I'm using 1893, the year of the World's Columbian Exposition in Chicago, as my arbitary starting date, but I could stick my hand into a perpetual calendar and come up with a half dozen just as good. Nice round 1900, the year that Max Planck defined the quantum, is an excellent alternative. Perhaps better is the year 1895, a true unforeseeable skittering into the unknown, the year in which Wilhelm Conrad Röntgen discovered X-rays. (Those of you without easy access to an umlaut font can spell it Roentgen.)

Flight had been predicted and discussed for decades; the telephone and telegraph emerged out of mechanical signaling devices; electricity was known to the ancients. X-rays seemed to pop up out of nowhere, unexpected, unimagined. Even the name is perfect; despite attempts to call them Röntgen Rays, sucessful in many languages, "X," a standard scientific modifier for anything as yet unknown, stuck like glue in English and elsewhere. Why not? Nothing could be more symbolic of the unknown, of the mysterious and wondrous lurking in scientific acheivement, than these rays that could reveal the inside of your body. No wonder Röntgen was the first recipient of the Nobel Prize for Physics. (History reveals that others doing similar experiments had seen similar effects earlier; Röntgen gets the credit because he published first. The world learned about X-rays in early 1896. Does that make 1896 a better arbitrary starting point? Arbitrarily, no.)

Rays were already known to science, to be sure. Sunlight itself was the most obvious of rays, literally visible as such, or at least apparently so. William Herschel, the astronomer already famous for the discovery of Uranus, had discovered infrared radiation in 1800 with ultraviolet radiation quickly following the next year after Johann Wilhelm Ritter looked at the other end of visible light. Scientists feverishly explored Hertzian waves, what was soon called radio, after Heinrich Hertz demonstrated them in 1887.

That frenzy paled before the reaction to X-Rays. A device that could see inside the body blew the minds of the Victorian mindset already offended and excited by a mere exposure of an ankle. X-Rays had endless possibilities for good and for evil, all of them exploited by doctors, quacks, photographers, moviemakers, writers, inventors, and pundits long before any true understanding of the new phenomena was remotely possible.