Alex McColgan
speaker
29,301 appearances
104 recordings
1 series
first heard Nov 2024
last heard 4d ago
Alex McColgan’s voice in public audio — every appearance, attributed to the second.
Trend
recordings per month · last 12 monthsRecordings per month over the last 12 months — 68 in all, peaking in Aug 2026 with 11.
Appearances
Other neutrinos will have come from more cataclysmic origins, such as a supermassive black hole, supernovae, or any other cosmic event with enough energy to rip atoms into their subatomic particles.
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Similar to electrons, neutrinos belong to the lepton family of particles, meaning that they do not interact with other matter through the strong nuclear force that binds other subatomic particles like protons and neutrons together.
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Unlike electrons, they are neutral and have almost no mass whatsoever.
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This lack of charge and tiny mass means that they can only interact with other particles through the weak nuclear force, giving them their ghostly quality and making them one of the most difficult particles for scientists to detect.
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So much so, that even when we do measure their presence, it is only through the impact they have on other particles.
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If that wasn't spooky enough, neutrinos can also pass through our entire planet without acknowledging the existence of a single atom in the crust, mantle, core, or any other layer of the Earth, flying straight out of the other side completely unnoticed.
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There are trillions of neutrinos surging through you every single second, and yet, over your entire lifetime, there is only a 1 in 4 chance that even one of those neutrinos will interact with an atom that belongs to your body.
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Here we find further demonstration of the neutrino's complete refusal to engage with matter in the universe.
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Photons, created in those same nuclear reactions, may take 1 million years between bursting out of the sun's centre to leaping off the surface into space.
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They are constantly absorbed and emitted in random directions over and over again by the atoms in our star.
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resulting in a long, meandering path to escape.
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Neutrinos instead zoom straight out of the sun in just 2 seconds, travelling at almost the speed of light itself.
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As far as standard model particles go, neutrinos are certainly the more coy and antisocial of the group, but on occasion they do mingle with other matter, and in the process can create a drama of energetic particle events cascading out in their wake.
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It is this cascade IceCube is trying to observe.
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They might seem strange,
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But the 5,160 detectors, or DOMS, suspended down between 1.5 and 2.5km in the darkness of the ice shelf, are in fact light detectors.
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The sun's rays have of course been completely swallowed up by the thousands of metres of compressed ice that lie above, but that doesn't mean there is no light at all down here.
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Neutrinos and cosmic rays can penetrate into the ice, and when they collide with the atoms of frozen water, they cause particles, like muons, to spring into existence.
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Muons are the key to identifying a neutrino interaction.
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As the newly created muon hurtles through the incredibly clear and dense ice, it can exceed the speed it takes light to move through that same ice.
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Showing 1941–1960 of 29,301 · page 98 of 1466
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