Nonspecific fever. Kids infected with coxsackievirus usually establish an unexpected fever that lasts about 3 days. Often the fever comes in two waves â it is there for a day or two, disappears for a couple of days, then returns for about 3 days.
Albert Einstein proposed the idea the light exists of quanta of energy that he called photons.
Wave-Particle Duality. At first, physicists were reluctant to accept the dual nature of light. After all, many of us humans like to have one right answer. But Einstein paved the way in 1905 by embracing wave-particle duality. We've already discussed the photoelectric effect, which led Einstein to describe light as a photon. Later that year, however, he added a twist to the story in a paper introducing special relativity.