Pitching a baseball at 0.9c?

vhbelvadi

I came across this from xkcd today. The question seems interesting, but I was wondering if this expplanation quite covers this or are there other possibilities? (Also, is something wrong with this explanation?)

Basically they're dealing with a baseball pitched at relativistic speeds.

http://what-if.xkcd.com/1/

BruceW

haha, yeah, something like that would probably happen. The ball would definitely get destroyed. Particle accelerators must be vacuum for this reason - if there was air in there, then the particles would collide with them. So if there was a ball going at this speed, then all the particles in the ball would collide with the air particles, giving off ridiculous amounts of energy.

vhbelvadi

@BruceW - An open air particle accelerator--my thoughts exactly!
So, basically, it's 150g of particles colliding with air molecules, so wouldn't the collision (for now let's assume there's no batter for a good distance) cause the entire ball to disintegrate resulting in the generation of energy we can't quite handle?
Or will it be within comparatively safe limits?

BruceW

at 0.9c, the kinetic energy is at a similar level to the rest mass energy. And from what you know about E=mc^2, this is going to be a huge amount of energy since we have a tenth of a kilogram of mass to play with.

Edit: So, specifically, the energy output of the explosion will be of the order of c^2 times by 1/10 kilogram