1 A few types of cells are large enough to be seen by the unaided eye. The human egg (ovum) is the largest cell in the body, and can (just) be seen without the aid of a microscope. 2  Most cells are small for two main reasons:  The cellâs nucleus can only control a certain volume of active cytoplasm.
The atomic nucleus is the small, dense region consisting of protons and neutrons at the center of an atom, discovered in 1911 by Ernest Rutherford based on the 1909 GeigerâMarsden gold foil experiment.
Scientific Contributions. Edward Teller is often referred to as the father of the hydrogen bomb.. After the Soviet Union detonated its first atomic bomb in 1949, Teller worked to convince President Truman to develop a crash program for the hydrogen bomb, which he beleived was feasible.