by jimwalton » Tue Jul 09, 2013 2:07 pm
Hey, great conversation. Thanks. I'll admit that I'm not an astrophysicist. It's my understanding (and correct me if I am wrong), that the theory behind the Big Bang believes that about 15 billion years ago, space, time, and the universe began when an initial singularity with zero dimensions sudden began expanding unimaginably rapidly. I guess I'm considering that something with zero dimensions constitutes "nothing." My question is, if it had zero dimensions, from where did the original energy derive to cause the bang, and also from where did matter that is of gargantuan proportions come?
As far as your second point, the flaw in your reasoning comes in that you are starting from yourself rather than from infinity past. If you start with yourself, you start with a reference point. But if you start from infinity past, you will never even find the starting point, let alone a reference point. If I were to take a walk to an infinitely distant point in space, it would not just take me a long time to get there; rather, I would never get there. No matter how man steps I took, a part of the journey would still remain. I would never arrive at my destination. That's what I mean by infinity cannot be traversed.
Similarly, if I were to start counting to infinity, it would not just take me a long time to get there; I would never get there. It doesn't matter how long I had been counting for, I would still only have counted to a finite number. It is impossible to traverse the infinite set of numbers between zero and infinity. The point is that this also applies to the past. If the past were infinite, I wouldn't even find a place to start, let alone a place I could call "the present." "The present" would not just take a long time to the present to arrive; rather, it would never arrive. No matter how much time had passed, we would still be "walking" through the infinite past. It is impossible to traverse an infinite period of time.
Clearly, though, the present has arrived, the past has been traversed. The past, therefore, cannot be infinite, but must rather be finite. The universe has a beginning. That's the thought process anyway.
I am considering causality from the standpoint of agency (what Aristotle would have considered efficient cause, if I understand him correctly), since time is a relativity governed by matter, energy, and velocity. Again, I'm not a physicist, but it's my understanding that if there is a theoretical singularity of zero dimensions, space and time don't exist, and any causal theory would have to be based on agency rather than energy or matter.