Lee Smolin Quotes

Relativity and... quantum... remain incomplete. ...the main reason each is incomplete is the existence of the other. The mind calls for a third theory to unify all of physics, and for a simple reason. Nature is... "unified." …interconnected, in that everything interacts with everything else.

Spacetime... turns out to be discrete, described by a structure called spin foam.

Thinking in time is not relativism but a form of relationalism... the truest description of something consists of specifying its relationships to other parts of the system it is part of.

We have known since the middle of the nineteenth century that the world is not composed only of particles. ...the world is also composed of fields. ...General relativity is a theory of... the gravitational field. ...Because there are three sets of field lines, the gravitational field defines a network of relationships having to do with how the... lines link with one another. ...This is why we call relativity a relational theory.

The positive energy theorem was for half a century or more an open challenge to relativists. Many attempts were made to prove flat spacetime was stable, but none completely succeeded completely until a majestic tour de force of geometric reasoning of Shoen and Yau. This was followed two years later by a proof of Witten, which was as elegant as it was short. It is this proof of Witten’s that we take as a template here for the quantum theory.

We are the result of processes much more complicated than the small aspects of our lives and societies over which we have some control.

There is nothing beyond the world except what we see, no background to it except its particular history.

There is no meaning to space that is independent of the relationships among real things of the world. ...Space is nothing apart from the things that exist. ...If we take out all the words we are not left with an empty sentence, we are left with nothing.

Is the flow of time something real, or might our sense of time passing be just an illusion that hides the fact that what is real is only a vast collection of memories?

The first principle of cosmology must be 'There is nothing outside the universe'. This is not to exclude religion or mysticism... But if it is knowledge that we desire... we need to seek answers to questions about the things we can see... only things that exist in the universe.

In the theory of electric fields it is assumed that points have meaning. ...Physicists using general relativity... cannot speak of a point, except by naming some features of the field lines that will uniquely distinguish that point. ...the network of relationships evolve with time... constantly changing.

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.

The landscape problem and the problem of background independence are closely linked. The latter is the only route the former has to experimental confirmation.

While most people... were seeking to modify the principles of either relativity or quantum theory, we surprised ourselves (and many other people) by succeeding in putting them together without modifying their principles.

Calculation establishes that a quantum positive energy theorem may be possible using a representation based on the Ashtekar connection. Left open is a key question of whether this use of the Ashtekar connection is necessary or whether a positive quantum energy result can be achieved for representations based on other connections, i.e., for [other] values of the Immirzi parameter.