A photon can cross a billion light-years while accumulating no elapsed time along its path. Special relativity links space ...

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The blue dot on a smartphone map feels like simple magic, but it depends on one of the least intuitive ideas in physics.

Physicists, mathematicians and philosophers have been exploring the possibility of going forward to the future or back to the ...

Time travel has shifted from pure fantasy to a serious, if highly constrained, topic in modern physics. The equations that describe gravity, quantum fields and the structure of spacetime now allow ...

When an object moves extremely fast—close to the speed of light—certain basic assumptions that we take for granted no longer apply. This is the central consequence of Albert Einstein's special theory ...

Strangely, although we feel as if we sweep through time on the knife-edge between the fixed past and the open future, that edge—the present—appears nowhere in the existing laws of physics. In Albert ...

BOULDER- Black holes, time travel and E= mc^2. They are all related to Albert Einstein's Theory of Relativity. How many of us, though, can actually explain any of it? This year, Einstein's theory ...

EVER since Arthur Eddington travelled to the island of Príncipe off Africa to measure starlight bending around the sun during a 1919 eclipse, evidence for Einstein’s theory of general relativity has ...

One of the most mind-bending aspects of Albert Einstein's Theory of Relativity is time dilation. Time moves more slowly for a person in motion compared to a person at rest. This effect also applies in ...

How would our world be viewed by observers moving faster than light in a vacuum? Such a picture would be clearly different from what we encounter every day. "We should expect to see not only phenomena ...