Entropy came up in one of my last questions. Can one of you physics buffs give me a clear example/analogy of how entropy works both in the universe and inside that cell/capsule.

Don't need wikipedia links, an original explanation would be much appreciated, thanks.

Google the Second Law of Thermodynamics.

You should get all of the information you need :3

http://www.youtube.com/watch?v=vLACGFhDOp0

http://www.youtube.com/watch?v=uQSoaiubuA0

These two videos go together and are good explanations of entropy

The universe for some reason seeks balance, but there is also a conservation of initial energy.

To satisfy both principles, states of higher order (less random, like a young star) will over time slowly become less ordered (interstellar dust, dark matter) and the energy will turn into less useful forms.

Useful forms of energy: light, reactive chemical, gravity potential, kinetic, and sometimes concentrated heat energy become other forms and eventually heat and sound, which are Brownian, incoherent, and not useful to us in any way.

The reason that things with order become less orderly is because the rate of change of one form of energy is proportional to the actual amount of that kind of energy. More abundant forms of energy will deplete faster while less abundant ones will actually grow because other forms of energy are transforming into it. This concept is directly analogous to diffusion and osmosis which any textbook can explain in clear detail.

Best way to visualize this flow of energy: Imagine a box with two partitions sealed in the middle by a divider. One side of the box contains a volume gas while the other has a vacuum. If you remove the divider, why does the gas move to fill the entire box? It is actually because of entropy, in this case because of the random motion of molecules. On the side with gas, there is a lot of kinetic energy (motion) and a lot of molecules and therefore some go into the other side. On the side without gas, there are no molecules, so it makes sense that none would be able to move into the other part of the box. When it reaches equilibrium, or the highest amount of randomness, both sides will have the same amount of gas, heat, motion, etc moving into the other side and all throughout.

The reason we can exist despite constantly decreasing order is because processes of disorder (the sun) can be used to fuel processes of order (us) so long as the net amount of disorder is greater than it was before.

This post was edited by EndlessSky on Mar 19 2012 12:51pm

Well...

To clarify: Things don't turn into heat and sound. The energy they give off during catabolism is lost in these forms.

And I would be careful with stating that they are oxidized into less useful forms, as, even atomically, it is all put to use.

That nit-pickyness aside... Well put :3