Why is Charlie angry at Alice at the end of the date.

Charlie is angry because Alice was not reciprocating his affection. Charlie wants romance, he wants their outing to be a real date.... he wants to hold her hand. Alice, however, is made very uncomfortable by Charlie's advances. She doesn't want to hurt him, and she tells him that this is wrong time for emotional ties. He is in the midst of a very important experiment, an experiment that could better the lives of so many people.... and that beyond Professor Nemur and Dr. Strauss, he was obligated to all the people who could be helped.... the people who will follow the path he is forging.