Monthly Archives: October 2011

Q: What is “spin” in particle physics? Why is it different from just ordinary rotation?

Physicist: “Spin” or sometimes “nuclear spin” or “intrinsic spin” is the quantum version of angular momentum.  Unlike regular angular momentum, spin has nothing to do with actual spinning. Normally angular momentum takes the form of an object’s tendency to continue … Continue reading

Posted in -- By the Physicist, Equations, Math, Particle Physics, Physics, Quantum Theory | 50 Comments

Q: What is Bayes’ rule and how do I use it to improve my life?

Mathematician: Bayes’ theorem in one of the most practically useful equations coming from the field of probability. If you take its implications to heart it will make you better at figuring out the truth in a variety of situations. What … Continue reading

Posted in -- By the Mathematician, Equations, Math, Probability | 8 Comments

Q: Are there universal truths?

Physicist: That something exists, that it is more complex than trivially simple, and it includes me (cogito ergo sum, and all that). It doesn’t seem like you can say much more.  At least, this brain-in-a-box can’t. Philosopher: Depends on what … Continue reading

Posted in -- By the Physicist, -- Guest Author, Philosophical | 6 Comments

Q: What’s the difference between black holes and worm holes? Could black holes take you to other universes?

Physicist: The short answer is: A worm hole is a “tube made of spacetime” that connects two different regions.  If it’s set up right, you could enter one side of the tube and exit the other end somewhere else, or … Continue reading

Posted in -- By the Physicist, Astronomy, Math, Physics, Relativity | 33 Comments

Q: Is there an equation that determines whether a question gets answered on ask a mathematician/physicist?

Mathematician: Yes, but neither the Physicist nor I know it, and its shortest representation in standard mathematical notation is much too long to ever be written down. More precisely, there are an infinite number of such equations. These equations “exist” … Continue reading

Posted in -- By the Mathematician, Philosophical | 8 Comments

Q: If you could hear through space as though it were filled with air, what would you hear?

Physicist: You’d be able to hear the Sun, and nothing else.  Maybe at night you’d be able to hear your own thoughts. Owing to the nature of how things like sound and light spread out, the loudness and brightness of … Continue reading

Posted in -- By the Physicist, Astronomy, Physics | 9 Comments