what's the speed of dark?
Gentoo Linux - another day, another USE flag.
Why, increase the speed of light, of course!
Couldn't this be used to reduce latency on inter/intra continental backbones? It be kinda wierd though... If you're talking on VOIP... would the caller on the other end hear your voice before you say it?
http://arstechnica.com/news.ars/post/20070816-fast er-than-the-speed-of-light-no-i-dont-think-so.html
Ahhh - sort of like how "Linux" is used in the place of "Operating System", when it's really just a kernel...
I get it...
Who is general failure, and why is he reading my hard drive?
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.
Clearly this is the classic group velocity vs. velocity error again. And I don't even know what that means.
Remember... ZG9uJ3QgZm9yZ2V0IHRvIGRyaW5rIHlvdXIgb3ZhbHRpbmU=
And lo, the greatest joke post title ever finally gets to be used!
stuff |
As you aptly noted, I omitted the "C", which represents the Speed of Light, which was likewise absent in this case.
Thus, what appeared to be a simple gaff to the untrained eye is actually a sophisticated reference en passant.
That's my story and I'm sticking to it.
"Waste not one watt!" - CZ
http://en.wikipedia.org/wiki/Quantum_tunneling
They did not break the speed of light, end of story.
These guys mentioned microwaves and broken laws, they must be terrorist planning on making a bomb that explodes before it exists. Call Bush, he'll understand it and stop them.
Fight Spammers!
2) Light can and always could go faster than 3X10^8m/s. 3X10^8m/s is the group velocity of the wave, but individual frequencies of light go faster or slower. Since you need the whole wave packet to know the structure of the packet (ie get information), your stuck waiting for t = D/c time, but you can detect the quicker phases earlier. Read up a good fluid mechanics or advanced optics book for the differences between phase and group velocity.
3) This still doesn't make time travel possible. Time is still going forward, even saying the group velocity of light was broken. You could get ahead of light and see something that happened in the past, earlier than you should have, because you can communicate quicker than light, but it still is an event in the past. You could move to a location you otherwise wouldn't be able to be at by the given time moving below the speed of light, and have an effect you couldn't have had at that point in time otherwise, but you didn't go into the future, in the way normally thought, time kept ticking, you just traveled a different path through space-time, that normally was excluded.
I'm a n00b, or a non-quantum guy. So this may be stupid.
If you have a light which is traveling faster than the speed of light, then isn't there a simple test that can be done to determine if this is actually happening or not? Arrange the light source and a viewer at a distance apart where the speed of light can be empirically measured. Maybe 2 light second apart, so 599584916m apart. Have the viewer remotely start the light source with something such as a laser. If the viewer can see the light turn on in less than 2 seconds, then the light is traveling faster than 299792458m/s. Otherwise, it will take 1 second for the remote signal to reach the light source, a few ns to turn on, and 1 second for the light to get back to the viewer.
If this was legit, it'd be a great experiment for NASA as they could decrease the lag on their games...er..space ships.
and I'd like to join the big pile of Slashdotters who have/will clawed you to bits for your ignorance of physics. My personal approach is going to be:
LEARN TO SPELL!!
Thanks.
Whence? Hence. Whither? Thither.
i actually posted this comment tomorrow
It's on your flying car. It ought to be arriving soon.
I bought it a science gadget store three years ago and it is still rotating.
How about we have one single science discussion where it does not degenerate into a political bashing session. Please. I'd love to be able to read about a cool development in science without having to read about Bush, Clinton, Republicans, Democrats, or anything other than funny "you broke it, you buy it" jokes about the subject. Let's all stop obsessing on politics for just one freaking story. Please?
A Haiku: my language choices/assembler pascal lisp c/old school programmer
That's the stupidest thing I ever heard.
being a lazy, semi-literate, quasi-scientist trained at one of canada's finest institutions, (and being lazy meaning i never really understood the difference between group velocity and wave velocity when we are talking about discreet photons...plus just being plain lazy...) I figure that i can rig up the nuker at work to emit these faster than light photons and zap my computer (somehow anyway i'll work that out later..) then using the old Austrian's tricks, i should be able to get my work done faster without actually doing anything... hmmm... I might even be able to extend my idea to help out some of my coworkers... not all of them mind you.. they need to work...
