End of the Universe

[pokefan]

how do u belive the universe will end.

here are some theoreys found on wikipedia:

Big Freeze or Heat Death
Main articles: Big Freeze and Heat death of the universe
The Big Freeze is a scenario under which continued expansion results in a universe that is too cold to sustain life. It could, in the absence of dark energy, occur only under a flat or hyperbolic geometry, because such geometries then are a necessary condition for a universe that expands forever. With a positive cosmological constant, it could also occur in a closed universe. A related scenario is Heat Death, which states that the universe goes to a state of maximum entropy in which everything is evenly distributed, and there are no gradients — which are needed to sustain information processing, one form of which is life. The Heat Death scenario is compatible with any of the three spatial models, but requires that the universe reach an eventual temperature minimum.

[edit] Big Rip: Finite Lifespan

Main article: Big Rip
In the special case of phantom dark energy, which has even more negative pressure than a simple cosmological constant, the density of dark energy increases with time, causing the rate of acceleration to increase, leading to a steady increase in the Hubble constant. As a result, all material objects in the universe, starting with galaxies and eventually (in a finite time) all life forms, no matter how small, will disintegrate into unbound elementary particles and radiation, ripped apart by the phantom energy force and shooting apart from each other. The end state of the universe is a singularity, as the dark energy density and expansion rate becomes infinite. For a possible timeline based on current physical theories, see 1 E19 s and more.

[edit] Big Crunch


The Big Crunch. The vertical axis can be considered as either plus or minus time.


Main article: Big Crunch
The Big Crunch theory is a symmetric view of the ultimate fate of the universe. Just as the Big Bang started a cosmological expansion, this theory postulates that the average density of the universe is enough to stop its expansion and begin contracting. The end result is unknown; a simple extrapolation would have all the matter and space-time in the universe collapse into a dimensionless singularity, but at these scales unknown quantum effects need to be considered (See Quantum gravity).
This scenario allows the Big Bang to have been immediately preceded by the Big Crunch of a preceding universe. If this occurs repeatedly, we have an oscillatory universe. The universe could then consist of an infinite sequence of finite universes, each finite universe ending with a Big Crunch that is also the Big Bang of the next universe. Theoretically, the oscillating universe could not be reconciled with the second law of thermodynamics: entropy would build up from oscillation to oscillation and cause heat death. Other measurements suggested the universe is not closed. These arguments caused cosmologists to abandon the oscillating universe model. A somewhat similar idea is embraced by the cyclic model, but this idea evades heat death, because of an expansion of the branes that dilutes entropy accumulated in the previous cycle.

[edit] Big Bounce

Main article: Big Bounce
The Big Bounce is a theorized scientific model related to the creation of the known Universe. It derives from the oscillatory universe or cyclic repetition interpretation of the Big Bang where the first cosmological event was the result of the collapse of a previous universe.
According to one version of the Big Bang theory of cosmology, in the beginning the universe had infinite density. Such a description seems to be at odds with everything else in physics, and especially quantum mechanics and its uncertainty principle.[citation needed] It is not surprising, therefore, that quantum mechanics has given rise to an alternative version of the Big Bang theory. Also, if the universe is closed, this theory would predict that once this incarnation of the universe collapses it will spawn another universe in an event similar to the Big Bang after a universal singularity is reached or a repulsive quantum force causes re-expansion.

[edit] Multiverse: no complete end

Main article: Multiverse
The multiverse hypothesis states that our universe is but one universe among infinite parallel universes, possibly with different physical laws. Whatever the ultimate fate of our universe may be, almost all parallel universes will have different fates. And while many universes may be closed, many others may be open. The multiverse as a whole may never end completely.

[edit] False vacuum

If the vacuum is not in its lowest energy state (a false vacuum), it could collapse into a lower energy state.[citation needed] This is called the vacuum metastability event. This has the potential to fundamentally alter our universe; in more audacious scenarios even the various physical constants could have different values, severely affecting the foundations of matter, energy, and spacetime.

