|electromagnetic radiation emitted in narrow beams tangential to the orbit of very high energy charged particles, such as electrons, spiralling along the lines of force in a strong magnetic field. It occurs in synchrotron accelerators and in many cosmic environments, such as radio galaxies and supernova remnants|
|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
Electromagnetic radiation emitted by high-energy particles that are moving in a circular path, as in a synchrotron particle accelerator. Energy lost by synchrotron radiation increases rapidly as particles approach the speed of light.