Let’s just take a moment to applaud the slipper animalcule! Who? What? The slipper animalcule, also known as the paramecium, is a tiny creature that’s smaller than the dot on this i. But why should we celebrate it? What’s so special about it? This tiny little thing deserves a huge round of applause simply for being alive. That’s more of an achievement than you might think! And I’m going to tell you why.

Danish professor Henrik Schärfe has created a robot version1 of himself. When the professor and his robot are together, people have to look twice to tell which one is the person and which one is the machine. The robot can’t do very much at the moment. It can move a bit, but what it does best is look like its creator. It can’t do anything else. Not even talk. But I’ll eat a whole sack full of rabbit food if someone, at some point in the future, doesn’t design a robot that looks just like a person, that can give intelligent answers to your questions, and that can even play soccer with you. In fact, I think we’ll be smart enough to build one within 30 years. But making a slipper animalcule? That task is thousands of times trickier.

The tiny paramecium can’t do very much. It can swim a bit, doing the breaststroke with its minuscule hairs. It can drink dirty ditchwater and munch on the bacteria that are in the water. It can pee the water back out again. Well, it’s more like sweating than peeing. It can mate with another slipper animalcule. It can divide itself in two so that there are suddenly two slipper animalcules instead of one. What else can it do? Um . . . almost nothing at all.

The slipper animalcule might be capable of doing less than Professor Schärfe’s robot, but it can do one thing that a machine will never be able to: it can die. Of course, a robot can break, but that’s different. We can often repair something that’s broken, but we can never bring something back to life after it’s died. Life is very special, even though quintillions of creatures have already lived on Earth.