Loop quantum gravity: Does space-time come in tiny chunks?

Unifying quantum mechanics with general relativity is the ultimate dream — or nightmare — of physics. It would be a way to finally describe the force of gravity with the tools of quantum mechanics, unlocking how gravity works when it’s really strong and at really small scales. Einstein’s theory of general relativity tells us that … Read more

What Is Spacetime Really Made Of?

Natalie Paquette spends her time thinking about how to grow an extra dimension. Start with little circles, scattered across every point in space and time—a curlicue dimension, looped back onto itself. Then shrink those circles down, smaller and smaller, tightening the loop, until a curious transformation occurs: the dimension stops seeming tiny and instead becomes … Read more

In a First, an ‘Atomic Fountain’ Has Measured the Curvature of Spacetime

In 1797, English scientist Henry Cavendish measured the strength of gravity with a contraption made of lead spheres, wooden rods and wire. In the 21st century, scientists are doing something very similar with rather more sophisticated tools: atoms. Gravity might be an early subject in introductory physics classes, but that doesn’t mean scientists aren’t still trying to … Read more

Curvature of space-time measured using ‘atomic fountain’

In 1797, English scientist Henry Cavendish measured the strength of gravity with a contraption made of lead spheres, wooden rods and wire. In the 21st century, scientists are doing something very similar with rather more sophisticated tools: atoms. Gravity might be an early subject in introductory physics classes, but that doesn’t mean scientists aren’t still … Read more

Einstein: A pair of pulsars in a tight embrace have proved his theories right again

After monitoring a pair of pulsars in tight orbit around one another for 16 years, astronomers conclude that their behaviour is consistent with Einstein’s predictions Space 13 December 2021 By Chen Ly Artistic impression of the double system, where two active pulsars orbit each other in just 147 minutes Michael Kramer/MPIfR Einstein’s famous theory of … Read more