Entropy isn't a physical thing, it's a computed quantity that informs us about the state of a system. A decreasing-entropy universe requires some interpretation of what decreasing entropy means in the specific contexts where we talk about entropy.
For example, entropy in thermodynamics means that heat spreads out rather than concentrates, gasses diffuse instead of concentrating, etc. Maybe your interpretation of negative-entropy means that fires suck heat out of the surrounding areas. Maybe it means that gasses concentrate naturally, so if you had a closed box and you left it alone then the atmospheric gas inside would separate into layers of oxygen, nitrogen, etc. by density. Maybe it means that if you shatter a teacup the pieces slowly glue themselves back together.
Entropy is just an observational quantity that describes what we see in the real world. It describes the physical behavior we see in the real world, and the "opposite" of real behavior is not well defined. There is only one realistic, correct behavior. There are infinitely many incorrect behaviors you can pick from.
EZ-PEAS t1_iza4krp wrote
Reply to comment by ruamru123 in Ask Anything Wednesday - Physics, Astronomy, Earth and Planetary Science by AutoModerator
Entropy isn't a physical thing, it's a computed quantity that informs us about the state of a system. A decreasing-entropy universe requires some interpretation of what decreasing entropy means in the specific contexts where we talk about entropy.
For example, entropy in thermodynamics means that heat spreads out rather than concentrates, gasses diffuse instead of concentrating, etc. Maybe your interpretation of negative-entropy means that fires suck heat out of the surrounding areas. Maybe it means that gasses concentrate naturally, so if you had a closed box and you left it alone then the atmospheric gas inside would separate into layers of oxygen, nitrogen, etc. by density. Maybe it means that if you shatter a teacup the pieces slowly glue themselves back together.
Entropy is just an observational quantity that describes what we see in the real world. It describes the physical behavior we see in the real world, and the "opposite" of real behavior is not well defined. There is only one realistic, correct behavior. There are infinitely many incorrect behaviors you can pick from.