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PBS Space Time
How We Know The Earth Is Ancient
Season 6
Episode 11
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 shocking and humbling.
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17:41
Galaxies older than the universe? Webb's findings keep defying our best explanations.
16:16
Earth's core: solid or liquid? Yes — we know more about distant galaxies than our own interior.
14:42
Gödel found a time-travel solution in General Relativity, revealing spacetime can loop on itself.
18:46
Tardigrades can survive almost anything—even most of Mars. But one Martian chemical stops even them.
18:18
The Higgs boson may open a portal to hidden particles that could explain dark matter.
19:02
The universe expands faster. “Dark energy” may not be constant after all.
16:26
There’s a new generation of experiments that may unlock the gravity particle.
18:33
The universe thrums with quantum fields, except something may be missing: the sterile neutrino.
18:42
Gravitons, the particle of quantum gravity, may be impossible to detect.
25:02
2025 was the international year of quantum science, but today we examine its origins.
21:17
We’ve found lots of “habitable” worlds but we don’t know what factors are needed for life.
