The first thing that came to mind for the missing bolt was Dirac "reciprocal space". Can lightning sometimes end up in reciprocal space? If so, it should be some kind of Fourier transform. This site turned up:
http://www.rodenburg.org/theory/Reciprocalspace20.html ... which is interesting, but another site other may actually give us a better and mundane explanation: http://news.nationalgeographic.com/news/2010/12/101223-lightning-x-rays-came ra-science-technology/ Which suggests that a lightning bolt carries almost all its x-ray radiation in its tip. Thus, if an observer saw only lots of x-rays and no flash of light, a plausible explanation is that the bolt was coming directing at the observer. Another observer located almost anywhere else far removed, could see the bolt from its side angle as a string-like bolt. But if that bolt is mostly in your line of sight, it would be mostly dark. OK, then why was the observer not fried by the bolt coming directly towards him - if the bolt was aligned in his direct line of sight? Although most lightning strikes do hit the ground or a structure on earth, some don't, especially at high altitude. Lightning is defined as a massive electrostatic discharge between electrically charged regions within clouds, or between a cloud and the Earth's surface. Pilots report lightning flashes which start and terminate in clouds without ever going to ground. Presumably there are pockets of differing polarity at altitude and occasionally will be aligned in such a way that the lightning will come directly at the observer but be intercepted by the opposite polarity before it hits the observer, with only the high energy radiation to show for it. IOW - if the observer happened to be located in an airplane, so that both pockets of charge were aligned in his line of sight, he might never see the flash itself - only the radiation. The flash would be a small dot of light which would not stand out like a bolt would. Note: this is NOT a claim of factuality - simply a "flash" suggestion, so to speak. -----Original Message----- From: Terry Blanton http://www.washingtonpost.com/national/health-science/thunderstorms-contain- dark-lightning-invisible-pulses-of-powerful-radiation/2013/04/08/1c796ebc-8a 76-11e2-a051-6810d606108d_story.html Sometimes its flashes are invisible, just sudden pulses of unexpectedly powerful radiation.