Alex McColgan

speaker

29,301 appearances 104 recordings 1 series first heard Nov 2024 last heard 2d ago

Alex McColgan’s voice in public audio — every appearance, attributed to the second.

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recordings per month · last 12 months

Recordings per month over the last 12 months — 68 in all, peaking in Aug 2026 with 11.

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Astrum Space · What We Detected in the Strangest Quantum Experiments on Earth · 7 Sep 2026 podcast

Unlike matter on Earth, stars aren't even made of atoms and molecules, where negatively charged electron clouds orbit positively charged nuclei. voice-verified

Stars are so hot that electrons can escape atomic orbits entirely. voice-verified

The resulting soup of charged particles, ions and free electrons is known as plasma, and it's in plasma that nuclear fusion can take place. voice-verified

Now plasma is by far the most common material in the universe, making up well over 99.9% of visible voice-verified

that is, non-dark matter. voice-verified

But we are part of the 0.1%, that small amount of matter in the universe that's cool enough that in general, electrons confined to orbitals and chemistry, not nuclear physics, dominates, allowing cool balls of rock covered in oceans of water like Earth to form. voice-verified

For us, creating such conditions, making plasma that's hot enough to sustain fusion and containing it, is a considerable challenge. voice-verified

You see, the Sun has one quite literal giant advantage on its side. voice-verified

It's so huge that the force of gravity holds the plasma in a near-perfect sphere, with pressure at its core reaching 150 grams per centimeter cubed, so dense a teaspoon would weigh close to a kilogram. voice-verified

The biggest fusion reactor on Earth, ITER in France, a leading international project that hopes to be operational in 2034, will use just a few grams of plasma material in a chamber of 830 cubic metres. voice-verified

Because it's under such low pressure, meaning particles aren't squeezed together like they are in the sun, this plasma has to be much, much hotter to achieve fusion. voice-verified

150 million degrees Celsius, as opposed to 15 million degrees at the core of the sun. voice-verified

Now, fairly obviously, you can't just hold a material like this in a container made of normal matter. voice-verified

If it contacted the sides, it would cool, electrons would condense into atomic orbitals, and it would no longer be plasma. voice-verified

And of course, it goes without saying that the container itself would be damaged beyond repair, so the plasma needs to be isolated in a vacuum. voice-verified

Two approaches have been put forward to achieve this, the first of which is magnetic confinement fusion. voice-verified

Because plasma is a soup of charged particles, voice-verified

positively charged ions and negative electrons, it can be manipulated by magnetic fields. voice-verified

Magnetic confinement takes advantage of this by using a ring of powerful magnets to hold plasma in a continuous donut-shaped blob in which fusion can take place. voice-verified

There are a number of different types, stellarators and reversed field pinch devices, but the leading design is called the tokamak. voice-verified

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