ELI5: Explain Like I'm 5

Aleksandr Mikhailovich Lyapunov

Alexander Mikhailovich Lyapunov was a Russian mathematician. He was famous for coming up with a way to figure out how things might change over time. He was very good at finding patterns and equations that could help predict how something might change in the future. That's why he's still remembered today as one of the most brilliant mathematicians ever.