Bedrock: Earth's Earliest History Dylan Wilmeth
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- 科学
This podcast starts at the beginning of Earth's prehistory and works forward through time. Bedrock will explore the first 90% of Earth’s past, a time known as the Precambrian Era. Before humans, before dinosaurs… there was the Precambrian.
The Earth was an incredibly alien world, but not a dead one.
Along the way, you will build a mental toolkit to see the world like a geologist. You will never look at a mountain, the moon, or pond scum in quite the same way again.
Welcome to Bedrock.
For transcripts, visuals, and references, check out https://www.bedrockpodcast.com
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33: A Thin Line
What are the oldest disputed fossils on Earth? Why are they disputed?
Today, we wrap up our tour of Nuvvuagittuq in northern Quebec, 3.8 billion years ago, March 3rd on the Earth Calendar. In 2017, microscopic rusty threads were discovered inside these rocks, thinner than a human hair. Were they bacteria, or something else entirely? Stay tuned to find out!
Extra Credit: Learn how to make a chemical garden, or find a piece of chert, flint, jasper, agate, or onyx.
Common Descent Interview: https://youtu.be/amQ9rntfKV0?feature=shared -
32: Pumping Iron
Where does humanity get most of its' iron, and what do these rocks tell us about the ancient Earth?
Today, we'll learn about banded iron formations, the backbone of the modern steel industry an important stop in the search for early life and oxygen, and a rock that is impossible to make today. It's rare to find a rock as important to both economics and research. Along the way, we'll take a breath of fresh air, meet orange pond scum in a forest stream, and find a dagger carved from a meteorite.
Extra Credit: Find as many steel objects as possible around you, or search for bog iron in a local swamp. -
31: Trench Warfare
What are Earth's oldest volcanic rocks, and how did they form?
Today, we'll explore the seafloor 3.8 billion years ago through dark basalt rocks in Nuvvuagittuq, northern Quebec. Along the way, we'll earn a green belt in geology, rest our heads on volcanic pillows and journey to the deepest spot in the modern ocean.
Extra Credit: Try to find dark black basalt in a building or countertop near you. -
30: Alternative Canadian Rock
What's the next step after the oldest rock on Earth?
Today, we'll move the story forward 200 million years and 1,000 miles.
The time: 3.8 billion years ago... or maybe much older (March 3 on the Earth Calendar).
The place: Nuvvuagittuq (noo-voo-ah-git-took), Quebec, Canada, in the lands of the Inuit.
In this episode, we'll learn how this seaside outcrop was found and the ongoing debate about its' exact age. Depending on who you talk to, these are either the second-oldest rocks on Earth, or almost as old as the Earth itself. -
29: The Goldilocks Planet
If the sun was dimmer 4 billion years ago, how did the Earth stay warm?
Today, we learn how just a small percent of Earth's atmosphere goes a long way in controlling global climate, both today and in the ancient past. Along the way, we'll visit an imaginary frozen Earth without any sun, a hazy giant moon of Saturn, and learn exactly what the greenhouse effect is.
Extra credit: Visit a greenhouse, or find a cleaning product with ammonia. -
28: The Dark Side of the Sun
How has the Sun changed over the past 4 billion years?
While the Sun may seem unalterable, it has brightened dramatically over Earth's history, with major implications for our world. Today, we'll meet a team of women who catalogued thousands of stars in the 1800s, play in a galactic ball pit, and puzzle over a cosmic paradox alongside Carl Sagan.
Extra Credit: Watch Cosmos (1980)