Wednesday, June 05, 2013

Interview With David Gross

Wired as an interview with Nobel Laureate David J. Gross.

I think the title of the piece is misleading. It seems that he is urging more of a 'revolution' in theoretical physics, not ALL of physics.

These days, Gross enjoys challenging young physicists as they chalk equations at the Kavli Institute for Theoretical Physics, the think tank funded by the National Science Foundation that he ran from 1997 until stepping down last year. He is eager for younger scientists to surpass his achievements, to break the impasse of under-determination that currently troubles particle physics, whereby competing theories predict the same physical results and may therefore be immune to experimental verification within the lifetime of the universe.

Gross characterizes theoretical physics as rife with esoteric speculations, a strange superposition of practical robustness and theoretical confusion. He has problems with the popularizing of “multiverses” and “landscapes” of infinite worlds, which are held up as emblematic of physical reality. Sometimes, he says, science is just plain stuck until new data, or a revolutionary idea, busts the status quo. But he is optimistic: Experience tells him that objects that once could not be directly observed, such as quarks and gluons, can be proven to exist. Someday, perhaps the same will be true for the ideas of strings and branes and the holographic boundaries that foreshadow the future of physics.
He has an interesting, but not surprising, take on String theory:

Simons Science: Is it possible to falsify string theory/quantum field theory? Or is that a purely philosophical question?

Gross: The question of how we decide whether our theories are correct or wrong or falsifiable has a philosophical aspect. But in the absence of empirical data, can we really judge the validity of a theory? Perhaps. Can philosophy by itself resolve such an ontological quandary? I doubt it. Philosophers who contribute to making physics are, thereby, physicists!

Now, in the last century, great physicists such as Ernst Mach, Bohr and Einstein were also philosophers who were concerned with developing theories of knowledge. Einstein famously criticized Heisenberg for focusing only on observable entities, when there can be indirect evidence for entities that cannot be seen. It may be the same with string theory.


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