Billions and Billions also includes a reproduction of "The Common Enemy," a paper of his that points to uncomfortable truths in the recent history of the US and the Soviet Union. In the piece, Sagan urged both countries to think in the long-term, and repeatedly used the pointed phrase: "We make mistakes. We kill our own." The essay was published in both countries (with some censorship in the Russian version).
Sagan begins the book by describing exponents. I was puzzled at first, but then he segued into the vastness of our universe, and how we can begin to comprehend the scale of it using math. He also pointed out how exponential notation can be applied to population growth, microbial organisms, and radioactive elements. The elegance of the narrative flow made me swoon.
Part I of Billions and Billions occupies itself with physics, astronomy, and related fields. He makes it all seem so fun and wonderful and enchanting. In Part II, Sagan earnestly implores humans to recognize our commonality before we destroy our earth. It's the only one we have! He documents efforts by scientists and religious leaders to work together toward the cause of environmental preservation.
In the final part of the book, Sagan adds his reasoned input into the abortion debate. He talks about the different political strategies we use in everyday life, advocates for nuclear arms reduction, and, at the end, shares details about his sickness with readers. He was diagnosed with a rare disease that eventually took his life in 1996, when he caught pneumonia that his weakened immune system couldn't fight off.
His beloved wife and cowriter, Ann Druyan (referred fondly as "Annie" throughout the book) wrote the epilogue of Billions and Billions, because Sagan passed away before its completion. I was sobbing throughout the whole thing. It's so inspiring that we had (and still have, in Ann) people with so much love and enthusiasm for life, who think nothing of sharing that love and their enormous talents and clear-eyed insights with the rest of us. If I had known about Carl and Ann in high school, I'm confident I would have chosen to study environmental sciences in college, my poor math skills be damned.
Well, that's what kids are for, amirite? "Mommy didn't get to be a scientist, so here's a chemistry set and a TI-84 and the complete works of Sagan, Einstein, Curie, Planck, Bohr, Salk, and Fermi. Happy fifth birthday!"
Best. Mommy. Ever.