Dang. Like in 1800, there were a billion human beings on this planet, and that was more than had ever been seen before. And we live more than twice as long, on average, as humans did just two centuries ago, largely due to improved health care for women in childbirth and their infants, but also thanks to antibiotics and the second agricultural revolution that began in the 1950s, the so-called Green Revolution, that saw increased use of chemical fertilizers lead to dramatically higher crop yields. Of course, these gains haven't been evenly distributed around the world, but chances are, if you're watching this, you a. survive childbirth, and b. feel reasonably confident that your children will as well. That's a new feeling for humans, and as a parent, I can assure you, it's a miracle and one to be celebrated. We study history so that we can understand these changes, and so that we can remember both what we've gained and lost in getting to where we are. Next week, our last week, we'll look at the many facets of globalization that aren't causes for celebration.