Legend has it that Isaac Newton had the moment of inspiration that would lead to his theory of gravity when, on a warm afternoon, he saw an apple fall from a tree and wondered why it should fall down ...

What could be more familiar than gravity? Drop something and gravity pulls it to the floor, right? And in school we learn that gravity is what guides the moon in orbit around Earth, and Earth in its ...

The idea is still new and requires a lot of assumptions in its calculations to make it work. Over the years, experimental results have been mixed. When you purchase through links on our site, we may ...

Quantum gravity is an attempt to reconcile two theories of physics. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Quantum gravity is an attempt ...