The Quest for New Physics Beyond Einstein and the LHC

By Jennifer Ouellette on at

All eyes are currently on the upgraded Large Hadron Collider as it ramps up its hunt for new physics. But some physicists are already looking beyond and pinning their hopes on an even bigger machine, four times the size of the LHC. One of them is Nima Arkani-Hamed, the subject of a recent extensive profile by Natalie Wolchover at Quanta.

Much of the article focuses on Arkani-Hamed’s championing of a controversial proposal to build the world’s largest particle accelerator in China — reaching energies of 100-TeV — in hopes of spotting evidence of something exciting beyond the so-called Standard Model (evidence for supersymmetric particles, perhaps, or for extra dimensions). It’s controversial mostly because of the staggering price tag — and the fact that even with such a large, powerful machine, it might still not be enough to yield the answers physicists seek. So particle physics is at a bit of crosswords. (As LHC physicist Joe Incandela told Quanta, “We all feel like this can’t be the end. We’ve got to take it one more step.”)

But Arkani-Hamed also made waves back in 2013 when he and one of his students, Jaroslav Trnka, introduced a bizarre geometric object they dubbed an “amplitudehedron.” As Wolchover writes:

They uncovered a multifaceted geometric object whose volume encodes the outcomes of particle collisions — beastly numbers to calculate with traditional methods. The discovery suggested that the usual picture of particles interacting in space and time is obscuring something far simpler: the timeless logic of intersecting lines and planes. Although the “amplituhedron” ... initially described a simplified version of particle physics, researchers are now working to extend its geometry to describe more realistic particle interactions and forces, including gravity.

One Physicist's Quest for New Physics Beyond Einstein and the LHC

It’s all the personal details Wolchover digs up that makes Arkani-Hamed come alive, particularly his family’s harrowing escape from Iran during the reign of the Ayatollah Khomeini, when he was only 10. (He nearly died of a high fever en route between Iran and Turkey; the family was rescued by Kurdish nomads and eventually landed in Canada.)

We learn about his precocious high school and college years; his voracious consumption of espresso and Coke Zero; his erratic sleeping schedule (“I sleep the way lions eat — very little for stretches of time, punctuated by huge and delicious feasts”); and his penchant for flouting parking rules during his tenures at Berkeley and Harvard.

Moving to Princeton’s Institute for Theoretical Physics apparently resolved his parking woes, but he still finds other ways to push against the boundaries. One of my favourite scenes in David Kaplan’s excellent documentary, Particle Fever, features Kaplan and Arkani-Hamed contemplating an outdoor sculpture garden at the ITP. Something about it bothers Arkani-Hamed — “It’s taking a lot of random things and making some order out of it.” — and eventually he just starts moving pieces around in search of a more philosophically pleasing configuration, the artist’s original intent be damned.

All in all, it’s a fascinating portrait of one of the top minds at the forefront of theoretical physics.

[Via Quanta]

[Images: (top) Beatrice de Gea/Quanta. (bottom) A sketch of the amplituhedron by Nima Arkani-Hamed.]