[luke warm]

if true, what exactly does it mean?

Quote

A pair of German physicists claim to have broken the speed of light - an achievement that would undermine our entire understanding of space and time.

According to Einstein's special theory of relativity, it would require an infinite amount of energy to propel an object at more than 186,000 miles per second.

However, Dr Gunter Nimtz and Dr Alfons Stahlhofen, of the University of Koblenz, say they may have breached a key tenet of that theory.

The pair say they have conducted an experiment in which microwave photons - energetic packets of light - travelled "instantaneously" between a pair of prisms that had been moved up to 3ft apart.

Being able to travel faster than the speed of light would lead to a wide variety of bizarre consequences.

For instance, an astronaut moving faster than it would theoretically arrive at a destination before leaving.

The scientists were investigating a phenomenon called quantum tunnelling, which allows sub-atomic particles to break apparently unbreakable laws.

Dr Nimtz told New Scientist magazine: "For the time being, this is the only violation of special relativity that I know of."

link

[dicklont]

It means we will boldy go where no man has gone before.

[Lobowolf]

It means a few more people might realize that the pronounements of scientists are not unassailable truths, but the best explanations available at the time.

[gwnn]

Small particles don't really have velocity and position and all that jazz. Astronauts usually do. I would wait with the revolutionary articles until they repeat their experiments with an apple. Or at least a tardigrade.

[kenberg]

Whatever it means, it's exciting.

Einstein developed his theory at least partly in response to experimental facts that could not be explained within the framework of Newtonian theory. It worked well, but now there are more facts. Science marches on. It is most important for people to understand that when this happens it is cause to celebrate the self-examination and self-correcting nature of the scientific enterprise. Knowledge increases, we need to enlarge and correct the underlying theory. Newton and Einstein were both great scientists. There will be more greatness in the future.

Others are in a better position than I to carefully explain these theories.

[Fluffy]

microwave photons? I am no big expert but photons have no mass. I always understood relativity as to that a mass need infinite energy to reach speed of light.

And that is because mass is not constant, and the faster you go, the more mass you "relatively" have, and the more energy you need to accelerate.

I don't really understand why photons will travel at infinite speed, let alone how can anyone test it with any accuracy O_o

But well, if only light can travel faster than light, maybe light can travel in time. I remember thinking of this weird theory long ago. I Wanted to make an optic cable to my computer and listen to a know port. After all who knows, maybe I could send messages to myself from the future!


Oh, one more thing, if I understood it correctly, if a mass gets to light speed, his relativity mass will be infinite. That would generate infinite gravity for the whole universe, not something we are gonna survive.

Now gerben will come and tell me how wrong I am

[blackshoe]

Photons have no rest mass - they're never at rest, they always move. At the speed of light, according to Relativity theory.

The mass formula is m=m0/sqrt(1-v^2/c^2). Since the rest mass (m0) of a photon (for which v=c) is zero, m is 0/0, which means "undefined".

If a photon can be demonstrated to have moved faster than light, then both Special and General Relativity have a problem. OTOH, on the scale of the speed of light, 3 feet ain't much. I remember an early attempt (by myself, so I mean "early in my life" not in the history of physics) to duplicate the michaelson-morley experiment, which disproved the then-prevalent theory of a "luminous aether". I concluded initially that the speed of light was, as I recall, something close to 29 miles per hour. Then I found the error in my experimental setup.

[Winstonm]

Lobowolf, on Oct 26 2009, 06:01 PM, said:

It means a few more people might realize that the pronounements of scientists are not unassailable truths, but the best explanations available at the time.

Hopefully, people will learn the same truth about religious doctrines, too.

[kfay]

Seems alright to me.

A few years ago I read an interesting article about some physicists who were using optic fibers and firing lasers through them such that the laser came out the other side of the cable before they even entered. I'll try to find it.

[Al_U_Card]

Theoretical physics, as mathematical as it is, is full of fudge factors, approximations and undefined conditions. It does serve us remarkably well for our needs at present but is far from an all-encompassing explanation for even the whats and whens....forget about the whys and wherefores

[mike777]

Guys pls note this was experimental physics...not theoretical


see the spooky action at a distance or two hole experiments.


http://en.wikipedia....tance_(physics)



http://en.wikipedia....slit_experiment

[MattieShoe]

I thought this was pretty normal type stuff for quantum physics. Haven't we known for 40+ years that either time travel or spooky action at a distance is required to explain observed weird quantum effects?

[mike777]

MattieShoe, on Oct 27 2009, 12:50 AM, said:

I thought this was pretty normal type stuff for quantum physics.  Haven't we known for 40+ years that either time travel or spooky action at a distance is required to explain observed weird quantum effects?

I think you assume "normal" or "everyone knows this" is a bit too much

Lets back up and assume 90% of us do not know this or understand this.

I grant I read this stuff 30-40 years ago and I am non math guy.

[Hanoi5]

If they did it in a galaxy far away a long time ago, why wouldn't we?

