The Fate of the Universe - High Energy Chaos or Heat Death?

Question

Here's one for the ages: Which will eventually win out, order or chaos? On one hand the 2nd Law says that basically everything tends to a state of maximum disorder (entropy), but also that all real processes are irreversible which generally means there is some heat given off / lost somewhere. This does increase the entropy of the universe, but causes the system to cool (i.e. lose some energy). A high entropy state is in general a high energy / temperature state, whereas if every process results in a heat loss, eventually the universe will cool and freeze at absolute zero since all of the finite avalable energy in the universe will have been lost to heat. Ironically this frozen universe end state would also be a state of MINIMUM entropy, since frozen matter/energy at absolute zero is in the most ordered state possible. So how will it all end up for this cozy little universe of ours...? A high-energy, maximum entropy stew of chaos, or a well-ordered frozen "heat death"?

Answer 1

You clearly do not understand entropy.

Entropy is about number of occupied microstates. A simple fact flowing from the 2nd law is that the Big Bang *must* have been the state of lowest entropy that the universe has ever been in (because entropy can only increase), yet it is also the time at which the universe *must* have been its hottest.

Answer 2

The jury is still out on this.  I vote for heat death, on the grounds that not only is the universe still expanding, but the rate of expansion has increased.  But we know nothing about invisible mass or negative energy, and the characteristics of these could profoundly affect the outcome.

Answer 3

Understand, "cool" implies ehthalpic, useful energy that establishes the temperature that will cool.  Consensus among legitimate astrophysicists is that our universe will go out with a whimper or like a candle finally burning itself out.  

Background temperature of our universe hovers around 4 deg K...closing in on absolute zero.  At K = 0, all enthalpic energy the universe started with during the big bang will have been converted to entropic energy.  And although there will be energy, entropic, there will be no temperature; the universe will not be hot in its demise.  It will be as cold as it can get.

Contrary  to "A high-energy, maximum entropy stew of chaos, or a well-ordered frozen "heat death"', the universe will end with a maximum entropy that is frozen in the sense it will be at K = 0 degrees.  That is, maximum entropy and frozen are not opposite outcomes as you assert.  

(In truth, the universe will not be frozen either, because freezing implies something to feeze.  At max entropy, there will be no matter because matter must have some enthalpic energy to hold it together as matter.  But rest assured, near 0 K, whatever matter still exists will be frozen.)

Further, it is inaccurate to say that entropy results from the loss of heat.  Entropy results from the conversion of enthalpy, useful energy, into useless energy.  That might result from heat losses, as you mention, like in a friction situation, but it might also be from the disassociation of a coherent, ordered body into a highly disordered one...like when Humpty Dumpty fell off his wall.