You can't go faster than the speed of light. Just can't happen.
"If you have nothing to hide, you have nothing to fear." - Every fascist, ever
How about we have one single science discussion where it does not degenerate into a political bashing session.
Please do not consider my sig as part of this comment where I say, "Thank You"
There is no "I disagree" mod for a reason. Flamebait, Troll, and Overrated are not substitutes.
explains that the German physicist's results aren't necessarily wrong, they are just being interpreted incorrectly.
Without RTFA, let me guess: It could be interpreted as traveling instantaneously, but *no* practical use, such as instantanious info transfer, can be made from it due to odd quantum rules that somehow show up at the last minute to muck up utility. Quantum is the Grand Teaser.
Table-ized A.I.
Disclaimer: IANAP, and it's actually two questions...
Your ad here. Ask me how!
This appears to be the case. This has already been proven false and not accurate, they are using group velocity which is not the same. Read this article to understand better:
7
http://news.scotsman.com/scitech.cfm?id=129512200
Give them a speeding ticket, of course. If you can be fined $100 for going 15mph over the speed limit, it is left as an exercise to the reader to estimate the fine for exceeding the speed limit by 2.3 billion miles an hour! I think it ought to be illegal to deprive our cash-strapped government from such an amount of revenue. It may even be considered immoral, if you think of all the starving children so much money could feed.
I am so sick and tired of these articles appearing in Slashdot. The titles are always sensationalist. The body is always misleading.
Someone with no understanding of Science seems to get a thrill out of believing something overthrows the order of the Science world, whether it is Cold Fusion, or the speed of light, or quantum theory.
When will it stop?
It is like the monthly news reports in the mainstream media telling us that "surprise surprise" obesity (especially around the belly) leads to heart disease, or wine/coffee is good/bad for you.
Waaaaahhhh!
It seesm we have a contradiction here:
... and ....
Well, if the "envelope" of the pulse travels faster then light, in some way, then the information carried by the very existence of that pulse does too, does it not? That is, since the "envelope" is somehow detectable, we assume, lest the experiment would be unsuccessful, then the very arrival of the edge of that faster-then-light envelope could be used to trigger some other process, therefore effectively allowing for faster-then-light communication. Please clarify if this is not so.
The problem there is that you're essentially proposing the equivalent of making a car instantly go from 50 km/h to 200 km/h, without it ever having a speed of 100 km/h in between (or any other between 50 and 200.) Only in this case you're proposing something like going from 0.5c to 2c without ever being at the other speeds in between.
Well... how?
Even if there wasn't the pesky issue of having c in between, that violates even Newtonian mechanics. Savagely. Since you're proposing that speed "jump" to essentially happen in exactly zero time (or you'd go through all the values in between), even by old Newtonian mechanics you're talking about an infinite force.
A polar bear is a cartesian bear after a coordinate transform.
Seriously.
This is much more characteristic of Microsoft's (a convicted monopolist) anti-competitive practices having something to do with open standards and embrace and extend. I'd finish the thought, but I think everyone knows where I'm going with this one.
Alternatively, this is like a car...
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.
Actually, if I recall it correctly, it was more of a limitation of SToR. You started having to divide by imaginary numbers once you started plugging in velocities above c. Even with a velocity of c, SToR stopped making sense because then you had to divide by 0.
Years ago we could have gone faster than today's speed of light.
That is because light used to travel faster than it does today. As Einstein supposed, the speed of light has been measured to be a function of time - C(t) - rather than a constant - C. It has been slowing down at a rate that matches in inverse-cosecant curve, based on measurements since the Michelson-Morley experiments. Naturally, all constants that are based on the speed of light are known to be changing accordingly. Hence, the mad search for "dark matter" and its properties of "funny energy" (yes, it is a technical term - Google it) in order to explain the change.
Now I pose the question: What changed? Did the speed of E-M wave propagation slow down? Else, did the rate that time passes speed up?
I'm not sure whether anybody is aware of it, but this really is old news. Ten(!) years ago, Dr. Nimtz published an experiment on how to tunnel data (specifically Mozart's symphony) at higher speeds than light. Read about it (in German) here http://www.wissenschaft.de/wissenschaft/hintergrun d/173235.html and here http://en.wikipedia.org/wiki/Faster-than-light
/ .
