On 25 November 1915, Albert Einstein presented his general theory of relativity at the Prussian Academy of Sciences. This theory is still considered to be the most important idea in modern physics.
The grandfather paradox is just one of the thorny logical problems that arise with the concept of time travel. But one physicist says he has resolved them.
A team of physicists affiliated with multiple institutions in China has measured a pulse of light in 37 dimensions. In their paper published in Science Advances, the group explains that their ...