Category Archives: — By the Physicist

Q: Why does the Earth orbit the Sun?

The original question was: What exactly causes the Earth’s rotation and revolution?  Does this occur due to centripetal force and the lack of friction to stop the Earth from spinning? IE- Newton’s First Law? If so, where did this centripetal … Continue reading

Posted in -- By the Physicist, Astronomy, Equations, Physics | 63 Comments

Q: If you suddenly replaced all the water drops in a rainbow with same-sized spheres of polished diamond, what would happen to the rainbow? How do you calculate the size of a rainbow?

Physicist: A normal rainbow is created when light enters a water droplet, bounces once off of the far side, and comes back out. Diamond “droplets” however don’t make rainbows.  In order to get a rainbow that exists, and isn’t in … Continue reading

Posted in -- By the Physicist, Equations, Geometry, Physics | 4 Comments

Q: If we meet aliens, will they have the same math and physics that we do?

Physicist: Similar.  We’re sure to have figured out stuff they haven’t, and they’re sure to have figured out stuff we haven’t.  But there’s likely to be a fair amount of overlap. Some things have a way of being figured out … Continue reading

Posted in -- By the Physicist, Philosophical | 12 Comments

Q: What would Earth be like to us if it were a cube instead of spherical? Is this even possible?

Physicist: The Earth is really round.  It’s not the roundest damn thing ever, but it’s up there.  If the Earth were the size of a basketball our mountains and valleys would be substantially smaller than the bumps on the surface … Continue reading

Posted in -- By the Physicist, Astronomy, Physics | 85 Comments

Q: How do velocities add? If I’m riding a beam of light and I throw a ball, why doesn’t the ball go faster than light?

Physicist: Everything in special relativity, no matter how weird, eventually boils down to the speed of light being the same to everyone.  It’s just not immediately obvious how.  The very short answer is: if v and w are pointing in … Continue reading

Posted in -- By the Physicist, Physics, Relativity | 23 Comments

Q: What is the universe expanding into? What’s outside the universe?

Physicist: Probably nothing.  We do know that the universe doesn’t need anything to expand into, and we haven’t seen any evidence that there is anything outside of the universe.  But there has still been some speculation. In the last hundred … Continue reading

Posted in -- By the Physicist, Astronomy, Philosophical, Physics | 63 Comments