Nekrotic:The first thing you learn in any class on relativity is the equivalence principle of general relativity: that gravitational mass and inertial mass are the same.
What does this mean?
Well, gravitational mass is what determines the gravitational field. Inertial mass is used in the equations of motion. If they're equivalent, then forces due to acceleration, whether induced by motion or by gravitation, if equal, will be indistinguishable.
Centripetal acceleration due to spinning in a circular space station would both
feel and
measure as if there were a gravitational acceleration pinning you to the floor. But the centripetal force is
not gravity, and
has nothing to do with gravity. We just can't their accelerations apart.
Got it?
Quote:
But maybe you think Bovi is more knowledgeable than I am about science. Fair enough. This is the same guy that asks me to prove that solid matter will condense when heat is applied, because apparently he's never cooked a hamburger on a BBQ before. But no worries, you believe who you want to believe.
Hold up. The water is evaporated out of the meat, and the solid fat melts into grease and drips out of the burger, into the grill. So the burger gets smaller, because that stuff isn't in it anymore. It's like turning grapes into raisins. But that doesn't mean "matter, when heated, condenses", that's way too general a claim.
You have to understand what's going on at the molecular level. Trying to keep it simple, you have basically two different tendencies. You have the heat energy of the individual molecules which will tend to make them fly around and away from each other, and you have the repulsion/attraction of their electron shells' electrical fields (this is what's responsible for crystal lattice structures in ice, diamond, and so on).
Within that you have different types of attraction/repulsion, like dipole-dipole interactions, the van Der Waals force, ionic bonding. But for simplicity's sake you can treat them all as cousins in the same family.
Matter being heated from a solid to a liquid will "condense", yep. Electrical field forces between molecules aren't strong enough to overcome their individual heat energy and keep them all still in an ordered lattice, but there's still enough attraction there to keep them together (liquid).
Matter being heated from liquid to gas will expand, as individual heat energies of molecules completely overcome their mutual electrical attraction. Eventually when it's far and away too powerful for the electrical forces to keep them together, the matter state changes from liquid to gas.
This leaves out all those state-change goodies like sublimation and such. Same principles, just the rate of reaction and states changed are a bit different.
Finally, the earth is not a closed system, and you can't apply the 2nd law to any systems which aren't closed. Arguing the universe is a closed system is true but facetious, as not all locales are at their lowest energy states yet. Call us in 120 billion years when all the stars have finished burning. Until then, higher energy / lower entropy states such as life will be possible.
