0:00 The magnet inside a typical hospital MRI is about three thousand times stronger than the one sticking your kid's art to the fridge.0:09 And it's only that powerful because of a truly bizarre state of matter.0:14 It's a world where electricity just...0:16 never stops.0:17 Right, and the physics behind that feels just as mysterious as the dark energy we were wrestling with in last week's episode.0:26 We were talking about this invisible 95 percent of the universe, but this is an invisible property hiding in plain sight.0:35 Exactly.0:35 It’s called superconductivity.0:37 Okay, so break that down for me.0:40 Super...0:40 conductivity.0:41 I get the parts, but what does it actually MEAN?0:44 It means zero electrical resistance.0:47 None.0:47 Imagine you're trying to walk down a super crowded hallway.0:51 Every person you bump into is resistance.0:54 You lose energy, you slow down.0:57 Mm-hm, that's a normal wire.0:59 The electrons are bumping into the atoms of the copper or whatever, losing energy as heat.1:05 Precisely.1:06 Now, imagine that same hallway is completely empty.1:09 You can just glide right through, no effort, no energy loss.1:13 That's a superconductor.1:15 Once you get the electricity flowing, it could theoretically flow FOREVER.1:20 Whoa.1:21 Forever?1:21 So if I made a loop of this stuff and zapped it once...1:25 The current would just keep circling.1:28 For years.1:28 We've done it in labs.1:30 Okay, that's a mind-bender.1:32 But there's a catch, right?1:34 Otherwise my phone charger wouldn't get warm.1:37 There is a VERY big catch.1:39 It has to be incredibly cold.1:41 Like, colder than the coldest place on Earth.1:44 We're talking hundreds of degrees below zero.1:47 So how does that work?1:49 Why does being cold suddenly make the hallway empty?1:52 Uh, it's not that the hallway gets empty, it's that the electrons learn a new trick.1:58 They start pairing up.2:00 They form these little teams called Cooper pairs.2:03 A buddy system!2:04 Sort of!2:05 And this pair can move through the atomic structure of the material without getting scattered.2:12 It’s like the pair has a special pass that lets it glide through the crowd untouched.2:18 The cold is what allows them to form that team in the first place.2:22 So that MRI machine...2:24 it's basically a giant, super-chilled loop of wire with a permanent current running through it?2:30 That's it.2:31 The wire is bathed in liquid helium to keep it at about minus 450 degrees Fahrenheit.2:37 That massive, persistent current creates the incredibly strong magnetic field.2:43 And that’s why you can’t bring, like, a metal oxygen tank into the room.2:48 You reaaaally can't.2:49 And it's the same principle behind maglev trains, like the ones in Japan and China.2:55 They use superconducting magnets to float the entire train above the track.3:00 No friction.3:01 So you get rid of the resistance in the wire, and you get rid of the friction on the track.3:08 It's all about eliminating waste.3:10 Exactly.3:10 And that brings us to the holy grail.3:13 The big dream.3:14 Let me guess.3:15 Doing this without the liquid helium.3:18 Doing this at room temperature.3:20 Or even just "high temperature," which to a physicist might still mean cooling with something like liquid nitrogen—which is way, WAY cheaper and easier to handle than liquid helium.3:32 Wait, what would that actually change?3:35 If you had a spool of wire that was a superconductor at, say, the temperature of a normal day.3:42 Everything.3:43 I mean, think about it.3:44 Up to ten percent of the electricity generated is lost as heat in power lines before it even gets to your house.3:52 Gone.3:52 Just...3:53 wasted.3:53 Poof.3:54 With room-temperature superconductors, that number goes to zero.3:58 You could build computers that are a hundred times faster because they don't generate waste heat.4:05 You could have perfect, lossless energy storage.4:08 It would change the world on a scale that's hard to even comprehend.4:13 It feels like we'd be stepping into a different physical reality.4:18 We would.4:19 We’d be unlocking a cheat code for physics that we've known about for a century but have only been able to use in the most extreme conditions.4:29 Finding that material, the one that works in the warm...4:32 that's the goal.4:34 It's probably the biggest materials science challenge of our time.4:38 And whoever cracks it, well, they won't just win a Nobel Prize.4:43 They'll have given us a brand new world.
