What would happen if you tried to hit a baseball pitched at 90% the speed of light?
Lots of physics happens, and then …
Everything within roughly a mile of the park is leveled, and a firestorm engulfs the surrounding city. The baseball diamond is now a sizable crater, centered a few hundred feet behind the former location of the backstop.
A careful reading of official Major League Baseball Rule 6.08(b) suggests that in this situation, the batter would be considered “hit by pitch”, and would be eligible to advance to first base.
One suspects a spitball. Every pitcher must be Homeland Severity seached for neutronium, ichor, carmot, relux, scrith, and ylem on his way to the mound. Searching for flubber would be profiling.