A physicist whose work finds simple mathematical systems exhibiting chaos. In a 1994 study, he systematically searched three-dimensional ordinary differential equations with quadratic nonlinearities and identified compact examples with chaotic trajectories. Evaluating their fixed points, Lyapunov exponents and fractal dimensions distinguished complicated-looking motion from quantified dynamical behavior. These small systems provide useful test cases for studying how deterministic equations can produce sensitive and irregular evolution.^[ref]

Marvin Minsky devised a microscopy apparatus using localized illumination and spatially selective detection. light from the chosen specimen point passes through the detection aperture, while much light from out-of-focus regions is rejected. Scanning that point builds an image with improved depth discrimination. His patent supplies an early physical design underlying confocal microscopy, linking the illumination geometry to which returning light is admitted to the detector.^[ref]

A researcher in optical engineering whose joint treatment of confocal microscopy connects instrument geometry with image formation. Source, specimen focus and detection pinhole occupy conjugate planes; scanning the illuminated region builds the image. The analysis explains how pinhole size trades light collection against depth discrimination, giving an optical basis for choosing an instrument setting.^[ref]

A researcher in optical imaging whose work with Brad Amos and Tony Wilson explains confocal optical sectioning. Their treatment connects depth discrimination with the combined illumination and detection point spread functions. It makes clear why the image depends on both focusing the exciting light and selecting which returning light reaches the detector.^[ref]

A researcher in optical microscopy whose joint account of confocal microscopy explains how illumination and detection are restricted to the same small volume. A pinhole rejects much of the light originating away from focus, while scanning assembles an image. This gives optical depth discrimination that helps separate structures overlapping in a conventional image.^[ref]

He helped develop laser-scanning confocal microscopes and designed instruments and production tooling for their manufacture.^[ref]

Barton Zwiebach's quantum-physics teaching derives probability current from the Schrödinger equation. Comparing the equation with its complex conjugate converts change of local probability density into the divergence of a flux. A wavefunction's spatial phase therefore determines motion that its magnitude alone does not reveal. The derivation connects a complex amplitude with conservation of total probability when no flux escapes through the boundary.^[ref]

A researcher whose joint work demonstrated surface imaging through quantum tunnelling. The experiment resolved atomic-scale steps and reconstructed surface arrangements with scanning tunneling microscopy, showing how a tiny current across a vacuum gap could serve as a local probe of surface structure.^[ref]

An experimental contributor to early scanning tunneling microscopy. The team used electron tunneling across a vacuum gap to image atomic-scale surface structure, including steps only one atomic layer high. This connected a highly distance-sensitive electrical signal with the geometry of a conducting surface.^[ref]

Heinrich Rohrer coauthored experiments controlling a vacuum gap small enough to measure electron tunnelling between a sharp probe and a surface. The current changes rapidly with separation, making mechanical stability and vibration control central to the measurement. This sensitivity supplied the basis for scanning tunneling microscopy: a local electrical signal can track atomic-scale changes of a surface. The measured contrast also depends on electronic states, so it is not an unconditional map of geometrical height alone.^[ref]

A physicist whose IBM research included the scanning tunneling microscope.^[ref]

Gerd Binnig coauthored early scanning tunneling microscopy measurements resolving atomic-scale surface features. A conducting tip and sample form a narrow vacuum barrier; scanning while monitoring or regulating the tunnelling current produces a spatially resolved signal. Observations of monoatomic steps and surface reconstructions showed how a strongly distance-sensitive quantum process could become an imaging method. The experiment joins precision mechanical control with the local electronic response of the specimen.^[ref]

A physicist who developed the scanning tunneling microscope at IBM.^[ref]

A researcher whose joint work on NIST calibrations in photometry explains how to maintain an optical measurement scale in practice. Repeated measurements of check lamps, subtraction of detector background and corrections for instrument response help distinguish a real change in a test source from drift in the measuring system.^[ref]

A researcher whose NIST work with colleagues documents photometric measurement standards and their transfer to instruments and lamps. Photometry weights radiation according to visual response; reproducible measurements therefore require control of source spectrum, geometry and detector response. The calibration procedures make a brightness-related reading comparable between different laboratories.^[ref]

A researcher whose joint NIST work establishes quantitative photometry. A calibrated photometer relates its electrical output to illuminance, with corrections for its wavelength response and the spectrum of the source being measured. Those corrections matter because equal optical powers at different wavelengths need not appear equally bright to a human observer.^[ref]

Yuqin Zong coauthored NIST calibration methods connecting optical detector output with reproducible quantities in photometry. A photometer's wavelength response and the test source's spectrum determine corrections needed to infer illuminance. Repeated reference measurements, background subtraction and controlled geometry help separate a changing light source from detector drift. The work turns a visual-response-weighted quantity into a transferable physical measurement scale.^[ref]

A researcher whose team compared the measured lifetimes of circulating muons with predictions from special relativity.^[ref]