Great Mysteries of Physics

The quest for a theory of everything – explaining all the forces and particles in the universe – is arguably the holy grail of physics. While each of our main theories of physics works extraordinaril…

What’s the difference between a living collection of matter, such as a tortoise, and an inanimate lump of it, such as a rock? They are, after all, both just made up of non-living atoms. The truth is,…

It is hard to shake the intuition that there's a real and objective physical world out there. If I see an umbrella on top of a shelf, I assume you do too. And if I don't look at the umbrella, I expec…

Interest in the multiverse theory, suggesting that our universe is just one of many, has spiked since the movie Everything Everywhere All At Once was released. The film follows Evelyn Wang on her jou…

Imagine a universe with extremely strong gravity. Stars would be able to form from very little material. They would be smaller than in our universe and live for a much shorter amount of time. But cou…

Without a sense of time, leading us from cradle to grave, our lives would make little sense. But on the most fundamental level, physicists aren't sure whether the sort of time we experience exists at…

"There is nothing new to discover in physics", declared the British physicist Lord Kelvin in 1900. That is no longer true. Today it is becoming increasingly clear that there are problems that physics…