The twin paradox

Michael J. Fox, Doc Brown and the DeLorean used as a time machine

Fasten your belts, take off for the future...

NIST scientists compared a pair of the finest atomic clocks available to prove that indeed, as relativity predicts, going up a flight of stairs accelerates your aging. Figure courtesy of NIST

A pair of aluminum atomic clocks verify Einstein's twin paradox and time dilation

Christopher Lloyd as Doc Brown, the inventor of the time machine in "Back to the Future". PR photo

The complete guide for the time traveler

Cosmic scene with DNA, stars, solvents and atomic circles in oral flow.

Philosophical implications of relativity

Cosmic scene with DNA, stars, solvents and atomic circles in oral flow.

Black holes and time travel

Cosmic scene with DNA, stars, solvents and atomic circles in oral flow.

Einstein's signature