My pet theory: all atoms decay back to hydrogen given enough time, gravity pulls them together, stars form, the universe is one big loop that self resets :)
This of course requires the decay of protons.
if time passes and there's no observable difference, did it pass? I guess it makes no meaningful difference, but it's not really answering the underlying question of if some variable is advancing or not.
If nobody logs in to a multiplayer game, does the game world still exist?
Sure there are files sitting on a server somewhere waiting to be read when the first user logs in, there may even be a physics engine polling abstract data structures for updates, but the game world doesn't render without players present with their computers bringing all this data into a coherent structure.
Also, for an extra existential kick, realize that it renders /independently/ in the GPU/CPU/RAM of each player's computer.
heat death just implies no work can be done. time still flows
First, in many local processes entropy moves from high to low (e.g. life). Nobody says that time is moving backwards for living things. It only increases if you consider the system it is embedded in as well. So this idea that entropy is time is something that only applies to the entire universe?
It's true that we don't see eggs unbreaking, or broken coffee cups flying off the floor and reassembling. This increase in entropy seems to give an "arrow" of time, but to my mind this view (ironically) confuses cause with effect.
If you have any causal system (cause preceding effects) then you will always see this type of entropic increase, by simple statistics. There are just many, many more ways for things to be scrambled and high entropy than ordered and low entropy.
So yes, entropy does tend to increase over time, but that's an effect of being in a causal system, not the system itself. At least, that's my view.
Perfectly true that entropy gets us in the end as we age, as the system breaks down and cannot sustain itself any longer. Although if we could fix those systems, there's no reason in principle we couldn't halt aging entirely.
I am slightly blending the concept of entropy and complexity. But "ordered complexity" is how I imagine it.
It works a bit like air conditioning: yeah, you can make one room cold, but only by making more heat outside the room. The overall temperature of the system increases.
Partly, but mostly because there would be no lunch, so there would be no illusion of lunch-time any more.
This is required to make Penrose's end state Conformal i.e. scale invariant, so that it can arbitrarily Cycle to a small scale to make a new Bing Bang Cosmology (CCC).
We also know that electrons eventually decay but it's something like 10^26 years, which is long enough to say that probably not many electrons in the solar system have decayed since the universe was born but the universe is really stupidly big, so it absolute numbers that could still be a lot of dead electrons. Maybe a solar system's worth.
Surprisingly there is no wikipedia page for this. Just rando articles.
You might be thinking of protons.
It's ridiculous to cite an unnamed paper while being unable to procure a single source on the internet and then proclaim it's equally likely that they might or might not decay. With everything we know about physics there is absolutely no way imaginable that they might decay.
A) We don’t know if all derivatives are >= 0. e.g. if the jerk rate is < 0, then you’d expect contraction eventually. Similarly, if the derivative of the jerk rate is < 0 & so on. So even accelerating expansion could eventually lead to contraction.
B) We don’t have a lot of very highly compelling evidence that the universe is actually accelerating (at least nowhere like we do for the Big Bang). For example, alternate models have proposed that our apparent perception of the expansion is simply as a result of the effect of non-uniform gravity throughout the universe & that the vaccuum of space between galaxies has even less time dilation and that’s what make it look like things are expanding.
In other words, I’d put the model of a permanently expanding universe as less likely to actually match reality.
The Big Bang happened at the "north pole" of spacetime. Eventually all matter and energy will reach the "south pole" and recombine. The Big Crunch theory will never die!
You can have all of my poptarts, I'm likely to check out.