Category Archives: Equations

Q: What is the “monogamy of entanglement”?

Physicist: The Monogamy of Entanglement is the statement that “maximally entangled” particles only show up in pairs.  Entanglement is a sliding scale, so things can be non-entangled or a little entangled, but when the quantum states of two things are … Continue reading

Posted in -- By the Physicist, Equations, Math, Physics, Quantum Theory | 12 Comments

Q: Why does gravity pull things toward the center of mass? What’s so special about the center of mass?

The original question was: How do you measure d in the equation for universal gravitation ()?  It can’t be the distance between the surfaces of the objects, or when they touched f would be “infinite.”  It can’t be the distance … Continue reading

Posted in -- By the Physicist, Equations, Philosophical, Physics | 30 Comments

Q: What is the most complicated equation?

Physicist: If you have plenty of chalkboard space and absolutely nothing better to do, you can write down numbers, letters (Greek if you’re δυσάρεστος), and mathematical operators and eventually you’ll have the longest equation ever written down.  So if you … Continue reading

Posted in -- By the Physicist, Equations, Math, Physics | 52 Comments

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 | 16 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 | 1 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 | 13 Comments