Published as "Fine Structure of the Hydrogen Atom by a Microwave Method" by Willis Lamb and Robert Retherford (1947) on Physical Review. This one actually has open accesses as of 2021, miracle! journals.aps.org/pr/pdf/10.1103/PhysRev.72.241

Microwave technology was developed in World War II for radar, notably at the MIT Radiation Laboratory. Before that, people were using much higher frequencies such as the visible spectrum. But to detect small energy differences, you need to look into longer wavelengths.

This experiment was fundamental to the development of quantum electrodynamics. As mentioned at Genius: Richard Feynman and Modern Physics by James Gleick (1994) chapter "Shrinking the infinities", before the experiment, people already knew that trying to add electromagnetism to the Dirac equation led to infinities using previous methods, and something needed to change urgently. However for the first time now the theorists had one precise number to try and hack their formulas to reach, not just a philosophical debate about infinities, and this led to major breakthroughs. The same book also describes the experiment briefly as:

It is two pages and a half long.

They were at Columbia University in the Columbia Radiation Laboratory. Robert was Willis' graduate student.

Previous less experiments had already hinted at this effect, but they were too imprecise to be sure.

Arc suppression refers to the techniques and methods employed to minimize or eliminate electrical arcing in various applications, particularly in electrical systems and circuits. Arcing occurs when an electrical current jumps between two conductive points, creating a plasma channel that can lead to energy loss, equipment damage, and safety hazards such as fires or electrical shocks.

Same as 2013 DNS census NS records basically, nothing came out.

Universal instantiation is a rule of inference in formal logic that allows one to derive a specific instance from a universally quantified statement. In simple terms, if something is true for all members of a certain set (as stated by a universal quantifier), one can conclude that it is true for any particular member of that set.