Evidence for the flatness of the universe also shows up in what's known as the critical density. At the critical density, a hypothetical universe would be flat and would eventually stop ...

Feast your eyes upon the first color—not the first one in this book of course, but the first color in the universe. This bright-hot glowing peachy orange didn’t exist until approximately ...

Today’s universe continues to expand, even accelerating. This forces physicists to introduce dark energy to explain this unusual acceleration. Little is known about the nature of dark energy.

The largest known star in the universe is UY Scuti. It has an estimated radius of 1.188 billion kilometers. If UY Scuti were the center of our solar system, its photosphere , or outer shell, would ...

"This is a unique opportunity to learn how the universe's first light emerged from the darkness." ...