## Articles

If only the fittest survive, how can we explain the evolution of altruism? Mathematics has some answers.

Why a positive test result doesn't necessarily mean you have the disease.

Journey to the limits of computation with a number that's easy to describe but can't be calculated.

Are there problems computers will never be able to solve, no matter how powerful they become?

In the 1930s Alan Turing discovered a computer program that is logically impossible. What other limits are there to computation?

Here's the ancient proof that there are infinitely many prime numbers.

Why a DNA match doesn't necessarily prove your guilt.

Marina Cortês is one of a growing number of physicists who believe time is fundamental. We ask her about the alternatives theories to the block universe, where time comes first.