The flash of light that appeared in Phoenix on March 8 has now been explained by Arizona Public Service as a breaker opening on an electric line. In other words, it was an electric arc. However, our experts are not so sure that this is an explanation for the flash, or a matter of explaining it away.
"I can say with fair certainty that this was NOT a strobe flash, electric arc or lightning flash, any of which would have started and ended much more abruptly. This one started very brightly but then faded out over a period of four or five frames (about 1/5 – 1/8 second) which is MUCH too long for any of those. No rolling shutter effects are visible in this clip, but this camera probably has a CCD imaging chip which would not be susceptible to these effects."