James Stewart
speaker
4,486 appearances
22 recordings
2 series
first heard Apr 2025
last heard 3d ago
James Stewart’s voice in public audio — every appearance, attributed to the second.
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recordings per month · last 12 monthsRecordings per month over the last 12 months — 17 in all, peaking in Sep 2026 with 3.
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Now, living things aren't very picky about this and will take in either type of carbon, really, but crucially, carbon-14 is radioactive and so breaks down naturally over time.
And what this means is the moment a plant or animal dies, the clock starts, effectively.
It stops taking in carbon-14, and as it decays, the amount of carbon-14 in the organism decreases.
Its half-life, therefore, that's the time taken for half of the carbon-14 in a sample to decay, is around 5,700 years.
As such, scientists can measure what percentage of the carbon in a sample is still carbon-14, and from that, can calculate how many years have passed since that organism died, which is pretty clever.
When used in tandem, these two techniques reveal incredible things.
Think of LiDAR as finding the where and the radiocarbon dating determining the when.
As amazing as all these discoveries undoubtedly are, they are just zoomed in examples of the mysteries the canopies hid, and they're hints of something far larger.
Really, Bolivia and Ecuador were just the close-ups.
The next step is the wide shot, and here, here's where things get wild.
In 2023, Brazilian geographer and remote sensing specialist Vinicius Peripato did something pretty bonkers.
He applied this same concept, but on a far larger scale, taking an Amazon-wide approach to hidden archeology.
He and his team used LIDAR data originally collected for forest biomass work and scanned 5,315 square kilometers across the basin, which, yes, might sound impressive, but remember, this is the Amazon.
That's roughly 0.08% of the whole thing.
But here's where it gets interesting, because even in that tiny slice of this monstrous green pie, they identified 24 previously undetected earthworks beneath the closed canopy.
Now, if you were to apply those same numbers to the unscanned parts of the rainforest, they estimated there are between 10,272 and 23,648 large-scale earthworks still
still waiting to be discovered, with many likely concentrated in southwestern Amazonia.
What?
Peripato's team also found statistical links between earthwork probability and dozens of domesticated tree species, 53 to be precise.
What this means in real terms is that ancient people shaped the forest.
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