How We Know The Earth Is Ancient

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In astronomy we talk about billions of years like it’s no big deal. But how can we be sure about timescales so far beyond the capacity for human intuition? Our discovery of what we now call deep time is very recent - as recent as our discovery of the true spatial vastness of our universe. And it came as scientists tried to measure the age of the Earth. What they found was as shocking and humbling as anything seen through the telescope.

Hosted by Matt O'Dowd
Written by Dan Falk & Matt O'Dowd
Graphics by Leonardo Scholzer, Yago Ballarini, & Pedro Osinski
Directed by: Andrew Kornhaber
Executive Producers: Eric Brown & Andrew Kornhaber

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[ben]

For laymen like me who habitually hit up spacetime and have learned a decent bit of physics, just wanted to say thanks for the breather. Please keep on just like you do with challenging material, I'm getting through it, but a breather episode is always welcome!

[imlaion]

"An oddly precise prediction given the source material"
I died

[canaldoxerxes]

I'm a geologist and and I feel acknowledged by this video.

[linksfood]

"The covid19 lock-down cannot interfere with the important work of talking about black holes". My general relativity professor disagrees. He cannot figure out how to any streaming services to save his life.

[zacharywoodman]

I love how every time Kant is mentioned on science You Tube is mentioned for his Galaxy speculations, and I'm here in philosophy-land knowing him for...other things.

[semaj_]

I enjoyed this diversion from the sometimes heady astrophysics topics, though I love those videos too. I wouldn't mind seeing more stuff like this every now and then before diving back into the craziness that is spacetime.

[terryendicott]

Deep time, deep space --- This requires Deep Thought.

[theletsplayer]

Day 1 in Brahma: We were born
Day 2: We were swallowed by the sun

[ThomasTrue]

James Hutton lived in the Holyrood area, right on the edge of Arthur's Seat, the 823ft high volcanic cone which dominates Edinburgh. He would take his daily walks there, and that was what first got him intrigued by rock formations. He then travelled throughout Scotland, which has hugely diverse geology, and other parts of the UK, studying and taking samples, which is what led this chemist to become the "Father of Geology".

But poor Hutton. He wanted to present his paper to the University of Edinburgh, but the Church of Scotland, who controlled the university, refused to allow him challenging the Biblical creation narrative. The church had also cast aspersions upon his character for even suggesting such. So it was the first reading of his paper was given rather to the Royal Society of Edinburgh, by his friend, Playfair, in a heavily abridged version.

Today there is an exhibition centre, Dynamic Earth, near where James Hutton lived, which tells the tale of our planet in a hugely fascinating and highly entertaining way.

[dianagibbs]

I'm also gently amused by the thought that ancient people in India, having developed math that included zero and could therefore be done fairly easily up to very large numbers, immediately used that math to attempt to determine the age of their universe. Humans are awesome at times.

[dreammfyre]

7:57 “Half-lives: 3”

Lol. That’s gotta be intentional.

[StrikeAxl]

The end of the episode almost made me cry at realizing how magnificent our planet and our universe is and how insignificant we are. I love this channel!

[Kneedragon]

I would panic at the ISCO but but temporal dilation means it all happens a bit too slowly to induce panic. Like death and taxes, you know it's going to happen, but, not today.

[thenasadude]

Know the difference:
Gamers: the cake is a lie
Geologists: the date is a lie

[imadeausernamethislongl]

Fun Fact: Genesis isn't even the oldest book in the Bible. If I remember correctly, Job is the oldest book in the Bible.

[DavidMaurand]

sometimes i feel we know more about cosmology than we do about our own planet. thanks for this piece.

[dalebewan]

Talking about how old things "feel" from a human perspective, I actually find the universe feels extraordinarily YOUNG given that our humble little backwater of a planet has been around for a significant portion (somewhere around 1/3) of its existence. Sure, it's unfathomably long compared to a human life; but given the chaotic churn of matter in the universe, stars and planets are being born all the time and dying all the time. The fact that our one has been around for a 1/3 of the total time of the universe either makes our planet really old or the universe really young. We know of stars much older than our sun, and can assume they have planets, so calling our planet "old" doesn't really fit. That just leaves us with a "young" universe.

(this is all completely subjective of course; the terms "young" and "old" don't have any practical use here)

[EazyE]

Space Time: "The earth is billions of years old."

*Ken Ham has entered the chat.

[thenout]

Guys, thanks for the great program, as always. BUT how could you not mention Clair Patterson?! That's the dude who first came up with the 4.5 billion figure. His story is absolutely astounding, as is his research itself. I'm amazed you didn't even mention him (or did I miss something?). Actually, this just happens to be story of Clair's life... a totally underappreciated but highly influential scientist - and philantrope.
(on another note: the updated graphics rock! )

[tonydai]

7:07 Just a correction, the Earth's surface is much hotter than expected, even when radiation is taken to consideration.
This is because the convection currents in the mantle bring up heat from the core.