So I just read through Jasmine's Abstraction, and a thought occured to me.

An average car has a mass of 4079 pounds, or about 1850 kilograms. Therefore an average car driving at 30 miles per hour (about 13.5 metres per second) would have 405kgm/s of momentum. An average human head has a mass of 5 kilograms, so 405kgm/s of momentum added to that head would give it a velocity of 81 metres per second. Impact force is the change in velocity divided by the time it took for that change to take place. However, the change in momentum applied by Jasmine's Abstraction is theoretically instantaneous anyway, so even a tiny addition to or subtraction from momentum in an object would (again, theoretically) cause infinite impact force. Practically speaking though, "instantaneous" does not exist, only very fast. But say the change in momentum took a tenth of a second. In the example above, that's still 810 Newtons of impact force, and that's from a relatively slow moving car. Think about what could be done with, say, a train.