Speed of light beaten - time travel possible!

[Space cat]

-- who calibrates the oscilloscope though???

We send ours away for calibration every year. I can't say where because that would be advertising.

Yes.....maybe they are just making it all up

A nanosecond is a long time in the subatomic world. "Short" is the time it takes light to cross a nucleus - about 10exp(-23) seconds.

I've got some old (around 1990) software that shows the periodic table with chemical and nuclear properties of all the elements. It gives the half-life of Be8 as a 10exp(-15) seconds, which is a millionth of a nanosecond. Maybe that was the limits our clocks at the time because more recent meaurements are about ten times shorter.

 

[Biker1959]

That's ok! I don't understand it either, except that none of the claims have yey been verified. So they will run more experiments to find out whether the data is corrrect (or not) over the next 6 months.

That's fine, when they have .....they can send it over for my appraisal

Someone is quick at wikipedia!

From http://en.wikipedia.org/wiki/Speed_of_light

In late September 2011, physicists working at CERN obtained results that seemed to suggest beams of neutrinos had travelled faster than the speed of light.[46] These findings have yet to be independently verified.[47]

 

[Space cat]

No, it's not. Look up, for example, Cherenkov radiation.

Cherenkov radiation occurs when a particle travels through a medium faster than the speed of light in that medium.

Example: The speed of light in water is about 0.72c. That's why, when you look down into water, things appear closer than they really are. If a particle enters the water faster than that, atoms ahead of it don't know it's coming until it hits them. They have no chance to get out of the way. What you get is the equivalent of a sonic boom.

 

[Monkeh]

No, it's not. Look up, for example, Cherenkov radiation.

Cherenkov radiation occurs when a particle travels through a medium faster than the speed of light in that medium.

Example: The speed of light in water is about 0.72c. That's why, when you look down into water, things appear closer than they really are. If a particle enters the water faster than that, atoms ahead of it don't know it's coming until it hits them. They have no chance to get out of the way. What you get is the equivalent of a sonic boom.

Which is still faster than the speed of light. The speed of light in a vacuum (c) and the speed of light (say, in our own atmosphere) are two different things.

I did explicitly say 'not in a vacuum', did I not?

 

[longdogs]

I was wondering, - If you had a powerfull torch in space and aimed it towards earth, the beam would be travelling at the speed of light. But, what if you threw the torch forwards towards earth, would the light arrive quicker?

 

[sooey]

No, but the wavelength would be shorter....or something like that.

 

[Space cat]

I did explicitly say 'not in a vacuum', did I not?

You did indeed but then implied that light could travel faster if it wasn't in a vacuum. Actually, it travels slower in anything other than a vacuum. Cherenkov radiation occurs precisely because a particle can travel through a medium (like water) faster than light in that medium.

No, but the wavelength would be shorter....

Correct. It's the same effect as you get when you hear a siren moving towards you. The sound reaches you at the same speed but at a higher frequency (shorter wavelength).

What's odd about light is that if you try to run away from it, you'll find that you can't do it. It will travel towards you at the same speed no matter how fast you try to escape - but the wavelength will get longer. The curious fact is that if somebody else, who isn't running, measures the speed of the same light they will get the same answer. This is the paradox that set Einstein thinking - and so Relativity was born.

 

[Monkeh]

I did explicitly say 'not in a vacuum', did I not?

You did indeed but then implied that light could travel faster if it wasn't in a vacuum. Actually, it travels slower in anything other than a vacuum. Cherenkov radiation occurs precisely because a particle can travel through a medium (like water) faster than light in that medium.

I implied no such thing.

 

[Space cat]

I implied no such thing.

Then I guess I misinterpretted this:

Oh, and the speed of light can be exceeded anyway. Just not in a vacuum.

 

[empip]

How good is the evidence so far?

The first thing is that it comes from an impeccable source: a large international group of scientists at Cern, the European Organisation for Nuclear Research, which is the world’s largest and most respected physics laboratory. Their scientific paper appears on the preprint server arXiv.

The experiment, known as Opera, beams neutrinos – ghostly subatomic particles with infinitesimal mass and no electric charge – from an accelerator at Cern headquarters outside Geneva to underground detectors at Gran Sasso in central Italy. Analysis of 15,000 neutrino detections shows that they complete the 730km journey 60 nanoseconds sooner than they would travelling at the speed of light...

The Paper... http://arxiv.org/ftp/arxiv/papers/1109/1109.4897.pdf

-0-

 

[sooey]

I implied no such thing.

Then I guess I misinterpretted this:

Oh, and the speed of light can be exceeded anyway. Just not in a vacuum.

I misinterpretted that too, probably because the speed of light that was being discussed as being broken in this thread, was the speed of light in a vacuum.

 

[Monkeh]

I implied no such thing.

Then I guess I misinterpretted this:

Oh, and the speed of light can be exceeded anyway. Just not in a vacuum.

You did. I said the speed of light can be exceeded, but not when in a vacuum. I'm not entirely sure how you can misinterpret that.

 

[Alarm]

Oh, and the speed of light can be exceeded anyway. Just not in a vacuum.

Well maybe not a hoover but a Dyson ?

 

[Monkeh]

Oh, and the speed of light can be exceeded anyway. Just not in a vacuum.

Well maybe not a hoover but a Dyson ?

Where's my can of troll spray..

 

[Susiejb]

my smiley was for Alarm ...... landed a bit late

must be the speed of light