During the latter part of the 20th century, string theory was put forward as a unifying theory of physics foundations. String ...

A new theory links gravity to quantum entropy and introduces the G-field, possibly explaining dark matter and cosmic ...

Einstein believed that black holes didn't really exist. But they do: that much we know. We don't know much else about them.

Using the mathematics of Einstein's 1915 theory of gravity, called general relativity, scientists can model the interior of a black hole. The problem is that, when they do this, general relativity ...

In the early 20th century, Albert Einstein’s theory of general relativity ... orbits of planets around the sun, the influence of the moon’s gravity on tides, the trajectories of comets and ...

We’ve wondered what powered the Sun for centuries. Early guesses included meteor showers, chemical combustion, and ...

This is usually called the Kelvin-Helmholtz contraction theory. It proposed that the Sun is contracting slowly, and this contraction heats the star by converting gravitational potential energy ...

Gravity pulls us to earth, a lesson you learn viscerally the first time you fall. Isaac Newton described gravity as a ...