Learn what gravity is as well as how two of the greatest scientific minds in history--Isaac Newton and Albert Einstein--finally unraveled most of the mystery surrounding this peculiar force, and how scientists today are continuing to search for answers to the remaining questions.

A not-so-simple concept -- Newton to the rescue -- Using Newton's law -- The mystery of the tides -- A better idea -- Relativity : making the case -- Dark matter, dark energy -- Extreme gravity.