Hamish Jolly, an ocean swimmer in Australia, wanted a wetsuit that would deter a curious shark from mistaking him for a potential source of nourishment. (Which, statistically, is rare, but certainly a fate worth avoiding.) Working with a team of scientists, he and his friends came up with a fresh approach — not a shark cage, not a suit of chain-mail, but a sleek suit that taps our growing understanding of shark vision.