Nicolas Rashevsky was a really smart man who came up with a lot of crazy cool ideas! He lived a long time ago and he used his big brain to help us better understand how things in our world work together.
He was very interested in things that could be measured, like how fast something moves or how big it is. He thought that if we looked at things in our world like they were connected to each other in a big web, we could figure out how everything worked together.
For example, he thought that if we could understand how plants grow and how animals eat, we could figure out how they are connected and how we could help them both grow better.
He also thought about how our bodies work and how sicknesses spread. He wanted to find a way to keep people healthy by understanding how things worked in our bodies.
So, in short, Nicolas Rashevsky was a really smart man who used his big brain to help us understand how things in our world are connected and work together.