Einstein

Light can travel for billions of years but it has no time

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Light can travel for billions of years but it has no time

A photon from a star billions of light-years away takes no time to reach a telescope. It’s not too little time. There is nothing. That result is not a measured or poetic way of speaking. It comes directly from the mathematics of special relativity, and it points to another strange thing about the nature of … Read more

Einstein predicted it a hundred years ago… and now they are measuring it alive: two stars are approaching each other like a cosmic clock.

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Historic portrait of Albert Einstein, whose theory of gravity predicted the orbital decay now being measured in a pair of dense stars

A hundred years ago, Albert Einstein predicted that massive objects in orbit would send small spirals into space themselves and gradually line up together. Astronomers are now watching that process happen, step by step, in dying stars about 4,000 light-years from Earth. Their slow collision is not just cosmic drama. It gives scientists the clearest … Read more