Pi isn’t about circles

We usually associate π with circles. It is usually defined as the ratio of the circumference of a circle to its…

Coin rotation paradox

Imagine we have 2 coins. The radius of the larger coin is 3 times the radius of the smaller coin.

Raven paradox

The raven paradox was invented by Carl Gustav Hempel in the 1940s. It raises the question of what should be considered evidence for…

Why are sin, cos and tan called sin, cos and tan?

A simple explanation of Bayes’ theorem

Bayes’ theorem allows us to calculate probabilities based on relevant prior knowledge. In…

Fourier’s ingenious proof that e is irrational

Euler’s number, e, is an important number in mathematics that appears in many…

Einstein’s proof of Pythagoras’ theorem

There are many proofs of Pythagoras’ theorem, but perhaps one of the most elegant is…

What is two to the power pi?

The exponential function for an irrational value of x

Factors of a prime squared minus one — a surprising result?

What is i to the power i?

The result is quite surprising!