There is an article in the current Philosophy (journal of the Royal Institute of Philosophy) about which I had some thoughts. I then found Bob Cooper’s An Infinity of Universes (C98/23), which I found interesting but did not understand. Here is a series of wonderings.
The article in Philosophy presents three arguments to support the possibility that the universe caused itself to exist, rendering the idea of an external cause, in particular God, unnecessary. The second argument, as I understand it, is as follows. Suppose that each (instantaneous) state of the universe is caused by the previous state(s) but that there is no first instant. That is, the first time unit in the universe’s existence (e.g. the first hour) is an open interval (0, 1]. The universe is finitely old but had no instant t = 0. Then each instant is caused by each previous instant but there is no first instant which would have to be caused by an external entity.
Firstly, this supposes that instants form a continuum. Perhaps there is a limit to the divisibility of instants. Then there would be a first one.
Secondly, the argument says we can go further and further back in time (conceptually) but this does not mean the universe has always existed. Does this mean anything; could it be true; is it true? It says that if we go back in time we will enter an hour, which really is one hour long, in which we can keep going back, finding ever prior causes, but will never get to the beginning of that hour and a first cause. However, we could do the same with any hour. Take the current hour, keep going back at finer and finer intervals, never reaching the instantaneous start of the hour. Each instant would still cause the subsequent one (if the supposition about causality is correct) and we would never have a first one. Does this mean that the universe from that hour caused itself? Surely not. What, then, is the difference with the first hour?
Thirdly, all this illustrates is each instant being caused by a previous instant. It does not show the whole system of causality being caused or arising by itself.
"The universe began." Does even that actually mean anything? It could mean "there was a time when none of this existed." This would make time independent of the universe, which I believe it is not supposed to be.
"The universe began" has the weaker meaning that the universe has an age - that time does not stretch back infinitely - using "infinitely" as in an infinite number of hours, not an infinitely divisible continuum. Our measurements of time come from our experience. To answer these questions, we need to analyse our experience of time, the reality behind it and the relation of that real time to the perceptible world.
Finally, if time is a bounded but open interval co-existent with space, should we not say the universe causes itself, tenselessly, rather than caused itself? Or perhaps that cause is only applicable within the universe, not to the universe as a whole. In which case, our spontaneous question, "Where did everything come from?" requires a different kind of answer.
Bob Cooper asks where white holes could be. A black hole sucks light in. A white hole would churn it out. Perhaps stars are the white holes. Is there any evidence for the nuclear reactions that are supposed to be going on inside stars, or is it possible that energy gets sucked into a black hole, passes through a wormhole and pours out of a star?
Nigel Perks
Nigel : interesting ! I think the ideas above are confusing because psychologically we cannot conceive of time not existing. Moreover, time only has meaning in the context of change, which is what we use to measure time. Without space or matter, that is, as currently understood, before the Big Bang, there’s no meaning to time as there’s nothing to change, let alone anything to measure change with.
The open interval idea seems to be a transformation of Stephen Hawking’s unbounded but finite universe. It’s also a bit like Wittgenstein’s "death is not an event in life" aphorism. We can talk about "any old hour" within time, but not about the first hour that way as it’s lower bound is outside of time. Also, the open interval notion isn’t proving that any interval is unbounded, only saying that it’s consistent that one could be.
With respect to your "white hole" thoughts - this is really the province of Physics SIG or SpaceSIG, but philosophically, I’d have thought the wielding of Occam’s Razor would be useful. We do know quite a bit about stars - we live near one. The nuclear reactions within stars are important for explaining how elements heavier than Helium arise (with Supernovae being required to explain elements heavier than Iron). We receive all sorts of nuclear reaction debris from the Sun in the form of cosmic rays. Nuclear reactions are necessary to explain the longevity of the stars, given their energy output. Now, maybe it would be possible to explain all these things based on the nuclear scrunching that would occur with matter falling into black holes, but we’d still have to explain the existence of black holes themselves. Current models have them arising from stars - so all stars couldn’t be the other end of black holes without chicken & egg arguments arising rather unnecessarily. Finally, stars & models of their evolution are well established concepts. Black holes, white holes & wormholes are all theoretical concepts. Black holes are unobservable except for their effects, and it is not certain that any of these have been observed. Wormholes are entirely theoretical and their stability is much debated - your thesis would need them to remain for billions of years. Hence, I think we should stick with the simpler theory, especially as there’s nothing much wrong with it.
Theo