Category Archives: Astronomy

Q: Is geocentrism really so wrong? Is the Sun being at the “center” (i.e. the Earth orbiting the Sun) just an arbitrary reference frame decision, and no more true than the Earth being at the center?

Physicist: When you walk around in this big crazy world, there aren’t any immediate reasons to suspect that the ground under your feet is doing anything more than sitting perfectly still (ring of fire notwithstanding).  Given that, when you look … Continue reading

Posted in -- By the Physicist, Astronomy, Experiments, Physics, Relativity | 19 Comments

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 | 11 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 | 11 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 | 32 Comments

Q: If the Sun pulls things directly toward it, then why does everything move in circles around it?

Physicist: Newton’s laws of motion say: Where MP and AP are the mass and acceleration of a planet, MS is the mass of the Sun, R is the distance between them, and G is a universal constant.  What this rather … Continue reading

Posted in -- By the Physicist, Astronomy, Evolution, Physics | 24 Comments

Q: How does Earth’s magnetic field protect us?

Physicist: High energy charged particles rain in on the Earth from all directions, most of them produced by the Sun.  If it weren’t for the Earth’s magnetic field we would be subject to bursts of radiation on the ground that … Continue reading

Posted in -- By the Physicist, Astronomy, Particle Physics, Physics | 10 Comments