Here's a fun brain teaser: How large does a random group of people have to be for there to be a 50% chance that at least two of the people will share a birthday? The answer is 23, which surprises many ...

Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and Fundamental Forces from Imperial College London.View full profile Alfredo has a PhD in Astrophysics and a Master's in Quantum ...

How many people need to be in a room before there's a greater probability than chance that two of them share a birthday? Numberphile approaches the famous birthday paradox without a computer.

The night I turned 21, I swaggered into a college watering hole in Camden, New Jersey. No longer would I flash a doctored Connecticut license and pose as a haggard 42-year-old Stonington man named ...