Tuesday, 10 January 2012

Heat death, thermodynamics and another paradox!!!


Hello interweb, back to science things and the universe I’m afraid,
Did you know that it is a widely accepted view that the universe from its inception through to present day and way into the future is made up of matter and dark matter which is concentrated in stars, galaxies and galaxy clusters? If you didn’t don’t worry you do now.
So what does this mean? This means that the universe is not in thermodynamic equilibrium and as a result objects can do physical work. (job dodgers take note, even the universe works) work  performed by a system is the energy transferred to another system that is measured by the external generalised mechanical constraints on the system.
The decay time for a super massive black hole of roughly 1 galaxy-mass (10 to the power of 11 solar masses) due to Hawking radiation is in the order of 10 to the power of 100 years, so entropy can be produced until at least that time.
After this time has been reached the universe will enter a dark era and will consist for the most part of a dilute gas of photons and leptons with very small amounts of matter left. Due to the small amounts of remaining matter left in the universe most activity will have tailed off with very low energy levels and due to a lack of matter any remaining activity will have enormous time scales.
 It is possible that with the lack of entropy production the universe will achieve heat death.
 Which brings me conveniently round to the Heat Death Paradox and as anybody who has read my ramblings on a regular basis knows I love a paradox.


The heat death paradox, is an argument attempting to use thermodynamics to make deductions about the nature of the universe. Specifically, it attempts to argue against an infinitely old, static model of the universe using reductio ad absurdum.
The argument holds that If the universe were infinite in extent it would also have to be infinitely old. Any hot object transfers heat to its cooler surroundings, until everything is at the same temperature. For two objects at the same temperature as much heat flows from one body as flows from the other, and the net effect is no change. If the universe were infinitely old there must have been enough time for the stars to cool and warm their surroundings. Everywhere should therefore be at the same temperature and there should either be no stars, or everything should be as hot as stars.
Since there are stars and the universe is not in thermal equilibrium it cannot be infinitely old; since it is not infinitely old it cannot be infinite in extent.
So there you have it, a bit of science for you to ponder and learn from, as I grow older I too learn things, I have learned to leave well (even pretty well) alone as you will only get burned. I often think about whether or not we are alone in the universe , Sometimes I think we are and other times I think that we are not, either way the thought of either is quite frankly staggering to my small mind.
Right then if that lot wasn’t drivel enough here is a bit more.
“Admit that your own private Mount Everest exists. That is half the battle.”
Peace out y'all, THE BAGSTAXXX

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