Category Archives: Astronomy

Q: If time is relative, then how can we talk about how old the universe is?

Physicist: One of the most profound insights ever made by peoplekind is that time is relative.  This isn’t some abstract idea, mistake, or mathematical artifact.  If you have two identically functioning clocks, you can start them together, move them to … Continue reading

Posted in -- By the Physicist, Astronomy, Physics, Relativity | 16 Comments

Q: Where is the middle of nowhere?

The original question was: Is there any location in intergalactic space which is so far away from anyplace that it would be impossible to see anything with normal naked eye vision?  No stars, but no galaxies, no nothing — just … Continue reading

Posted in Astronomy, Physics | 13 Comments

Proxima B!

Physicist: Good news!  There’s an Earth-sized planet in the habitable zone of Proxima Centauri, a star so named because it’s the closest star to Earth and it’s in the constellation Centarus.  This isn’t a question anyone asked, but I thought … Continue reading

Posted in -- By the Physicist, Astronomy, Physics | 13 Comments

Q: Is there anything unique about our solar system?

Physicist: Maybe. As far as stars go, ours is a dull as dishwater, middle of the road, dime a dozen, main sequence star.  You can’t spit in space without hitting a Sun-like star.  So this question is really about the … Continue reading

Posted in -- By the Physicist, Astronomy, Philosophical | 7 Comments

Q: What is dark energy?

Physicist: The universe is expanding and the rate of that expansion is accelerating.  If the universe were full of only matter (both regular and dark) and energy, then we’d expect that the expansion would be slowing.  Dark energy is the … Continue reading

Posted in -- By the Physicist, Astronomy, Physics, Relativity | 30 Comments

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 | 13 Comments