general relativity - Is time an illusion?

IS time an illusion?

I have tried thought experiment after TE and quite frankly I can't find any instance where time is defined wholly on its own. It is always a measurement of the interim between to events. We "see" it but it has no form... sounds like the definition of illusion.

Is it possible that we live in an "infinite now" and time is simply an effect rather than a dimension?

Answer

Is time an illusion?

No. I think it's best to think of it as something like heat. You know what heat is, especially if you put your hand on a stove: szzz aaargh! Heat is definitely not some illusion. However it is an "emergent property". Think about the kinetic theory of gases. The temperature of a hot gas is something like a measure of the average kinetic energy of the gas molecules. The faster they're moving, the hotter the gas. But if you examined one gas molecule, it has no property of heat or temperature, it just has its mass and motion.

GNUFDL image by Greg L, see Wikipedia

Time is something similar, but IMHO it's more like a cumulative measure of motion than an average measure of motion. And it definitely isn't an illusion, because a hundred years will kill you just as surely as a hundred degrees C.

Relativity tells us that time " slows" near a gravitational source. But we also know that light slows near the same. Is it possible that we live in an "infinite now" and the way we experience time is simply an effect of how fast light travels in our particular region of space?

I think so. Check out what Einstein said about the speed of light, and guys like Irwin Shapiro. And of course see A World without Time: The Forgotten Legacy of Godel and Einstein. The blurb for that book suggests that time does not exist, but IMHO it would be better to say time isn't what some people say it is. It's a dimension in the sense of measure, but not in the sense of freedom of motion. I can hop forward a metre, but you can't hop forward a second. You can suffer time dilation, but I can watch you every moment while you do. You don't disappear from the present and end up in the middle of next week. You just experience less local motion. It's like you're in slow-motion mode for a while. It isn't time travel, despite what you can read in the popscience articles.