String theory has long been touted as physicists' best candidate for describing the fundamental nature of the universe, with elementary particles and forces described as vibrations of tiny threads of ...

String theory's equations give rise to a near infinite variety of potential universes in a 'landscape.' This landscape is surrounded by a 'swampland' of solutions that are incompatible with any ...

If you could take an apple and break it into smaller and smaller parts, you would find molecules, then atoms, followed by subatomic particles like protons and the quarks and gluons that make them up.

Physicists may have uncovered a surprising new clue that string theory—the idea that the universe is built from unimaginably tiny vibrating strings—could be more than just a mathematical fantasy.

The fundamental constants of nature seem perfectly tuned to allow life to exist. If they were even a little bit different, we simply wouldn't be here. Given this grave existential fact, we are forced ...

In the earliest moments after the universe was born, everything changed—fast. This rapid expansion, known as cosmic inflation, was theorized to solve problems in the Big Bang model. It explains why ...

In 1980, Stephen Hawking gave his first lecture as Lucasian Professor at the University of Cambridge. The lecture was called “Is the end in sight for theoretical physics?” Hawking, who later became my ...

Scientists seeking the secrets of the universe would like to make a model that shows how all of nature’s forces and particles fit together. It would be nice to do it with Legos. But perhaps a better ...

In 1998, astronomers discovered dark energy. The finding, which transformed our conception of the cosmos, came with a little-known consequence: It threw a wrench into the already daunting task of ...