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 speed of light in a vacuum, usually denoted c, is a fundamental constant central to much of physics, particularly Einstein’s theory of relativity.

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.

In fact, variable speed of light theories have long been used to try to explain everything from dark energy to gravity itself. Let’s explore how constant this fundamental constant really is. 07 ...

In a nutshell, the constant speed of light wouldn't be able to explain why the universe today, as large as it is, is homogeneous in density, or largely uniform everywhere.

Many things in life are constant. The crushing sense of disappointment after finishing a bar of chocolate, for example. The unpredictability of 2016. And, of course, the speed of light. But, wait ...

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. The speed of light traveling through a vacuum is exactly 299,792,458 meters (983,571,056 ...

A team of Australian scientists has proposed that the speed of light may not be a constant, a revolutionary idea that could unseat one of the most cherished laws of modern physics -- Einstein's ...

In science fiction, spaceships moving at or beyond lightspeed enable all manner of universal exploration. But in Earth-bound reality, traveling at the speed of light (299,792,458 meters per second ...

The speed of light may not be constant, a possibility that could have broad implications for fields of cosmology and even astronomy, say physicists. Skip to main content. Open menu Close menu ...

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.