# A question about supposed faster than light movements.

• Mentat
Originally posted by MajinVegeta Suppose there's a speed limit for dots on the balloon, no dot can move across the balloon at more than one inch per second as seen from any other dot (we have to suppose that Lorentz transformations apply to such motions). But that's moving across the baloon's surface; it doesn't factor in the possibility that... the balloon is expanding and the dots are getting further and further away from each other. In summary, black holes don't work faster than the speed of light, but merely have a gravitational pull stronger than the escape velocity of light. If I put that

#### Mentat

A question about supposed "faster than light" movements.

I'm having a real problem understanding when people talk about the universe's expanding faster than the speed of light. Isn't that impossible? Also, I have heard that a black hole's gravitational pull works at a speed faster than that of light. Is this really true? If so, why doesn't someone arrive at the center of the black hole, before he/she arrives at the EH?

Any help would be greatly appreciated.

In regards to black holes, look at the following links (in order):

More on this

After reading those you should better understand what I've said in your time travel topic.

Black holes don't work faster tham the speed of light, but merely have a gravitational pull stronger than the escape velocity of light, but if I put that in the wrong words please tell me.

Oh, duh *slaps self on head*. I should have realized the obvious difference between sending a signal that travels faster than light, and having a curvature that creates an escape velocity beyond the value of c.

So, how about the expansion of space problem?

The expansion of the universe is not a speed, it's an increment of space. Distant galaxies are not retreating from us faster than light, nor we from them. Rather the space between is increasing, and there is no natural limit on how fast that can happen. All the appearances, including doppler effect, work just as if they were moving (or we were) at high speeds.

The expansion of the universe is not a speed, it's an increment of space. Distant galaxies are not retreating from us faster than light, nor we from them. Rather the space between is increasing, and there is no natural limit on how fast that can happen. All the appearances, including doppler effect, work just as if they were moving (or we were) at high speeds.

Could you be a little more clear on this, please? I don't understand how "the space between us is getting bigger..." is any different than "we are getting farther apart...".

The point is that neither we nor the remote galaxies are moving at those speeds. There are local motions but they are not what the expansion is about. What is happening is the space is being added in between (well, added everywhere away from gravity wells, including the space between us and old NCG whatzitzname). This addition is a new way to get farther apart, without using speed.

That reminds me, even though galaxies are not actually traveling faster than light away from each other, the doppler shift of light makes it appear that way. This creates an apparent event horizon at a particular distance away - say about 13-billion-l-years. It is interesting to think that this apparent EH has absolutely nothing to do with how old the universe really is.

If it did, the event horizon would have to recede from us over time. The very distance red-shifted galaxies would have less of a redshift over time. --What if it's not a coincidence, and the redshift has less to do with velocity than with gravitation.

Special relativity places a velocity limit of c between observers in an inertial (zero acceleration) frame. General relativity allows for the gravitational curvature of spacetime and its equivalent non-inertial acceleration. When the universe expands due to inflation, Hubble effect, or cosmological constant, it is attenuating the arena (spacetime) of events. Thus even locally fixed observers in such a universe can, separated over an adequate amount of space, be traveling relatively faster than the speed of light, and beyond each other's horizons.

The universe is supposed to exapand faster than c. Can it have an escape velocity? I know it sounds silly, but something like an escape velocity?

Originally posted by MajinVegeta
The universe is supposed to exapand faster than c. Can it have an escape velocity? I know it sounds silly, but something like an escape velocity?
That implies that there is something you can escape TO. There isn't.

Originally posted by MajinVegeta
The universe is supposed to exapand faster than c. Can it have an escape velocity? I know it sounds silly, but something like an escape velocity?

I repeat that the expansion is not a velocity, in the meaning of special relativity.

Maybe try the old model of blowing up a balloon with dots on it representing the galaxies. Suppose there's a speed limit for dots on the balloon, no dot can move across the balloon at more than one inch per second as seen from any other dot (we have to suppose that Lorentz transformations apply to such motions). But that's moving across the baloon's surface; it doesn't factor in the possibility that the surface itself is increasing as you blow the baloon up.

It's notorious that you can't push the balloon analogy very far, but this just shows the distinction I am trying to make.

the gravitation never work faster that speed of light
if we put a ball in vacuum...
and put it with a force
the ball will have a acceleration
and become fast and fast...
but when it reach the speed of light...
no force can give it again because it's a limit
like u run 10m/s and want to put the car which is move 10m/s too...

Let's look at this problem with the other standpoint. This is my point where universe consists of time and light only, where all other effects this manifestation these two, where light this zero point.
Immediately becomes obvious an absoluteness of speed of light. Hereinafter obviously that space and energy this effect of the change of time. The Mass --> Energy of the object this amount of Time which have the object. This is his Time Cycle. The Objects can interact by returning or takeing time. They lose its time through light radiation that reveals itself as expansion of space in our perception . This is the set of the past conditions of object. At termination of the Time Cycle the object stops its existence and moves to zero level. BH is object which does not spend its time. He is capable to take it only.

## 1. Can anything travel faster than the speed of light?

According to Einstein's theory of relativity, the speed of light is the ultimate speed limit in the universe. It is not possible for anything, including particles or information, to travel faster than the speed of light.

## 2. What is the supposed theory behind faster-than-light movements?

There are a few theories that suggest the possibility of faster-than-light movements, such as wormholes, Alcubierre drive, and quantum tunneling. However, these theories are still hypothetical and have not been proven or observed in the real world.

## 3. Is there any evidence of faster-than-light movements?

Currently, there is no scientific evidence to support the existence of faster-than-light movements. All experiments and observations have shown that the speed of light is the maximum speed at which anything can travel in the universe.

## 4. How does the concept of faster-than-light movements relate to time travel?

Some theories of faster-than-light movements, such as wormholes, suggest that they could also be used for time travel. However, this is purely speculative and has not been proven or observed in the real world. The concept of time travel is still a subject of debate and research among scientists.

## 5. Could faster-than-light movements be possible in the future?

While it is currently not possible to travel faster than the speed of light, there is always the potential for new scientific discoveries and breakthroughs that could change our understanding of the universe. However, any theories or technologies related to faster-than-light travel would need to be supported by solid evidence and experiments before they can be considered a possibility.