A physicist working on the mathematical structure of general relativity. His review with David Garfinkle explains why the Penrose singularity theorem changed the understanding of gravitational collapse: a trapped surface, together with the theorem’s causal and energy assumptions, forces geodesic incompleteness. The conclusion does not depend on choosing an exactly spherical model of a collapsing star. Their account distinguishes the theorem’s precise mathematical conclusion from an informal claim that a particular curvature quantity must diverge.^[ref]

A physicist who uses numerical relativity to study strong gravitational fields, especially curvature singularities and gravitational collapse. His simulations test how the Einstein field equations behave close to a singularity, including whether the behavior found in symmetric models survives when symmetry restrictions are removed.^[ref]

With José M. Martín Senovilla, he reviewed how the Penrose singularity theorem connects gravitational collapse with geodesic incompleteness.^[ref]

An experimental optical physicist who coauthored a single-beam gradient-force optical trap for dielectric particles. A tightly focused laser creates a restoring force toward the high-intensity region, allowing a small particle to be held without mechanical contact. The work helped establish optical manipulation as a practical way to control microscopic objects.^[ref]

A physicist who, with P. J. E. Peebles, calculated the evolution of primordial density fluctuations through cosmological recombination. Integrating the photon collision equation treated the transition between tightly coupled radiation and matter and freely propagating radiation. The calculation linked an assumed initial power spectrum to later density structure and residual radiation anisotropy.^[ref]

Giorgio Parisi developed a hierarchical description of spin glass order in mean-field theory. The large number of competing low-energy states requires more information than one scalar order parameter: the replica construction uses an infinite hierarchy, related to overlaps between states. This organizes complex collective behavior arising from frustrated interactions and disorder. The result is a specific mean-field solution strategy, rather than an assumption that every disordered material has an identical phase structure.^[ref]

A physicist who researched spin glasses and became a professor of theoretical physics in Rome in 1981.^[ref]

A theoretical physicist who, with Philip Warren Anderson, developed a description of spin glasses using an order parameter based on persistent local-spin correlations. A material can lack a net magnetization while individual spins retain memory of their orientation. Edwards's own account connects this problem with ideas from disordered polymer networks and explains the use of replicas in calculating thermodynamic behavior.^[ref]

A physicist who researched spin glasses and became Oxford’s Wykeham Professor of Physics in 1989.^[ref]

A physicist who researched spin glasses and held a professorship in the physics of metals at Leiden.^[ref]

Francis Halzen initiated IceCube, using a large volume of Antarctic ice as a medium for neutrino detection. Optical modules record Cherenkov radiation from secondary charged particles. Their arrival times and detected light allow reconstruction of a particle's direction and deposited energy. Because atmospheric particles also produce signals, identifying cosmic neutrinos requires event selection and explicit background estimates. The instrument connects high-energy particle with observations of distant astrophysical sources.^[ref]

A physicist who initiated IceCube and researched particle, astrophysics and cosmology.^[ref]

An experimental physicist who, with John A. Mydosh, studied magnetic ordering in gold-iron alloys. Measurements of thermoelectric power and low-field magnetic susceptibility across iron concentrations linked transport anomalies with changes in magnetic behavior. Sharp susceptibility features provided a way to track ordering in a chemically disordered material, motivating the study of competing interactions in spin glasses.^[ref]

Pierre Agostini coauthored the measurement of a train of attosecond optical pulses synthesized from high harmonic generation. Measuring only the harmonic intensities does not determine the pulse train: the relative spectral phases are also needed. Their two-colour photoionization measurement recovered those spectral phases, giving reconstructed peaks about 250 attoseconds wide. This joined generation with a measurable test of temporal structure, rather than inferring a short pulse solely from a broad optical spectrum.^[ref]

A physicist researching high harmonic generation and interactions between lasers and matter.^[ref]

