The finitude of the universe makes a prior to the Big Bang almost inevitable

Addressing Con's questions (Q1) There are many philosophical arguments that entail that an infinite past is illogical [. .. ], how would you deal with those objections? If this is what Con means, I'm familiar with the infinite regress problem. I think however, it arises mainly due to the human concept of assuming everything needs a beginning. At least physically and logically an infinite past is possible. There are actually models of possible universes allowed by both general relativity and quantum field theory, which are temporally closed, with time being circular [1]. In these, an event can cause itself. The infinite regress problem should arise there as well in a sense, as there is no first cause for any event, but still these universes are not prohibited by any physical or logical means. (Q2) Does your argument only work if the first state of time is a singularity, or does the argument work with with any first state of time at t=0? The problem with any first state of time is, that by definition it must be a singularity. This corresponds to the fact I tried to address in (A 1) and (A 2) - that any definition of values like velocity, energy, etc. must break down at a beginning of time. (Q3) Some would argue that time wouldn't even exist at a singularity at t=0, only after the expansion is when time exists, how does this effect the argument? I think this would entail a logical contradiction. Assuming "time begins to exist after something" already depends on a notion of time being present before time starts to exist. Even if the singularity would be excluded from our notion of time - as I tried to describe in (A 2) - we would be left with all current conservation laws and a continuous, differentiable time at t=0. Thus, if the singularity weren't at a beginning of time, from current physics it necessarily follows that there should have been a prior state of time as well. If the beginning of time weren't singular, it couldn't be the beginning of time. (Q4) Can you put your main argument for in syllogism form [. .. ]? I'll try to summarize my main (first) argument a bit more clearly, especially on the physical part:(P1) A beginning of time is necessarily singular(P2) In a singularity, the definition of a physical property C breaks down(P3) From (P1) and (P2) follows: At a beginning of time, the physical property C was undefined for all objects(P4) At all times after the beginning of time, all conservation laws applied(P5) A conservation law for a physical property C ensures (among other things), that if C is undefined, it cannot get defined(P6) From (P4) and (P5): If C is principally undefined at t=0, it can never get defined(P7) The property C is currently defined for an object(P8) Since (P6) and (P7) contradict, there was no beginning of time (Q5) It seems as if your argument at best only shows that the nature of particles is what makes a prior to the Big Bang almost inevitable, but not a finite past by itself. How does your argument actually establish the resolution? For the argument (A 1) this is true. If different physics worked in our universe, a beginning of time could be possible. But the nature of particles (or more precisely physical laws in general, as (A 1) was more of a representative example) makes it at least in our universe impossible, at least according to what we currently know about physics. My argument establishes the resolution by demonstrating that according to all current scientific understanding, a beginning of time is impossible, and that thus the existence of time must extend indefinitely into the past, even if the existence of the universe (as defined in (D.1)) does not. In conclusion Con conceded my arguments and therefore the resolution can be seen as being established. This was an exceptionally fair move by Con. I want to thank him for this debate, hoping further, that it was interesting for all readers. Vote Pro. Sources [1] . http://en.wikipedia.org...