Yearly Archives: 2013

Q: What is the Planck length? What is its relevance?

Physicist: Physicists are among the laziest and most attractive people in the world, and as such don’t like to spend too much time doing real work.  In an effort to streamline equations “natural units” are used.  The idea behind natural … Continue reading

Posted in -- By the Physicist, Particle Physics, Physics, Quantum Theory | 41 Comments

Q: What causes friction? (and some other friction questions)

Physicist: Political conversations with family, for one. “Friction” is a blanket term to cover all of the wide variety of effects that make it difficult for one surface to slide past another. There a some chemical bonds (glue is an … Continue reading

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

Q: Is fire a plasma? What is plasma?

Physicist: Generally speaking, by the time a gas is hot enough to be seen, it’s a plasma. The big difference between regular gas and plasma is that in a plasma a fair fraction of the atoms are ionized.  That is, … Continue reading

Posted in -- By the Physicist, Physics | 22 Comments

Q: Why are determinants defined the weird way they are?

Physicist: This is a question that comes up a lot when you’re first studying linear algebra.  The determinant has a lot of tremendously useful properties, but it’s a weird operation.  You start with a matrix, take one number from every … Continue reading

Posted in -- By the Physicist, Math | 18 Comments

Q: Are white holes real?

Physicist: The Big Bang is sometimes described as being a white hole.  But if you think of a  white hole as something that’s the opposite of a black hole, then no: white holes aren’t real. They show up when you … Continue reading

Posted in -- By the Physicist, Astronomy, Math, Physics | 21 Comments

Q: If a photon doesn’t experience time, then how can it travel?

Physicist: It’s a little surprising this hasn’t been a post yet. In order to move from one place to another always takes a little time, no matter how fast you’re traveling.  But “time slows down close to the speed of … Continue reading

Posted in -- By the Physicist, Relativity | 364 Comments