- #1

kiki_danc

- 353

- 9

According to Carlo Rovelli in his latest book "The Order of Time"

https://www.amazon.com/dp/073521610X/?tag=pfamazon01-20

:

"The equations of loop quantum gravity on which I work are a modern version of the theory of Wheeler and DeWitt. There is no time variable in these equations."

then later...

"For this intermediate phase, where time is wholly indeterminate, we still have equations that tell us what happens. Equations without time.

This is the world described by loop theory.

Am I certain that this is the correct description of the world? I am not, but it is today the only coherent and complete way that I know of to think about the structure of spacetime without neglecting its quantum properties.

Loop quantum gravity shows that it is possible to write a coherent theory without fundamental space and time—and that it can be used to make qualitative predictions.

In a theory of this kind, time and space are no longer containers or general forms of the world. They are approximations of a quantum dynamic that in itself knows neither space nor time. There are only events and relations. It is the world without time of elementary physics."

A theory that knows neither space nor time appears to be more elegant.. too bad LQG folks still haven't approximated General Relativity in the classical limit. Can string theory be made to work without fundamental space and time too? How?