The Future of Fundamental Physics

I share with my readers the ideas about physics of this distinguished theoretical physicist Nima Arkani-Hamed

The principle text can be found in this pdf file. I have extracted the quotes below from this paper in order to provide you with a guide to what the principle themes Nima Arkani-Hamed is promoting. The text speaks for itself.

Quotes:

“Abstract:

Fundamental physics began the twentieth century with the twin revolutions of relativity and quantum mechanics, and much of the second half of the century was devoted to the construction of a theoretical structure unifying these radical ideas. But this foundation has also led us to a number of paradoxes in our understanding of nature. Attempts to make sense of quantum mechanics and gravity at the smallest distance scales lead inexorably to the conclusion that space-time is an approximate notion that must emerge from more primitive building blocks. Furthermore, violent short-distance quantum fluctuations in the vacuum seem to make the existence of a macroscopic world wildly implausible, and yet we live comfortably in a huge universe. What, if anything, tames these fluctuations? Why is there a macroscopic universe? These are two of the central theoretical challenges of fundamental physics in the twenty-first century. In this essay, I describe the circle of ideas surrounding these questions, as well as some of the theoretical and experimental fronts on which they are being attacked…”

“…But there is a deeper reason to suspect that something much more interesting and subtle than “atoms of space-time” is at play. The problems with space-time are not only localised to small distances; in a precise sense, “inside” regions of space-time cannot appear in any fundamental description of physics at all…”

“…The fact that quantum mechanics makes it impossible to determine precisely the position and velocity of a baseball is also irrelevant to a baseball player. However, it is of fundamental importance to physics that we cannot speak precisely of position and momentum, but only position or momentum…”

“…This simple observation has huge implications. As discussed above, precise observables require a separation of the world into a) an infinitely large measuring apparatus and b) the system being studied…”

“…It should be clear that we have arrived at a bifurcatory moment in the history of fundamental physics, a moment that has enormous implications for the future of the subject. With many theoretical speculations pointing in radically different directions, it is now up to experiment to render its verdict!…”

“…Today, however, we confront even deeper mysteries, such as coming to grips with emergent time and the application of quantum mechanics to the entire universe. These challenges call for a bigger shift in perspective. Is there any hope for taking such large steps without direct input from experiment?…” [Emergent time relates to the concept of ‘NOW’ and its associated simultaneity].

“…Why should it be possible to talk about Newton’s laws in such a different way, which seems to hide their most essential feature of deterministic evolution in time? [Which I agree with] We now know the deep answer to this question is that the world is quantum-mechanical…”

“…There must be a new way of thinking about quantum field theories, in which space-time locality is not the star of the show and these remarkable hidden structures are made manifest. Finding this reformulation might be analogous to discovering the least-action formulation of classical physics; by removing space-time from its primary place in our description of standard physics, we may be in a better position to make the leap to the next theory, where space-time finally ceases to exist…”

Also see my blog entitled “The emerging crisis in physics. Will physics soon need to take a new course of direction?