Mark writes in, hello again from Texas.

Human geography is the study of the patterns that have shaped.

Oh, I thought this guy was just coming out of nowhere saying this.

But this is the guy who we asked to write in and explain what human geography is.

Okay.

So in a way, he got right to the point.

This is very admirable of him.

Yeah. Mark writes in, hello again from Texas. Human geography is the study of the patterns that have shaped our understanding use and alteration of the Earth's surface. Then he moves right on. Here's more about rank size rule. There are two basic categories of countries. Number one, primate city countries, where the largest city is more

than twice the size of the second largest city. For example, in the UK, the largest city, London,

has a population of 8.3 million where the second largest city is Birmingham, at 2.3 million,

and then Manchester at 1.7. Number two, rank size rule countries, where the nth largest city is one over

the size of the largest. This is typically found in countries where there are numerous

cores, a political capital, an economic capital, a cultural capital, or many of each. Because

of this, there are many places of opportunity and not just one primate city

that draws in the most migrants. In the past, it also worked really well with MSAs, John,

metropolitan statistical areas. But the last decade saw tremendous growth in southern MSAs and has

altered these numbers. Think of it like having an nth of the opportunity. So L.A. is one-half

the opportunity of NYC and so on. R.S.R., rank-size rule, also works really well with Germany.

I was about to say, when he was talking up there about, you know, numerous cores, my first

thought was Germany.

Really? Yeah. Berlin, 3.7 million. Hamburg, one, one half of Berlin, 1.9 million. Munich,

one third of Berlin, 1.5 million. Cologne, one fourth of Berlin, 1.07 million. Frankfurt,

...