52 Scientific American, August 2020I am sitting alone at the head of a large conference table when
an oddly familiar voice greets me: “Hey, you must be Spiros!” I turn around to find Paul Rudd,
the Hollywood actor, wearing his famed disarming smile. He is in sweats, on his way back fromsome type of superhero training.
A few minutes later he and a bunch of other film people are sit-
ting around me. Rudd cuts straight to the chase: “So what kinds
of cool things happen when you shrink?” I have been flown in to
consult on the physics of Marvel Studios’ superhero flick Ant-Man,
and now I must deliver. Yet all I really know about shrinking to
ant size comes from watching Honey, I Shrunk the Kids! as a nine-
year-old. For a moment, I consider telling him that he’s got the
wrong guy, but there is no way I am going to let this opportunity
slip between my fingers. I may not know much about ants, but I
know a thing or two about quantum physics. “The concepts of time
and space lose their usual meaning when you shrink to the quan-
tum scale,” I reply with confidence. Reading the room, I can tell
that this is the last thing they expected to hear. But they are hooked.
The floor is mine for the next two hours, as I delve deeper and
deeper into the rules and weirdness of quantum mechanics.
A day later one of the producers e-mails me: “Hey, what should
we call the place you enter when you shrink to microscopic size?”
I type back: “How about the Quantum Realm?” Five years later,
in 2019, Marvel’s Avengers enter the Quantum Realm and travel
back in time to save the universe. All of a sudden, being an expert
in quantum physics seems pretty cool.
I was not always into physics or comic-book heroes. In college,
I majored in mathematics and computer science, spending my
summers trying to predict how one-dimensional DNA sequenc-
es folded into three-dimensional proteins. It was not until grad-
uate school that I took my first physics class beyond the basic col-
lege requirements. My Ph.D. adviser at the University of Califor-
nia, Davis, had decided to enroll me in graduate-level quantum
mechanics, and I had no choice but to go along with it. When on
the first day of class we were handed a one-page undergraduate-
level assessment test, I returned mine with my name and a smi-
ley face next to it. Still, I persisted, graduating in June 2008 with
a doctorate in applied mathematics and an emphasis on mathe-
matical physics and quantum information theory. Three months
later I would pack my things and move to Los Alamos, N.M., the
birthplace of the atomic bomb, to take a postdoctoral position at
Los Alamos National Laboratory. I did not know it at the time,
but during the next year I would delve deep within the quantum
realm. This is the story of what I discovered there and how I made
it back to tell Marvel the story.SOMETHING INTERESTING
It all began wIth a sImple questIon.
My adviser at Los Alamos, Matthew Hastings, a rising star and
one of the sharpest minds in physics, was sitting across from me
at a sushi restaurant when he popped the fateful question: “For
your postdoc here at the lab, do you want to start with a warm-
up, or do you want to work on something interesting?” Without
asking for further clarification, I answered, “I want to work on
something interesting.” He seemed pleased with my answer. Lat-
er that day he sent me a link to a list of 13 unsolved problems in
physics maintained by Michael Aizenman, a professor at Prince-
ton University and a towering figure in mathematical physics. I
was to work on the second problem on that list, a question posed
by mathematical physicists Joseph Avron and Ruedi Seiler: “Why
is the Hall conductance quantized?”
You may wonder what the Hall conductance is or what it
means for it to be quantized. I had the same questions back then.
No problem on the list besides the third—cryptically titled “Expo-
nents and Dimensions”—had “SOLVED!” next to it. ClickingIN BRIEFThe quantum Hall effect is a macroscopic phenom-
enon involving electric current across a conducting
surface that exhibits quantization—traditionallyreserved for the microscopic quantum realm.
Explaining why this effect is quantized had been
named a major unsolved problem in physics.Recently mathematical physicists answered the
question in a proof relying on topology—the study
of the properties of shapes.Spyridon Michalakis is a mathematical physicist
and manager of outreach for the Institute for
Quantum Information and Matter at the California
Institute of Technology.© 2020 Scientific American © 2020 Scientific American