Relativity

Decades of data have suggested the universe is flat, much like an infinite plane. But a new analysis reveals deep flaws in that simple conclusion

Physicists have observed the bizarre Terrell-Penrose effect in real life

Precisely calibrating clocks on Mars is harder than you’d think, because of some extremely esoteric physics

When space itself expands, weird things can happen—like galaxies breaking the universe’s ultimate speed limit

A nearly century-old offshoot of Einstein’s general theory of relativity may hold promise for solving the mysteries of dark matter, dark energy and more

Analyzing 1,504 supernovae into the distant universe, astronomers have shown the clearest evidence yet for cosmological time dilation as predicted by Einstein

For the first time, scientists observed matter’s free fall into a black hole’s “plunging region”

As the Event Horizon Telescope pursues ambitious upgrades, the project’s latest results reveal the magnetic fields around our galaxy’s supermassive black hole

According to Albert Einstein’s general theory of relativity, the universe remembers every gravitational wave—and scientists could soon test these cosmic recollections

The Laser Interferometer Space Antenna (LISA) will open a new era in astronomy that brings scientists to the brink of studying gravitational waves from the beginning of time

Light can be reflected not only in space but also in time—and researchers exploring such “time reflections” are finding a wealth of delightfully odd and useful effects

Quantum physics’ oddities seem less surprising if you stop thinking of atoms as tennis balls, and instead more like waves pushing through water