Length, time and volume are all examples of quantities close quantityA property that can exist as a magnitude, usually with a numerical value. For example, speed (quantity) is measured in metres per ...

Scientists carried out an experiment that realizes a new kind of quantum standard of resistance. It's based on the Quantum Anomalous Hall Effect. The precise measurement of electrical resistance is ...

One of the most important—and famous—results in quantum mechanics is the Heisenberg Uncertainty Principle (HUP). What is less known (at least to non-physicists) is that the HUP exists in two versions.

Scientists at the University of Würzburg and the German national metrology institute (PTB) have carried out an experiment that realizes a new kind of quantum standard of resistance. It's based on the ...