PSW Science

Jun Ye discusses how laser science and increasingly large coherent quantum systems are expanding precision measurement into nuclear physics. Experiments now maintain coherence in thousands of atoms for minutes and resolve quantum states of the thorium-229 nuclear transition. A vacuum-ultraviolet frequency comb enables coherent excitation of that transition and connects its frequency directly to a highly precise atomic clock. The lecture examines how this connection between atomic and nuclear measurement could support new tests of fundamental physics and nuclear clocks containing billions of absorbers, with the prospect of surpassing the timekeeping capabilities of existing atomic clocks.

Francis Halzen explains how the IceCube telescope uses detectors buried deep in Antarctic ice to observe high-energy neutrinos from the cosmos. The lecture describes construction of the observatory, the measurement of particle energies and directions, and the distinction between atmospheric backgrounds and neutrinos arriving from distant astrophysical sources. It connects the discovery of cosmic neutrinos with the search for the powerful accelerators that produce cosmic rays. Examples include the association with a flaring blazar and evidence identifying the active galaxy NGC 1068 as a neutrino source. Halzen discusses the role of rotating supermassive black holes, coordination with other observatories, and prospects for extending the detector.

Olivier Guyon explains the physics and engineering of extreme adaptive optics for directly imaging exoplanets. Atmospheric turbulence distorts incoming wavefronts; sensors measure those distortions and deformable mirrors apply compensating corrections. The lecture covers guide stars, fast detectors, actuators, real-time computing and control systems. Extreme adaptive optics requires correction rates above a kilohertz, mirrors with more than a thousand actuators and nanometer-scale measurements of optical aberrations. Guyon describes how integrated systems suppress and calibrate unwanted starlight, including approaches developed with the Subaru Extreme Adaptive Optics system. These advances support efforts to equip extremely large telescopes to image potentially habitable planets.

Eric Verdin examines advances in the biology of aging and their potential application to human health. The lecture distinguishes lifespan from healthspan and considers how research on aging mechanisms can inform the diagnosis and treatment of chronic diseases associated with getting older. Against the background of aging populations, Verdin explores the underlying causes of biological aging, the contributions of genetics and lifestyle, and approaches being investigated to extend healthy longevity. The discussion connects mechanistic research with the question of how a longer life can include more years of good health.

Henrik I. Christensen examines the scientific and engineering challenges involved in building intelligent robots that assist people. Advances in materials, embedded systems, sensors and machine learning support new combinations of perception, planning and actuation. The lecture considers the models underlying robot perception, planning and control, and how these components must be integrated into useful systems. Applications include customized manufacturing, transportation, security, support for older people and people with disabilities, and safer work for first responders in dangerous environments. Christensen discusses major research trends and the potential influence of these systems on work, home and leisure.

Gerald Joyce explores attempts to reconstruct features of RNA-based life in the laboratory. Under the RNA world hypothesis, early organisms used RNA to store information and catalyze replication before the emergence of DNA genomes. Directed evolution has produced RNA enzymes that copy diverse templates, synthesize structured and catalytic RNAs, and amplify short templates in an RNA-catalyzed analogue of the polymerase chain reaction. A variant can make DNA from an RNA template, suggesting a possible route between RNA and DNA genomes. Joyce also describes cross-chiral enzymes that synthesize RNA of opposite handedness and can assemble their own enantiomers from fragments. The lecture examines these complementary approaches to replicating functional RNA, their relevance to the origins of life, and potential diagnostic and clinical applications.