In recent posts I’ve been discussing whether the universe began or not.<\/p>\n
Perhaps the most important issue which I have not yet discussed, is the idea ( However, this type of time reparameterization may not be very physical once you get down to the Planck time, about $$10^{-43}$$ seconds, when quantum gravity effects become important.\u00a0 Times less than that might<\/em> not be well-defined.\u00a0 In any case, the Misner argument suggests that we need to be more careful to define what we mean by time having a beginning.<\/p>\n Similarly, atheist philosopher Quentin Smith has argued that<\/a> the standard Big Bang Model is inconsistent with divine creation, due to it not really<\/em> having a beginning, even though the past is finite.\u00a0 Smith argues that because the time $$t = 0$$ is singular, technically it shouldn’t be included in the spacetime, so actually only times with $$t > 0$$ exist.\u00a0 That means that there is no initial moment of creation, and therefore, he claims, God cannot have created the universe.<\/p>\n This is somewhat reminiscent of Hawking’s claim that the no boundary proposal doesn’t have the right sort of beginning, and it seems to me that my Fuzzing into Existence<\/a> post is also applicable.\u00a0 If God is like an author, then he can make a story in which time works in whatever way he pleases.<\/p>\n According to Smith, each time $$t$$ exists because the preceding times exist, and indeed the laws of physics hold at a given time $$t$$ (according to him) because <\/em>they hold at earlier times.\u00a0 Since each moment of time is fully explained by those before, he claims that the universe is therefore self-caused and therefore fully explained, with no more explanation possible.\u00a0 (Of course, if time is continuous, then we could make a similar infinite regress of times going back closer and closer to any finite time $$t$$.\u00a0 Smith has to struggle a bit to explain why his argument doesn’t apply there…)<\/p>\n Now to me, this seems like the sort of explanation which is really no explanation at all.\u00a0 A satisfying worldview should explain as much as possible with as few assumptions as possible.\u00a0 If the laws of physics have some property $$X$$ (e.g. having an electron field<\/em>, or whatever) now because they were like $$X$$ a minute ago, and so on all the way back arbitrarily close to the beginning, that doesn’t in any way satisfy my curiosity about why they are like $$X$$ instead of some other way $$Y$$ (say, having no charged particles<\/em>).\u00a0 For if they had been $$Y$$ for all time, I could have made the same argument.\u00a0 So it seems that there is a potentially meaningful question “Why are the laws of physics like $$X$$ rather than like $$Y$$”, which Smith’s statements do not really explain.\u00a0 Maybe there is no explanation, and we have to take $$X$$ being the way it is as a fundamental fact.\u00a0 But to say that there could not possibly be<\/em> an explanation seems rather dogmatic.<\/p>\n And if God exists, then he can explain this fact.\u00a0 God’s will chooses what the laws of physics will be for all time.\u00a0 So he can choose for the universe to be like $$X$$ instead of like $$Y$$.\u00a0 This would be the fundamental explanation.\u00a0 Whether or not it is a useful explanation for us as human beings, would depend on whether our puny minds can identify the actual reasons why God might prefer $$X$$ over $$Y$$.<\/p>\n The Kalam argument has some intuitive appeal if you think that the universe could not have begun without some causal reason.\u00a0 Evaluating this claim requires an analysis of what causation is, and why one would think in various situations that a cause is necessary.\u00a0 But the first preliminary question is whether there are any facts to be explained by the putative cause.\u00a0 It seems to me that there are.<\/p>\n All of the same reasoning about $$X$$ and $$Y$$ would also apply if time stretches back to $$-\\infty$$.\u00a0 There would still be various timeless facts about the universe which would not really be explained by the infinite regress.\u00a0 This suggests that the Kalam argument may be misguided to the extent that it attempts to prove God from a temporal beginning a finite time in the past.\u00a0 The most important issues are the same whether time goes back finitely or infinitely.<\/p>\n But having said all this, it does seem a little bit weirder that the universe should exist for a finite amount of time with no external explanation, than that it should exist for an infinite time with no explanation.\u00a0\u00a0 Historically, many materialists (such as Lucretius<\/a>) have believed that time is infinite, due to their belief that it is impossible for something to come from nothing.\u00a0 Conversely, monotheists have mostly believed that the universe has a beginning, either for philosophical reasons or because the Bible says so<\/a>.\u00a0 (St. Thomas Aquinas argued that God could<\/em> have created an infinite past, but that divine revelation tells us he didn’t.) To that extent, Big Bang cosmology appears to vindicate the standard religious view over the standard nonreligious one.<\/p>\n (Of course, the same cannot be said if\u2014unlike St. Thomas or St. Augustine\u2014one also takes the 6 day creation<\/a> about 6,000 years ago literally.\u00a0 Some fundamentalists have argued that this <\/em>problem can be solved by reparameterizing our coordinate system, but that just seems silly to me.\u00a0 Also, the days are not in the right order to correspond to the scientific chronology.)<\/p>\n But a Theist could believe that God created time going back infinitely, without contradicting themselves, so long as they are prepared to be flexible about what “creation” means.\u00a0 Similarly, an Atheist could believe that the universe just started existing 13.8 billion years ago for no reason, without contradicting themselves, so long as they are prepared to be flexible when deciding when explanations are called for.\u00a0 All four views are logically consistent; the real question is which viewpoint explains the most with the least.<\/p>\n","protected":false},"excerpt":{"rendered":" In recent posts I’ve been discussing whether the universe began or not. Perhaps the most important issue which I have not yet discussed, is the idea (I think originally due to Charles Misner, first pointed out by St.\u00a0Edward Arthur Milne, … Continue reading I think originally due to Charles Misner<\/del>, first pointed out by St.\u00a0Edward Arthur Milne, and independently by St. Charles Misner<\/em>) that it may not be well-defined whether time has a beginning or not.\u00a0 That is, suppose you have a model in which there is a time coordinate $$t$$, and time has a beginning in the sense that the only allowed times are $$t > 0$$.\u00a0 Well, in General Relativity we are free to use whatever time coordinate we like<\/a>, and nothing stops us from defining a new time coordinate in terms of the old one, let’s say $$\\tau = \\log(t)$$.\u00a0 If you look at a plot of the log function, you’ll see that $$\\tau$$ ranges from $$-\\infty$$ to $$+\\infty$$.<\/p>\n