From SF Chronicle:
(06-24) 10:56 PDT REDWOOD CITY -- A homeless man is on trial in San Mateo County on charges that he smacked a fellow transient in the face with a skateboard as the victim was engaged in a conversation about quantum physics, authorities said today.
Jason Everett Keller, 40, allegedly accosted another homeless man, Stephan Fava, on the 200 block of Grand Avenue in South San Francisco at about 1:45 p.m. March 30.
At the time, Fava was chatting with an acquaintance, who is also homeless, about “quantum physics and the splitting of atoms,” according to prosecutors.
Keller joined in the conversation and, for reasons unknown, got upset, authorities said. He picked up his skateboard and hit Fava in the face with it, splitting his lip, prosecutors said.
Fava also fell and broke his ankle, although how this happened wasn't exactly known, authorities said.
The attack was witnessed by two other people who told police that Fava had done nothing to provoke Keller, authorities said.
Keller is expected to take the stand at his jury trial in the Redwood City courtroom of Superior Court Judge James Ellis.