Tachyons, faster-than-light particles, challenge Einstein's theory, hinting at time travel. New models suggest they may reshape physics, causality, and cosmic expansion.

Ever since Einstein revealed his special theory of relativity, we've known that time travel—at least moving forward through time—is possible. Einstein didn't pull this theory, or even the ...

Einstein's idea about time slowing down sounds fine in theory, but how can you be sure he's right? One way would be to hop in a rocket and travel near the speed of light. Yet everything we know ...

A theoretical particle that travels faster than light, the tachyon has long intrigued physicists and fueled decades of speculation. Initially conceived as a possible solution to quantum and relativity ...

Euclid space telescope sent some images back to Earth during an early testing phase. While reviewing the pictures, astronomer ...

Does the universe have an edge? Is time travel possible? What is a black hole, and in what sense are space, time and gravity a matter of "geometry"? The modern theory of spacetime introduced by ...

enabling us to compare our findings with Einstein's predictions." As light takes time to travel across space, looking far out into the distant universe is the same as looking back billions of ...