Stupid Godtech weapons 1: Relativistic Baseball Cannon

What is it

Based on this XKCD comic is the first stupid Godtech weapon the Relativistic Baseball Cannon. The cannon is a handheld weapon roughly the size of a modern shotgun. A series of rails make up the barrel with a top loaded magazine, a pistol grip and a battery. When fired in a vacuum a baseball is accelerated to 0.99c doing incredible damage to whatever it hits. The real interesting part is when its fired in atmosphere. In atmosphere the baseball turns instantly into plasma before going off like a fusion bomb killing the user and everything around them.

How to use it in game

The weapon when given to players should initiate a knowledge check to see what it is. A successful check tells them it's a Baseball Cannon that shoots the baseball out to 0.99c. In the event of a failed check they’ll know its a baseball cannon but that’s all. Further knowledge checks or simply if the players know that shooting it in Atmo is bad is enough of a reason for the PCs to not use it there. Now in the event that it is used in an atmosphere by the players the will unfortunately meet their end as a rapidly expanding cloud of plasma.