Top 15 Lee Smolin Quotes

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.

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 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 show that some known classical results have particularly simple derivations within the Ashtekar formalism. These include Witten's positive energy theorem...

One of the evident facts about the world is the stability of empty space-time. In classical general relativity we can explain this as a consequence of the positive energy theorem... the positive energy theorem must extend in some suitable form to any viable quantum theory of gravity.

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.

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.

If we believe that the task of physics is the discovery of a timeless mathematical equation that captures every aspect of the universe, then we believe that the truth about the universe lies outside the universe.

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

We seem to have an ingrained idea that if something is valuable, it exists outside of time.

Having begun my life in science searching for the equation beyond time, I now believe that the deepest secret of the universe is that its essence rests in how it unfolds moment by moment in time.

Special pleading that the standards of science should be lessened to admit explanations with no falsifiable consequences, in order to keep alive a bold speculative idea, should be strongly resisted. ...ultimately science is not interested in what might be true, it is interested only in what can be convincingly demonstrated by deductions from observational evidence.

The landscape problem represents a serious problem in the development of science. Its solution requires... the construction of speculative cosmological scenarios, which posit regions or epochs of our universe for which we presently have no observable evidence. Nonetheless we must insist on taking seriously only scenarios and hypotheses that make falsifiable or strongly verifiable predictions, otherwise people can just make stuff up and the distinction between science and mythology becomes porous. ...there are already candidate solutions that make real, falsifiable predictions.

The hypothesis underlying all approaches to the landscape is that there is a cosmological setting in which different regions or epochs of the universe can have different effective laws. This implies the existence of spacetime regions not directly observable... These regions must either be in the past of our big bang, or far enough away from us to be causally unrelated.

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