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Does Time Exist?

bigthink.com

41–50 of 73 posts

Re: Does Time Exist?

#41

afaict, "time" is simply a measure of matter in motion... ie resonant frequency or how long it takes a liquid to flow x distance. Thus, time is just a mental construct, not a "dimension", and "time travel" is not possible. There is only "now".

Unless all "times" exist at every "moment" and we are merely switching consciousness between those. Maybe we are not even switching, because by "going backwards" we would be losing memories and would not know, that we went backwards. Same goes for forwards. It only seems forward, because our memories change that way. Maybe we are all just coping, trying to make any sense of every state, future, past, present, existing "all the time".

Re: Does Time Exist?

#44
post #13

To me it's pretty intuitive that time isn't real (outside of being a concept). We just use time as an elaborate way to explain our movement through distances (and how fast or slow we cover those distances), that's about it. The twin paradox[1] does a good job of explaining this. There's no discernable difference between today and lets say, arbitrarily, 1984. The only difference is our movement through that spatial di…

Given that the speed of light directly relates time and distance in (to the best of our extremely precise measurements to date) an absolute manner, then if time doesn't exist, neither does distance. Also, as TFA mentions any dismissal of time as a concept must also deal with thermodynamics.

here is another way of looking at it: the speed of light actually shows us the maximum speed of causality (how fast can a change in point A in space propagate). Some might speculate that the same speed of causality is observed in everything, it just so happens that most transformation happen in place giving us the illusion that we are stationary in space.

Re: Does Time Exist?

#46

To me it's pretty intuitive that time isn't real (outside of being a concept). We just use time as an elaborate way to explain our movement through distances (and how fast or slow we cover those distances), that's about it. The twin paradox[1] does a good job of explaining this. There's no discernable difference between today and lets say, arbitrarily, 1984. The only difference is our movement through that spatial di…

When I was younger I imagined in my head that a specific moment in time is literally just all of the information about the observable universe -- the position, momentum, temperature, etc of all of the particles in existence relative to one another. I’m running on very little sleep right now so be prepared for a little woo here; I’m expecting someone smarter to come correct some misconceptions in my take and hoping to learn a little bit from that.

For me, that idea always been enough to get by (without existential questions), albeit it's a little bit different from the three-axis-plus-time description in the article. It explains really intuitively why reverse time travel isn't possible (non-reversible reactions, energy required to reverse the entire universe into a previous state, etc). It also makes it intuitive that time does exist, since "time" is a noun referring to the overall state of the universe - a specific state in a set of states that at least appears to progress sequentially... but perhaps does not. Actually, looking at the questions in the article, it seems to jump out that time is uncountably infinite (since "absolute time" cannot exist). Even so, the “arrow” of time would be evident from within any of these states because there is only one direction that certain starting conditions can lead. “Time” does not account for parts of the universe in isolation, but rather all of it as a whole - so there are always plenty of pointers.

Edit: This seems to be a naive/flawed way of understanding canjobear's statement: > Time is the direction in which entropy always increases. It's the most real thing there is.

I want to rephrase to, "if time doesn't exist, how do we know where things are?" or "if time doesn't exist, how do things move?" - which seem to get back to the 3-axes-plus-time description.

Re: Does Time Exist?

#47
post #5

I’ve been wondering a lot lately if it’s possible that time is felt differently (I guess moves ) for us on an individual level.

As I approach 40, a year feels about as long as a month did when I was elementary-school aged. I worry that if the current rate-of-increase continues, my last decade will feel weeks long.

I feel the same way about my time in elementary school. My theory is that it was boredom that made school time feel so slow. Summer vacation always seemed to fly by.

Re: Does Time Exist?

#48
when all matter turns to EM radiation, at the end of the universe (arguendo), then time will cease to be measurable, and so will distance.

Re: Does Time Exist?

#50

Time is the direction in which entropy always increases. It's the most real thing there is.

Or at least tends to increase. Entropy can always spontaneously decrease, or can simply not increase for a moment. This was actually discussed a week ago! [1] As discussed in those comments, entropy isn't well-formulated outside of equilibrium states, and is subjective: it is a function of an observer's knowledge of the system (particularly microstates).

I'd say time is very real, and an inescapable part of experience (no experience without change). As for time being the most real, we only know it through experience, so I think of it as secondary, along with space, etc.

[1]: https://news.ycombinator.com/item?id=31164725

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