The speed of light – the fastest speed in the universe – reveals mind-blowing truths about reality. Why does this limit exist ...

Year? A light-year is the distance light travels in one year. Light moves incredibly fast — about 186,000 miles (300,000 ...

There will be light, feebly, at the end. In all its forms—visible and invisible—it saturates the universe. Light is more than a little bit inscrutable. Modern physics has sliced the stuff of ...

The Universe began in a burst of light nearly 14 billion years ago, but as it expanded and cooled, darkness set in. Today, while almost a trillion galaxies exist within our cosmic horizon ...

The rate of expansion of the universe today is a figure known as the Hubble constant, which is typically measured in units of ...

This, together with satellite measurements of the fraction of the universe’s first light, known as the Cosmic Microwave Background (CMB), that is scattered by electrons freed during reionization ...