Major Contibution to Physics
His main contributions have been so far to the quantum theory of gravity, to which he has been a co-inventor and major contributor to two major directions, loop quantum gravity and deformed special relativity. He also contributes to cosmology, through his proposal of cosmological natural selection: a falsifiable mechanism to explain the choice of the laws of physics. He has also contributed to quantum field theory, the foundations of quantum mechanics, theoretical biology, the philosophy of science and economics. He is the author of more than 150 scientific papers and numerous essays and writings for the public on science.
The loop quantum gravity is important because is a theory that attempts to describe the quantum properties of the universe and gravity. It is also a theory of quantum space and quantum time because, according to general relativity, the geometry of spacetime is a manifestation of gravity. It has the same nature as the granularity of the photons in the quantum theory of electromagnetism or the discrete levels of the energy of the atoms. Here, it is space itself that is discrete. In other words, there is a minimum distance possible to travel through it.