By gravity I assume you mean alcohol content... is this named after the measuring instrument I remember by dad using to control alcohol mixture when I was a kid? He ran a farm, and he used industrial 96% for some disinfectant stuff. I remember him pouring the mix into this test tube looking thing where this widget would sink further down the stronger the mix was.

Also, I drank a 20something% beer once. It was strong enough to not resemble the beer in taste, and insanely pricey. I remember it being very brown and very thick. Any idea what they most likely did to achieve this ABV?

As I also enjoy a whiskey now and then I am not fundamentally opposed to high alcohol content... but I prefer that my beer actually tastes like beer and not an IG Farben byproduct.