Scientists pushed photons across the universe to test the speed of light—and found Einstein’s cosmic speed limit still holds ...

The idea was first hypothesized about 70 years ago. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. In a bizarre repercussion of Albert ...

Every generation grows up with starships that jump across galaxies in a heartbeat, but the real universe is far less forgiving than the screen. The same physics that lets GPS satellites work and ...

The universe comes with a built‑in speed cap, a hard limit that shapes everything from how stars shine to how cause and effect unfold. That limit is usually described as the speed of light, yet the ...

Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and Fundamental Forces from Imperial College London.View full profile Alfredo has a PhD in Astrophysics and a Master's in Quantum ...

What's more, when you're traveling at or close to the speed of light, the distance between where you are and where you're going gets shorter. That is, space itself becomes more compact in the ...

My telescope, set up for astrophotography in my light-polluted San Diego backyard, was pointed at a galaxy unfathomably far from Earth. My wife, Cristina, walked up just as the first space photo ...

Imagine you’re in a car driving across the country watching the landscape. A tree in the distance gets closer to your car, passes right by you, then moves off again in the distance behind you. Of ...

If there is an absolute law in the universe, it’s that nothing can travel faster than the speed of light. For science-fiction enthusiasts, that’s a bit depressing. Space is big, and while the speed of ...

The speed of light is the fastest anything can travel. What happens to a photon from a galaxy 25 million light years away on its journey toward Earth? When you purchase through links on our site, we ...