The universe comes with a built‑in speed cap, a hard limit that shapes everything from how stars shine to how cause and ...

On one hand, the speed of light is just a number: 299,792,458 meters per second. And on the other, it’s one of the most important constants that appears in nature and defines the relationship of ...

Let’s explore how constant this speed of light fundamental constant really is. One of the most fundamental physics facts is that the speed of light in a vacuum is constant for all observers. But can ...

Einstein’s claim that the speed of light is constant has survived more than a century of scrutiny—but scientists are still daring to test it. Some theories of quantum gravity suggest light might ...

The speed of light has been one of science’s most trusted markers of stability. For more than a century, the idea that light moves through space at a constant speed has supported some of physics’ most ...

Breakthroughs, discoveries, and DIY tips sent six days a week. Terms of Service and Privacy Policy. Back in 2018, astronomers examining the ruins of two collided ...

In 1676, by studying the motion of Jupiter's moon Io, Danish astronomer Ole Rømer calculated that light travels at a finite speed. Two years later, building on data gathered by Rømer, Dutch ...

The most distant galaxies in this deep field image from the James Webb Space Telescope appear as small, faint dots—and are receding from us faster than the speed of light due to cosmic expansion. If ...

Here, a calcite crystal is struck with a laser operating at 445 nanometers, fluorescing and displaying properties of birefringence. Unlike the standard picture of light breaking into individual ...

(via PBS Space Time) One of the most fundamental physics facts is that the speed of light in a vacuum is constant for all observers. But can we really be sure that the speed of light wasn’t different ...