Originally posted by twhitehead
Just to be clear, what do you mean by 'begins to exist'? Are we talking about a change of state (where energy is conserved and the standard laws of physics are followed) such as when I put some planks of wood together and a chair 'begins to exist'. Or are we talking about something else?
Would an electron positron pair appearing out of empty space qualif dimensions of space time"?
Why doesn't my browser know how to spell "onwards"?
The assumption 1) is unwarranted. There is no reason whatsoever to believe it to be the case. There is no evidence to support it. It is just made up so you can claim 3).
Premise (1) is constantly validated by our experience, therefore far more plausible and reasonable than its denial. It is rooted in the metaphysical intuition that something cannot come into being from nothing, like magic.
just to be clear, what do you mean by 'begins to exist'? Are we talking about a change of state (where energy is conserved and the standard laws of physics are followed) such as when I put some planks of wood together and a chair 'begins to exist'. Or are we talking about something else?
It is a general causal principle: whatever has a beginning has a cause. We can apply it to anything, whether a change of state, a few planks of wood coalescing into a chair, or the beginning of the universe itself.
Would an electron positron pair appearing out of empty space qualify?
Empty space, of course, is not really "empty".
Are we talking about within the framework of the known dimensions of space time, or are you adding another hypothetical dimension within which time itself can be thought of as beginning to exist?
Premise (1) is a metaphysical principle which applies to events within the universe as well as the universe itself—there is no need to add another hypothetical dimension.
Do you define "the universe" as "all that exists", or "from the big bang onwards" or "within the current known dimensions of space time"?
The universe is defined first and foremost in opposition to non-being. Prior to the singularity, according to the Standard Big Bang Model, there was literally nothing. At the singularity the universe began. Thus the universe includes everything from the singularity onwards.