1/19/2008 7:08:59 PM
Do you know what any of the things that you just discussed are?
3/18/2008 3:20:56 AM
Not quite as stupid as it would seem - if the earth converted all of the heat it receives from the sun into useful mechanical work, it would be a perpetual motion machine of the second kind. For any mechanism to produce useful mechanical work output from thermal energy input, there has to be a certain amount of this heat that is dumped back out of it again at a lower temperature - it can't use all of it. I believe, in the case of the earth, that this would be the heat that radiates out into space from the side of the planet that faces away from the sun, but I've never bothered to analyse a control volume of the entire planet in terms of a heat engine. It might be an interesting intellectual exercise for me to do some day.
3/18/2008 2:19:46 PM
I agree. The sun/wet-planet combination seems to cause the perpetual motion machine known as Weather ... that is, until one of the components changes its configuration. At that point, another "perpetual" mechanism will likely take place.
3/18/2008 3:17:13 PM
Yes (for a very, very small value of perpetuity).
3/18/2008 3:51:24 PM
4/27/2011 9:55:57 AM
6/13/2011 1:41:08 PM
le wild epic fa-
whaaaa! kill it with fire!!! RUN!!! RUN FOR YOUR LIVES!!!
3/29/2012 1:09:18 AM
Yes, just exactly like how an appliance you plug into a wall socket for power is a perpetual motion machine.
3/29/2012 2:27:31 AM