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A second has been defined as 9,192,631,770 swings of a microwave field tuned to a cesium atom. The definition works: satellite navigation, power grids and financial timestamps all rest on it. The…
Physicists at Ben-Gurion University of the Negev, working with colleagues in Germany, Britain and the United States, have measured the quantum phase that develops between two halves of a single…
A team led by the University of Texas at Arlington has measured the speed of air moving through a hypersonic ground-test facility by tagging the air's own nitrogen molecules with a laser pulse and…
The XENON Collaboration reports that it has measured low-energy neutrinos from the Sun, using a detector built to search for dark matter. The result rejects the background-only hypothesis at a…
Ask a physicist how a particle gets from here to there and the answer can sound like a joke at the expense of common sense: it goes every way it possibly can. Straight across, out to the side and…
A group at EPFL reports gallium nitride diodes, grown on silicon wafers, that block more than 3.9 kilovolts before breaking down while their on-resistance, measured per unit of chip area, stays as…
A rubidium atom interferometer aboard the China Space Station has completed an in-orbit quantum test of the weak equivalence principle, the rule that objects fall at the same rate regardless of what…
A femtosecond is a millionth of a billionth of a second, and for chemistry it is the natural unit: atoms in a molecule take tens or hundreds of femtoseconds to rearrange. Electrons are quicker. They…
A laboratory experiment with rotating liquid metal has reached a state of turbulent convection that theory predicts for the interiors of planets and stars and that laboratories have struggled to…
Physicists at the National Institute of Standards and Technology have run superconducting single-photon detectors whose sensing wire is a tenth of a millimeter wide, more than 100 times wider than…
Energy inside molecules does not simply teleport from one place to the next. It has to be carried, and some kinds of energy are far harder to carry than others. The stubborn case is the "triplet," a…
Nobody has ever put a thermometer 5,000 kilometers down. The temperature at Earth's center is inferred, not measured, and one of the load-bearing numbers behind that inference is the melting point of…