Meanwhile, your entire existence (and the existence of any object) can be plotted on what’s called a world line, a curving path through spacetime starting at your birth and ending at your death. A ...

From Newton’s falling apple to Einstein’s curved spacetime, our understanding of gravity has come a long way, yet this ...

Foundational work During the 1930s, Matvej Bronštejn conducted the first in-depth study of quantum gravity, exposing its difference from quantum electrodynamics. Credit: G E Gorelik Reconciling ...

(via Sabine Hossenfelder) To us normal people, cause and effect are linked together in a distinct order. The cause occurs first, and the effect follows after. But according to a new paper, that causal ...

Quantum mechanics is our most successful physical theory. Created to account for atomic phenomena, it has a vast range of applications extending well beyond the atomic realm, from predicting the ...

“How quantum mechanics and gravity fit together is one of the most important outstanding problems in physics,” Kathryn Zurek, a theoretical physicist at the California Institute of Technology (Caltech ...

There are some things in life that just sort of happen. Desks get covered in dust and scraps of paper. Clothes get dirty and the laundry basket fills up. Weeds slowly creep across an untended ...

The original version of this story appeared in Quanta Magazine. Two blind spots torture physicists: the birth of the universe and the center of a black hole. The former may feel like a moment in time ...

There is no question that quantum theory is correct. It’s been proven over and over, both in the lab and through practical achievement. But the question remains: is it always correct? Quantum ...

Scientists propose a bold test of string theory by identifying a hypothetical five-particle family, called a 5-plet, that string theory cannot produce. If such a particle were found at the LHC, it ...

During the 20th century, physicists introduced and refined string theory, a theoretical framework that promised to unite quantum mechanics and general relativity. Instead of point-like particles, ...