There's even been coverage about his tunneling experiments occasionally in the nightly show "Space Night" broadcast on the German TV station "Bayern Alpha" http://www.br-online.de/wissen-bildung/spacenight
Somehow this experiment keeps turning up now and then, causing wild speculation and discussions every time.
all objects exist with mass
...
photons have no mass
therefore photons do not exist.
light travels at 186,000 miles/hour
photons travel faster than light
photons are nothing
nothing travels faster than light
no wonder I failed logic. It doesn't even make sense to me.
qed
But who said anything about the base of natural logarithms being broken?
Why does the word 'Orbo' come to mind?
Welcome to Slashdot. You must be new here.
Since when does being a Socialist mean 'someone who has a different opinion than me'?
It's better to be the foot on the boot than the face on the pavement. ~~ tkx Kadin2048
You were also kind enough to omit the first name "Max", just in case some people didn't know what the speed of light represented.
Thus, what appeared to be a simple gaff to the untrained eye is actually a sophisticated reference en passant.
Now if I could just figure out why Euler's constant is to be henceforth disregarded...
what if the information is there but the human brain (or transmission between eyes and the brain) cant detect particles moving faster than light... what if our equipment cant registrate particle faster than C en we dont know it...
just trying 2 look at things differently with my noob questions
(SuprcoW)
Heh. It's just a visual illustration, it's not the whole model. Yes, the illustration is inexact, in just the way you've described. But it's just a visual aid, no more.
:)
Rest assured that the real equations _don't_ involve rubber sheets and extra downward forces.
The issue there is, well, what was point 3 in my previous message: your RL intuition and imagination fail you miserably in both quantum and relativistic domains. (Here "you" meaning "everybody.") Just because you have the equations, doesn't mean you can actually imagine it, without getting cross-eyed and a nasty headache. Hence such imperfect visual aids as the rubber sheet. That rubber sheet model isn't the actual general relativity model, it's just something close enough to your RL experiences and intuition so you can picture it in your head.
But, yes, it's an imperfect visual aid, if that's what you were trying to say. If you can come up with a better one, I'm sure a ton of physicists and physics teachers will thank you for it
But if you're trying to actually use that illustration as _the_ model, it's a bit like saying that a rose can't exist because the picture of a rose is flat and doesn't smell. Or that a pipe can't possibly work, because the drawing of it is on paper, and paper would burn if you tried to put tobacco in it and light it.
A polar bear is a cartesian bear after a coordinate transform.
A well reasoned response. Thank you.
A Haiku: my language choices/assembler pascal lisp c/old school programmer
Touché.. Although you did forget the Nazi comparison. I will still give you 3 stars for this one. :)
A Haiku: my language choices/assembler pascal lisp c/old school programmer
No, I'm not new, and in fact, my un is lower than yours. I was apparently not thinking when I requested logic instead of political screeds. My bad.
A Haiku: my language choices/assembler pascal lisp c/old school programmer
At the risk of getting trounced on by all the scientists here, i disagree with Einstein's theory about the speed of light. I believe that it's possible to go faster and that we'll eventually (in a few thousand years) have the technology to do so. Einstein's theories are based on what we know of in the universe. We as humans are really rather primitive and haven't even developed a decent form of space travel yet. We know very little about the universe in general. Einstein's theories were based on what he knew at the time. They may stand up for the next 10 years, 100 years, or even 1000 years, but eventually they will be expanded and changed as we gather information on the universe.
I assume I can use my new quantum tunnel NIC to retrieve yesterdays data.
I was going to write this up and submit it to the scientific community but thought it would probably get more exposure here. So here goes...
Why The Expansion of the Universe is Accelerating
It's simple. There is a near infinite amount of mass in the universe, and most of it has already expanded beyond our current location in space. Since most of it is beyond our current expansion point, then as we get closer to this unseen mass (and farther away from the universe's center of mass), the stronger is its pull of gravity upon us. Hence, we accelerate towards it at an ever increasing rate.
Yeah, OK, mark me O.T., but one day you'll see.
Have they used hand-optimized assembler because C was not fast enough, or because they broke [GC]C?
cpghost at Cordula's Web.
Sorry couldn't resist a bad bun, but I suspect tachyons are one of those things that are scientifically plausible but don't exist. Tachyons would be able to interact with our universe through photons and we don't seem to see a lot of unexplainable photons around.
