Q. Dr. Rabbit has observed people with cameras undergoing some strange behaviour.

(a)When I was at a conference in North Carolina, one of the physics graduate students (who should have known better!) was trying to take a picture of the overheads projected on a white screen. Because the room was darkened, he used a flash. Explain why this is a bad idea and what his pictures are likely to show.

(b)I mentioned to him that he most likely must not be using his flash so he turned it off. He then proceeded to try and take pictures of the participants in darkened room. Describe why this is a bad idea and what his pictures are possible to show.

(c)I once observed a woman on an airplane at night with a camera. As we flew low over Washington DC she was impressed with the view of the city lights in the dark. She stood back in the aisle and tried to take the picture by the window using her flash. Clarify why this is a bad idea and what her pictures are probable to show.