Change Quote by Edward Witten

“The key question for a quantum theory of gravity is then the following: Can we extend to quantum theory the principle that space has…

— Lee Smolin

In Einstein's general relativity the structure of space can change but not its topology. Topology is the property of something that doesn't change when…

— Edward Witten

“Now, at the outset of the twenty-first century, we stand on the verge of a new revolution. The search for a deeper theory than…

— Marcus Chown

I am not aware of any sensible theory of how classical gravity could interact with quantum matter, and I can't imagine how such a…

— Alan Guth

“Both loop quantum gravity and string theory assert that there is an atomic structure to space. In the next two chapters we shall see…

— Lee Smolin

“The loop approach to quantum gravity is now a thriving field of research. Many of the older ideas, such as supergravity and the study…

— Lee Smolin

“So, in the end, the most improbable and hence the most puzzling aspect of space is its very existence. The simple fact that we…

— Lee Smolin

Whether you can go back in time is held in the grip of the law of quantum gravity. We are several decades away from…

— Kip Thorne

We have to have a combination of general relativity that describes the warping of space and time, and quantum physics, which describes the uncertainties…

— Kip Thorne

The extreme weakness of quantum gravitational effects now poses some philosophical problems; maybe nature is trying to tell us something new here: maybe we…

— Richard P. Feynman

We're going to need a definitive quantum theory of gravity, which is part of a grand unified theory - it's the main missing piece.

— Kip Thorne

Quantum mechanics as it stands would be perfect if we didn’t have the quantum-gravity issue and a few other very deep fundamental problems.

— Gerard 't Hooft