Friday, June 15, 2007

Bugging Greg

Well, I've promised to try not to bug Greg about things that are far outside of his field of expertise...


And so I expect to be thrashed soundly for asking this...


But what the hell is time?

3 comments:

Holly said...

I'll be interested in what Greg has to say about this, but he's asleep and I'm not. However... I always kinda thought 'time' was a generic term for a class of measurements, ultimately indicating change of state. In other words, time is the vocabulary of alteration.

Although, I have nurtured a theory that time is something we're immersed in, like aquatic things are immersed in their environment, and that someday we'll evolve by creeping out of time and onto the rough shores of ... something else.

gregvw said...

As far as I know, the answer to this question is still the subject of debate and many a wild hypothesis. I certainly can't give you anything more authoritative than what you could look up on various respectable science web sites. Finally, as you mentioned, this is not really my area in that I have just had some undergraduate modern physics and some graduate quantum mechanics in my background.

As far as I understand, the evidence points to space and time as being a single entity rather than two. We know that the "passage of time" depends on the frame of reference and that the velocity of this frame affects the relative rate at which time passes. We also know that gravity and acceleration are closely related and could be the same thing and also that the passage of time depends on gravity which in turn depends on mass, which is really a condensed form of energy. Most respectable physicists regard time and energy to be strictly positive quantities as they are reciprocal dimensions of each other, it would not make mathematical sense if one could be negative and the other could not.

What does this mean? My guess is that space-time is a byproduct of the big bang and that there was none beforehand.
The apparent passage of time is an artifact caused by the warping of the space-time fabric from the presence of matter and perhaps its motion.

Rufus said...

This makes good sense, I think. Nevertheless, I need to absorb it. In some ways it seems to correspond entirely with how I experience being- a process of temporally framed change. In other ways, it seems difficult to imagine space as a unity in the same way that time is experienced. Anyway, thanks for the suggestions.