The degree was first awarded in the United States in the early 20th century and was created as a modern version of the old European doctor of law degree (such as the Dottore in Giurisprudenza in Italy and the Juris Utriusque Doctor in Germany and central Europe).
An electromagnetic pulse (EMP) is an intense burst of electromagnetic (EM) energy caused by an abrupt, rapid acceleration of charged particles, usually electron s. An EMP can contain energy components over a large part of the EM spectrum , from very-low-frequency ( VLF ) radio to ultraviolet ( UV ) wavelength s. A lightning strike produces a localized EMP that gives rise to large electrical current s in nearby wires. A single current surge can damage sensitive hardware such as computers and peripherals. All electronic and communications systems should have some form of protection against the effects of an EMP.
The letters spell burnt out computers and other electrical systems and perhaps even a return to the dark ages if it were to mark the beginning of a nuclear war. But it doesn't need to be that way. Once you understand EMP, you can take a few simple precautions to protect yourself and equipment from it.