I was driving home one night, a little under a year ago, and the sky turned completely white for about 8 seconds. Mind you it was completely clear, no clouds or any kind of moisture in the atmosphere or anything. And it wasnt just one spot either, it was the same, stark white everywhere all across the horizon. But besides the sky nothing else had changed, everything else on the ground was the same exact shade, coloring and shadowing as it had before. It was as if some one had inverted the colors of the sky and only the sky. Then it just… changed back. Still fucks me up and actually made me go see a neurologist, he said everything was fine, no signs of a stroke or aneurysm or anything.