## Articles

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

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

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

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

Has the future already already been written? Is time just an illusion? Take a step outside of spacetime with cosmologist Marina Cortês to discover the *block universe*.

Fundamental physics says time is symmetric - so why does time move forwards for us in a block universe?

Is time real? Are we just puppets living out a future already written? Marina Cortês explains why she thinks time is fundamental and that we don't live in a block universe.

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.