Entropy among the stars?

Question

If thermodynamics states that everything tends to move toward a lower state of energy by expanding, becoming more disordered, and colder, then why within space do we see complex ordered and hot structures.
It would seem to me that stars break the laws of thermodynamics becuase a cold dispersed cloud of gas clumps together tightly to heat up and form heavier more complex elements. Does this seem backward to anyone else? Is gravity missing within the laws of thermodynamics, and if so it it were added would you be able to predict the formation of galaxies and their distributions based soley on thermodynamics?

Answer 1

Entropy is alive and well. Just because a system is complicated doesn't mean that entropy isn't happening. The cloud of gas to highly organized star is a good example. Here we have the original condition (gas cloud of Hydrogen) unorganized but very high in potential energy. As gravity influences the cloud it begins to contract. True it is becoming more organized, but what else is happening? As it contracts it begins to heat up. This radiates energy to space and is lost. If there is enough gas and enough is pulled together, then we have a young star fire up it's fusion engine and it begins shining and radiating intensely. But as the fusion continues, more hydrogen is fused to helium and more complex atoms. True the star is becoming more complex, however it's potential energy is always decreasing as more of it's fuel is burned. When it gets to iron it has reached a dead end. Iron is truly complicated, but it takes more energy to fuse iron into a higher element than it releases. Thus the core rapidly loses energy and the star begins collapsing. The star is truly complicated at this point but it's overall energy content has whithered remarkably from what was available in the original gas cloud. Eventually, given enough time the star would become a black dwarf, no fusion occurring and the same temperature as the surrounding space. It would have an impressive gravity well, but each individual atom contributes the same gravity mass as before so gravity (quantity, potential, and effect) itself doesn't change and doesn't change the outcome of the system from a high energy state to a lower energy state over time.

Answer 2

The second law of thermodynamics does not require everything to lose energy all the time. It only says that when thermal energy is released, you will not be able to recover all the energy. In a universe without entropy, stars could live, die, and be reborn cyclically forever. In reality, the next generation of stars can not capture all the energy dissipated by the preceding one, and the universe will eventually run down completely.

You are correct that gravity is not affected by this. Gravitational potential and other forms of mechanical energy can be transferred without increasing entropy.

Answer 3

The law includes "in a closed system". A gas cloud that collapses into a star is not a closed system - other stars, supernova explosions, changes in gravitation and radiation all come from "outside" the gas cloud to help it collapse and form a star. Fusion may produce heat, but the energy expended by the star is an increase in entropy, stars don't violate thermodynamics.

Answer 4

99.999% of space is dark and cold. If the laws of thermodynamics were so easily broken, do you really think no one would have noticed? Do you really think they'd be called 'laws'?

Put energy into a system, and you can reverse entropy. A cold dark cloud of hydrogen that is set spinning has had energy put into it, and it will collapse gravitationally to form a star.

Answer 5

The gravity is part of an open system that allows out side influences to give the appearance of circumventing the laws of thermodynamics.