Apocalypse Cancelled, Sorry, No Ticket Refunds
Maybe some of us would like to read stories and commentary that:
/. memes and GNAA trolls
1) aren't dupes
2) have intentionally misleading headlines
3) are full of poorly used
4) have been posted by Roland containing links to that fuckers own site
Face it, it ain't gonna happen, so go get a tissue to dry up those tears and quit your fucking whining.
http://arstechnica.com/news.ars/post/20070816-fast er-than-the-speed-of-light-no-i-dont-think-so.html /
And maybe she can adopt there.
Spa fon? SQUAA TRONT!
"Flyin' in just a sweet place,
Never been known to fail..."
...every time I cast a shadow.
I'm thinking about it, therefore I might be.
In Soviet Russia, politics obsess on you!
In lieu of mod points, I bow down to thee!
I think the problem here is that the speed of light is relative to the medium it travels through. It is very possible that in the experiment stated that they produced an effect that allows photons to travel faster than the speed of light in a medium other than a vacuum. The fact that they used two prisms and microwave radiation as a medium proves only that they exceeded the speed of light in a medium of prisms and microwave radiation. Correct me if I'm wrong, but it is not possible to exceed the speed of light in a vacuum. That is precisely what the limiting factor in Einstein's equation, E=mc^2 expresses. If something were to exceed the speed of light in a vacuum, then it would become infinitely massive and infinitesimally small, thus creating a black hole.... The rest is quantum physics, which is so full of theories I don't care to explain, or know for that matter. Everyone thing you know is now false, and everything you thought impossible is now normal. "I feel like I'm in Alice in Wonderland"-- NSA Judge on warrantless wiretapping
The Speed of Light limitation is in regards to Matter, i.e. something with Mass.
Actually, no. Relativity limits the speed of information transmission, too. At least if you want to keep causality. If you can transmit information faster than the speed of light, you can in theory violate causality.
Causality, relativity, FTL - pick two.
No, he's New Here.
-
- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
How many scientists does it take to replace a 'broken speed of light'?
#756762 +(2114)- [X]
The Fishchaser: we should tell the japaneese we found a planet full of giant tentacle monsters and their females are somehow little school girls
The Fishchaser: we'll be going faster than the speed of light in a week
No doubt you know what you're talking about, but I could use a bit more explanation here. (Insert usual disclaimer about me being a dysmathic humanities guy.)
You say that individual frequencies of light travel at varying rates. Do you really mean to say that red light travels at a different speed from blue light (or gamma rays)? That's news to me. So the famous "c" is actually an average of the whole electromagnetic spectrum?
I'm also having trouble thinking about a "packet" of light. Yes, I know about the problems of describing light as particles vs. waves, and all that. But you seem to be saying that "packets" of lights (are they the same as photons?) have parts, and that these parts travel at different rates. So each packet has a length? The fastest part (the "head" of the packet) arrives first...and the tail trails in belatedly? And doesn't an individual photon have a single distinct frequency, in any case? I must be totally misunderstanding you.
I wish we could read the paper this is all based on; I doubt whether the author of the cited article understood the research he was reporting. By the way, c is a constant only in a vaccuum, so any light traveling through prisms (or even air) is going to be going slower than c anyway. Did the researchers claim they had exceeded the speed of light in vacuo?
Great men are almost always bad men--Lord Acton's Corollary
We know that the speed of light is variable. It can be reduced to feet per second. We know that quantum tunneling happens in semiconductors, like the ones I'm using right now (and so are you). The Germans extended the range of quantum tunneling to 3 feet. We know that x-rays travel faster than the speed of light in water, producing cerenkov radiation. We have known since Alcubierre published in 1993, that warp drive is possible, "violating" the speed of light, but not in such a way that GR or SR (I forget which) is violated. Physicists in the zeitgeist of the times needed an absolute, having rejected the concept of an absolute reference frame for philosophical reasons, and Einstein latched upon light. Lightspeed is an arbitrary absolute.
Nice to see that Godwin's law still holds.
All I get when I play with microwave photons is a persistent fish smell in the kitchen.
Bury me in mashed potatoes.
You got photons on the futon! I aint cleaning up that mess.
