On the New Yorker, an interesting article on Yitang Zhang, the mathematician who in 2013 proved a theorem in number theory according to which there are infinitely many pairs of prime numbers that differ by 70 million or less. The theorem may not sound really interesting, but actually it is the first proof to establish the existence of a finite bound for prime gaps, resolving a weak form of the twin prime conjecture.

Here you can find the article. Good reading!