“What you’re seeing here is an interesting thing…This whole holographic story is the most radical thing that has happened to our understanding of space, time, matter, since the invention of quantum mechanics and relativity.” —Leonard Susskind
This weekend is the 5th annual World Science Festival in New York, whose mission is “to cultivate a general public informed by science, inspired by its wonder, convinced of its value, and prepared to engage with its implications for the future.” In five years it has become one of the premier settings in the United States for the public to engage with science — complete with long lectures, panels, a street fair, and spectacular and esoteric demonstrations of science in action and scientists “at work”.
Last year’s program included a cosmology and physics lecture that caught my eye — a panel on the holographic principle in string theory titled A Thin Sheet of Reality, featuring four of the key contributors of this new speculative theory, Raphael Bousso, Gerard ’t Hooft, Leonard Susskind, and Hermann Verlinde. Briefly, the holographic principle states that all of three-dimensional reality can be described as a two-dimensional sheet or surface of information that extends to the limits of the observable universe, what Bousso calls “a universal relation between geometry [surface area] and information” in spacetime. For now, the caveat is that the holographic principle gives physicists an absolute measure of the quantity of information in a region of space, but the exact form and quality if that information is totally unknown — imagine storing a Whitney Houston (RIP) song on your computer, but then losing that MPEG algorithm that tells the computer how to decode the 0’s and 1’s into soaring vocals and black turtleneck sweaters. The goal for Bousso, ’t Hooft, Susskind, and Verlinde has been to resolve the Hawking black hole information paradox — that quantum information about energy and matter is irretrievably lost inside of a black hole — and in so doing present a unified theory of gravitation, matter, and energy.
If all of this sounds absolutely bat-shit-insane, then you should definitely set aside 90 minutes and watch the panel talk. However, this talk is not just an introduction to a physical theory given by any ordinary physics professor, but also an historical discussion of the development of the theory as told by the physicists who came up with it! Seen this way, lots of cool issues that historians of science might call “science and the public” start to jump out. The first thing is seeing theoretical physicists try to describe a non-intuitive theory to a totally lay audience without mathematics: it takes about an hour for any of it to finally make much sense!
Aside from personal tales of how physics works from the inside (like trying and failing to have an argument with Stephen Hawking), the really good stuff comes at the end of the panel, when the moderator prompts Bousso, ’t Hooft, Susskind, and Verlinde to share their vision of where the holographic principle is going, and why it might be important. ’t Hooft’s imperatives especially, to “ask nasty questions,” are interesting in just how basic his demands are: the restoration of causality and determinacy to quantum mechanics, the subsequent elaboration of the holographic principle to account for dynamics and change over time, and perhaps even a “pre-quantum theory” that describes classical, relativistic, and quantum physics in general! Susskind’s response is classic: “I wouldn’t bet on it!”
Additional reference: Bousso, Raphael (5 Aug 2002). "The holographic principle". Review of Modern Physics 74 (3): 825–874. arXiv:hep-th/0203101. Bibcode2002RvMP...74..825B. doi:10.1103/RevModPhys.74.825