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MechaMadness
2013-Feb-06, 05:10 AM
Im just curious, do you guys believe the Universe will end with a Big Crunch, or will it stretch out forever?

tnjrp
2013-Feb-06, 06:25 AM
"Believe" is problematic word. The models pertaining to the far ends of time are all rather speculative at the moment AFAIK. However a classical Big Crunch (BC) seems unlikely, given the observations. Up to about the turn of the century I do believe most cosmological models predicted endless expansion and eventual heat death of the universe. Observing dark energy brought about the possibility of the opposite of BC, Big Rip (BR). In some models, BR is actually followed by a sort of BC with the "universe coming back empty".

Cougar
2013-Feb-07, 03:50 PM
However a classical Big Crunch (BC) seems unlikely, given the observations.

I'd take that a bit further and say a big crunch is pretty much ruled out - if there's not a drastic change in what is currently observed. Of course, predictions are always hard, especially about the future.

publiusr
2013-Feb-09, 08:53 PM
Chances are, Lord kelvin was right in the end. A cold, empty universe.

ASTRO BOY
2013-Feb-09, 09:53 PM
How do we define the "End of the Universe"?
Stars will all eventually die, WD's Pulsars etc will become black featurless cinders in space, BH's will evaporate, Protons will probably end up decaying.....But Space and time will continue on expanding regardless according to latest data.

Twisted Wit
2013-Feb-14, 06:00 AM
I guess the dark energy is not going anywhere either.

Squink
2013-Feb-14, 07:42 PM
Spacetime'll probably just stretch out and get diluted until there's no possible way to measure the interval between one second and the next. Since no one could measure past that point...

tnjrp
2013-Feb-19, 05:46 AM
Heat death is a somewhat well defined state, more specifically that of total thermodynamic equilibrium.

Meanwhile, the Higgs boson discovery invigorates the old(ish) metastability issue, according to some physicists at least:
http://cosmiclog.nbcnews.com/_news/2013/02/18/17006552-will-our-universe-end-in-a-big-slurp-higgs-like-particle-suggests-it-might

Cougar
2013-Feb-19, 06:44 PM
Meanwhile, the Higgs boson discovery invigorates the old(ish) metastability issue, according to some physicists at least:
http://cosmiclog.nbcnews.com/_news/2013/02/18/17006552-will-our-universe-end-in-a-big-slurp-higgs-like-particle-suggests-it-might

This article is typical in its sensationalism.


"He said the parameters for our universe, including the Higgs mass value as well as the mass of another subatomic particle known as the top quark, suggest that we're just at the edge of stability, in a "metastable" state."

But the paper linked to in the article basically said the error bars are still too large to know if the vacuum is in a potentially metastable state or not.

tnjrp
2013-Feb-21, 06:15 AM
Ethan Siegel agrees, the news made it to his "Worst kind of science hype" top of the recents:
http://scienceblogs.com/startswithabang/2013/02/20/the-worst-kind-of-science-hype/

Still, since the possibility of a phase shift destroying/reseting our universe has not been conclusively ruled out, it's worth mentioning in a "cosmological eschatology" thread.