The Cosmic Dark Ages

We live in the stelliferous era. Somewhere between 10 and 1000 billion trillion stars fill the observable universe with light. But there was a time before the first star ignited. A time we call the cosmic dark ages.

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Hosted by Matt O'Dowd
Written by Matt O'Dowd
Graphics by Aaron Havley
Directed by Andrew Kornhaber
Produced By: Kornhaber Brown

In astronomy we study things that are very far away. It’s a powerful challenge because even the brightest objects are almost impossibly faint when you view them from the other side of the universe. But there’s an up side. If the light from some space object took billions of years to get to us then we see that object as it was billions of years ago. In this way we can peer back in time and literally see the past in motion. In fact we’re able to see some of the first stars and galaxies to ever form. But if we look beyond, both in distance and in time, there is … nothing. Darkness. For the hundred million years or so between the formation of the first atom and the formation of the first star there were no light sources in the universe. These were the cosmic dark ages. It’s a period of cosmic history rarely discussed because it’s hellishly difficult to observe. Fortunately scientists are devilishly clever. So what do we know about the time before stars?

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سلطان الخليفي

[nolanwestrich]

It never fails to amaze me how much scientists can find out with so little. This entire episode was about a single point of light teaching us about millions of years of the early universe.
Edit: I forgot to mention that this single point of light was incredibly faint.

[grahamspilsted]

'The Cosmic Dark Ages' sounds like a great name for an atmospheric black metal album.

[bobrewbobroctor]

I think I've watched all of your videos to date. Now I have enough surface knowledge of physics to sound pretentious at parties... in all seriousness though, your videos have me teetering on going back to college to pursue a PhD. Keep up the great work!

[johnqpublic]

Since discovering this channel a couple years ago, it has become one of my most favorites. Thank you for all the hard work.

[tomrivlin]

Matt: Ends the episode by saying Grumpy Cat both can and can't has cheezburger.
Grumpy Cat: [dies the next day]
Matt really can see through all of space and time, huh

[corcorandm]

So you could use the Lyman-alpha forest to map when (aka where) along the path the hydrogen gasses were, and how large and (with less resolution) how dense they were at the time. Amazing.

[Salty_Nutella]

Matt: Dark Ages

Aliens: *IT'S TIME FOR A CRUSADE*

[SM-cqmm]

I finally watched every single video of this channel, starting from the first video of Super Mario, I loved this channel, it taught me a lot and now this new knowledge can be used to confuse my friends with stuff that they have no idea about lol, and as a wise man once joked about neutrinos, "it will pass straight through their heads"

[coolbath]

My house is having a blackout while watching this. I admit it's.. immersive.

[lynniesaade]

Upvoted just for "you shouldn't need a reason to talk about quasars."

[Reportro]

Pecs looking good professor Matt, keep pumping iron like a dying neutron star.

[upaya]

I LOVE how you described the electron jumping orbitals! ... I wish the American public education system used symbols more analogous to what the “orbitals” would actually “look” like as you did here... as opposed to the almost planetary model they were using. I think a lot of people know that representation is outdated, leaving kids skeptical of a classes far more tedious (and described a LOT less interestingly) than SpaceTime... I might have kept paying attention more myself lol

[Sage_the_Turt]

"i'll get back to how on earth we could possibly know this in a bit" good that was good i liked it good job

[ToxicTerrance]

"Somewhere between 10 - 100, 000, 000, 000, 000, 000 stars.."






That's how I heard it... Lol

[RME]

They're always interesting, but this one in particular lucidly explained a lot. Thanks, Matt! You Rock!

[brittanylea]

"But before we get to that, we're going to take a moment to talk about..."

"...Quasars."

Was expecting an ad. Yay for something much more fun :p

[janpietercornet]

So... the early universe was a photon-baryon opqaue plasma in which light was trapped. Then recombination occurred and the photons were freed, ultimately leading to what we now see as the CMB. Then a few million years later, reionization happened, turning most of the interstellar gas back into plasma, but it's somehow still transparent?I had to dive back into previous episodes, getting as far back as the original CMB episode by Gabe... but it's still somewhat puzzling. I think in the dense early universe, photons were trapped because free electrons were just densely packed, while in the current, expanded universe, the interstellar gas is dispersed enough that the gas and free electrons don't really impede the photons?

[edibleapeman]

I just watched this episode and it made sense the whole way through. Send help.

[MaceG]

By far one of my favorite channels ever. Keep up the great work guys!! Excellent episode, big props to the tight, understandable writing and fantastic accompanying visuals.

[dvsteve]

Evidence that Matt has the Space and Time stones. Just saying.