For some reason, this view of time fell nicely in place in my mind (not “Aha! So that’s how it is?” but “Yes, that’s how it is.”), so if it’s wrong, we’re a lot of people to be mistaken in the same way.
But that doesn’t dissolve the “What happened before the Big Bang?” question. I point at our world and ask “Where does this configuration come from?”, you point at the Big Bang, I ask the same question, and you say “Wrong question.”. Huh?
If you ask about a configuration X, “Where does this configuration come from?” I will point at a configuration W for which the flow from W to X is very high. If you ask, “Well, where does W come from?” I will point to a configuration V for which the flow from V to W is very high. We can play this game for a long time, but at each iteration I will almost certainly be pointing to a lower-entropy configuration than the last. Finally I may point to A, the one-point configuration. If you ask, “Where does A come from?” I have to say, “There is nowhere it comes from with any significant probability.” At best I can give you a uniform distribution over all configurations with epsilon entropy. But all this means is that no configuration has A in its likely future.
The thing is, it doesn’t make sense to ask what is the probability of a configuration like A, external to the universe itself: you can only ask the probability that a sufficiently long path passing through some specific configuration or set of configurations will have A in
its future, or
its past.
The probability of the former is probably 0, so we don’t expect a singularity in the future. That of the latter is probably 1, so we do expect a singularity in the past.
For some reason, this view of time fell nicely in place in my mind (not “Aha! So that’s how it is?” but “Yes, that’s how it is.”), so if it’s wrong, we’re a lot of people to be mistaken in the same way.
But that doesn’t dissolve the “What happened before the Big Bang?” question. I point at our world and ask “Where does this configuration come from?”, you point at the Big Bang, I ask the same question, and you say “Wrong question.”. Huh?
Super-late answer!
If you ask about a configuration X, “Where does this configuration come from?” I will point at a configuration W for which the flow from W to X is very high. If you ask, “Well, where does W come from?” I will point to a configuration V for which the flow from V to W is very high. We can play this game for a long time, but at each iteration I will almost certainly be pointing to a lower-entropy configuration than the last. Finally I may point to A, the one-point configuration. If you ask, “Where does A come from?” I have to say, “There is nowhere it comes from with any significant probability.” At best I can give you a uniform distribution over all configurations with epsilon entropy. But all this means is that no configuration has A in its likely future.
The thing is, it doesn’t make sense to ask what is the probability of a configuration like A, external to the universe itself: you can only ask the probability that a sufficiently long path passing through some specific configuration or set of configurations will have A in
its future, or
its past. The probability of the former is probably 0, so we don’t expect a singularity in the future. That of the latter is probably 1, so we do expect a singularity in the past.