Did light shine in the universe’s earliest moments, or was it hidden from view? While this question may seem simple at first, ...

Imagine the ultimate version of a toy Universe: it's expanding, it's full of material, and through it all, there's one photon ⁠— or quantum of light ⁠— that we keep track of and forbid ...

This is a very hypothetical form of dark matter, the mysterious, invisible substance that accounts for roughly 80% of all the mass in the universe, yet doesn't seem to interact with light.

For the first time in history, we can explore the universe through a rich blend of senses—seeing, touching, and hearing astronomical data—in ways that deepen our understanding of space. While ...

Remember that photons can do two things: They can roam freely through the universe, existing as independent entities (this is light), and they do the legwork of mediating the electromagnetic force ...

Photons are odd little beasts. They can act like waves. They can act like particles. They are teeny tiny messengers of force. They are carriers of energy. If you're enjoying this article, consider ...

We can't see all the way back to the Big Bang. The early Universe was filled with a thick, murky, opaque fog of ionized plasma. This medium was impenetrable to light; any photons moving through ...

Many other stars in the universe use the same fusion process as the sun. These stars may vary in size and brightness, but they all generate light and heat through nuclear fusion.

Intergalactic gas clouds are slightly hotter than they should be, new research claims, and theoretical particles called 'dark photons' could explain it. When you purchase through links on our site ...

We can't see all the way back to the Big Bang. The early Universe was filled with a thick, murky, opaque fog of ionized plasma. This medium was impenetrable to light; any photons moving through ...