I... propose that time and its passage are fundamental and real and the hopes and beliefs about timeless truths and timeless realms are mythology. - Lee Smolin

In string theory one studies strings moving in a fixed classical spacetime. ...what we call a background-dependent approach. ...One of the fundamental discoveries of Einstein is that there is no fixed background. The very geometry of space and time is a dynamical system that evolves in time. The experimental observations that energy leaks from binary pulsars in the form of gravitational waves—at the rate predicted by general relativity to the... accuracy of eleven decimal places—tell us that there is no more a fixed background of spacetime geometry than there are fixed crystal spheres holding the planets up.

The suggestion was that a positive energy proof for general relativity could be gotten by restricting supergravity to its bosonic sector, which is general relativity.

To be human is to be suspended between danger and opportunity. ...The challenge of life is to choose wisely, from the enormous number of possible dangers, what's worth worrying about. It is also about choosing, from all the opportunities... always in the face of incomplete knowledge of the consequences.