a couple of nights ago, while continuing with the reading of "The Tao of Physics" I stumbled upon an idea that kept me entertained overturning a while and here to share it ... talking about it.
The universe is constantly expanding from the "big bang" (t = 0 +) so that all galaxies are far apart. The speed of separation between galaxies is relative to the distance between them. In the picture above it is evident that the rate at which galaxies are separated opposite is much greater than that between neighboring galaxies.
This leads to the limiting case in which distant galaxies are receding from us at velocities approaching the speed of light. These are the most distant galaxies that we can still see.
What
is not much more distant galaxies are receding from us at speeds faster than the speed of light so we will never see. This means that the light emitted comes to us but ... away rather than closer! is like a comet tail that breaks from its source.
The visible universe
In the second image, placing us in the white point, the larger circle would be the border where the separation rate is lower than the speed of light, what is beyond ... never see! and ... why there? update (27-8-2k9):
To help figure it out. Suppose we are "light" and go on an airplane in flight. For more than running away from the plane, they will never match the speed thereof. So despite our legs fast ... we will continue moving away from the output port. (Even with the suicidal leap hehe)
to procrastinate a bit:
Wikipedia: bigbang theory, hubble Act
