All matter is made of atoms; looking at the atomic hypothesis; surveying the contributions of later scientists such as John Dalton; discovering why atoms are invisible to light microscopes, but not to the scanning transmission electron microscope.

Peering inside atoms to find mostly empty space, along with electrons and a compact nucleus composed of protons and neutrons; how these particles are discovered; how physicists use more complex tools to uncover hundreds of even smaller objects.

Probing the wave-particle duality of light; tracing the debate over the nature of light to 1801, when Thomas Young shows that light is a wave; a century later, Einstein proves that light also behaves as a particle; other matter with this identity.

Dr. Lincoln confronts a paradox that governs the behavior of particles sharing the same quantum state; the rules of quantum mechanics defy every attempt to explain what seems inexplicable; Erwin Schrödinger's thought experiment; other examples.

How Dr. Lincoln routinely conducts experiments that show the bizarre effects of Einstein's special theory of relativity; like quantum theory, relativity strains credulity; at relativistic speeds, clocks really do slow down and length contracts.

Pondering how the speed of light can be the same for everyone; how the speed of light is determined; considering the hypothesized medium for light propagation, the aether; examining proof that the speed of light is constant for all observers.