Category Archives: Physics

Q: How hard would it be to keep the Moon from drifting away?

Physicist: Almost prohibitively! Ever since the Moon entered the scene 4.5 billion years ago, it’s been slowly drifting away.  Initially it was around 15 times closer and bigger across in the sky.  The effects that push it away decrease rapidly … Continue reading

Posted in -- By the Physicist, Astronomy, Engineering, Physics | 7 Comments

Q: Where is all the anti-matter?

Physicist: Anti-matter is exactly the same as ordinary matter but opposite, in very much the same way that a left hand is exactly the same as a right hand… but opposite.  Every anti-particle has exactly the same mass as their … Continue reading

Posted in -- By the Physicist, Particle Physics, Physics | 14 Comments

Q: Is reactionless propulsion possible?

Physicist: In a word: no. A reactionless drive is basically a closed box with the ability to just start moving, on its own, without touching or exuding anything.  The classic sci-fi tropes of silent flying cars or hovering UFOs are … Continue reading

Posted in -- By the Physicist, Physics, Relativity | 15 Comments

Q: How can I set up a random gift exchange that’s different from year to year?

The original question was: I’ve got a large family and we do a yearly gift exchange one person to one person. And I’d like to make a algorithm or something to do random selection without repeating for some time. And … Continue reading

Posted in -- By the Physicist, Combinatorics, Experiments, Math | 2 Comments

There’s something new under the Sun!

Physicist: Good news! On October 19th, for the first time in history, we detected an object inside of our solar system that originated somewhere else.  It’s a rock the size of a stadium that passed inside of Mercury’s orbit and … Continue reading

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

Q: Is it more efficient to keep keep a swimming pool warm or let it get cold and heat it up again?

The original question: I’m having a debate with my wife that I think you can help us resolve.  We have a swimming pool in our back yard.  It has an electric heater, which we set to keep the pool water … Continue reading

Posted in -- By the Physicist, Engineering, Physics | 15 Comments