There is likely a deep connection between the study of quantum foundations on the one hand, and the much sought after quantum theory of gravity on the other. Despite the enormous success of quantum theory, there are issues in our understanding of the theory, which need addressing. These include: the nature of the quantum to classical transition, the peculiar nature of quantum non-locality, the problem of time in quantum theory, the extreme dependence of the theory on its own classical limit, and the physical meaning of the wave function. Could it be that addressing these issues requires us to reformulate / modify quantum theory, in such a way that we get rid of the theory's dependence on its own limit, and on classical space-time? If that is the case, then introducing non-classical space-time in quantum theory naturally leads us to a falsifiable quantum theory of gravity. This is the viewpoint developed in the ongoing video lecture series `Thinking about Quantum Gravity'. The lectures are addressed to those undergraduate and graduate students in physics who would like to research in quantum gravity. It is not expected that the viewer will agree with everything that is said in these lectures. Rather, it is hoped that you will find something to think about, as you develop your own thinking towards quantum gravity.
[youtube: -TleM9cGBK4, 560, 315]
The first video is available on YouTube and every video gives the link to the next one. Your comments and criticisms will be greatly appreciated. Thank you.
Updated on August 16, 2019: A new quantum theory of gravity has now been developed, based on these ideas. The theory is called Non-commutative Matter-Gravity, and unifies matter fermions with space-time geometry, by introducing the new concept of an atom of space-time-matter. Details are available in the paper at
A new quantum theory of gravity
Update 22nd November, 2019
New Blogspot: Schrodinger's cat, and Einstein's space-time, in the 21st century
--
Tejinder P. Singh
Tata Institute of Fundamental Research, Mumbai