• maniacal_gaff@lemmy.world
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    9 months ago

    the only element on Earth cold enough to make an MRI machine work.

    I didn’t know that elements had a defined temperature. Bang up reporting there, NBC.

    • anton@lemmy.blahaj.zone
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      9 months ago

      Helium doesn’t freeze because quantum mechanics. gestures furious
      That means liquid helium can cool stuff to temperatures where nitrogen would be solid. This is used on the superconducting magnets in MRIs.

    • tate@lemmy.sdf.org
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      9 months ago

      Elements certainly do have defined temperatures! In this case it’s the freezing temperature that matters, which for helium is… not.

    • Cocodapuf@lemmy.world
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      9 months ago

      Well, they’re not really wrong, there’s are only two elements that make any sense to use here, helium and hydrogen.

      The thing is, the job they want these elements for is as a coolant. The best state of matter for a coolant is definitely liquid, a liquid flows much better and makes better contact for thermal transfer than a solid, and it’s much more dense than a gas (so it can pull more heat away).

      But, at these very low temperatures, the only elements that won’t freeze into a solid are helium and hydrogen. That said, hydrogen would make an even more efficient coolant than helium, so they’re wrong that helium is the only elements that works. Hydrogen is pretty impractical though, it’s hard to contain, it reacts with everything, it’s more expensive.