is light really the fastest phenomena in the universe???

[neelam]

hi guys i was wondering is light really the fastest phenomena in the universe?or is it the known fastest medium?

there might might be some planet in the universe which may be spinning on its axis faster than the speed of light.

[Matthew.Blake]

The only thing faster than light is gossip I'm afraid.

[tinvek]

and the speed a fart spreads in a lift

[Rosanella]

hi guys i was wondering is light really the fastest phenomena in the universe?or is it the known fastest medium?

there might might be some planet in the universe which may be spinning on its axis faster than the speed of light.

Yes, as far as we know. I don't think that there could be a planet spinning faster than light, in fact, it wouldn't even make it to yet another rotation once it reaches about 365.4 km/s, let alone ~ 3.0 x 10^6 km/s (the speed of light) because if would tear itself apart due to centripetal forces overcoming gravity.

It just doesn't work like that.

[crovax]

Well, if nothing has changed since I finished my physics course in University 3 years ago than speed of light is the fastest way for object or information to travel. Hovewer that was not totally physics oriented faculty so we may have missed some very exotic stuff (though I remember studying lots of exotic stuff).

[Matthew.Blake]

Yes, as far as we know. I don't think that there could be a planet spinning faster than light, in fact, it wouldn't even make it to yet another rotation once it reaches about 365.4 km/s, let alone ~ 3.0 x 10^6 km/s (the speed of light) because if would tear itself apart due to centripetal forces overcoming gravity.

It just doesn't work like that.

Gravity will be providing some of the centripetal force holding the planet's rocks in a circular path. What happens is the centripetal force required becomes larger than gravity and the tension between adjoining pieces of rock can supply so the rock no longer moves in a circular path.

[acey]

When electron spin was first proposed in 1925 it was pointed out that under the required conditions the surface of the electron would be moving faster than light. Electrons have subsequently been interpreted as "point particles".

George Eugene Uhlenbeck - Wikipedia, the free encyclopedia

There are hypothetcial "tachyons" that would travel faster than light, but you get all sorts of horrible consequences that we'd probably have noticed by now, so these theories don't have much support.

Tachyon - Wikipedia, the free encyclopedia

By "speed of light", of course, we mean the speed of any radiation whose corresponding particle has zero rest-mass, in other words all electromagnetic and gravitational radiation. And that seems to be the ultimate speed limit.

Gravitational wave - Wikipedia, the free encyclopedia

But when light passes through a medium it slows down, and in those cases it's possible to beat light (resulting in Cerenkov radiation - the optical equivalent of a sonic boom).

Cherenkov radiation - Wikipedia, the free encyclopedia

Gunter Nimtz has done experiments using quantum tunnelling and in 1994 he claimed to have transmitted Mozart's 40th symphony at 4.7 times the speed of light, but his interpretation of his results is contested.

Günter Nimtz - Wikipedia, the free encyclopedia

[acey]

One more thing, about spinning planets/stars etc:

If a spinning body decreases in radius then its rotation rate increases (because of conservation of angular momentum), so when stars collapse the resulting neutron star spins very fast (as much as 1000 times per second). So you could guess that if a star is initially large enough, and shrinks small enough, then there's no limit on how fast its surface could be moving, and you might expect black holes to spin "faster than light". The problem was studied by Kerr in the 1970s and he found that there is in fact a maximum rotation rate for black holes (based on general relativity).

Rotating black hole - Wikipedia, the free encyclopedia

[661-pete]

Gunter Nimtz has done experiments using quantum tunnelling and in 1994 he claimed to have transmitted Mozart's 40th symphony at 4.7 times the speed of light, but his interpretation of his results is contested.

I prefer to listen to Mozart's no. 40 at its correct tempo: Molto allegro. I doubt if the first violins could keep up at 4.7 times C!

Very strange things start happening to a rotating body when its surface is moving at close to the speed of light (viz. the Tipler cylinder and other weird phenomena, including time travel!) But I think space-time would so distort itself, that it would not be possible for material to appear to move past other material at more than the speed of light. no matter how fast you think you are spinning your object! Einstein enforces his speed limit well!

That is not to say that an entity which is not a material body nor anything carrying information, cannot appear to 'move' faster than light though! Consider the following experiment: you place a very powerful laser on a turntable (on Earth) and project its beam on the Moon (about 400000 Km away). If you now rotate the turntable at a rate of say, one radian per second (about 1 rev. every 6 seconds) then the spot of light projected on the moon will appear to sweep across its surface at 400000 Km/s - which is more than the speed of light. But this is quite OK in Relativity because neither matter nor information are being transmitted from point to point at that speed.

[jonbarr87]

I thought technically "energy" and the force of gravity were almost instantaneous? But I may have fallen asleep in that part.....

[bish]

This may be going off track, and no doubt somebody will correct me. Apparently there are subatomic particles that act in pairs so that if one spins in a particular direction the other will do so too at exactly the same time whatever the distance. Not sure if this counts as information between them travelling instantaneously.

[jonbarr87]

I think thats delving into the quantum side of life.... which is ungodly hard to comprehend IMO lol (if memory serves me right)

[Matthew.Blake]

This may be going off track, and no doubt somebody will correct me. Apparently there are subatomic particles that act in pairs so that if one spins in a particular direction the other will do so too at exactly the same time whatever the distance. Not sure if this counts as information between them travelling instantaneously.

