SSI Special Report: The Quigg
By Shawne Neeper and
(Photo by Shawne Neeper)
In his opening address
for the SLAC Summer Institute (SSI) entitled Nature’s Greatest Puzzles,
theorist Chris Quigg of Fermilab set the tone for two weeks’ worth of
exploration into ten of nature’s greatest physics questions. First, he
challenged attending scientists to describe how their current work
relates to one of the ten great questions—or is otherwise irresistibly
fascinating. Second, propose the eleventh puzzle.
“The spirit of those
opening remarks was partly that I’m uncomfortable with the idea of
‘great questions’,” Quigg said. On the one hand, he argued, it’s often
by asking small questions that scientists find clues to sweeping
ideas—as hot-air balloonist Hess’s curiosity about air conductivity led
him to propose the existence of cosmic radiation. “These people had no
idea they were answering a great question. They were just curious about
a small thing.”
On the flip side, Quigg
sought to stir SSI attendees’ imaginations about the broad implications
of their own experiments. “It’s very easy, especially when you’re a
student and are doing things because someone else told to you, to not
think about why the work is so interesting or important.”
Enter the Quigg
challenge. As homework, Quigg asked attendees to explain their work’s
importance to a Great Question in only a paragraph or two. Science
writers could be lurking behind any tree, Quigg warned; scientists had
best be prepared. He was right. Many participants later found themselves
facing a reporter’s notebook at SSI functions, and most had done their
“The world is made of
matter but not antimatter [Question 8] for no apparent reason,” said
SUNY Stonybrook graduate student Ilektra Christidi of her experiments in
rare particle decays. “So we want to explain how it happened” by
examining how different flavors of particles mix.
Nature’s Greatest Puzzles
1. Where and what is dark matter?
2. How massive are neutrinos?
3. What are the implications of the
4. What are the origins of mass?
5. Why is there a spectrum of
6. Why is gravity so weak?
7. Is nature supersymmetric?
8. Why is the Universe made of
matter and not anti-matter?
9. Where do ultra-high-energy cosmic
rays come from?
10. Did the Universe inflate at
“If inflation occurred
at all [Question 10], it was at energies that we wouldn’t be able to
probe with present [high-energy physics] technologies,” said Caltech
graduate student Tristan Smith. His thesis project explores how future
experiments in NASA’s Beyond Einstein program could measure faint
ripples in the geometry of space—proof that inflation did take place.
“That would tell you how the large-scale structures of the
universe—galaxies, clusters of galaxies—formed.”
One of the mysteries of
neutrinos is exactly how heavy they are [Question 2]. University of
Kentucky’s Susan Gardner is trying to improve estimates on their mass by
looking at tritium decay. The ultimate goal? “There is an intrinsic joy
in human understanding,” she said, quoting Latin poet Lucretius: “Happy
is he who understands the nature of things.”
The next leap in
understanding nature was the focus of the second—but also
eleventh—challenge. In his opening address, Quigg presented a list of
ten great physics puzzles, from CP violation to the flat universe, and
challenged his audience to come up with an eleventh. Quigg received 37
entries from SSI’s array of physicists, students, university faculty and
someone claiming to be George Bush.
The winning entry won
neutrino theorist Yasaman Farzan a bottle of Iron Horse Brut California
sparkling wine, signed by SLAC director Jonathan Dorfan and other
physics noteworthies. Honorable mention and a copy of Peter Galison’s
Einstein’s Clocks, Poincare’s Maps: Empires of Time went to Marco
Zanetti, a student at Padova University in Italy, for his question about
time, and to Thomas Topel, a Colorado State graduate student, for his
question about symmetry breaking in grand unified theories.
On August 11, Farzan
presented an 11-minute talk on her eleventh great question, Is the
Lorentz invariance exact? Lorentz invariance—a principle of special
relativity—states that laws of physics are identical for observers
moving at constant velocity relative to each other. “Hopefully in the
future we will learn that this is not the final word, and we will find
something even stranger,” said Farzan, who will defend her Ph.D. thesis
at the Sissa Institute in Trieste, Italy in October, “and this will help
us to revolutionize physics again.”
For further information
on SSI, see:
For more on the 11th
Challenge entries, see: