Knowtex

Jamaican sprinter Usain Bolt set the record Sunday for the 100-meter dash at 9.58 seconds. But Southern Methodist University's professor Peter Weyand, who specializes in the biomechanics of running, says runners still haven't come close to approaching human speed potential.

Together with scientist Adam Rutherford, Alok Jha from The Guardian traces back the story of cells, from their discovery by a Dutch textile merchant in the 17th century to the present.