Lee Smolin is an American physicist and author of Three Roads to Quantum Gravity and The Trouble with Physics who co-authored with Sundance Bilson-Thompson two papers on how braids and twists may be the basic building blocks of atoms.
Quotes by Lee Smolin in Time One
There is no way we can have two theories of nature covering different phenomena, as if one had nothing to do with the other. Any claim for a final theory must be a complete theory of nature. It must encompass all we know.
SU(5) is the most elegant way imaginable of unifying quarks with leptons, and it leads to a codification of the properties of the standard model in simple terms. Even after twenty-five years I still find it stunning that SU(5) doesn’t work.
In this way, time is represented as if it were another dimension of space. Motion is frozen, and a whole history of constant motion and change is presented to us as something static and unchanging. If I had to guess (and guessing is what I do for a living), this is the scene of the crime.
No matter how smart she is, no matter how modern her methods and how tricky her reasoning, a detective cannot be a good detective unless in the end the bad guys are found out. It is the same with science.
The problem of how to make a theory of a whole universe is thus the problem of how to construct a theory without making any reference to anything that exists … outside of the system we are describing.
[N]o one has been able to construct a theory which is completely satisfactory as a unification of quantum mechanics and relativity. It is still not even clear whether this can be accomplished without a radical change in the basic principles of either, or both, theories.
According to general relativity every bit of the collapsed star and every particle that falls afterwards into the black hole will end up at a last moment of time, at which the density of matter and strength of the gravitational field become infinite.
One can … always ask, why is the universe where it is, rather than ten feet to the left, or rotated 30 degrees? Or, why did the universe not start five minutes later? This is sometimes called the problem of under-determination: nothing in the laws of physics answers the question of why the universe is where it is, rather than translated or rotated.
In science, detective movies, love or any other area of life, when one is confronted with a situation in which the old assumptions are no longer working as they used to, it is perhaps time to look for new questions to ask.
General relativity and supergravity, in any Spacetime dimension greater than or equal to 2 + 1, can be written as gauge theories, such that the configuration space is the space of a connection field, Aa, on a spatial manifold Σ. The metric information is contained in the conjugate momenta. The gauge symmetry includes the diffeomorphisms of a Spacetime manifold, usually taken to be Σ x R. The dynamics takes a simple form that can be understood as a constrained topological field theory. This means that the action contains one term, which is a certain topological field theory called BF theory, plus another term which generates a quadratic constraint.
Quantum cosmology is a controversial subject. There are approaches to quantum cosmology that take the mathematical structure of the theory to be the same as that of ordinary quantum mechanics. … All other approaches propose that the formal structure of quantum theory must be modified for the theory to be sensibly applied to cosmology.
The most popular theories, such as supersymmetry, have many more free parameters – the simplest supersymmetric extension of the Standard Model has 105 additional parameters. This means that the theory is unlikely to be tested in upcoming experiments.
Has physics reached an impasse, and what can we do about it? One source of the crisis is that many … theories have many freely adjustable parameters. As a result, some theories make no predictions at all.…