The assassination of President John F. Kennedy is the greatest murder mystery in American history.

That's Rob Reiner. Rob called me Soledad O'Brien and asked me what I knew about this crime.

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Hey, and welcome to the short stuff. The whole gang's here, even in spirit. So let's go. Stuff you should know.

Yeah, you put this one together. This is a good one. We're talking about the magnetic field and specifically the switching of Earth's magnetic pole. And I guess we should just start talking about what the magnetic field of the Earth is, right?

Yeah, you kind of can't really get past that one because apparently it seems to be fairly peculiar to Earth to have a really solid inner core made of, I think, iron and nickel and that that is basically bathed in a bath of molten outer core. And because that molten outer core is constantly roiling and convecting and doing all sorts of crazy motions, it actually produces a dynamo effect where a magnetic field is generated. That inner core essentially becomes a giant bar magnet with a north pole and a south pole. And that magnetic field radiates from the center of the Earth outward into outer space. And it does some pretty cool stuff. One, it prevents high energy particles that are bombarding Earth at all time from reaching Earth generally and killing us. Just shooting right through your throat and out the other side. So life can exist on Earth and then, less importantly, but more beautifully, also creates the auroras.

And also why I wear a Kevlar turtleneck, actually. Not a dickie, really, because it gets warm in the summer.

Yeah, that's smart.

So you've got that bipolar core. We have the North Pole and the South Pole geographically. Like, we know where those are. We've mapped those out. They're great. Everyone loves them, but they really have nothing to do with the actual magnetic poles of the Earth. Two different things. The Earth's poles, as we will see, they move around a lot because of that molten core is unstable and it moves. That roiling sort of molten gunk you were talking about is weaker in some places, it's stronger in some places. And you kind of likened it to a pot of water, like, bubbling, and the bubbles pop and fade away. Same thing is going on there that creates instability and sort of just movement.

Yeah. So suffice to say that the Earth's magnetic field is not constantly stable. It's constantly changing. And since some spots are weaker than other spots, that means the poles can actually move around. And they do. They wander about. It's called excursions. And they can move all over the place. And as a matter of fact, what seems to pass, what seems to be a threshold, they flip. And all of a sudden, the South Pole is at the geographical North Pole area and the North Pole is down in Antarctica somewhere. And it happens. And we've just recently learned about this kind of thing.

Yeah. It's called polarity reversal. There's some disagreement among the scientific community about how often this happens, how quickly it happens. There was a study in 2020 from the Scripps Oceanographic Institute in San Diego. San Diego, right.

Yeah.

SD. I didn't think it was south dakota.

Definitely.

Or southern durham, north carolina.

It could have been that one. It's definitely not South Dakota, though, I'll tell you that.

Yeah. So they had a new model based on 100,000 years worth of data, and they said, Actually, these poles are wandering, like, a lot. It's a real walkabout. They're wandering about ten degrees a year. That is equal to the distance between Atlanta and Toronto, or, for Aussie friends, Brisbane and Melbourne. Or if you're in London, those are the three places that listen to us, basically.

Sure.

Canada, Australia and the UK. Or London and Prague. And that is about ten times what scientists thought before this study came out.

Yeah. The Pole can wander that far in a year. A year. When you hear about this, you're like, okay, that's weird. I didn't know they could move. Maybe it just kind of gyrates a little bit. No, it can travel from Toronto to Atlanta in a year and back, and it wanders all over the place. It's not like it follows, like, a set line, because, again, the molten inner or outer courts roiling. It looks probably a lot like the surface of the sun. And so all the little spots and weird areas and everything, that's where the kind of, like, the magnetic poles actually travel, like down a Planko set, essentially, but a severe plinko set, if you can wrap your mind around that kind of thing.

All right, well, I'm going to wrap my mind around it and we're going to take a break and I'm going to unwrap my mind right after this.

The assassination of President John F. Kennedy is the greatest murder mystery in American history.

That's rob briner. Rob called me, Soledad O'Brien, and asked me what I knew about this crime. I know 60 years later, new leads are still emerging. To me, an award winning journalist, that's the making of an incredible story. And on this podcast you're going to hear it told by one of America's greatest storytellers.

We'll ask who had the motive to assassinate a sitting president? My dad, Bob JFK, screwed us at the Bay of Pigs and then he screwed us after the Cuban Missile Crisis. We'll reveal why Lee Harvey Oswald isn't who they said he was. I was under the impression that Lee, who was being trained for a specific operation, then we'll pull the curtain back on the COVID up, the american people need to know the truth.

Listen to who killed JFK on the iHeartRadio App Apple podcasts or wherever you get your podcasts.

From Wall Street to Main Street and from Hollywood to Washington, the news is filled with decisions, turning points, deals, and collisions. I'm Tim O'Brien, the senior executive editor for Bloomberg Opinion, and I'm your host for Crash Course, a weekly podcast from Bloomberg. And iHeartRadio Every week on Crash Course, I'll bring listeners directly into the arenas where epic upheavals occur, and I'm going to explore the lessons we can learn when creativity and ambition collide with competition and power. Each Tuesday, I'll talk to Bloomberg reporters around the world, as well as experts and big names in the news. Together, we'll explore business, political, and social disruption and what we can learn from them. I'm Tim O'Brien, host of Crash Course, a new weekly podcast from Bloomberg, and iHeartRadio listen to Crash Course every Tuesday on the iHeartRadio App Apple podcasts or wherever you get your podcasts.

