Okay, I'll start but I can't confess to know a great deal about astronomy or theoretical physics.
Using wave theory, light from a source travelling away from you would have an increased wavelength, essentially each wave is being slightly increased. This causes a shift in its perceived colour towards the red end of the visual spectrum. The opposite happens with an object moving towards you and creates a shift towards the blue end of the visual spectrum.

Not sure what the stuff about space-time curvature and gravitational waves is about entirely. Any chance you could explain it in layperson's terms?

Gravitational waves is a theory that simply moving your arm creates a small gravitatinoal oscillation (Like a sound or light wave. think of the gravity your arm is giving off. highpoint of the wave. now your arm is gone, the wave is lower)

On a different topic, there is an argument that all phtons in the universe are the same age from whence they were created at the big bang. this is INCORRECT. although relatavistic distortion causes the photons to experience 0 travel time, a phton coming from the sun is not actually very old in universal time.
As soon as a photon impacts an object (Like a mirror), its energy is absorbed into the objects electron shells, causing them to jump around a bit, and then release another photon in order to return to base energy state. Now, this photon is of the EXACT SAME wavelength as the original photon, so its not the original photon, but one that looks identical. Now, interestingly, this means that you are not looking at the same light produced by your face when you look in a mirror. It is an identical photon configuration created as a result of the light from your face striking the mirror surface.

Now, onto something i have been VERY eager to discuss. it is possible to travel faster than light!
Now, anyone with a basic knowledge of relativity will know that as you get faster, time will go slower. Now, it is also known that, relative to a stationary observer, you cannot go fatster than c , the speed of light, or 299,792,458 metres per second (In other words, mind-bogglingly fast).
Now, let us propose an experiment where one has a ship, that can easily obtain relatavistic velocities, in open space, sitting near a track of interstellar beacons spaced about 2000 km apart. Now, the ship only knows how far the beacons are apart, so, it simply measures the amount of time between the passing of one beacon and the next. Now, as his clock is running slower as he gains speed, he will record less and less time between each beacon pass, and thus interpret that as greater speed.
THIS excel spreadsheet shows it alot better
Now, this is actually interesting, as the subjective speed of the spacecraft actually approaches infinity as the craft approaches c.
Interesting, huh?
(Do correct me if i got my formulas wrong. Most sites i went to for reference on this seemed to be deliberately vague and never gave me a rock-hard answer)

Observed vs. actual speed isn't a problem here... The problem is MASS. As you go faster, your mass increases (mass as a measure of inertia), and it becomes harder and harder for you to accelerate. As it nears infinity, you need nearly infinite force to accelerate (a = F/m, a = acceleration, F = needed force, m = mass). Now I know that standing mass and high-velocity mass aren't one and the same, I just use this to illustrate what happens (the actual factor is momentum )
Even photons, which have no standing mass (when they stop, they disappear - to stop them, you must absorb their energy), *act* like they do have mass, simply because they have momentum. You could say (and be wrong, but this is a simplified illustration) that a photon has 0 mass which is multiplied by infinity (Lorentz factor is inf. @ the speed of light) and get a singular mass, the smallest amount of mass any particle may have. This is also the reason light is considered both a wave and a particle... (well, actually, everything is, but more about that later)
So, no, it is not possible to travel faster than light, we have no means to make matter (particles) behave like radiation (waves) without 'destroying' it. (actually, converting to energy, since mass and energy are two possible states of any existance in this universe)

I am just wondering, if space ships(a and b) travelled apart at the speed of 250 Mm/s (megameters, a thousand thousand meters) the distance between would increase by 500Mm/s so acording to that could A travell away at 500Mm/s from startionary B, by alowing the extra speed from the princible above???

Edited by - NuttyProSci-Fi3000 on 6/24/2006 12:37:53 PM

Not really... the speed you could potentially have a large spreading speed (that is, the combined speeds of the two objects). The speed of one may appear higher relative to the other object.