Category Archives: — By the Physicist

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

Q: What is energy? What is “pure energy” like?

Physicist: Unfortunately, “pure energy” isn’t really a thing.  Whenever you hear someone talking about something or other being “turned into pure energy”, you’re listening to someone who could stand to be a little more specific about what kind of energy.  … Continue reading

Posted in -- By the Physicist, Physics | 59 Comments

Q: Why is Schrodinger’s cat both dead and alive? Is this not a paradox?

One of the original questions was: A basic rule of logic is that something cannot contradict itself. It is impossible for P to be true and not true. Doesn’t Schrödinger’s cat violate this law and therefore invalidate logic? Physicist: The … Continue reading

Posted in -- By the Physicist, Logic, Physics, Quantum Theory | 48 Comments

Q: What kind of telescope would be needed to see a person on a planet in a different solar system?

Physicist: When talking about telescopes there are two quantities to take into account; the “light gathering power” and the “resolving power” of the telescope.  “Light gathering power” is just how much light can be collected by the telescope.  “Resolving power” … Continue reading

Posted in -- By the Physicist, Astronomy, Physics | 16 Comments