Category Archives: Physics

Q: Why is our Moon drifting away while Mars’ moons are falling?

The original question was: I know the Moon is getting further away because tides/friction/conservation of angular momentum.  This video claims Phobos is getting closer to Mars because of tidal forces, what gives?  Obviously no oceans to drag around but what … Continue reading

Posted in -- By the Physicist, Astronomy, Physics | 9 Comments

Q: Why do we (people) wave our arms when we fall? Is it for attention?

The original question was: When I am about to fall backwards I spin my arms up over my head then down . This seems to help in preventing my fall somewhat. Is this some form of conservation of angular momentum? Physicist: Actually, … Continue reading

Posted in -- By the Physicist, Physics | 2 Comments

Q: What is the state of matter in deep space?

The original question was: What might be the state of matter in [interstellar space]. Average temperature is 2.7K , so all the gases like hydrogen, helium should be in liquid or solid state? Physicist: Matter in deep space tends to take … Continue reading

Posted in -- By the Physicist, Astronomy, Physics | 9 Comments

Q: After the heat death of the universe will anything ever happen again?

Physicist: If you wait forever, then you might see something happen.  But the more practical answer is: no. The universe does a lot of stuff (for example, whatever you did today), but literally everything that ever happens increases entropy.  In … Continue reading

Posted in -- By the Physicist, Entropy/Information, Physics | 7 Comments

Q: Why does kinetic energy increase as velocity squared?

The original question was: … the formula for kinetic energy is and the formula for momentum is .  I ran into these in physics class long ago and was really bothered by the first formula.  How can energy go up … Continue reading

Posted in -- By the Physicist, Physics | 2 Comments

Q: Since the Earth is spinning and orbiting and whatnot, are we experiencing time wrong because of time dilation?

Physicist: A little! The movement of Earth, as well as the Earth’s gravity, change how much time we experience compared to other objects in the universe.  If we were to occasionally compare our clocks to clocks in tight orbits around … Continue reading

Posted in -- By the Physicist, Astronomy, Relativity | 11 Comments