Nostradamus (1503–1566) was a French doctor who also studied the stars and wrote a book of short poems about things he believed would happen later. Some people believe he had special powers, and that those lines about the future are right. Others say the poems are written in such an open way that you can fit them to almost any later story if you try — and both kinds of reader are still around. In everyday English the name also gets stretched: calling someone 'a Nostradamus' means they talk as if they can see what is coming, sometimes in praise, more often with a little doubt. It is a person's name, so it keeps a capital letter.