BACKGROUND The generation and control of coherent electromagnetic waves, such as
those provided by electronic oscillators in the radio frequency domain or lasers in the optical …

General relativity (GR) was proven via the direct detection of gravitational waves from the
mergers of the binary black holes and binary neutron stars by the advanced LIGO and …

Optical atomic clocks represent the state of the art in the frontier of modern measurement
science. In this article a detailed review on the development of optical atomic clocks that are …

We review experimental progress on optical atomic clocks and frequency transfer, and
consider the prospects of using these technologies for geodetic measurements. Today …

The status of experimental tests of general relativity and of theoretical frameworks for
analyzing them is reviewed and updated. Einstein's equivalence principle (EEP) is well …

Quantum mechanics, through the Heisenberg uncertainty principle, imposes limits on the
precision of measurement. Conventional measurement techniques typically fail to reach …

Fundamental constants are a cornerstone of our physical laws. Any constant varying in
space and/or time would reflect the existence of an almost massless field that couples to …

The proton is the primary building block of the visible Universe, but many of its properties—
such as its charge radius and its anomalous magnetic moment—are not well understood …

This paper presents a review of the current state of the art in the research field of cold and
ultracold molecules. It serves as an introduction to the focus issue ofNew Journal of Physics …

1.1. Background This article reports work carried out under the auspices of the Committee
on Data for Science and Technology (CODATA) Task Group on Fundamental Constants. 1 It …