[luke warm]

Winstonm, on Oct 26 2009, 08:25 PM, said:

Lobowolf, on Oct 26 2009, 06:01 PM, said:

It means a few more people might realize that the pronounements of scientists are not unassailable truths, but the best explanations available at the time.

Hopefully, people will learn the same truth about religious doctrines, too.

huh?

[gwnn]

the link doesnt work for me

http://www.telegraph.co.uk/science/science...d-of-light.html

this does

Anyway I'd be happy if someone finally came up with something new, it's a sad state of affairs that most recent Physics Nobel Prize are awarded for research in the 70's or older, this years for optical fibers. I mean it's nice to have fast internet but is this really the best all the millions and millions of cutting edge physicists can come up with . And I'm not implying that I could do better at choosing a worthy prize winner or I will do something revolutionary, in fact I'm not criticizing anybody. It just makes me a little sad.

Anyway wikipedia has another opinion.

Quote

He and his coauthors have been publishing papers on this subject since 1992,[1] which involve light beams, prisms, and mirrors.

1994 Nimtz and Horst Aichmann shown an experiment at the laboratories of Hewlett-Packard using microwaves through a straitened passage of a waveguide. Nimtz says that the Frequency modulated (FM) signals transports the 40th symphony of Wolfgang Amadeus Mozart 4.7 times faster than light due to the effect of quantum tunnelling.

In a 2007 paper[2] described an experiment which sent a beam of microwaves towards a pair of prisms. The angle provided for total internal reflection and setting up an evanescent wave. Because the second prism was close to the first prism, some light leaked across that gap. The transmitted and reflected waves arrived at detectors at the same time, despite the transmitted light having also traversed the distance of the gap. This is the basis for the assertion of faster-than-c transmission of information.

However, Chris Lee has stated that there is no new physics involved here, and that the apparent faster-than-c transmission can be explained by carefully considering how the time of arrival is measured (whether the group velocity or some other measure). [3] A recent paper by Herbert Winful[4] was written in order to point out errors in Nimtz' interpretation.[2] According to that article, far from contradicting special relativity, in reality Nimtz has rather provided a trivial experimental confirmation for it.

Aephraim M. Steinberg [1] of the University of Toronto has also stated that Nimtz has not demonstrated causality violation (which would be implied by transmitting information faster than light). Steinberg also uses a classical argument.[1]

The understanding of Nimtz and Stahlhoven is that tunneling is the one and only observed violation of special relativity[5] but according to them, that is not a violation of causality: due to the temporal extent of every signal it is impossible to transport information into the past. They claim that tunneling can be explained with virtual photons like Richard Feynman predicted.[6]

http://en.wikipedia....C3%BCnter_Nimtz

[helene_t]

Wikipedia (http://en.wikipedia....C3%BCnter_Nimtz) has a more recent article on the issue. Apparantly, the experiment was flawed. (sorry just noticed Csaba posted the same)

Quote

It means a few more people might realize that the pronounements of scientists are not unassailable truths, but the best explanations available at the time.

Yeah that is pretty much the definition of science. Not sure what this story tells us. Maybe that there is a huge difference between a genuine scientific revolution, and a single sensational experiment that hasn't been confirmed by peers.

[cherdanno]

Lobowolf, on Oct 26 2009, 06:01 PM, said:

It means a few more people might realize that the pronounements of scientists are not unassailable truths, but the best explanations available at the time.

I would call it "best available models", in the case of physics at least.

[helene_t]

MattieShoe, on Oct 27 2009, 06:50 AM, said:

I thought this was pretty normal type stuff for quantum physics. Haven't we known for 40+ years that either time travel or spooky action at a distance is required to explain observed weird quantum effects?

Quantum teleportation of an object would teleport the information required to reassemble the object. Not sure if I quite understand the difference between an object and the information required to reassemble it, but I think this microwave photon story is different.

[phil_20686]

Perhaps what we shouhld learn from this is that science is alot harder than the media makes it appear.

I know nothing in particular about this experiment, but normally when these claims are mmade there turns out to be an error in understanding/interpretation. Also, they normal study light in some object that has a high refrative index, so violations of the speed of light normally arent what you think.

Here i looked it up specially:
http://arxiv.org/ftp...8/0708.0681.pdf

Amusingly the authers are rather more spot on than the article about the paper. Essentially tunneneling happens in zero time or close to, but you can only tunnel across very short spaces as the wave equation needs to exist on the far side of the barrier, and this is typically of order of one wavelength. There is no violation of causality because of the difficulty of determining the exact position/time measurements. In particularl the faster than light propagation is caused by a virtual photon, which obviously can;t be measured, since it isnt real.

What needs to be disarded is the idea of a photon being in a particular place. It isnt really anywhere, the wave function propagates across the barrier, and existrs on teh far side, and when the wave function interacts the wave function will collapse localising the photon. If the interaction is with the little tail of the wave function on teh far side of the barrier then the photon becomes localised on the far side, but it's a little odd to talk of causality violation in this case, as the photon wasnt really anywhere before it was 'here', so you cant really talk of a speed in the clsssical sense for a tunneling procedure.

Information transfer is rather more complicated, and I don't fully understand it myself.