Comments on: How could the universe expand faster than the speed of light? That seems impossible!

By: Dan

Dan — Wed, 16 Sep 2009 13:10:26 +0000

“This is why cops have to stay parked.” No they don’t. They can clock you from a parked position, moving towards you, moving away from you or moving behind you, and especially if you are driving thru Wisconsin.

By: Seibt

Seibt — Thu, 03 Sep 2009 05:38:23 +0000

the speed of light reflects the speed at which the university is expanding at. Nothing in the universe can go faster than the speed the university is expanding at. Time is the reciprocal of the relative speed an object moves relative to the speed the universe is expansion at.

to post 3. – as long as each flash light is traveling slower than the speed of light then the light from each flashlight will reach the other.The point of time you switch on the flash light is irrelevant.

By: Orien Rigney

Orien Rigney — Wed, 08 Jul 2009 12:20:57 +0000

Even after the universe was quite old, perhaps a few million years or so; there was no gravity until galaxies began forming. Attraction and repulsion? Yes. But gravity is an intrinsic quality of magnetism and several others, of speed.

By: keith

keith — Mon, 06 Jul 2009 16:00:36 +0000

There is one thing which can travel at more than the speed of light. Suppose we put the Queen in a rocket propelled outwards from Earth at 0.9c (good idea if you ask me). After 2 years it crashes into a piece of space debris and she is killed. At that very instant the Prince of Wales becomes King, despite the fact that she is 1.8 light years away. So monarchy travels at infinite speed. Of course it helps that it has no mass (nor any point either, if you ask me).

By: AJ

AJ — Thu, 07 May 2009 20:51:47 +0000

A car traveling 30mph on a 2 mile long track will take 2 minutes to travel over 1/2 the track. At what speed must the car travel over the 2nd half of the track to average 60mph over the entire 2 miles?

By: philocinemas

philocinemas — Thu, 07 May 2009 02:52:13 +0000

I am not a physicist, but I think I can explain the constant speed of light very simply. The faster you travel, whether on a planet or in a spaceship, the slower your personal experience of time is (it is relative). When you look out in space, whether up in the sky or out of your spaceship, everything appears to be speeding up due to your personal experience of time (the faster you go, the slower your own time seems) versus the rest of the universe. Therefore the light actually catches you faster because you are experiencing slower time (the two negate each other, creating a constant speed of light).

This is very similar to gravity. The mass of an object increases its attraction (speed), but the greater the mass, the slower its acceleration (the two negate each other and so all objects fall at the same rate). Galileo proved this by dropping two objects of different masses from a great height and showing that they landed at the same time. 350 years later we proved it again on the moon with the famous feather and lead ball experiment.

By: Aardwolf

Aardwolf — Wed, 08 Apr 2009 16:56:08 +0000

Douchemaster T,

I agree, but light still needs to travel from point a to point b. If space has expanded (faster than light) between point a and b, how can light overcome that expanded distance?

One other point, if space is expanding between galaxies (but oddly not inside them) how is it possible for galaxies to collide? Galaxies move very slowly compared to these expansion velocities.

By: Nick

Nick — Thu, 02 Apr 2009 15:18:16 +0000

Question – somewhere I read that we cannot measure motion of a body relative to “Absolute Space”, that motion of a body can only be measured relative to other bodies. Is that because Absolute Space is expanding faster than the speed of light (which would make sense of the fact that bodies confined to speed of light therefore have no no motion relative to Absolute Space) ?

By: Douchemaster T

Douchemaster T — Tue, 27 Jan 2009 19:43:16 +0000

@Nardwolf

Light is does not travel relative to the expanding light sources (galaxies).

By: Aardwolf

Aardwolf — Mon, 12 Jan 2009 01:09:41 +0000

If the space between galaxies is expanding at greater than the speed of light, how is it possible that any light reaches us from those galaxies at all?

For example, 2 galaxies are 10 billion light years apart, and the space between is expanding at C. After 5 billion years the light from one has travelled half the original distance, however, due to the expansion the remaining distance to travel is 10 billion light years.

How can light overcome the expansion of space if it is greater than C? Surely galaxies should only be visible while the space between them is expanding at less than C.