RE: Physics questions
May 9, 2019 at 6:27 pm
(This post was last modified: May 9, 2019 at 6:32 pm by Anomalocaris.)
(May 9, 2019 at 5:16 pm)ignoramus Wrote:(May 8, 2019 at 10:19 pm)Anomalocaris Wrote: If we somehow cool the whole solar system to absolute zero degrees, that doesn’t mean all the planet’s will stop dead in their orbits. They will go merrily on around the sun as they have always done, and all the orbital energy of the cohesive motion of their molecules around the sun will still all be there. So all sorts of things can still happen, depriving their energy from sources other than random molecular motion.
Chuck, would we even have a sun if we cooled the whole solar system to absolute zero?
The sun obviously can’t continue to radiate away thermal energy if it is at absolute zero. Although it as with all else will continue to radiate due to hawking radiation, so it will never truly be at absolute zero. But that doesn’t matter to the main point of the thought experiment. It’s mass will still be there, exerting gravity just as it did before, binding all the planets into the same orbits and orbital motions as before. In other words the gravitational potential energy and the cohesive kinetic would be totally unaffected if you lower the system to absolute zero by removing all random molecular kinetic energy from the solar system by cooling everything to zero degrees absolute.