Who is David Phillips from Things Not Seen and what is their importance?

David Phillips is Bobby's dad. David is a physicist at FermiLab, where they smash atoms, take pictures of the pieces, and evaluate them. David has a scientific answer for everything that happens, but he is at a loss when Bobby becomes invisible. Mr. Phillips too has been taking his relationship with Bobby for granted. He realizes this once he has the car accident with his wife and after Bobby turns invisible. Mr. Phillips changes his outlook on work and life in general after these incidents occur.