Faster than the speed of light

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Big Bang Singularity

The matter and energy present in this universe may come from the black hole radiation from the big bang singularity!
 
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This question goes back to the first couple of posts.
Posted By: marcus
Viper, you and I are receding at twice the speed of light from the people (if there are any) living in a certain galaxy which was observed only last year.
I don't understand how this is possible. I always believed that anything with mass could not travel at or over c. Isn't it true that its mass will increase to infinity when it reaches c? Mentat offered an explanation stating that it could be observed traveling >c using the redshift. I know what the redshift is, but how does that make it possible for something to travel >c?
-HBar
 
  • #53
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we're only moving 2c relative to people oppostite us in the galaxy. we're still moving far below c relative to c itself. (which is the constant) and so are they.
 
  • #54
If you put a laser on a turntable, and spin it around really fast then the 'dot' on a far away wall can be made to appear to travel faster than light.

Similarly if you look up at the night sky and spin around then the stars in the distance will appear to travel faster than light.

The 'trick' in both of these cases is the concept of an inertial frame. In both cases the 'objects' are accellerating but no forces are acting on them. For the stars your not in an inertial frame and for the 'dot' it is because the dot isn't actually a thing. it's all in your head.

I suppose if space is expanding then its definitly NOT an inertial frame.


P.S.

Don't the electric and magnetic forces individually act instananiously at a distance.
 
  • #55
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I liked your post, Funkee!

However, I don't quite get it about the light. True, it has no mass, but it has energy, and isn't mass just a certain state of energy? I certainly wouldn't consider it to be fit for this case...
 
  • #56
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Special Relativity(SR) states that all observers should observe light travelling at c by contracting making time faster. If someone travels >c, he should contract to minus length and time becomes negative, which means that you form a body of antiparticles.

But if you travel at c, which requires infinty energy, would contract to zero size and time would be infinitely fast, which is equals to zero time. This would prove that infinty and zero are the same. [?]

Reply to tail: I'd give you a clue. A photon has a mass at rest that is zero.
 
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  • #57
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Originally posted by physicskid Reply to tail: I'd give you a clue. A photon has a mass at rest that is zero. [/B]
Wrong, as there are no photons at rest.

'Rest mass' is a term not used very often nowadays, as it implies something that is not.
 
  • #58
Funkee
What about quantum tunneling? They recorded data onto a laser beam and induced it to travel at 5c via quantum tunneling. I had always assumed that tunneling would surpass time, happening "immediately". But how come it stops at 5c?

And suppose we had a film with a frame rate high enough to view the particle, if we could see it that is, going by, and that if we slow down the film we could see the particle at a position between the starting point and the destination, although quantum tunneling, as I understand it prescribes one particle can just as easily tunnel to a point 100 billion light years away, which is the supposed benefit and possible use for tunneling for time travel, yet even at 5c or a limited speed, it would take far too long to get there.

Or is this "speed" just a measure of how long it will take to "tunnel" its way? It would take a second to tunnel 1,500,000 km? (5 x 300,000). Why the delay? And why this exact delay? Can it be altered? Can it be bent and stretched with a gravitational force proving that it indeed moves through space time, but if the path is unaffected can we suppose that it has simply created a wormhole in spacetime?
 
  • #59
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Whatever you have seen in the news, and whatever you may have assumed, no experiment has been done which has anything travelling at faster than c, the speed of light in a vacuum. Either the experiments worked with non standard media where their definition of "speed" or even "travel" is not what you think, or they confused phase and group velocity, or the reporters flatly misrepresented the experiment.
 
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Funkee
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Originally posted by Funkee
Really now? That the experiment in Cologne, headed by Nimtz encoded Mozarts 40th symphony onto photons and produced the signal that travelledat nearly 5c. 4.7c to be precise

Here are all the Faster Than Light experiments to date including the mentioned:

http://www.aei-potsdam.mpg.de/~mpoessel/Physik/FTL/tunnelingftl.html
Exactly the kind of reporting junk I was talking about. See this, for starts.
 
  • #62
Funkee
Well that simply goes back to my question regarding quantum tunneling. Whether or not it is a transposition of a particle, or one "wormhole-like" surpassing time.

There was another study that I can't locate regarding separated entangled electrons and their spins, in that reversing a spin of one, will also reverse that of the other. Are these electrons communicating at a certain speed, such as c, taking 1 second to change if they are 300,000km apart? Or does it surpass time, happening immediately regardless of distance? If so how, but if it takes time, and we supposedly had an atom where two electrons would be such a distance apart, what effect does it have on the atom if for 1 second the electrons in the orbital are spinning in the same direction? Then we can apply thisw to the microscopic scale, where for an unimaginably but existant small period of time, the 2 electrons spin in the same manner. Does it possibly change the interaction of one atom with another, or does anyone have an idea onto what'll happen within that period of time?
 
  • #63
Funkee
Well my own question was answered by a friend of mine. For those of you unaware, it is Bell's theorem.

It states that due to the uncertainty of the position of an electron, it could be a light year away, and not affect any delay in a reaction, Einstein calling it "Spooky Action At A Distance."
 

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