Saturday, October 10, 2009

The edge of the universe

How many times have you looked up at the sky and thought; "where does it end?" Well according to astronomers, the visible universe can be seen to a distance of about 13 billion light years. The visible universe meaning the matter in the universe that is detectable through its radiant energy, be it light or radio waves. Nothing is seen beyond this point because as you are looking deeper into space you are looking farther back in time; current theories about the formation of the universe give the date of the Big Bang, or the moment of creation of all we know, at about 13 billion years ago. So as you are looking farther and farther out, you reach a point where the light of the object you are looking at started its journey shortly after the big bang. Its a strange and eerie effect, and in essence the entire sky is a sort of time machine. But I wondered, what would you find if you were able to go out to the last galaxy, on the edge of the expansion, and fly out past it? Suppose it was totally empty?
One strange thing occurred to me immediately. If you went farther and farther out, until that last galaxy you past was for whatever reason no longer detectable, you would lose all points of reference, so it would be difficult if not impossible to prove you were moving, or to calculate which direction you were moving in. You would be completely lost. The concept of the space around you having dimensions would be greatly diminished. Which made me think, does matter somehow create the space around it? If you can no longer detect motion or direction, is the space around you for all intents and purposes now nonexistent? If you are in a universe with say just two objects in it, you can always measure distance and velocity between the two objects. But what if you are in a spacecraft that has flown so far out into the cosmos that no other objects are longer visible? You might still have velocity, but since you are not moving towards anything and cannot detect anything to be moving away from, you may be from one frame of reference motionless. So for this reason, I theorize that the "edge of the universe" is the self imposed limit of detection of physical matter. once you reach that point, where you cannot detect any physical object except your space craft, you may have reached a sort of edge. I will ponder this idea later...

No comments: