'Cosmos' Season 1 finale: 'Unafraid of the Dark,' kind of worried about the mob

"Cosmos" Season 1 comes to an end with its finale episode, "Unafraid of the Dark." With the focus turning once again to the outer expanses of the universe and the big ideas that try to encompass it, Neil deGrasse Tyson -- with an assist by Carl Sagan himself -- teaches audiences about the vast darkness that makes up so much of everything.

He also talks about the angry mobs that want to destroy everything. It turns out that the ignorant hordes are way more dangerous than any dark matter or energy.

Science stuff to remember

There are two big, scientific concepts introduced and discussed in the Season 1 finale. They are related too -- dark matter and dark energy.

Dark matter is simply all of the undetectable mass that seems to permeate the universe, causing all sorts of anomalies in gravitation and the observable cosmos. Dark energy, meanwhile, is the inexplicable energy that speeds up the universe, even when gravity and all other physics theories say things should slow down.

Why are they called "dark"? That's because science doesn't really know too much about either this kind of matter or energy. There are all sorts of complicated theories (far too mathematical for easy explanation on "Cosmos") but none that really explain what's going on.

It's really kind of fitting that a show aiming to explain the universe ends on a note of the unknown. "Cosmos" is almost poetic that way.

What about those mobs?

Tyson brings up a rather interesting subplot in his discussion of the dark forces of the universe: the angry mob. The episode begins in the semi-fabled Library of Alexandria, notoriously destroyed in later years by a "mob," as Tyson put it.

He doesn't say it explicitly, but the blame for the end of the Library has always been laid at the feet of religiously motivated groups (a controversial point in history). Thus, "What will happen the next time the mob comes?" is a question that totally hints at anti-science crusaders destroying our digital world of wonders.

"Cosmos" does stick to its themes, doesn't it?

Your heroes of the week

The finale's "heroes of science" are a rather varied group. You've got a German named Hess who took dangerous balloon trips in order to learn that there was radioactivity coming from space (what we now call cosmic rays).

Then there is Fritz Zwicky, a 1930s-era physicist who made a whole bunch of advances in the understanding of supernovas, neutron stars and the bending of light by gravity.

Finally, there's Vera Rubin, an astronomer who noted stars on the outer edges of galaxies moving faster than they should. This paved the way for the dark energy theories.

And the biggest heroes of all, Voyagers 1 and 2

NASA's Voyager probes, launched in the late 1970s and totally something that Carl Sagan worked on, are hugely important to planetary science. Over the course of more than 10 years, the probes took photos and transmitted other data back to Earth. Then they shot off into space, never to return home.

There's a golden record on each of the spaceships, filled with everything an intelligent alien would need to understand humanity. What exactly? Well, there are greetings, hydrogen atoms, neutron stars and Chuck Berry's recording of "Johnny B. Goode."

Will aliens understand all that? It probably depends on whether or not they read drawn figures the same way we do and have a similar understanding of physics. It may also depend in their tastes in music.

It all goes back to Sagan

"Cosmos" is and always has been the baby of late astrophysicist Carl Sagan. It's thus fitting that the season ends with the man's famous "blue dot" speech. The Earth is small, the universe is big and you can't trust anyone -- even the hosts of "Cosmos" -- to tell you about it.

It's also the place that sent rock music into space though, so it all evens out.

Photo/Video credit: FOX