Good morning, John. So next week, a particularly unhinged episode of Dear Hank and John is gonna go up. We were just a total mess, because we accidentally talked for 90 minutes before the podcast started, so we didn't have enough time to record the podcast.

And I think that the first question that was asked was from Avery, who asked, " I was wondering how or if we know that the Earth is straight up and down with the Northern hemisphere on top and the Southern hemisphere on the bottom," which led to much hilarity, but to continue a discussion that you have not heard yet, because the podcast isn't out, I wanna talk about a time when we humans got something right.

Now, Avery, there is no up. It's all arbitrary. It's just stuff that we sort of feel and decide. For example, I live in a river valley where three rivers come together, and if you're gonna go into the Bitter Root Valley and you're from Missoula, you can actually tell something about a person by what they say. If they are new to town and don't have a lot of relationship with the land, they say that they're gonna go down the Bitter Root, whereas if they've been around for a while or they have a deeper connection to the land, they say they're gonna go up the Bitter Root.

This is because, when you're going from Missoula to the Bitter Root Valley, you are going south, but you are also going upstream and uphill. The Bitter Root River, unlike most rivers in America, though this is just by coincidence, flows from south to north. And weirdly, this feels a little weird to us, even though there's no reason why a river should go in any particular direction. Like, the Nile also goes from south to north.

This confusion implicates as faulty the entire idea of south as down, and, of course, south is very, very much not down. Globes and maps only show north as on top because someone decided that. Who? I don't know, but I wanna make the very strong case that, if they had to choose, and I think they did, they made - get this - the right decision.

Things are a mess in this world, and we understandably focus a lot on the things that we got wrong, for example, like that there are 12 months in a year. This is terrible. If there were 13 months instead of 12 every month would be - get this - 28 days long, except for one, which would be 27 days long. And 28 days divided by 7 is 4, so every month would have exactly 4 weeks in it. Every month would start on a Monday and end on a Sunday. Every holiday would happen on the same day every year, and then, at the end of the year, we'd have one month that was one day short, we'd have one week that was one day short, and we'd all be like, "Ah, this is the cute fun week where we all act weird, 'cause there's only six days."

This is a historical screw-up that we all have to live with forever, but maps in the past often would have either west or east at the top, and if we had ended up in the universe where we got stuck with this, it would've been historically bad, because we spin, so the actual, like, location of where west is moves around in space. I can't even get my head around how hard it would be to conceive of how the Earth is if I imagined that west was up. Like, it just breaks me.

So we absolutely dodged a cosmic bullet here. Now, if it had ended up with south on the top, this would not have broken my brain, but it would have been a subpar choice to having north on the top, because the Southern hemisphere is 80% ocean while the Northern hemisphere is just 60% ocean, so there's twice as much land in the Northern hemisphere. Also, 90% of the people live in the Northern hemisphere.

Now, what I'm not saying is that this has no drawbacks. There are negative consequences to having settled on north as up on maps. For example, no one knows whether or not to say up or down the Bitter Root. More importantly, we show some unconscious bias toward things in the Southern hemisphere, and when researchers test people, they unconsciously assign more value to places that are further north. But also there is huge value in having some kind of standardization here, where we all agree that one part of the map is always up, and so we don't have to be thinking about it and getting it wrong.

There were pros and cons to this choice. It had negative effects, but we made the right call, and we ended up avoiding a problem that we never have to think about, whereas I always have to think about the fact that we could have lived in a world where Halloween was always on a Friday night every year. John, I'll see you on Tuesday, which is some random day of the month.