According to HowStuffWorks.com, walruses can sleep and swim at the same time, too. While in the water, walruses can choose between sleeping underwater or above. A walrus can hold its breath for five minutes, just enough time for a nap. For a deeper sleep, walruses inflate spaces inside their body, called pharyngeal pouches, with up to 13 gallons of air.
Jeremy Bentham introduced the principle of utilitarianism to the penal system. He suggested that the penal system should ensure that the punishment causes more pain to the criminal than the pleasure they derived from the crime. The situation would, in turn, deter the individual from future participation in the crime.
Newton also made seminal contributions to optics and shares credit with Gottfried Leibniz for the development of calculus. He is particularly remembered for his applications of mathematics to mechanics, especially fluid mechanics, and for his pioneering work in probability and statistics.