Proof of God

Mike Flynn · #11 2nd October 2003, 07:02 PM

Originally Posted by the_malevolent_milk_man

Not to be nit picky but batteries do not lose their energy due to entropy. Everything experiences entropy but it has very little effect on the battery. It's caused by self discharge which is due to internal chemistry changes within the battery. Different batteries made with different materials lose their charge at different rates, this is again due to the internal chemistry and structure that affects the self discharge rate.

Chemistry is not really my area, but...

When chemical reactions happen spontaneously and there is a change in energy, in this case the loss of chemical potential, this can be accompanied by a corresponding increase in entropy, correct?

I suppose there are exceptions where the reverse is true...like the formation of ice crystals when water loses heat and loses entropy as well.

Anyone know which is the case for an electrochemical reaction like a battery?

LorentzHA · #12 2nd October 2003, 10:46 PM

I thought it was an increase in entropy for an electrochemical gradient. Such as the build up of H+ in the inner mitochondrial membrane (electrochemical gradient in chemiosmosis electron transport chain) Not Chemistry but Biochemistry and we did deal with entropy as explained as the amount of energy available to do work. As H+'s increase entropy goes up like water behind a dam. Sorry not exactly a battery but the Biochem version of...my 2 cents...

the_malevolent_milk_man · #13 3rd October 2003, 12:09 AM

I guess in a weird way you could say entropy aids the self discharge since the oxygen formations cause it to leak more. However it is an actual electrical discharge that drains the battery. There are some batteries that can eliminate the oxygen by turning it to hydrogen on the positive side which will greatly lengthen the batteries life but not all of it can be dealt with and corrosion and depolorization still occur within the battery. However the battery also leaks gas so you will be losing some energy that way.

Still, technically it stems from the materials used and their chemical properties that cause the self discharge. If they didn't react in a harmful manner and the casing didn't outgas then theoretically the battery would last forever on the shelf. In that ideal situation the battery would remain at equilibrium with the surrounding room and lose as much thermal energy as it gains. In the real world the only real entropy is from the escaping gas, the rest is chemical reactions and self discharge which drains the actual electrical energy. So yeah it is kinda entropy but it's just not the whole story.

edit: weird, all my text went white

LaserCool · #14 3rd October 2003, 09:03 PM

Originally Posted by Mike Flynn

Now that would be a hard thing to prove using the laws of physics I'd say...since they are strictly born from the measurable parts of this universe. Anything beyond this universe is of course, pure speculation scientifically speaking...but that doesn't mean it doesn't exist. Perhaps the above is just your opinion, then?
..Why not use a
carrot instead of a stick?

In the context of the post, I guess I might have been clearer. I like to use philosophical techniques to answer things that science is mute on (did a minor in philosophy). My section regarding "in the universe" and "outside the universe" rests upon a philosophical foundation, not physics itself.

Often I find that one has to be firm with amateurs, especially the ones that are trying to use science to underpin a non-scientific premiss. The consequence of not being clear in your disagreement is often, as I have found, that your statement is taken as tacit agreement with their particular brand of nonsense.