[edit] Many worlds quantum mechanics

The Many-worlds interpretation of Quantum mechanics predicts that the universe will not end this way -provided many worlds is true-. Each time a quantum event happens which causes the universe to decay from false vacuum to true Vacuum state the universe splits. In one or more new worlds the universe decays. In the other new world or worlds the universe continues as before.
See Possibility that the universe is a false vacuum

[edit] Cosmic uncertainty

Each possibility described so far is based on very simple form for the dark energy equation of state. But as the name is meant to imply, we know almost nothing of the real physics of the dark energy. If the theory of inflation is true, the universe went through an episode dominated by a different form of dark energy in the first moments of the big bang; but inflation ended, indicating an equation of state much more complicated than those assumed so far for present-day dark energy. It is possible that the dark energy equation of state could change again resulting in an event that would have consequences which are extremely difficult to parametrize or predict.

Copyright Wikiperdia.org

i belive in the big crunch or perhaps multi verse

[Justice and Mercy]

I don't think the universe will end.

[Juvenal]

For me, the Universe will end sometime this century with the probable cause being heart failure - perhaps compounded by cancer, thrombosis or aneurysm, maybe even blunt trauma (taking my driving and social skills into account).

If the Universe actually has an independent existence outside of my mind (and don't you go trying to convince me to the contrary because I haven't yet decided if you have an independent existence) ...then I think it is heading for Heat Death (i.e. maximum entropy).

All of the other theories are currently on shaky ground pending some seminal experiment that indicates they are not just wishfull thinking. Personally I like the Many Worlds Interpretation, but I cannot imagine any way it could be proven.

[Dayman]

Heat Death is what's going to happen as far as we know at the moment.

[Cataclysm]

Heat Death is what's going to happen as far as we know at the moment.

I prefer the term Big Chill. It matches the Big Bang.

I'd really really like to see the universe die in the Big Crunch. Why? Because we can assume that once the universe crunches into singularity it could rebound in another Big Bang, creating a cycle!

[pokefan]

I'd really really like to see the universe die in the Big Crunch. Why? Because we can assume that once the universe crunches into singularity it could rebound in another Big Bang, creating a cycle!

i read that somewhere. i think they called the Big Beat. like a heart beat

[Nutsack]

First of all, I'd like to state that I hold the same amount of respect for the theory of "Dark Energy" as I do for a pile of rat feces. Using simple logic and considering that the universe is not accelerating in the expansion, but rather slowing down - the universe might stop it's expansion, retract because of gravity all the way back to singularity - whereas all energy and matter is compressed into photons and cause another Big Bang.

[Gwendylyn]

Using simple logic and considering that the universe is not accelerating in the expansion, but rather slowing down - the universe might stop it's expansion, retract because of gravity all the way back to singularity - whereas all energy and matter is compressed into photons and cause another Big Bang.

Except all current data from the past 5+ years shows that the universe is indeed accelerating. The Big Crunch theory has been placed on the sidelines unless new data (which could conceivably happen) arises to support it.

The Big Crunch is quite poetic. I think people like the idea of it because they don't want to believe there is a definite end (heat death), but would rather accept a temporary death followed by a new universe.

[Tarif]

I don't understand any of this but I'm fascinated. I liked the idea of a big crunch...societies with their histories all written down, there'd have to be at least one place where something knew what was going on, that the universe was contracting... they're sitting there on some planet waiting for the edge of the universe to come and wtfpwn their existence out of...existence.

Seems a bit poetic.

but I'm rambling

[Chaigidel]

all things end, there is no exception.

[Ramashan]

The Universe, for me, is just too big to conceptualize and if it is going to end and how is rather irrelivant since we and our planet and possibly our sun are unlikely to be around if and when it does so to experience it.

The thing that boggles my mind is; If there was a big bang and the Universe expanded out to create all we know of today in the vastness of space, what is it expanding into?

Or, when we speak of the 'Universe coming to an end' are we only talking about the re-organization of matter in the Universe and not the infinite endless spacial void that matter is in?

[chris_uk_83]

The idea of Heat Death is a bit of a miserable one, instead of going out with a bang in the way it was formed, the universe slowly fizzles out as the individual stars get too far away from each other to have an effect on their neighbours, eventually the stars die and are never reborn. Chilliness ensues. Brrr.

[Chaigidel]

not really that miserable, I think it would quite possibly be more miserable if it never ended.