0:00 Everything we see in the night sky—every star, every galaxy, you, me, this microphone—all of it makes up less than five percent of the known universe.0:12 Yeah.0:12 And it’s that other ninety-five percent that keeps me up at night.0:18 It’s a lot like what we were circling last week, with trying to create life from scratch.0:25 We can see all the parts, but the fundamental force holding it all together is… well, it’s just a blank.0:34 So that ninety-five percent, that's dark matter and dark energy.0:40 Let's start with dark matter.0:42 The name itself sounds like something from a comic book.0:47 What are we actually talking about?0:50 We're talking about a ghost.0:52 A ghost that outweighs everyone at the party by a factor of five.0:57 We can't see it, we can't touch it, it doesn't interact with light.1:03 But we see what it does.1:05 We see galaxies spinning so fast they should fly apart, but something's holding them together.1:13 Gravity.1:14 Exactly.1:14 There is way more gravitational pull in those galaxies than all the visible matter can account for.1:23 So, our hypothesis, our placeholder, is "dark matter." It's the "x" in the equation.1:30 It's the mass we need for our theory of gravity to work.1:34 Okay, so we've been looking for this "x" for a while now.1:39 Decades, right?1:40 What have we tried?1:42 Oh, everything.1:43 We've built detectors deep underground in old mines, like the LUX-ZEPLIN experiment, trying to shield them from cosmic rays so they can spot a theoretical dark matter particle—a WIMP—bumping into a nucleus.2:00 And?2:01 Nothing.2:01 Silence.2:02 We've used the Large Hadron Collider to smash particles together, hoping to see some energy go missing, carried away by a dark matter particle we can’t detect.2:15 Still nothing.2:17 We've been looking for the ghost, and the house is just… empty.2:22 That sounds… profoundly frustrating.2:25 It is.2:25 And it isn't.2:26 This is where I think it gets really compelling.2:30 The persistent failure is telling us something.2:34 This reminds me of the search for the luminiferous aether in the late 1800s.2:41 The what?2:41 The aether.2:42 Scientists thought light waves needed a medium to travel through, like sound needs air.2:50 They called it the aether.2:52 They ran experiment after experiment to detect it, and every single one failed.2:58 And they failed because it just wasn't there.3:02 Right.3:03 The failure wasn't a dead end.3:05 It was the answer.3:07 It forced a complete rethinking, which led directly to Einstein and the theory of relativity.3:15 No aether needed.3:16 So the question we have to ask now is… is dark matter our aether?3:21 Is this decades-long failure a sign that we’re not just looking in the wrong place, but that we’re asking the wrong QUESTION entirely?3:33 Wait—so you’re saying maybe the problem isn't some missing particle, but our understanding of gravity itself?3:42 It’s the uncomfortable possibility, isn't it?3:46 That maybe on the scale of galaxies, General Relativity is… incomplete.3:52 And this thing we call dark matter is just a phantom, a symptom of our own misunderstanding.3:59 The same goes for dark energy, which is even more bizarre.4:04 Right, the thing that’s supposedly making the universe expand faster and faster.4:11 A force we had to invent to explain an observation.4:15 The universe's expansion is accelerating.4:18 Why?4:19 Uh… dark energy.4:20 It’s a placeholder for the biggest gap in our knowledge.4:25 It makes up almost seventy percent of the universe, and we know absolutely nothing concrete about it.4:33 We just know the books don't balance without it.4:37 So we're left with this cosmic accounting problem.4:42 Ninety-five percent of the balance sheet is just one big line item that says "miscellaneous." That's a perfect way to put it.4:52 And honestly?4:53 I wouldn't have it any other way.4:56 If we had found the WIMP particle in the first mine shaft we dug, the story would be over.5:03 It would be a new particle, sure.5:06 But this?5:07 This stubborn, elegant, universe-spanning mystery… it tells us that the map we have is not just incomplete, it might be drawn in the wrong projection entirely.5:20 And finding the edges of your map is the only way you can start to imagine a new world.
