Dark energy vs. modified gravity: Which one will prevail?

Einstein's theory of general relativity predicts the existence of dark energy—a mysterious form of energy that permeates space and accelerates the expansion of the Universe. But what if Einstein was wrong and there was ...

Travel through wormholes is possible, but slow

A Harvard physicist has shown that wormholes can exist: tunnels in curved space-time, connecting two distant places, through which travel is possible.

Testing the symmetry of space-time by means of atomic clocks

In his Special Theory of Relativity, Einstein formulated the hypothesis according to which the speed of light is always the same, no matter what the conditions are. It may, however, be possible that—according to theoretical ...

Studying how time is perceived in space

Einstein predicted that time slows down the faster you travel and the time-dilation hypothesis has since been proven by flying atomic clocks on aircraft.

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