# Category Archives: — By the Physicist

## 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 | 14 Comments

## There’s something new under the Sun!

Physicist: Good news! On October 19th, for the first time in history, we detected an object inside of our solar system that originated somewhere else.  It’s a rock the size of a stadium that passed inside of Mercury’s orbit and … Continue reading

Posted in -- By the Physicist, Astronomy | 7 Comments

## Q: Is it more efficient to keep keep a swimming pool warm or let it get cold and heat it up again?

The original question: I’m having a debate with my wife that I think you can help us resolve.  We have a swimming pool in our back yard.  It has an electric heater, which we set to keep the pool water … Continue reading

Posted in -- By the Physicist, Engineering, Physics | 15 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 | Comments Off on Q: What determines the size of the bright spot when you focus sunlight with a lens?

## 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 | 11 Comments

## Burning Man 2017

Long ago, Ask a Mathematician / Ask a Physicist was two guys sitting around in the desert talking to strangers about whatever came to mind.  It’s been a while, but we’re heading back to Burning Man for more of the … Continue reading

Posted in -- By the Physicist | 8 Comments