There is no right to feel safe thru security vaudeville at the expense of everyone's freedom, privacy and tax money.
see: here and here
Apparently a mod didn't find it funny either. Oh, well.
"If you have nothing to hide, you have nothing to fear." - Every fascist, ever
How about we have one single science discussion where it does not degenerate into a political bashing session.
Geeks discussions tend to an almost RainMan-esque single minded droning, especially when it comes to science or anything technical.
Geeks also tend to have a level of political activism approaching that of a tree sloth. A fossilized tree sloth.
A community filled with Asberger's and Asberger's-lite.
During the Bush Sr. and Clinton Presidencies I couldn't have told you who was who. They were all Republicrats. I didn't know who was who, I didn't care who was who, and I liked it that way.
The fact that a bunch of geeks are apparently incapable of discussion any subject - even a reported potential violation of the speed of light - without the Bush situation intruding in one way or another in virtually every single topic... wow. Just how astronomically off-the-charts bad does the Bush situation have to be to do that?
The Bush situation has become like a buffer overrun trashing out into everything and anything in system memory.
Oops... I know I know... that should have been a car analogy. My bad.
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
light is made of photons... the speed of photons are consistent... thus, that is how the speed of light is determined. If you can't make a photon travel faster than the speed of light because light is made of photons, thus the speed of light is the speed of the photon. If anything, what they are saying is that they made one photon travel faster than the other... OR... the speed of photons is not constant... but scientists already acknowledge that. What's more interesting is that the properties of one photon or electron (both considered to be "waves", not matter) can be affected by another despite the distance between them... whether that is microscopic or on the order of light years. THAT is the fundamental idea that really shakes the grounds of special relativity!
programming myself into obsolescence
This is not a case of confusing group velocity with particle velocity. It is also not a case of quantum entaglement. What happens here is that those people found that tunneling happened instantaneously at their experiment, but they reflected all the tunneled photons back to the original side.
Well, now I'm curious about what would happen if those photons wheren't reflected, and how did they "know" about the other side of the prism if they took no time traveling trought it. Does that count as information moving, and (since the answer I get will be no) why not.?
Rethinking email
There have been many, many experiments in superluminosity (things seemingly traveling faster than light), however, quantum tunneling is certainly not a case of information moving faster than light.
Quantum tunneling is when a particle passes through a region in which its presence is disallowed according to classical mechanics. However, in this region, the particle's wave function satisfies the time-independent Schroedinger equation and takes the form of an exponentially decreasing function (as opposed to the time-dependent solutions, which are a superposition of sines and cosines). Since the equation is not dependent on time, it would be a mistake to claim that the particle is actually moving through that space.
So yes, if you choose to interpret speed as distance over time, you could say that something travels faster than light, but at the quantum level such interpretations are meaningless, and you can't even claim that it's the same particle that comes out the other side of the potential barrier.
Ass-burgers? Crossing our borders? Stealing our jobs? Sleeping with our livestock?! I blame Bush!
Thanks for pointing out an error in my critism. The physicist's probably don't share the thinking of the article writer. It seems every other month someone is saying that they made light travel faster than c, or slower for that matter. Usually that is followed by an article claiming this, but not stating that it is phase velocity not group, or they do, but don't explain the difference so people get really excited.
Wikipedia got it right, after I did a little editing of their derivation (they had the final line as vg = v, when it should have been vg = c). See:
http://en.wikipedia.org/wiki/Phase_velocity
http://en.wikipedia.org/wiki/Group_velocity#Matter _wave_group_velocity
Anyways, this is a subject that requires a lot of math, to properly understand what the formulas mean. In my physics studies, it would have taken 3 calculus courses, 2 classical mechanics courses, and a quantum course to really grasp it. That is what us physicists do, we take ten courses to understand a concept I hope to explain in 5-10 minutes. Not very smart, or very smart depending on the side of the fence your on :)
You appear to understand the concept of the wave-particle duality of light. Light behaves like a particle at times, and like a wave sometimes. The funny thing is light doesn't behave like a wave. A wave is a mathematical construction going both ways infinitely far. What we really mean is a piece of a wave, since it has a fixed source and hits a fixed target. This is a soliton (just like in the Star Trek the next generation episode, with the experimental soliton wave engine, if you ever seen it). From wikipedia's article on soliton's:
1) represent waves of permanent form;
2) are localised, so that they decay or approach a constant at infinity;
3) can interact strongly with other solitons, but they emerge from the collision unchanged apart from a phase shift.
