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Isolated Fury
03-14-2005, 01:53 PM
The heat-death of the universe is when the universe has reached a state of maximum entropy. This happens when all available energy (such as from a hot source) has moved to places of less energy (such as a colder source). Once this has happened, no more work can be extracted from the universe. Since heat ceases to flow, no more work can be acquired from heat transfer. This same kind of equilibrium state will also happen with all other forms of energy (mechanical, electrical, etc.). Since no more work can be extracted from the universe at that point, it is effectively dead, especially for the purposes of humankind.

This concept is quite different from what is commonly referred to as cold death. Cold death is when the universe continues to expand forever. Because of this expansion, the universe continues to cool down. Eventually, the universe will be too cold to support any life. It will end in a whimper. The opposite of cold death, as you can see, is NOT heat death, but actually the big crunch. The big crunch occurs when the universe has enough matter density to contract back on itself, eventually shrinking to a point. This shrinking will cause the temperature to rise, resulting in a very hot end of the universe.

The heat death of the universe will only occur if the universe will last for an infinite amount of time (i.e there will be no big crunch).

It will occur because, according to the second law of thermodynamics, the amount of entropy in a system must always increase. The amount of entropy in a system is a measure of how disordered the system is - the higher the entropy, the more disordered it is.

It is sometimes easier to imagine if you think of an experiment on earth. A chemical reaction will only occur if it results in an increase of entropy. Let us imagine burning petrol. We start of with a liquid that contains atoms arranged in long chains - fairly ordered. When we burn it, we create a lot of heat, as well as water vapor and carbon dioxide. Both of these are small gaseous molecules, so the amount of disorder of the atoms in their molecules has increased. The temperature of the surroundings has also increased.

Now let's think of what this means for the universe. Any reaction that takes place will either result in the products becoming less ordered, or heat being given off. This means at some time far in the future, when all the possible reactions have taken place, all that will be left is heat (i.e. electromagnetic radiation) and fundamental particles. No reactions will be possible, because the universe will have reached its maximum entropy. The only reactions that can take place will result in a decrease of entropy, which is not possible, so in effect the universe will have died.


My physics class has started to learn about heat death. Our teacher finds the subject humerous - as do most of my classmates. But when I think about it, it's pretty disturbing. Knowing that the universe will end so...disappointingly it's just horrible. I was hoping for like a chain of nuclear explosions or something. Anything a little more violent would satisfy my primal needs. :)

the_GoDdEsS
03-14-2005, 02:00 PM
I just skimmed through your post because I've read about that shit in my bookies before. And it's fascinating.

Isolated Fury
03-14-2005, 02:06 PM
It's only really the increase of entropy in the universe. Since entropy reduces the "quality" of the energy with disorder, we aren't able to use it anymore. There will be no source of heat moving from high to low temperatures.

My teacher also has this concept called his Cuban Refugee Analysis. It says that if none of the Cubans that come to America on small cardboard boxes would make it, they would never come over. But since some of them don't drown or get lost, a lot of them try to come to American hoping to succeed.
He then tied this to the flow of heat from high temperatures to low temperatures.


Psst! Don't tell him I said this, but I think he's crazy! He went to West Point and now he's kinda cuckoo.

Tijs
03-14-2005, 02:07 PM
Indeed it is. The universe is one interesting mysterious place.
We had a discussion about this subject in another topic though.. but that was a few months ago, and it was off-topic.

HeadAroundU
03-14-2005, 02:14 PM
Its fascinating but I don't have a time for studying those things!
I have o lot of informations about universe from TV!I like watchig scientific shit:)

TheUnholyNightbringer
03-14-2005, 03:42 PM
The scary thing about that is, it makes perfect sense. Damn, we're fucked.

nitropenguin!
03-14-2005, 03:45 PM
I'm scared... someone hold me. >.<

TheUnholyNightbringer
03-14-2005, 03:46 PM
Come into my sweet embrace.

*Holds out arms lovingly*

nitropenguin!
03-14-2005, 03:52 PM
Benignant Nightbringer <3 *hugs* Yes, our compassionate bubble will protect us! Excellent.

TheUnholyNightbringer
03-14-2005, 03:53 PM
None can breach our totally cool hippy-love defences. Not even total universal collapse.

Isolated Fury
03-14-2005, 03:55 PM
Just think, if you don't do any work at all and just sit there, you're helping the existance of humanity. Your lack of work is bringing down the universal average of heat generation!

So, good job, slackers! Keep up the good work (no pun intended)!

TheUnholyNightbringer
03-14-2005, 03:56 PM
Just think, if you don't do any work at all and just sit there, you're helping the existance of humanity. Your lack of work is bringing down the universal average of heat generation!

So, good job, slackers! Keep up the good work (no pun intended)!

At last, a feasible excuse for doing nothing. I will pay you in gold.

Isolated Fury
03-14-2005, 04:00 PM
At last, a feasible excuse for doing nothing. I will pay you in gold.

You're welcome. I require no payment - only your blood. :)

nitropenguin!
03-14-2005, 04:04 PM
Fury you are.. a genius! How much blood?

Isolated Fury
03-14-2005, 04:13 PM
Oh, you know...the usual.

Only enough to stop your heart. That's all.