I don’t think it’s been ruled out for certain, but I believe the data is looking incredibly bad for big crunch enthusiasts, since the discovery of dark energy.
Edit: from the Big Crunch Wikipedia page:
The vast majority of evidence indicates that this hypothesis is not correct. Instead, astronomical observations show that the expansion of the universe is accelerating rather than being slowed by gravity, suggesting that a Big Chill is more likely. However, some physicists have proposed that a “Big Crunch-style” event could result from a dark energy fluctuation.
I take issue with discovery. To say there’s a mysterious inexplicable expansion of the universe hardly qualifies as such. It sounds more like a failure to understand our physical laws than to posit the presence of mysterious and otherwise undetectable entity.
The use of the word “discovery” in this case was carefully considered. The discovery of “dark energy” refers to the effect: the unexpected acceleration of the expansion of space. The fact that the expansion is accelerating was a discovery, and dark energy is just the name given to “whatever causes that”.
We don’t know that for fact, we can’t even agree on the age of the universe. Maybe there’s a big crunch
I don’t think it’s been ruled out for certain, but I believe the data is looking incredibly bad for big crunch enthusiasts, since the discovery of dark energy.
Edit: from the Big Crunch Wikipedia page:
Dark energy is a bit of a meme, have the inconsistencies with jws and hubble been resolved yet?
I take issue with discovery. To say there’s a mysterious inexplicable expansion of the universe hardly qualifies as such. It sounds more like a failure to understand our physical laws than to posit the presence of mysterious and otherwise undetectable entity.
The use of the word “discovery” in this case was carefully considered. The discovery of “dark energy” refers to the effect: the unexpected acceleration of the expansion of space. The fact that the expansion is accelerating was a discovery, and dark energy is just the name given to “whatever causes that”.