But here's the thing - it's not really a flash at all, or at least, not something flashy enough to fall into my definition of a flash. A flash to me is something biggish. A lightning flash. The flash of a torch. A flasher. Something flashy.
But the green supposed flash is just a little teensy thing. More of a wink, or even just a momentary blink. And you've really got to be focused on just the right spot right up to the crucial fraction of a second, or else you'll blink and miss it.
The mini-phenomenon is not rocket science. I purposely haven't Googled it, so I could stand to be corrected, but here's how I see it.
Although I'm no Stephen Hawking, I do mix paints from time to time and, on a clear evening, there is a big yellow globe about to dip under an horizon which is the top edge of this big blue thing.
At just the crucial moment, when the tippy tip topmost of the yellow thing is disappearing below the big blue thing, for a split second there exists just the right angle of refraction for yellow shining through blue to give out a little green splodge of light - demonstrating what every kindergarten kid at the paint table learns, that a little bit of blue mixed with yellow gives you a nice green. (The same kid also quickly learns that, despite what teacher says, mixing red and blue never never produces purple, but only ever a rich tone of mud - magenta is the true primary colour you need to make purple.)
So there it is, but I think the reason most people miss it altogether is that the pre-conditioning has been wrong. They may have heard about the green flash, and naturally they're looking for ... well, a flash. Maybe something that lights up a good chunk of the horizon - not a little wink that requires careful scrutiny to spot.
In other words, it's been over-hyped. Like with convention centres. And America's Cup racing. And how all Auckland needs is one final multibillion-dollar motorway and it'll provide the key to unlocking the gridlock.
I was out leaning on the front deck the other evening. Conditions were clear and I was confident I was going to get the green light.
A gentleman was out walking and we exchanged greetings. "Waiting for the green flash?" he asked, somewhat facetiously I suspect. I replied; "Yes, as a matter of fact I am."
"Never seen it," remarked this man of a not a few years and in a tone that suggested it was all a bit of bulldust. Sometimes it pays to lower the horizons.
Frank Greenall has a Master's degree and managed Far North Adult Literacy before moving to Wanganui.