The first quantum revolution was in Biology.
Physicists first started using the word "quantum" in the early 20th century as a way to describe the basic make-up of our universe at the smallest scale.
There was a nagging unanswered question scientists and philosophers had been asking about physical reality for millennia. If you break matter down to smaller and smaller chunks, will you get to the smallest chunk possible, the basic building blocks of matter, or not? Is matter infinitely divisible? We are familiar with the answer to that question now. Matter is made of atoms, and smaller atom like particles, so yes, matter is made of building blocks.
And energy, it turns out, comes in small packages as well, called quanta (plural form of quantum). It is quantized. It all fits together with the e-equals-emcee-squared concept. Matter and energy are equivalent and ultimately grainy, pixelated and, at the smallest scale, freakin weird. We refer to this discovery about physical reality as the quantum revolution.
But the living world is also quantized. Everything that is alive is made up of a bunch of small building blocks called cells. Your cat, the tree in your lawn, the ants on your floor, the mold on your bread, they’re all made out of a bunch of little blocks, or sacks, with molecules inside. Cells can combine to form all kinds of shapes and sizes, organs and organisms, one of the most complicated being homo sapiens and their conscious brain.
If you chop up a living creature, you will eventually get to the smallest chunks they are composed of, the cells. Of course, you can chop up cells too and look at the molecular stew inside, but at that point we aren’t looking at the biological world anymore. The point is that plants and animals aren’t just homogenous bodies which can be divided in any old way. We are made of organs made of cells, which are then, yes, tiny bags of chemicals.
Robert Hooke discovered the first cell back in the 17th century, and the cell theory of life was first proposed in 1839 by a couple'a German guys. It seems like we don't hear as much about this revolution as we do about quantum physics, but it was just as epoch making. Our bodies are communities of trillions of tiny living blobs. Weird.
Life on earth began when the first cell came into existence. It took a while for single cells to start congregating to form multi-celled organisms, but there have always been single celled organisms hanging around since the big-biological-bang. One of them is bacteria. Another is yeast. And yeast, my friends, is what gives life to bread.