gravity

A Dark Energy Battle

Two decades ago, scientists found that the Universe’s expansion is accelerating. This was the complete opposite of what had been expected: the expansion should be slowing down due to gravity, not speeding up. At first,…


Gravity working … different?

A controversial approach to gravity that challenges Albert Einstein and suggests dark matter doesn’t exist has passed its first test. The vast majority of physicists agree that gravity acts according to rules laid down in…


Einstein and Planck Extended?

Erik Verlinde published his paper on gravity as an emergent property, not unlike temperature, making the need for dark matter obsolete. It’s tempting to look for this kind of solutions, as it’s never a satisfying…


Does dark matter exist? And how about gravity?

Erik Peter Verlinde (born 21 January 1962) is a Dutch theoretical physicist and string theorist. He is the identical twin brother of physicist Herman Verlinde. The Verlinde formula, which is important in conformal field theory…


Check your gravity facts

Gravity: we barely ever think about it, at least until we slip on ice or stumble on the stairs. To many ancient thinkers, gravity wasn’t even a force—it was just the natural tendency of objects…


When space wobbles

Our ears are now open to gravity’s faint symphony. On September 18, the Advanced Laser Interferometer Gravitational-Wave Observatory, or Advanced LIGO, began to listen for gravitational waves, cosmic ripples that subtly warp the fabric of…


Dark Energy, a primer

Looking up at the night sky reveals a small piece of the cosmos—patches of stars speckled across a dark, black void. Though the universe appears stationary to the naked eye, it is expanding at an…