One single scientist created three inventions that accidentally caused the deaths of millions of people, including himself. Not only that, they decreased the average intelligence of people all around the world, increased crime rates, and caused two completely separate environmental disasters that we are still dealing with today. Part of this video is sponsored by Wren.
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More about them at the end of the show.
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In 1944, as a young chemist who had just finished his
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Master's, Clair Patterson went to work on the Manhattan Project,
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building the first nuclear weapons.
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His job was to concentrate uranium-235, the fissile fuel for bombs
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from the much more common uranium-238.
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And this required huge machines, mass spectrometers, which separated
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the two types of uranium by their slight difference in mass.
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After the war, Patterson went back to grad school to get his
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PhD, he picked a research project that would take
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advantage of his experience with mass spectrometers:
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measuring the age of the Earth.
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Radioactive rocks are effectively clocks.
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Uranium-238, for example, decays into thorium and then protactinium,
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and then 12 More decays until it ends up as lead-206, which is stable.
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The rate of this decay is consistent and can be
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measured. It takes four and a half billion years for half of
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a sample of U-238. to decay into lead-206
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Patterson's PhD project was to determine the age of the Earth by measuring
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the ratio of uranium to lead in primordial rocks,
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but to calibrate his instrument, first he used zircon crystals whose
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ages were known.
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Zircon is ideal for this purpose,
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because when it forms it contains trace amounts of
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uranium but absolutely no lead.
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So any lead that you later find inside a zircon, you know must be the product
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of a uranium decay.
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Patterson was tasked with measuring the lead content,
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and another student, George Tilton, measured uranium
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Tilton 's uranium measurements were fine. They matched predictions.
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But Patterson's lead measurements were all
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over the place. And they were many many times higher than
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they expected.
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We'd take George's uranium and my lead...
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Not right Patterson!
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There was lead there that didn't belong there.
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So where was all this extra lead coming from?
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That mystery would take over the rest of Clair Patterson's life
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and bring him to the literal ends of the earth.
Engine Knocking
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In 1908, a woman was driving across the Belle Isle bridge
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in Detroit. When her car stalled.
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A passing motorist stopped to help.
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In those days cars needed to be hand cranked to start.
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He knelt down and turned the crank,
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and the engine roared to life. A little too suddenly.
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The man couldn't get out of the way. The crank handle hit him in
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the face and broke his jaw.
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He died as a result of his injuries.
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His name was Byron Carter, and he was the founder of his own car company.
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So he was well connected in the Detroit Auto scene.
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He counted among his close friends, the founder of Cadillac, Henry Leland.
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Leland was so distraught over his friend's
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death that he resolved to eliminate hand cranks from his vehicles.
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Leland hired Charles Kettering to create a self-
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starting car. And by 1911, he had a working prototype.
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Hand cranking was difficult and dangerous, and best left to men,
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but a car that started itself
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changed everything.
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The world's first crankless car
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was the Cadillac Model 30. It was much more powerful than
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cars before it. It had a top speed of 45 miles per hour and
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40 horsepower, double the Ford Model T. The Model 30 was a
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huge success for Cadillac, doubling the company's annual
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sales, but it had a problem. It was deafeningly loud.
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In internal combustion engines a piston compresses the fuel-air mixture,
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which is then ignited by a spark from the spark plug.
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The expanding hot gases push the piston back down.
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The problem with the Model 30 engine was it
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compressed the fuel-air mixture more than previous
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models so much in fact, that often the fuel would
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spontaneously combust before the spark from the spark plug.
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So rather than orderly, perfectly timed explosions,
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you'd get multiple haphazard combustions leading to
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turbulent pressure waves inside the cylinder. The
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resulting sound led the problem
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To become known as engine knocking.
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Knocking wasn't just hard on the ears, it hurt the engine's
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performance, it reduced power output and lowered fuel
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efficiency. The vibrations also damaged the piston and
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walls of the cylinder shortening the life of the
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engine.
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The good news was that engine knocking could be corrected by
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changing the fuel. Different fuels can withstand different
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levels of compression before detonating n-heptane for
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example, will spontaneously combust under only a little
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compression. Iso-octane, on the other hand can withstand a
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much higher compression ratio before it auto ignites. So
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it's much less likely to cause knocking. To quantify how much
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compression a fuel can withstand scientists came up
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with the octane rating system, they arbitrarily set
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iso-octane to have a rating of 100 and n-heptane a rating of
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zero. Now real fuels aren't made up of only these two
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ingredients. They're a mix of lots of different
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hydrocarbons. But the octane rating tells you what mixture
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of octane and heptane gives equivalent performance. For
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example, 98 octane fuel can withstand the same compression
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as a mixture of 98% octane and 2% heptane. Now, I'm going to
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take a little bit of 98 octane fuel and put it in this
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piston. And when I compress it,
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nothing happens which is exactly what you'd expect.
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This fuel can withstand a lot of compression. Diesel has an
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octane rating of 20. So it acts like a mixture of 20%
iso-octane and 80% n-heptane. If I put a little bit of
diesel in there, let's see what happens with the same
compression ratio.
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There you go. You get a little explosion in there. That's
because this is a low octane fuel. I mean, that's what
diesel is meant to do. You compress it and it ignites. but you don't want this sort of fuel in an engine with
spark plugs. The reason fancy cars demand high octane fuel
is to prevent knocking in their high-compression
high-performance engines.
Tetraethyl Lead
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Kettering wanted to find an additive which would increa