Massachusetts Institute of Technology

Project Title

Quantum Space II

Project Summary

In the beginning of the last century theoretical physics was revolutionized with the emergence of quantum mechanics and Einstein's theory of general relativity. These theories have been extremely successful in explaining nature at very small scales and at very large scales. However, two problems have remained open since the inception of these theories. One problem concerns the foundations of quantum mechanics. Although quantum mechanics is so successful it is still fundamentally unclear how to relate the theory to the classical world around us. Quantum mechanics, in principle, allows for states of nature in which the same large object is in two places at once. This means we need a reason why we have not seen such states. In our proposal, we give such a reason by proposing a new relation between the classical world and the quantum world. The other problem concerns the union of quantum mechanics and general relativity. These two theories have been around for nearly a century but we still have no way of combining them. We are lacking a quantum theory of gravity. We propose such a theory by providing a new mechanism for the emergence of gravity. No propagation without gravitation is the basic principle behind our approach.

Technical Abstract

The research in this proposal is concerned with the foundations of quantum mechanics and with quantum gravity. On the first subject, we argue that three misguided steps in the standard understanding of quantum mechanics prevent us from solving the measurement problem. The first step is the notion of classical objects. We argue that the classical world can be understood as consisting of special quantum mechanical states. The second step is the tension between the deterministic nature of the Schroedinger equation and the observed probabilistic nature of quantum mechanics. We show that with our definition of classicality probability is a necessary consequence. The last step is that we assign properties to microscopic objects that they cannot have. We show that these three steps are the problems that make quantum mechanics so puzzling. Taken together our solutions to the three problems constitute a solution to the measurement problem. In quantum gravity we continue the program of internal relativity. We propose to derive geometry from the low-lying excitations of a solidstate system. We show how Newtonian gravity naturally arises in such a system. We furthermore propose to apply the theory to the early universe and show that we can reproduce the observed spectrum of the cosmic microwave background radiation.

Hide Technical Abstract

The research in this proposal is concerned with the foundations of quantum mechanics and with quantum gravity. On the first subject, we argue that three misguided steps in the standard understanding of quantum mechanics prevent us from solving the measurement problem. The first step is the notion of classical objects. We argue that the classical world can be understood as consisting of special quantum mechanical states. The second step is the tension between the deterministic nature of the Schroedinger equation and the observed probabilistic nature of quantum mechanics. We show that with our definition of classicality probability is a necessary consequence. The last step is that we assign properties to microscopic objects that they cannot have. We show that these three steps are the problems that make quantum mechanics so puzzling. Taken together our solutions to the three problems constitute a solution to the measurement problem. In quantum gravity we continue the program of internal relativity. We propose to derive geometry from the low-lying excitations of a solidstate system. We show how Newtonian gravity naturally arises in such a system. We furthermore propose to apply the theory to the early universe and show that we can reproduce the observed spectrum of the cosmic microwave background radiation.

Hide Technical Abstract

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