What Happens After the Universe Ends?
Why Hacker News recommends it
HN recommends it as a clearer explanation of Penrose's cyclic cosmology than comment threads can give.
What it is
PBS Space Time explains Roger Penrose's conformal cyclic cosmology, in which the far future of our universe becomes the big bang of the next. It explores what could come after the universe ends.
Recommended by 2 HN commenters across 2 different months, 2020 to 2023.
What Hacker News said
Recommends tiborsaas · 2020-10 · on “An earlier universe can still be observed today, says Roger Penrose”
According to CCC and to my understanding, it is sort of the case. The universe has undergone a "scale change" which marks the beginning of a new Epoch. It's explained in this PBS Space Time episode much better: [this video]
Recommends haxiomic · 2021-09 · on “The universe has already made almost all the stars it will ever make”
This dramatic visualization of the timeline for the rest of the universe is well worth a watch to get a feel for what we believe the future of the universe to look like [TIMELAPSE OF THE FUTURE: A Journey to the End of Time] [LINK] However, when you get to the end (which is perhaps a little depressing!), I'd recommend learning a bit about what we think could come 'after' this period, where the universe has become so isotropic and homogenous no clocks or measuring systems of any kind can be developed so the universe loses any sense of size or energy – it's been proposed that this creates opportunity for a new universe to exist [What Happens After the Universe Ends?] [this video] These are fields o
Cites Ygg2 · 2020-10 · on “An earlier universe can still be observed today, says Roger Penrose”
Argument was a bit more complicated. Basically when all particles are moving at speed of light, time becomes meaningless and you can consider space to be infinitely small. I.e. identical conditions to Big Bang [this video]
Cites tzs · 2022-01 · on “A delightful quirk of relativity theory”
There was a PBS Space Time episode about a year ago that covered what I think is the same recent Penrose idea that you have mentioned [1]. [1] [this video]
Cites Ygg2 · 2023-05 · on “‘The Godfather of A.I.’ Leaves Google and Warns of Danger Ahead”
In conformal cyclic cosmology (CCC for short), the heat death of universe looks a lot like big bang. Essentially once all matter is reduced to photons (and massless particles) there is nothing to track time (or space), light can be understood as being everywhere all at once, thus causing huge amount of energy and with very little entropy. [PBS Spacetime on CCC] [this video]