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?
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?
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.