Category Archives: Math

Q: How does “1+2+3+4+5+… = -1/12” make any sense?

Physicist: When wondering across the vast plains of the internet, you may have come across this bizarre fact, that , and immediately wondered: Why isn’t it infinity?  How can it be a fraction?  Wait… it’s negative? An unfortunate conclusion may … Continue reading

Posted in -- By the Physicist, Equations, Math, Number Theory | 9 Comments

Q: What determines the size of the bright spot when you focus sunlight with a lens?

Physicist: This question really appeals to my ten-year-old self.  If you’ve never tried to burn something with a lens, collect three pairs of sunglasses, a magnifying lens, and something you dislike.  On a bright day, put on all three pairs … Continue reading

Posted in -- By the Physicist, Equations, Geometry, Math, Physics | Leave a comment

Q: Why are numerical methods necessary? If we can’t get exact solutions, then how do we know when our approximate solutions are any good?

Physicist: When a problem can be solved exactly and in less time than forever, then it is “analytically solvable”.  For example, “Jack has 2 apples and Jill has 3 apples, how many apples do they have together?” is analytically solvable.  … Continue reading

Posted in -- By the Physicist, Computer Science, Equations, Math | 10 Comments

Q: How can something be “proven” in science or math?

The original question was: … it confuses me that abstract concepts, such as Banach-Tarski, and other concepts in pure mathematics and theoretical physics, can be considered to have been “proven”.  Is it not the case that one can only prove … Continue reading

Posted in -- By the Physicist, Conventions, Math, Philosophical | 7 Comments

Teleportation! In space!

Physicist: This isn’t a question anybody asked, just an interesting goings-on. A few weeks ago QUESS (QUantum Experiments at Space Scale) began teleporting quantum information to and from the Micius satellite and between ground stations 1200 km apart.  This is … Continue reading

Posted in -- By the Physicist, Entropy/Information, Physics, Quantum Theory | 14 Comments

Q: If you’ve got different amounts of debt in different accounts with different interest rates, how should you pay them down?

Physicist: Focus on the one with the highest interest rate.  Get rid of it first, completely, before moving on to the next.  Debt is a like spiders.  If you can only kill a few at a time, kill the ones … Continue reading

Posted in -- By the Physicist, Math | 5 Comments