Thread: Is time an illusion?

Originally Posted by JoannaB

Interestingly, we speak of three space and only one time dimension: is that because time is less complex than space or just that our perception of time is less complex because we have a limited understanding of time whereas we understand space much better?

It's because 3 axes describe a static space perfectly well, but in order to understand a universe with movement we need one more dimension - the dimension of time. Time is the 4th dimension needed to complete the static 3-dimensional model of the universe. You can accurately describe a box using only depth, width and height, but if the box moves then that's not enough.

Very cool thoughts about the metaphors.

As for the main question - I think before we can really talk about whether time is an illusion we need to very clearly define exactly what we mean by time. There are several theories about what it is, but no real consensus, and I think people sometimes mean different things when they say 'time'. Some people are referring to the calendar time OP mentioned, some people are thinking about a theoretical line with an arrow or whatever. These are human conceptions of time. As far as I'm concerned, all time really is is simply the fact that things can move. In a universe with time there can be movement and thus there can be organic life. In a universe without movement there could be no life unless you're theorizing disembodied life.

My 2¢ anyway.

** Edit

... Which brings up the question - if there is no movement in the universe, would time exist? Sort of a tree/sound question, only it actually makes more sense. Let's say all life has long since died and entropy has done it's thing and nothing is moving anymore. Probably a scientific impossibility, but this is a thought experiment. Nothing moves, and there's no living thing to measure the fact. Does time exist?

I wonder if it's even possible in this universe for nothing to move? Ok then, lets postulate a universe where nothing does move. Does time exist there?