The speed of light is a fundamental constant, approximately 299,792,458 meters per second. It's the same for all observers and hasn't changed measurably over billions of years. Nothing can travel ...

How do we know the speed of light – and why does it have a speed limit at all? Leah Crane explores the history of one of the ...

The fact that the speed of light is constant in a vacuum is one of the cornerstones of Einstein’s theory of special relativity. But it's not obvious why this should be the case, or even whether it's ...

The speed of light is constant, or so textbooks say. But some scientists are exploring the possibility that this cosmic speed limit changes, a consequence of the nature of the vacuum of space. The ...

Anyone who took Physics 101 has had this fact drilled into their head: The speed of light is a constant, traveling at 186,000 miles per second. In fact, it’s the cornerstone of much of modern physics, ...

Researchers suggesting that the speed of light varies have come up with a numerical prediction that will allow their theory to be tested. Many theories in physics are built upon the idea that the ...

Albert Einstein might be known for a great many things, but even the layman might be familiar with at least one thing: E = mc 2, the formula for mass-energy equivalence. However, a critical part of ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. Back in 2018, astronomers examining the ruins of two collided ...

We wouldn’t notice. Or we’d die. Depends on how much it changed. Relativity already tells us what would happen if the speed of light were to change, and the answer is nothing. Consider a stationary ...

The speed of light isn’t just a number — it’s the foundation of reality. But new research into how light behaves across space ...