Monday, May 17, 2010

even more on time

The question of what was before or after time has always bugged me, as well as how time could come into existence with the creation of the universe, since shouldn't there always have been time? But if time always existed, at what time was the creation of the universe? 10.30 on a Tuesday morning? This has always been baffling. Well I read a little bit the other day about Aristotle, and how he says that time is the measure of change. I have since tried to read the relevent part (Physics iv, 10-14) but Aristotle is a cagey bugger and rarely makes anything particularly clear, at least to my sullied brain. So apologies if you know about Aristotle and my simpleton's take on it offends you.

Aristotle says that time is a measure of change. (That's as much Aristotle as I understand. The rest is my interpretation.) Time doesn't exist inandof itself, it only exists as a by-product of change, as a means to measure change. Therefore in the pre-created universe (a rather nice impossibility), the changeless void, there was no time. Only when the universe began to change - changing from a changeless to a changing universe, which was the very first change - did time become apparent. So the act of creation was to institute change in a changeless universe.

This doesn't really take account of where the matter of the universe came from (it came from nowhere, obviously), nor how something changes from being changeless to changing, but it does neatly wed the beginning of time to the beginning of the universe (or at least the beginning of the changing universe).

So creation was the change from changeless to changing. And the end of the universe will be the change back, as change slows down until there is no change, although you suspect that the changes just get further and further apart, until there is a long period of changelessness, which eventually changes again back into changing - the universe slowing right down until it appears to be dead, and then starting up again. But you can't really have a period of changelessness, since if there is no change there is no time, since there is nothing to measure. To an observer, the 'periods' of changelessness would be instantaneous. So perhaps the universe wouldn't slow down at all, but would just one day change back to changelessness. That might mean that everyone was just left doing whatever they were doing at that time for a timeless eternity, but they wouldn't mind much and in any case I think you can safely discount this paragraph.

Time being thought of as a measure helps to explain why it was sometimes (not any more, apparently) called the 4th dimension, since you measure an event's height, length, depth and time, which is something else I hadn't got my head around. If you can think of other things you measure: price, stupidity, number of votes, etc, you can bring a whole new dimension to any argument you might be having.

I guess change being the cornerstone of the creation of the universe is why down-and-outs are always asking for more change. And even the Conservatives were telling people to vote for change recently.

Obviously I welcome anybody who can explain to me how wrong I am. Although you might have your work cut out.

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