Lisa Randall is one of the world's leading theoretical physicists. And she has done the rest of us blockheads the favor of putting some of her big ideas in plain English in a pair of general-audience books, Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions (2005) and more recently, Knocking On Heaven's Door: How Physics and Scientific Thinking Illuminate the Universe and the Modern World (2011).
WEIGHING IN Randall.
Randall, a Harvard professor, is due to speak at the RISD Auditorium February 2 at 7:30 pm as part of "Shared Voices: The RISD Presidential Speaker Series." All the tickets for the event are reserved, but the public can register at sharedvoices.risd.edu to attend a free simulcast at the Chace Center's Metcalf Auditorium at 20 North Main Street (preference will be given to RISD students, faculty, staff, alumni, and trustees).
The lecture will also be streamed live on the site and available to watch on demand a couple of weeks later. The final speaker in the series, Wired magazine co-founder Kevin Kelly, appears March 14. All of the tickets for his talk are already reserved, too, but the public can get on the ticket waiting list on the site.
We caught up with Randall, lecturing in Europe, for a Q&A via email. Her responses are lightly edited for clarity.
EXPLAIN, IN LAYMAN'S TERMS, THE CONCEPT OF "SCALES" IN PHYSICS AND HOW IT MIGHT AFFECT THE WAY WE VIEW THE WORLD. Scales in physics refers to many things, but two of the most important in particle physics are distance and energy. As engineers and scientists develop better technology, people explore regions that were previously inaccessible. That allows us to discover that the nature of matter itself can change at different scales. For example, the world of an atom looks nothing like the table I'm writing on. And the world of the nucleus, and quarks inside that is very different from that of the atom. The ingredients change and the ways in which we efficiently describe them, too, as we probe deeper into the inner core of matter.
The interesting thing is that the description on larger scales is still valid. We just learn that it is an approximation — one that is completely adequate until you have [enough] precision or resolution to see the description fail.
YOU WRITE ABOUT THE SCIENTIFIC WAY OF THINKING AND YOU'VE SUGGESTED IT MIGHT HAVE CAUGHT THE WALL STREET IMPLOSION BEFORE IT HAPPENED. HOW? It's always too easy to say things could have been anticipated so I won't necessarily make such a strong statement. But I do think for example that uncertainties — a crucial aspect of scientific understanding — were underestimated. When risk was computed, people looked back in time over the previous 10 years, and asked what their methods would predict using that data. But the 10-year period was not long enough to see all possible fluctuations and changes. In physics, when we estimate the reliability of our results, it's crucial to state clearly the underlying assumptions and the underlying parameters and how well we know them. That way we know under which conditions the predictions hold. It's not clear this was always done on Wall Street.