This is a lot of useful properties for our model, 2) localized, so they have a beginning and end, 1) their shape doesn't change as they move through the medium, 3) they are preserved when they go through each other. Think of two different colours of light pointed to meet each other. If you place a screen at the intersection, you see the blended colour, but once you move past it the individual colours still exist. So a soliton has the properties we want to describe light.
When you see light as a wave, you can't distinguish between photons, but they are blended together (superimposed). After a couple more advanced math courses (mainly to get Fourier analysis), you can grind through the math and see that for the soliton to keep its shape, different frequencies will have to move at different speeds. Since one frequency is going up and down faster than the other, the shape would change if they moved together at the same speed. But sense you are seeing light as a wave, you can't see the individual photons, so you have to wait the whole normal speed of light time to make out the whole shape of the wave, ie. get information. You won't have enough information to workout the individual components of the group of photons until the last bit of the packet or soliton reaches the detector.
Now something that will blow your mind. If you take electromagnetism, and express it as a field, and then apply quantum mechanics to the field, you end up with what is called quantum electrodynamics, (you'd be in your last year of undergrad before you may see this, if particle physics is offered at that level at your school, but a lot of people don't see it until their PhD quantum course). Here light is a field (a photon is the particle responsible for transmitting the intera
Actually, no. If you go faster than the speed of light, then there is an inertial frame of reference (as valid as any other, since that's relativity) in which you have gone backwards in time.
I am trolling
OMG - My anonymous coward snail is after me again... =D
Who is general failure, and why is he reading my hard drive?
Mayam Bialik is an actress? Could have fooled me.
*sigh* Discoveries like these are all to often over sensationalized by the media.
The actual paper by Nimtz and Stahlhofen is available in the arXiv, a physics preprint server: http://arxiv.org/abs/0708.0681, I'm surprised it wasn't linked to in the article.
The non-communication theorem seems to be predicated on the idea that we cannot select a quantum state without observation, and that observation can only occur by re-entangling quantum particles. Because re-entanglement would break the prior entanglements, this would prevent using, say, electrom spins in faster-than-light communications. However, I believe that this may be predicated on a technological rather than an essential limitation as I will explain below (and provide details of an experiment which should prove or disprove my theories). Feel free to experiment along these lines. I can always find this post if you don't give me credit
In short the untested (and thought to be untestable) question is: Is the limitation one of actual shared information? Or is it one of the mechanics of quantum entanglement?
Imagine the following aparatus: pairs of photons emitted out opposite sides of an aparatus similar to the Bern fiberoptics experiments. Polarity of photons is entangled. As in Bern, we can shift that polarity and show a corresponding shift on the other side. Unlike the Bern experiments, we attach in the fiber-optic lines, small birefringent beam splitters that split the beam into different components based on polarization. All substances have refractive indexes so introducing a device which changes the refractive index for portions of the beam based on polarization components should not introduce additional quantum entanglements.
Now we should be able to test the following questions:
1) Now that we have selected streams of entangled particles without direct observation or quantum entangelment based on quantum properties, are they still entangled?
2) Can we use such a system for teleporting information across a distance connected by fiberoptic cables?
and of course the larger question:
3) Is the noncommunication theorem predicated on essental quantum limitations or is it simply a technological limitation?
LedgerSMB: Open source Accounting/ERP
Photons have no standing mass. I.e. if you were to "stop" a photon, it would cease to have mass (technically, its mass would be infinitessimal).
Einsten predicted that as an object approaches the spead of light, its mass would increase to infinity.
The question is: what does 0 * infinity equal? In this case, the photon moving at the speed of light (an infinite number of times greater than its standing mass of 0) has a small, but finite mass hence the momentum, gravity lenses, etc.
It might be more appropriate to say that a photon has an infinitessimal standing mass, and a small but finite mass while moving at the speed of light.
LedgerSMB: Open source Accounting/ERP
Fact: Everything I say is fiction.
Lots of things appear to defy the basic laws of gravity- Hot-Air balloons float upward, feathers fall slower than rocks, wood floats on water. All of these things could be used to 'disprove' gravity. Even if you know about Air Pressure and can disprove the above discrepancies, it's not evident that Gravity is constant everywhere, or that planetary motion (and solar motion) can be explained by gravity.
