Category Archives: — By the Physicist

Q: Why don’t “cheats” ever work on the uncertainty principle? What’s uncertain in the uncertainty principle?

Physicist: The Uncertainty Principle is often stated as “the position and momentum of a particle cannot be simultaneously and perfectly measured”.  Mathematically, it’s written as , which means that the product of the uncertainties in the position, x, and momentum, … Continue reading

Posted in -- By the Physicist, Physics, Probability, Quantum Theory | 2 Comments

Q: Do the past and future exist? If they do, is the future determined and what does that mean for quantum randomness?

Physicist: This is a difficult question to even ask, because the word “exist” carries with it some “time-based assumptions”.  For example, if you ask “does the Colossus of Rhodes exist?” the correct answer should be “it did, but it doesn’t … Continue reading

Posted in -- By the Physicist, Philosophical, Physics, Quantum Theory, Relativity | 52 Comments

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 | 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