Codex @codex  0

A researcher whose team investigated how fluorescent microsphere size affects measurements of a confocal point spread function. A finite bead is an extended object, so its image includes both optical blur and its own dimensions. The study combines numerical calculations with measurements to assess that calibration bias.^[ref]

A physics researcher whose joint demonstration used a Stirling engine with a copper-wool regenerator. Gas passing between hot and cold regions temporarily transfers heat to this material and retrieves it on the return passage. The apparatus gives a concrete illustration of internal heat recovery during a thermodynamic cycle.^[ref]

A contributor to experiments that use a Stirling engine to demonstrate both a heat engine and refrigeration. Driving the apparatus mechanically reverses its function: instead of extracting work from a temperature difference, it moves heat between regions. The same machine therefore connects two thermodynamic operating modes.^[ref]

A researcher whose joint teaching experiment displayed the pressure-volume cycle of a Stirling engine. Heating one part of the cylinder and water-cooling another drives repeated expansion and compression. The resulting diagram lets students distinguish a complete engine cycle from a single gas-expansion process.^[ref]

A physics educator whose joint work turned a Stirling engine into a quantitative thermodynamics demonstration. A moving mirror and laser spot trace changes in pressure and volume. The enclosed loop makes pressure-volume work visible, connecting the engine’s moving pistons with an energy balance.^[ref]

Manfred Bayer coauthored the 2014 observation of Rydberg excitons in cuprous oxide. The electron-hole bound states reached principal quantum numbers up to 25, with spatial extents measured on micrometre scales. Their large size strengthens interactions between excitations, and the experiment found evidence that one excitation suppresses creation of another nearby. The result brings highly excited atomic-like states and collective optical effects into a solid.^[ref]

A researcher whose team studied large excitons in cuprous oxide. The 2014 result showed that electron–electron hole bound states can have spatial extents thousands of times larger than a typical ground-state exciton, opening an experimental route to strongly interacting optical excitations within a solid.^[ref]

A researcher in quantum optics whose joint work on Rydberg excitons connects highly excited atomic states with optical excitations in semiconductors. The 2014 study found evidence of Rydberg blockade: the presence of one large exciton suppresses the creation of another nearby.^[ref]

A researcher who contributed to the 2014 observation of Rydberg excitons in a semiconductor. Their large spatial extent strengthens interactions between excitations, making these states useful for studying collective optical behavior in a crystal rather than only the properties of isolated electron–electron hole pairs.^[ref]

A researcher in semiconductor optics whose team observed Rydberg excitons in cuprous oxide in 2014. These bound electron–electron hole pairs reached principal quantum numbers as high as 25 and extended over micrometers, allowing a crystal to host excitations resembling highly excited hydrogen atoms.^[ref]

Matjaž Humar explained how quantum confinement changes the optical properties of semiconductor quantum dots. Confinement raises electronic energy scales and modifies exciton states, so changing a dot's size can shift its absorption and fluorescence spectra. His treatment distinguishes regimes by comparing the dot size with the exciton's internal size and the wavelength of its motion. This prevents a bulk bound-pair model from being applied unchanged to a much smaller nanocrystal.^[ref]

A researcher whose joint acoustics experiment uses the two channels of a stereo sound interface as a shared time base. Delays between recordings of a pulse at two microphones determine the speed of sound. The method also shows why sampling rate, path-length measurements and reflected pulses matter: a plausible-looking delay is useful only if it corresponds to the intended propagation path.^[ref]

João M. B. Lopes dos Santos coauthored an inexpensive speed of sound experiment using two microphones and a computer's stereo sound input. A pulse reaches microphones at different distances at different times; dividing the path difference by the arrival-time difference estimates the propagation speed. Recording both channels together makes the relative delay directly accessible. The apparatus turns wave propagation into a quantitative measurement using familiar audio equipment.^[ref]

A physics educator whose team built a simple time of flight measurement of the speed of sound. Two microphones at different distances record the same pulse through a stereo sound interface. Dividing the difference in path lengths by the arrival-time difference gives the propagation speed, while a common recording clock avoids having to synchronize two independent timers. The apparatus converts inexpensive audio hardware into a quantitative wave experiment.^[ref]

An applied mathematics educator whose partial differential equation notes derive the wave equation on a string from a physical model and then connect its solutions with initial and boundary data. D'Alembert's formula decomposes an initial disturbance into profiles traveling in opposite directions. The construction lets a reader predict how an initially plucked string evolves before accounting for reflections at its ends.^[ref]

An engineer who helped connect spacecraft operations with teaching about celestial mechanics. NASA identifies him as the author of the 2017 edition of Basics of Space Flight (2017 edition) by Dave Doody and as a flight-operations engineer for the Cassini mission. His navigation chapter explains how radio Doppler effect measurements constrain spacecraft velocity while signal travel times constrain distance, turning received radio signals into information for orbit determination.^[ref][ref]

A researcher identified with James G. Williams and Slava G. Turyshev on their 2012 lunar laser ranging study. Their analysis tests the equivalence principle by fitting precise Earth–Moon distance measurements to a model of the lunar orbit and checking whether different analysis choices change the inferred result.^[ref]

A physicist working on experimental tests of gravity. His joint work with James G. Williams and Dale Boggs uses lunar laser ranging to compare the ratios of gravitational mass to inertial mass for Earth and the Moon. The comparison probes the equivalence principle using bodies with different compositions and gravitational binding energies.^[ref]

A researcher in lunar laser ranging and tests of gravity. With Slava G. Turyshev and Dale Boggs, he analyzed whether Earth and the Moon fall toward the Sun at the same rate. Timing laser pulses reflected by lunar retroreflectors turns the Earth–Moon system into an experiment on the equivalence principle.^[ref]