You are reading a copy of my copyrighted post.
- It exists. Yup.
- It has volume. Nope. It has one measureable spatial quality, which is wavelength. To ask what the other two dimensions of a photon are ('volume' implies three) is meaningless. Remember, a photon is a packet of energy, a propogating electromagnetic wave (the electric and magnetic components at right angls to each other). It has no well-defined volume.
- It is "detectable as a particle/atom or whatever". Ummm... Oh dear. A particle, in some sense, certainly: google "wave-particle duality". An atom, no.
To get back to the issue at hand, the thing which might be confusing you is that is has no rest-mass. If it *did* have rest-mass, it couldn't move at the speed of light. But it certainly does have mass in the sense that it is moving, so has kinetic energy, and, as Einstein pointed out, energy and mass are just two words for the same thing. It's energy due to its momentum is given by E=h*frequency=hc/wavelength.
What's purple and commutes? An Abelian grape.
...that was partly responsible for this whole mini media frenzy, I just wanted to add a couple things. First off, the media coverage has been (I suppose not surprisingly) all about reporting Guenter Nimtz's sensational claims without hearing from the other side. The other side, in this case, is definitely the mainstream point of view... and Aephraim Steinberg at the Univ. of Toronto makes a very compelling counter-argument. The train analogy he uses is helpful.
But if you want to get more geeky, you don't even need to use any quantum mechanics or even relativity to explain what Nimtz is observing. You can also explain it using good old classical physics. What Steinberg is saying is that the microwave, which is a packet of some finite size, gets slightly delayed as it hits the edge of the prism. There's a component of the wavefront that continues propagating into the gap past the reflective surface. (Technically, this is called the wavefront's "evanescent mode" -- meaning it has a wavelength measured in imaginary numbers... so there's no physical wave in this region of space.) And if there's a small gap separating the two prisms, the wavefront returns to the physical world, with a real wavelength again, back inside the second prism. That's what quantum physics would call "photon tunneling." The seemingly faster-than-light transmission speed is just the consequence of the wavefront's being slowed down at the boundary between prism and air. So the sum-total of time the wavefront spent in transit seems faster-than-light when you only look at one portion of its overall trip. But other portions of its trip (i.e. at that boundary between prism and air) were being slowed down.
Of course to explain this in all its gory detail -- and I've kind of done a butcher job here -- requires a lot more words than we had room for in this piece. So the train analogy had to do.
The other thing, to get even more geeky -- and extra-credit is definitely awarded to anyone who picked this up in the story -- there is no such thing as 33 cm microwaves. (Wavelength too long.) That's a typo. It's 33 mm.
Consider this a big ol' nerdy D'OH!
Well, we can mostly agree then. As I was saying, that visual aid isn't accurate at all. Doubly so if taken literally.
There are even more problems than you describe. The dragging the space frame for a rotating body (e.g., Earth) is probably more accurately described by a gas, than by a rubber sheet, for example. A rubber sheet would just get twisted and start offering more and more resistance.
It's just that noone else figure out a way to visualize those equations. There just isn't any good way, same as (at the other end of the spectrum) there's no good way to visualize something that's both particle and wave. So we're kinda stuck with it as the thing which comes the closest. Although, as you correctly noticed, not that close at all. You do have to make the mental exercise of ignoring that you use gravity to explain gravity.
But, as I was saying, if you can come up with a better one, we'll all be grateful for that.
A polar bear is a cartesian bear after a coordinate transform.
Criticism of our nations worst president will get old the day all the damage done to our Constitutional government has been undone. Not a day sooner.
Anyway, if it's off topic let the mods do their job and quit bitching.
We hope your rules and wisdom choke you / Now we are one in everlasting peace
Now we can go back to visit Einstein and laugh(ed) at his face.
Seriously, guys, don't quit your day jobs. I may have to start filtering on the "funny" comments...
LS
There is a fine line between being a cultivated citizen and being someone else's crop. - A. J. Patrick Liszkie
Afaik, Einstein and many others were presented with 'adjusted'
Maxwell Equations according Dr. Heaviside in 1875.
