For more than a century, modern physics has rested on two towering frameworks that do not quite agree with each other.

The rapid acceleration of the universe’s expansion continues to challenge our understanding of fundamental physics. Why the universe is expanding faster and faster remains one of the most intriguing ...

Einstein’s claim that the speed of light is constant has survived more than a century of scrutiny—but scientists are still daring to test it. Some theories of quantum gravity suggest light might ...

A new physics paper takes a step toward creating a long-sought "theory of everything" by uniting gravity with the quantum world. However, the new theory remains far from being proven observationally.

Physicists have spent decades treating mass as something the universe simply hands to particles, a property encoded in equations rather than explained from first principles. A new proposal argues that ...

The theory of relativity describes two connected scientific theories developed by the physicist Albert Einstein: special relativity and general relativity. Collectively, relativity is the idea the ...

If the universe was a soundtrack, we have been humming it our whole life. Every atom in our body, every star in the sky, every beam of light is part of a piece of music that never stops playing.

Teaching relativity to a dog may sound like a hopeless mental exercise, but physics professor Chad Orzel says it actually makes the job of teaching relativity to humans easier. "It makes the whole ...

You may think of physics as a way to explain the behaviors of things like black holes, colliding particles, falling apples, and quantum computers. But a small group physicists today is working on a ...