23 Apr 07
Originally posted by sonhouseyou missed my point. think about it . .. information is traveling faster than the speed of light, because the phenomenon communicates information about the arc's production: wavelengths, frequencies, mass, . .. . . .it's just a fascinating reality, don't freak out, you started it . . now go make a move in that game that is waiting for you
But you still can't use it to send information faster than C. Not even gravity can go faster than C. Big Al proved that.
23 Apr 07
Originally posted by coquetteSuppose the following experiment:
you missed my point. think about it . .. information is traveling faster than the speed of light, because the phenomenon communicates information about the arc's production: wavelengths, frequencies, mass, . .. . . .it's just a fascinating reality, don't freak out, you started it . . now go make a move in that game that is waiting for you
We have three points - A situated on earth, B and C situated on Moon, quite far from each other.
Then we send information from A in a laser beam first to B, then we sweep the laser point from B to C. The laser point goes from B to C in a supra luminous speed, and no one argues about that.
The effect of this is that after B has gotten the information first and C gets the same information a picosecond later. Then it is easy to get the impression that the information actually did travel from B to C in a velocity faster than light. Not so.
The information gets from A to B in velocity of light, then from A to C in the velocity of light. No information goes from B to C.
coquette and everyone else with the same opinion including Einstein are right. Information can never propagate faster than light.
23 Apr 07
There is a way come to think. The restriction is local, which means that if the space-time you are in is expanding you can have two things seperating at faster than light speed. The objects are moving slower than light relative to observers close to them, but because the manifold is expanding you get a sort of inverted event horizon beyond which points are moving away from us faster than light speed. See http://en.wikipedia.org/wiki/De_Sitter_space for a fairly mathematically intensive discussion or the entry on De_Sitter_universes (there's a link in the preamble) for a less intense discussion.
23 Apr 07
Originally posted by toyboy64Everything can be faster than the speed of light according to this new study.
This is a joke😀 What is faster than the speed of light. Answer on May 1st or until someone guesses it.
True story from a web link outta harvard....just google experiment slowed down speed of light.
"Two years ago we slowed it down to 38 miles an hour; now we've been able to park it then bring it back up to full speed." Lene Hau isn't talking about a used motorbike, but about light – that ethereal, life-sustaining stuff that normally travels 93 million miles from the sun in about eight minutes.
Less than five years ago, the speed of light was considered one of the universe's great constants. Albert Einstein theorized that light cannot travel faster than 186,282 miles per second. No one has proved him wrong, but he never said that it couldn't go slower.
Hau, 41, a professor of physics at Harvard, admits that the famous genius would "probably be stunned" at the results of her experiments. Working at the Rowland Institute for Science, overlooking the Charles River and the gold dome of the state Capitol in Boston, she and her colleagues slowed light 20 million-fold in 1999, to an incredible 38 miles an hour. They did it by passing a beam of light through a small cloud of atoms cooled to temperatures a billion times colder than those in the spaces between stars. The atom cloud was suspended magnetically in a chamber pumped down to a vacuum 100 trillion times lower than the pressure of air in the room where you are reading this.
23 Apr 07
Originally posted by uzlessWhen we talk about the speed of light we normaly talk about speed of light in vacuum. We already know that the light not always go at 300.000 km/sec, this is kid stuff. Light traverses glass with a considerable lower speed, for one example.
Everything can be faster than the speed of light according to this new study.
True story from a web link outta harvard....just google experiment slowed down speed of light.
"Two years ago we slowed it down to 38 miles an hour; now we've been able to park it then bring it back up to full speed." Lene Hau isn't talking about a used motorbike, but ab ...[text shortened]... 00 trillion times lower than the pressure of air in the room where you are reading this.
24 Apr 07
Originally posted by FabianFnasIt answers the question posed by the original thread....
When we talk about the speed of light we normaly talk about speed of light in vacuum. We already know that the light not always go at 300.000 km/sec, this is kid stuff. Light traverses glass with a considerable lower speed, for one example.
25 Apr 07
Originally posted by FabianFnasThere is Cherenkov radiation that happens when something goes faster than the speed of light IN THAT MEDIUM, which shows up in water used for cooling nuclear reactors and fusion reactor experiments, electrons may travel faster than light in water and generate this light that results from the interactions.
When we talk about the speed of light we normaly talk about speed of light in vacuum. We already know that the light not always go at 300.000 km/sec, this is kid stuff. Light traverses glass with a considerable lower speed, for one example.
The only thing even in the bad science of Tachyons which have been proven not to be possible, tachyons would never go SLOWER than the speed of light. No Tachs have ever been found and most likely never will. ( Tachy science if you ask me🙂
26 Apr 07
Originally posted by sonhouseWho's proved that tachyons don't exist? When you write down Electro-Weak theory the Higgs sector is tachyonic - the vacuum is unstable and when you expand around the minimum of the potential the resulting effective theory you get is non-tachyonic, but that doesn't stop the basic theory being written down in terms of a particle that has an imaginary mass.
There is Cherenkov radiation that happens when something goes faster than the speed of light IN THAT MEDIUM, which shows up in water used for cooling nuclear reactors and fusion reactor experiments, electrons may travel faster than light in water and generate this light that results from the interactions.
The only thing even in the bad science of Tachyons ...[text shortened]... light. No Tachs have ever been found and most likely never will. ( Tachy science if you ask me🙂
26 Apr 07
Originally posted by DeepThoughtDon't know if you saw the series "The elegant universe" by Brian Greene, here is the link:
Who's proved that tachyons don't exist? When you write down Electro-Weak theory the Higgs sector is tachyonic - the vacuum is unstable and when you expand around the minimum of the potential the resulting effective theory you get is non-tachyonic, but that doesn't stop the basic theory being written down in terms of a particle that has an imaginary mass.
http://www.pbs.org/wgbh/nova/elegant/
That was the source for my statement tachyons are proven not to exist. Something in string theory I think. But of course string theory has so many solutions, there could be one which allows tachyons anyway so it's probably still up in the air.
26 Apr 07
Originally posted by sonhouseIn Electro-weak theory the tachyonic vaccuum is unstable, which is why you get symmetry breaking. It's not clear to me if the unbroken theory contains "physical tachyons" or if it's a mathematical artifact. I've been out of the field for about a decade and have no idea what the current state of thinking about all this stuff is. Thanks for the link, I'll give that a read when I've got time.
Don't know if you saw the series "The elegant universe" by Brian Greene, here is the link:
http://www.pbs.org/wgbh/nova/elegant/
That was the source for my statement tachyons are proven not to exist. Something in string theory I think. But of course string theory has so many solutions, there could be one which allows tachyons anyway so it's probably still up in the air.
I wonder if tachyonic particles could provide an explanation for dark matter. Dark matter (apparently) has negative pressure, which is such an odd concept that it seems to me that you'd need something like a faster than light particle to bring it about.