[Flint]

We can begin by imagining the enactment of laws which ban all non-government possession of firearms.

That's not a world without guns. From this point on the whole article is a bunch of BS.

[NovemberCharlie]

From this point on the whole article is a bunch of BS.

Did you actually read the article? It wasn't until several pooints later that they actually reached a world with no guns, and they only did that by violating a law of physics.