Ferenc Krausz coauthored a 2001 demonstration of attosecond timing using photoionization. A synchronized visible electric field changes the energy distribution of photoelectrons released by a soft-X-ray optical pulse. Scanning their relative delay converts an otherwise inaccessible time interval into a measured electron spectrum. The report inferred a soft-X-ray duration of $650\pm 150$ attoseconds and demonstrated an instrument for probing electron dynamics on that scale.^[ref]

A physicist who leads research in attosecond physics.^[ref]

Klaus Hasselmann explained how rapid, irregular weather fluctuations can generate slow climate variability. His 1976 Hasselmann stochastic climate model separates fast atmospheric variables from more slowly responding components such as the ocean and cryosphere, retaining the fluctuating forcing that simple time averaging would discard. Slow components integrate that forcing; stabilizing climate feedbacks prevent the variance from growing without bound. This supplies a mechanism for internally generated variability even when the external conditions do not vary.^[ref]

A physicist who developed stochastic climate models and founded the Max Planck Institute for Meteorology in 1975.^[ref]

Alain Aspect, Jean Dalibard and Gérard Roger tested Bell inequalities using pairs of photons and rapidly changing polarization analyzers. An acousto-optical switch in each arm routed light toward one of two polarizers; switching near $50\mathrm{MHz}$ changed the effective setting on a timescale shorter than the photon transit time between the analyzers. The measured correlations violated the tested Bell inequality. These switches were driven at incommensurate frequencies, so their role should be distinguished from the independently randomized settings of later experiments.^[ref]

A physicist researching quantum optics and the foundations of quantum mechanics.^[ref]

Dik Bouwmeester coauthored the 1997 optical demonstration of quantum teleportation. A joint Bell-state measurement on an input photon and one member of an entangled pair conditionally transferred the input polarization quantum state to the other member. The reported experiment selected a particular detected outcome. The process consumes the shared entanglement and requires classical information about the measurement result; it does not send a usable message faster than light.^[ref]

A physicist researching quantum optics and quantum information science.^[ref]

Harald Weinfurter coauthored the preparation and observation of three-photon GHZ states. The experiment combined two entangled photon pairs and selected appropriate coincidence detections, producing a conditional three-photon quantum state with polarization correlations beyond those of independent pairs. Its value was to make a genuinely multipartite entangled state available to direct measurement.^[ref]

A physicist who holds an experimental quantum-physics chair at LMU Munich.^[ref]

Anton Zeilinger coauthored an experiment preparing GHZ states of three spatially separated photons. The distinguishing feature is the quantum coherence between the two three-photon alternatives: recording the same populations alone would also be compatible with an incoherent mixture. Measurements in additional polarization bases tested this distinction, making three-party entanglement an experimental resource for investigating local realism.^[ref]

A physicist researching quantum optics and quantum foundations.^[ref]

An experimental optical physicist who coauthored attosecond pulse measurements. Combining a short extreme-ultraviolet excitation with a synchronized optical field lets emitted photoelectrons carry information about the pulse's timing. This makes a subfemtosecond optical event measurable through an electron-energy distribution rather than by an electronic stopwatch.^[ref]

John M. Martinis coauthored a 1985 observation of quantized energy levels in a current-biased Josephson junction. The relevant coordinate was the phase difference across an electrical circuit element, rather than the position of one isolated particle. The measured levels agreed with a quantum mechanics calculation using junction parameters measured in the classical regime. This showed that a fabricated superconducting circuit could possess a discrete excitation spectrum suitable for controlled quantum experiments.^[ref]

A physicist researching superconducting devices and quantum computers based on Josephson junctions.^[ref]

Stanley Block coauthored a pressure-measurement method using the sharp fluorescence lines of ruby inside a diamond anvil cell. Compression shifts the line energies, allowing a tiny optical marker to report pressure in a region inaccessible to an ordinary mechanical gauge. Calibration turns that spectral shift into a quantitative pressure reading. Line broadening can also reveal departures from uniform hydrostatic compression, so the spectrum contains information about the measurement conditions as well as the mean pressure.^[ref]

A physicist who led crystallographic research and developed ruby fluorescence pressure measurements.^[ref]