do you believe in it? more importantly, if yes/no, what's the reason why / why not?
i have had a great number of very enjoyable discussions with people about this topic. some say that it is unknowable what the eventual fate of the universe will be, because we can never have experimental confirmation that things will keep on moving forever, unless we wait for the end of the universe, which will never come (or at which point the knowledge would be useless).
however, i keep thinking that cosmic expansion will lift things out of a gravitational potential over time. i'm assuming that we're all inside a big black hole (the whole universe is a black hole as an object with the mass of the entire observable universe just so happens to have a schwarzschild diameter of about the diameter of the entire observable universe). as the universe expands, its density decreases, therefore its schwarzschild radius decreases and we will eventually leave the black hole without doing anything for it; this obviously adds energy to the system.
or, in case cosmic expansion does not continue exponentially (but slows down over time), then the laws of physics would change over time; then, according to noether's theorem, we could extract useful energy out of that change of laws over time. also black holes could grow to infinite size simply feeding on cosmic microwave background radiation continuously in this case¹. which we could use as an energy source.
[1]: do the differential equation, you get dM/dt ∝ M²·u₀/a(t) where M is the mass of the black hole, M² is proportional to the surface area, a(t) is the scale factor, and u₀ is the CMB density at current time. If a(t) is less than exponential, i.e. less than exp(Ht), then M(t) diverges in finite time for any black hole with big enough start mass.
sorry for such a verbose post :)
The universe doesn’t care whether we believe in its heat death. It does get mildly annoyed at being anthropomorphized though.
The problem is, the closer we get to heat death, the closer we get to a state where universal forces won’t reliably line up like they do today, and there’s no way to properly simulate this state from within our current universe.
That is to say, even if we can perfectly model what MAY happen, when we get to the point where forces will all act on matter and energy at the quantum level with the same level of influence, we’d need to have fully and completely modeled the universe to figure out what happens next.
Personally, I’m of the opinion that it all happens next, and won’t be for the first time.