How would you measure the spin of the 'receiving' electron to look for the change from superposition of states to a well defined state without changing it yourself?

[acey]

This is the Einstein-Podolsky-Rosen (EPR) thought experiment, considered in detail by Bell.

The separated particles are entangled in the sense that knowing the spin of one enables you to know the spin of the other. That's like splitting a pair of gloves, finding you've got the left one, and knowing the other must be right. The quantum twist is that there's a choice of measurements that can be made on the particle, leading to a choice of predictions about the other, and these choices are mutually exclusive. Namely, you could measure the spin in the x-direction and thus infer the x-spin of the other particle. Or you could have chosen y- instead, but the uncertainty principle says you can't have x- and y- spins simultaneously, and the Copenhagen interpretation of quantum mechanics says the x- or y- spin values don't even exist until they're measured. The implication is that your choice to measure x-spin (rather than y) sends an instantaneous signal to the other particle, telling it to have a certain value of x-spin.

In fact you can't send information in this way (you can't choose the spin value in any direction, only decide which one to measure), so it doesn't violate relativity. But it still appears that there's a "non-local" connection between the separated particles, confirmed by Bell's theoretical analysis and some famous experiments by Alain Aspect in the 1970s.

Bell's theorem - Wikipedia, the free encyclopedia

[bish]

Thanks for clearing that up acey. It was something I had read about a while ago (may have been 'A Brief History of Time') but couldn't remember all the details!

[Theninjagecko]

Well, if nothing has changed since I finished my physics course in University 3 years ago than speed of light is the fastest way for object or information to travel. Hovewer that was not totally physics oriented faculty so we may have missed some very exotic stuff (though I remember studying lots of exotic stuff).

Not really. I believe an experiment was done that allowed electrons to flow through a piece of steal and reach the other end faster than light could do the same distance. Something to do with quantum tunneling.

[Tim]

I suppose if things were travelling faster than the speed of light, not only would they be invisible, time would have no bearing on them, and they would be able to pass through objects. I wonder how you would go about detecting something with those properties?

[lulu57]

Nothing beats the speed of a £5 note as it transmutes into coppers...

[vhbelvadi]

hi guys i was wondering is light really the fastest phenomena in the universe?or is it the known fastest medium?

there might might be some planet in the universe which may be spinning on its axis faster than the speed of light.

If there is anything faster than light, time dilation occurs and everyting becomes meaningless.

[PS: If you don't know what time dilation is, let me know]

[vhbelvadi]

I suppose if things were travelling faster than the speed of light, not only would they be invisible, time would have no bearing on them, and they would be able to pass through objects. I wonder how you would go about detecting something with those properties?

Interesting, TJ; but would your argument not support the fact that there may be things travelling faster than light - it's just that we haven't been able to detect them (yet)?

And nice quote: ...trying to fill the unforgiving minute with sixty seconds' worth of distance run......

[MeerkatinBKK]

Could it be said that in a sense space itself travels at FTL speed? The universe is thought to be over 90bn ly across, yet is less than 14bn years old. So in effect a galaxy far enough away from us (eg 15bn ly away) has appeared to have moved away from us FTL. Of course in reality it hasn't, but the expansion of space gives us that illusion.

Or do I the wrong end of the stick have? Once again.

Nick

[vhbelvadi]

Could it be said that in a sense space itself travels at FTL speed? The universe is thought to be over 90bn ly across, yet is less than 14bn years old. So in effect a galaxy far enough away from us (eg 15bn ly away) has appeared to have moved away from us FTL. Of course in reality it hasn't, but the expansion of space gives us that illusion.

Or do I the wrong end of the stick have? Once again.

Nick

Personally, I don't think so. As I see it, if space is tralvelling FTL, then everything in space - including us - is travelling FTL. So time dilation occurs everywhere.

WAIT! On second thoughts, if everything travels FTL, and if everything has time dilation, then woun't life be normal (at FTL speed, though)?

Hmmm...interesting!

[Milamber]

Yes, because it's relative. However, it would mean the universal speed limit is doubled, no?

Arthur

PS - Did a certain Mr Pratchett not once postulate that the unit of inheritance was faster than light? If the King dies on one side of the planet, and his son is on the other, light would take (allowing for the corner) maybe half a second. And yet, at the instant of the King's death, the son is King - the inheritance particle, and thus the Kingly mantle, having translated instantly across the intervening distance.

[narrowbandpaul]

beat me too it.

its called the de Sitter Horizon (iirc). Here the expansion of the universe, the Hubble Flow, is greater than the speed of light. Any object that passes through the horizon, or any object that the horizon passes through depending on how you look at it, is forever lost. We recieve no light from them.

Is this allow by relativity. Yes.

Information is restricted to slower than light travel, but spacetime that carries the galaxies can travel faster than light. This is surely the fastest 'thing' in the universe, the universe itself!

[vhbelvadi]

beat me too it.

its called the de Sitter Horizon (iirc). Here the expansion of the universe, the Hubble Flow, is greater than the speed of light. Any object that passes through the horizon, or any object that the horizon passes through depending on how you look at it, is forever lost. We recieve no light from them.

Is this allow by relativity. Yes.

Information is restricted to slower than light travel, but spacetime that carries the galaxies can travel faster than light. This is surely the fastest 'thing' in the universe, the universe itself!

Must give a thought on this. . .