I was actually thinking that the surface of the earth relative to the core rotates at 1040 miles per hour. Also that the speed of the earth relative to the sun is 67,000 miles per hour, though that could be too deadly. (Edit: Since I was curious, casting arresto momentum with the sun as a frame of reference on a 50kg person would release 22 gigajoules. IE, you’d turn them into a kinetic kill weapon with destructive force equal to 5 tons of TNT)
But you’re right, arresting the momentum could be brutal in a lot of different ways.
Presumably, you’d need some kind of conceptual shift like with partial Transfiguration before you could do this. It seems like an implicit rule of Potterverse magic that it works according to the laws of physics you instinctively expect (or perhaps the ones the designer expected), so you have to “jailbreak” the spell before it can work in an updated, relativistic model.
I was actually thinking that the surface of the earth relative to the core rotates at 1040 miles per hour. Also that the speed of the earth relative to the sun is 67,000 miles per hour, though that could be too deadly. (Edit: Since I was curious, casting arresto momentum with the sun as a frame of reference on a 50kg person would release 22 gigajoules. IE, you’d turn them into a kinetic kill weapon with destructive force equal to 5 tons of TNT)
But you’re right, arresting the momentum could be brutal in a lot of different ways.
Presumably, you’d need some kind of conceptual shift like with partial Transfiguration before you could do this. It seems like an implicit rule of Potterverse magic that it works according to the laws of physics you instinctively expect (or perhaps the ones the designer expected), so you have to “jailbreak” the spell before it can work in an updated, relativistic model.
The same thing would happen with Apparition, floo travel, etc. I’m pretty sure you just aren’t allowed to manipulate momentum that way.