Answer 1:
The notion that the universe will reach
equilibrium is referred to as the heat death of
the universe. The second law of thermodynamics
states that entropy increases over time in
a closed system. Therefore, given sufficient time,
there should reach a state where energy in the
universe is evenly distributed. If this were to
occur, there would be no temperature differences
exploitable to do, perform work. Some
speculate that this would begin a dark period with
little energy and things occurring over very long
time scales. Basically, a universe with very few
types of particles and not a lot of activity.
This is indeed a controversial topic among
physicists. I should also note that it's a bit
tricky and controversial to apply what we know
about thermodynamics to the universe as a whole
for a few reasons. One is that in thermodynamics,
we talk about the system and the surroundings.
For the universe, it does not make sense to
call the universe the system as we cannot define
the surroundings, and therefore should not be
treated as a closed thermodynamic system.
Another reason is that it is tricky to apply ideas
of thermodynamic equilibrium to constituents of
the universe that have never been in
thermodynamic equilibrium. It comes down to
the following: not everyone agrees on how to
define entropy for a nonequilibrium system. It is
definitely something to ponder, but not worry
about. The decay time of a supermassive black hole
is about 10100 years, meaning that it
will take this long for heat death to occur.
|
Answer 2:
Good question. For one thing, life would not be
possible, since life depends on gradients that
would not exist if the universe were in perfect
equilibrium.
The thing that we don't know is that the rate
of expansion of the universe is increasing, which
is a non-equilibrium process that we don't
understand. If the expansion continues forever
(if!), and if protons decay (theorized but never
observed), then all particles of the universe will
be drawn to infinity in all directions to the
point where no particle will ever interact with
another again, except maybe for black holes. If
black holes evaporate (which they are thought to),
then it depends on what they evaporate into.
Both of these possibilities are so far in the
future that it is quite possible that the
expansion of the universe will be doing something
else then.
Click Here to return to the search form.
|
