Monthly Archives: May 2013

Basic math with infinity

Physicist: Several questions about doing basic math with infinity have been emailed over the years, so here’s a bunch of them!  (More can be added later) Infinity comes in a lot of shapes and flavors.  However, the most straightforward infinity … Continue reading

Posted in -- By the Physicist, Math | 16 Comments

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 | 39 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 | 6 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 | 18 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 | 17 Comments