Who is Michele Besso from Einstein's Dreams and what is their importance?

Besso is Einstein's close friend, but Einstein does not confide his dreams in Besso. He spends time with Besso and talks to Besso about his ideas. Besso has great admiration for Einstein. Although Besso doubts whether Einstein can tackle the nature of time or find a way to become closer to God, Besso also knows that Einstein is brilliant and seems to him capable of anything, even at the young age of twenty-six. Besso worries about Einstein and tries to make sure that Einstein will be okay without any company while Besso's brother comes to visit.