Why doesn't everything freeze naturally?

Everything does freeze naturally, in space. The earth is constantly receiving energy from the sun, which keeps the earth nice and warm for the most part.

For more detailed information, look up Thermodynamics . What you’re asking is what processes create thermal equilibrium in a system (an open system in this case). I wish I had a good simple way to explain it.

@xyzzy Awesome job of deducing what the questioner meant!

indeed! :)

xyzzy is exactly right. The earth and it’s atmosphere is what is known as an open system, meaning that it receives a constant inflow of energy from the sun (and a tiny bit of matter from cosmic dust and meteors). Luckily we have an atmosphere that traps just about the right amount of energy (in the form of heat) for water to exist in the liquid phase, which is in large part what makes Earth a habitable planet.

Certainly, if the sun turned off or if our atmosphere disappeared, we would lose our source of energy/heat and “room temperature” would drop rapidly and dramatically and everything would tend to get colder. Luckily those things won’t be happening any time soon! On the other hand, Earth’s atmosphere recently gained properties that allow it to trap more heat, meaning that “room temperature” is slowly rising. Because heat is a form of energy, the system is able to contain more energy – this is the reason for increased storm intensity associated with climate change.

And some heat is produced internally in the planet. But the sun provides a majority of the heat felt on the surface.

INSUFFICIENT DATA FOR MEANINGFUL ANSWER

Wow, @schenectandy, you’re vehement. Please, though, try not to hold back so much. Let it out sometimes :)

;)

http://www.multivax.com/last_question.html

While I agree with xyzzy about the thermodynamics, it’s also very probable that matter would never completely freeze, even if the sun died. In fact, the background radiation fo the universe (about 2.7 degrees Kelvin) is the temperature of atoms in interstellar space, where they are not warmed by stars like the sun. The complete cessation of atomic motion is called Absolute Zero and is defined as 0 degrees Kelvin. There are a number of ways to think about why this doesn’t occur naturally…

Quantum mechanics (and the mathematical structure that supports it) predicts that electrons and atoms will never actually stop moving at the atomic scale. One way to see this is to consider the wave function of the atom in the ground (lowest energy) state. The wave function cannot be zero everywhere and so it must be curved somewhere (to satisfy boundary conditions of being zero at each edge). Curved wave functions imply kinetic energy, therefore if the wave function is curved there is some energy in the system.

Another way to think of this intuitively is to realize that cooling any atom to Absolute Zero would require it transferring all of it’s energy to another atom. That other atom would need to be colder than Absolute Zero in order for the first atom to reach Absolute Zero through this transfer. Alternatively, you can think of heat-transfer as the collision of atoms and molecules. But there is no collision which can occur that leads to one atom losing all of its energy.

Finally, you can consider the electric charge on the protons and electrons. The theory of electrodynamics tells us that there is potential energy stored in the atom because the electron and proton are attracted to each other. This electrical force is quite strong (many orders of magnitude stronger than gravity). Ceasing the kinetic motion of the electron relative to the proton will not decrease this potential energy because the attraction based on electric charge is still there. In fact, using the (outdated, classical) Bohr model of the atom, the electron orbits around the proton like a satellite. It is then the motion of the electron which keeps it from finally running into the proton. Thus, even if you could stop the radial motion of the electron, it would still be moving until it collided with the proton. This would then produce some unknown kind of reaction that would certainly involve energy, thereby heating the atom above Absolute Zero.

So, my answers to this question are very late. But it’s fun to think about.