Category Archives: Math

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 | 6 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

Q: In base ten 1=0.999…, but what about in other bases? What about in base 1?

Physicist: Yup! The “0.999… thing” has been done before, but here’s the idea.  When we write 0.9, 0.99, 0.999, 0.9999, etc. we’re writing a sequence of numbers that gets closer and closer to 1.  Specifically, if there are N 9’s, … Continue reading

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

Q: How many samples do you need to take to know how big a set is?

The Original Question Was: I have machine … and when I press a button, it shows me one object that it selects randomly. There are enough objects that simply pressing the button until I no longer see new objects is … Continue reading

Posted in -- By the Physicist, Combinatorics, Math, Probability | 3 Comments