All right, so we were talking about this thing is the it's really Holland. These poles are moving around and they can actually flip. And the last time that happened was about 42,000 years ago in what's called the Lachamp, I guess the Lachamp Excursion. Great band name. And this was the lava flow in France, of which it was named after because of the fossil record, I guess, that we discovered in the 1960s. And during this excursion, the North Pole went across North America, then said, all right, now I'm going to drop down into the Pacific or through the Pacific to Antarctica, and then I'm the North Pole, by the way, and I'm going to stay there in Antarctica for about 400 years. And then I'm going to go back up through the Indian Ocean to the actual geographical North Pole.

Yeah, roughly that area back to generally where the magnetic North Pole typically is. Right.

Yeah.

That's really fast. 400 years on a geological timescale is like a blink is too slow as a description or analogy. And so the lashampus excursion seems to have had some pretty significant effects on the planet that 42,000 years ago coincides with a bunch of weird stuff that happened on Earth. There was a lot of glaciers that expanded and all sorts of surprising places. The wind patterns changed globally. The megafauna, a lot of megafauna species disappeared from the fossil records, and so too did the neanderthals.

That's right.

It was a really significant period of surprising and kind of dismal activity in Earth's history. And they have traced this to basically a weakening of the magnetic field that it's probable the magnetic field became very weak and that allowed the poles to flip very quickly and that it wasn't necessarily the poles flipping that caused all of this weird stuff to happen, but that the magnetic field being weakened probably also let this weird stuff happening. So the reversal of polarity was a symptom just like, say, the disappearance of the neanderthals was or the change in wind patterns were. They were all symptoms of this weakened magnetic field around Earth.

Yeah, you talked about it sort of acting like a force field against that particle bombardment that probably weakened it enough that they were bombarded. The ozone layer was damaged, a lot of UV light is just baking the Earth and it was just bad. Bad enough where scientists obviously are like, well, when is this going to happen again? Because we're in store for something pretty rough. And what they've kind of come out with was a we're not sure exactly when it's going to happen again. Because you can't look back, I think you mentioned earlier, it doesn't necessarily happen in a pattern that you can count on.

Yeah.

Doesn't seem to. Yeah. So they can't say like, all right, well, here's when it's going to happen again. But they do think this was really the Lachamp Excursion was sort of a rare fast thing and if it does happen again, it'll probably be over the order of thousands of years and it's not going to be the kind of thing like most of the other times it happened. It was over a much slower time period. The lashamp was just so fast it wrecked everything. And it probably wouldn't be that bad if it happened again because it would be on a much slower thousands and thousands of years timeline.

Yeah. I mean, tens of thousands of years versus hundreds of years. That's pretty significant as far as differences go. Right. And if this sounds kind of like if it rings a bell, we talked a little bit about this in the plate tectonics episode, where the magnetic striping at the bottom of a sea is basically lava flows recording reversals in polarity of Earth's poles. This is very much what we're talking about. So because they think it happens over tens of thousands of years and if you look back in the fossil record, at other times that coincide with polarity reversals, there doesn't seem to have been anywhere near the kind of catastrophic events that came from the Lachamp excursion. They're not particularly worried about it. But we do know that if it did happen on like a normal slow timescale, we still have to adapt because a lot of our technology relies on a stable magnetic field.

Yeah, I mean, they have to take that stuff into account. Like when they look at the fossil record, maybe not much of anything happened because they weren't using satellites and they didn't have things floating around in space. But there's an area called the South Atlantic Anomaly between South America and South Africa where there is a weaker magnetic field than elsewhere on Earth. And when satellites and stuff go through there in spacecraft, there are issues.

They're like, can you hear me? Are you still there?

And they say, in space, no one can hear you scream.

Name that movie spaceballs.

Exactly. So that's an example of what can happen with just a somewhat weaker magnetic field. So they would have to account for that stuff ahead of time, know it's coming and account for it. I think there would be some economic impact, but I think who is it? The Cambridge Center for Risk Studies said that it could be, like, a six to $42 billion cost for the United States, which, honestly, that's chump change when you look at budgets of the United States.

Budy, that's a day. Yeah, a day.

So it's not like I mean, that's a lot of money, obviously, but it's not like that would wreck the American economy or anything.

It depends on how long it went on know?

Well, hey, I guess so.

I mean, if they didn't get up and running within a few hours, it could add up.

It could add up.

Speaking of knowing it's coming, I want to go ahead and stem the tide of emails. I know that Chuck was talking about alien, by the way.

Everyone.

How could Josh see spaceballs?

One other thing, Chuck, because the disappearance of the neanderthals coincides with the weakening of the magnetosphere and probably bombardment of UV radiation and ions, you may be right that the neanderthals really did melt. You might be onto something, man.

That's an old one.

You got anything else?

I got nothing else, JM.

Well, then short stuff is out.

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