In 1993 Art Bell had a radio interview with Al Bielek, where
Bielek said the following:
"Thomas Bearden has gone through this also, and derived the fact
that the original Maxwell equations as written by Maxwell in the
hand written versions, which are well over a hundred years old, are
_not_ what is currently taught in the universities, because Dr.
Heaviside in 1875, because they were hard to understand, and they
could not accept the idea that in the denominator E, as the
electrostatic field, was in Maxwell's original equations stated
that it propagates instantaneously throughout the universe, which
would immediate violate all of the ideas of relativity and c being
the limiting speed of everything in the universe.
So that part has been eliminated basicly from most of the college
texts. You may have some texts that show the original but I'm not
familiar with every book that is around. But nonetheless they
normally teach the truncated version developed by Heaviside in 1875
which was an attempt to simplify those equations and make them more
understandable."
So there's something hidden from public knowledge inside Maxwell's equations.
I made a webpage about this :
"Dark Matter, a result of the heliocentric doctrine "
http://crashrecovery.org/fixedearth/
See also
"Interview with Lt. Col. Thomas E. Bearden"
by Terry Patten and Michael Hutchison
http://twm.co.nz/beard_interview.htm
Robert
How we can discover if a photon is to be fined if we can't reach it with a telelaser?
I don't think it deserve extraordinary exception from 50mph speed limit law.
New rule please,
You have to have an ID less than 100,000 to make any "You must be new here jokes". If we agree to set it much lower please disregard this post.
Sit... Speak.... Shake.... Good Dog!
A gaff is a hook for landing fish or a cockney's home. The correct word is gaffe
This experiment is one I performed in my second year of my (ordinary not honours) physics degree thirty three years ago. The tunneling takes zero time as the photon does not transit the gap. The total journey time however is limited by the speed of light in the media involved. I could dig out my project report but this is ancient history as Einstein himself first performed this as a thought experiment and explained away the apparent breaking of relativity.
I think you accidentally attached your reply to the wrong post/person.
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
So they should be allowed to break it.
Talking about light speed what if we could travel at Near Light Speed ?
These folks say it possible.
http://nlspropulsion.net/default.aspx
Mass, as far as I know, have 2 properties; inertia and gravitation.
Inertia is basically just another word for momentum, which we all agree photons do have.
Gravitational mass ( and this is just me thinking out loud ) might theoretically be subdivided into gravitational source and gravitational drain. By gravitational source I mean mass that attracts other mass (bending space), and by gravitational drain I mean being attracted to other mass (accelerated by bent space).
"Ordinary" mass acts both as gravitational source and drain of course, and light certainly acts as gravitational drain (following spacetime curvature) but does it act as gravitational source?
Now that is an interesting question.
Consider the following scenario. We have an extremely heavy particle (say the mass of a small moon, I didn't say it was a very realistic scenario..) and it's anti-particle out in empty space at rest to each other. Slowly their gravitational fields will cause them to accelerate towards each other faster and faster, ending in a violent collision where all their mass and kinetic energy is released as photons. What happens to the gravitational field? If it disappears as the mass is converted to energy, what about the kinetic energy that was picked up as the particles accelerated down each others gravitational wells? If photons acts as gravitational source, then the gravitational field would still be there, and the photons would loose the energy climbing out of it. If not, did the "conservation of energy"-law just just look the other way and pretend it didn't happen?
And what about the relativistic mass that is gained with velocities close to c? It certainly has inertia, making it hard and harder to accelerate further, but does it also act as a gravitational source? If it did, it sounds like changing the frame of reference to close to c would dictate that planets ought suddenly to collapse from the relativistic mass and become black holes. Which I'm pretty certain it doesn't..
Jan Ove
HA HA HA!
No doubt Erwin is turning over in his grave, laughing at this one.
But he might not be.
Perhaps he's just in a 1/2 spin...
Shall we consult the quantum oracle?
.
- aqk
F U
It is an incorrect assumption of path that leads to claims of superluminal propagation with prisms. Evanescent fields (non-propagating fields) give everyone headaches and now headlines. But the claims were debunked in 2001. Check out: http://utol.ecen.ceat.okstate.edu/papers/paper70.p df
or
http://utol.ecen.ceat.okstate.edu/papers/paper66.p df
Feel free to educate me.
This is not a signature.