'Cosmos' episode 3: Flaming skulls and the Oort Cloud in 'When Knowledge Conquered Fear'
Baby stealing and flaming skulls
You might be excused if the beginning of this "Cosmos" episode confused you slightly. It begins with some poor baby left alone in a basket to look at the stars. While the baby is probably going, "Um, dude. Where's my mom? Why don't I get more than this blanket?," Neil deGrasse Tyson waxes poetic about pattern recognition and curiosity.
After stealing the baby (briefly), Tyson points out that people have always liked to make star pictures (aka, constellations) in order to add regularity to their lives. Unfortunately, comets causes problems with this. That's why people were scared of them.
And, considering how miserable life often was back in the bad old days, attributing bad things to comets wasn't likely to fail. There was always some calamity about to happen. Still, it would be cool if "Cosmos" had explained the exact origin of those flaming skulls.
Could there have been an ancient biker gang involved?
The cosmic snowball that makes little snowballs
Biker gangs, babies and skulls aside, the main point is comets. And comets come from the best-named place in the universe, the Oort Cloud.
Everyone should know about the Oort Cloud. Why? Well, there is the whole scientific reason -- it's a big ball of comets surrounding the solar system at a distance of about a light year. But there's also a more important reason: "Oort" is one of the single best words in science. Seriously, just say it out loud. "Oort, Oort, Oort ..."
Basically, we're talking about the Seussian character of science.
Anyway, comets. Gravity pulls the comets out of their Oort Cloud, tugging them into the solar system. The comet eventually heads into the Sun (if it misses a planet, that is). When the frozen bits get to warmer climes, there is melting and evaporation and tails and stuff.
Halley's foul mouth, Hooke's pot habit and Newton's misanthropy
Ah, heroes of science! They're often rather unpleasant and/or weird people. It makes it hard to worship them, no matter how hard "Cosmos" tries.
First of all, there's Edmund Halley. He did a bunch of science stuff (even if his map of the southern constellations meant virtually nothing to the navigators of the day -- they already knew how to get around) and owned a lot of books about fish.
Apparently, Halley also liked to say "Hell's bells" from an early age.
As for the comet, Halley figured out that the comets had elliptical (squished circles) orbits that often returned at regular intervals. Thus, a comet got named for him.
Then there's Robert Hooke. For the purposes of "Cosmos," he's a Disney villain who was really, really mean to Newton. But he was also a really great scientist who did a ridiculous amount of stuff. There was more to the guy than just pot-smoking. But hey -- this makes for a better story!
Now for Isaac Newton. You need to know two things about Newton in order to understand the "Cosmos" version of the story: 1) he was a genius who figured out gravity and some very important mathematics, 2) he was a crazy, mean jerk who didn't like anyone.
By the way, Newton used to stick things into his own eyeballs to see what would happen. Watch out for geniuses.