Ghost particles zipping through Antarctic ice.
Light-controlled neurons.
Molecules with twin “siblings.”
It sounds like science fiction, but each describes research that earned Nobel Prizes this past October – and the UC Irvine School of Physical Sciences forms a key part of the stories surrounding the Nobel-winning fields.
The late UC Irvine physicist and Nobel Laureate Frederick Reines co-discovered the neutrino in 1956. Also called ghost particles, neutrinos are subatomic particles that, though they’re the second-most abundant particle in the universe, are incredibly elusive. They almost never interact with other forms of matter, and can pass through a block of lead almost six trillion miles thick without ever interacting with another particle.
That’s why this year’s Nobel Prize in Physics is so notable: it went to a physicist (Francis Halzen of the University of Wisconsin, Madison) for spearheading the creation of the IceCube Neutrino Observatory, which, sitting in Antarctica at the South Pole, is a mile-scale instrument that detects neutrinos traveling from distant corners of the cosmos.
Steve Barwick, particle physicist in the UC Irvine Department of Physics & Astronomy, was instrumental in turning IceCube into a reality after he helped design and build an earlier Antarctic neutrino detector called the Antarctic Muon and Neutrino Detector Array (AMANDA).
“Soon after joining UCI, I became co-principle investigator along with Francis on AMANDA – the immediate predecessor of the IceCube experiment,” Barwick said. “We showed that instrumentation could be built to withstand the cold, installed in holes nearly a mile beneath the surface and could distinguish neutrinos from all the other signals that mimic neutrinos. Our team designed AMANDA to be ultra-reliable, given that the sensors were going to be trapped in the ice with no way to repair them.”
AMANDA demonstrated that the optical clarity of the ice was suitable for neutrino detection. “An Antarctic-based neutrino detector became feasible only after we measured that the ice was sufficiently transparent to the blue light generated by neutrino interactions,” Barwick said.
Barwick likened IceCube to the telescope designed by Galileo Galilei, the Italian astronomer who helped reveal that Earth and the other planets revolve around the sun.
“Galileo’s telescope, which revolutionized our understanding of our solar system and humanity’s place within it, was only six inches in diameter. Now, more than 400 years after Galileo, telescopes have grown to 33 feet in diameter, are located all over the planet and even in space. You can think of IceCube as being at the same pioneering stage as Galileo’s telescope, and one can only wonder where we will be 400 years from now.”
Another subatomic particle – the photon, or light – is the subject of the Nobel Prize in Physiology or Medicine, which went to three researchers (Karl Deisseroth of The Howard Hughes Medical Institute at Stanford University; Peter Hegemann of the Humboldt University of Berlin in Germany; Georg Nagel of the University of Wüzburg in Germany) whose work in a field called optogenetics reveals how light can alter neurons in the human brain.
It’s science that’s the purview of the lab of Professor Krzysztof Palczewski in the UC Irvine Department of Chemistry. “In my laboratory, we concentrate on native mammalian visual opsins — light-sensitive proteins in the eye found in retinal rod and cone cells — along with visual cycle biochemistry and the mechanisms underlying blinding retinal diseases,” Palczewski said. “Our goal is to understand, prevent and treat inherited retinal degeneration and macular degeneration through structural biology, small-molecule therapeutics and targeted genome editing.”
By contrast, Palczewski explained, optogenetics employs microbial opsins to introduce synthetic light sensitivity into cells that do not naturally respond to light, such as neurons in the brain. The two fields converge in the area of vision restoration: When advanced retinal disease destroys photoreceptors, optogenetic techniques can introduce genes into surviving retinal cells and convert them into surrogate photoreceptors – something that can offer a pathway to restore visual perception.
“This award powerfully illustrates the value of curiosity-driven basic science,” Palczewski said. “Hegemann and Nagel were originally studying single-celled pond algae simply to understand how these simple organisms navigate toward sunlight for photosynthesis. No one set out to invent a brain-control technology; yet that fundamental curiosity about light-gated algal channels ultimately produced the most versatile neurotechnology of our era.”
In nature, some molecules like amino acids exist as mirror image versions of one another. This phenomenon, called chirality, earned two researchers (Henri Kagan of Université Paris-Sud in France and Kenso Soai of the Tokyo University of Science) the 2026 Nobel Prize in Chemistry because they were able to synthesize the mirror version of molecules that are integral for biological processes in humans – something with implications for the development of things like pharmaceuticals.
Professor Vy Dong’s lab in the UC Irvine Department of Chemistry – home of the late UC Irvine radiochemist and Nobelist F. Sherwood Rowland – specializes in chirality.
“Chirality is our lab’s favorite topic,” Dong said. “We drew on Kagan’s early asymmetric hydrogenation work in our synthesis of dichotomin E – a cyclic peptide found in plants.”
Dichotomin E is a natural product isolated from the roots of Stellaria dichotoma var. lanceolata, a plant in the chickweed family. It’s what chemists call a cyclic peptide: five amino acids joined into a ring, rather than a straight chain. That ring – and the precise three-dimensional arrangement of its amino acids – can strongly influence biological activity.
Dichotomin E, Dong explained, has shown an ability to inhibit the growth of mouse leukemia cells in laboratory experiments. “That’s an intriguing early biological observation, not evidence that it treats cancer in people,” she said.
Dong’s group used a method pioneered by Kagan to synthesize dichotomin E with the correct three-dimensional structure. “This illustrates how fundamental advances in catalysis make it possible to construct and study complex molecules found in nature,” she said.“I love that Kagan and Soai were honored for showing how a tiny preference for one molecular hand can grow into a powerful one. Their fundamental discoveries help chemists make medicines with greater precision and explore why life uses one mirror-image form, from amino acids to DNA.”