Carl Zimmer

Pasteur is associated with vaccines.

Pasteur did other things as well, and he was also perhaps the first aerobiologist, because he got interested in the fact that, say, in a factory where beet juice was being fermented to make alcohol, sometimes it would spoil.

And he was able to determine that there were some, what we know now are bacteria that were getting into the beet juice.

And so it was interrupting the usual fermentation from the yeast.

that in itself was a huge discovery.

And, but he was saying, well, wait, so why are there these, what we call bacteria in the spoiled juice?

And he thought, well, maybe they just float in the air.

Yeah.

And this was really a controversial idea in say 1860, because, uh, you know, even then there were many people who were, were persuaded that, um,

When you found microorganisms in something, they were the result of spontaneous generation.

In other words, the beet juice spontaneously produced this life.

This was standard view of how life worked.

And Pasteur was like, I'm not sure I buy this.

And this basically led him into an incredible series of studies around Paris.

He would have a flask and he'd have a long neck on it.

And the flask was full of sterile broth and he would just take it places and he would just

hold it there for a while.

And eventually bacteria would fall down that long neck and they would settle in the broth and they would multiply in there.

They would turn cloudy.

So he could prove that there was life in the air.