Tuesday, September 13, 2011

Harvest Moon again tonight, or any night

Ok, I've tried to be reasonable about this moon issue, but Selavy has challenged me on it again. He was once my science teacher so it becomes increasingly frustrating to have him be so perpetually wrong about something, and even more so for him to site an internet article as defense for his mistake.  It's understandable how and why he and others often accept the evening that follows a full moon to be the night of a full moon. But in this case he, and ABC, and many other people worldwide, were wrong.

Here is how it works... The moon is full at an exact moment.  It is the moment that the moon is reflecting the maximum amount of light back towards the earth.  If you look on a calendar it will often show the date of a full moon. Naturally many people assume that the evening of that day the full moon will rise.  This is an easy mistake to understand.  But if the full moon occurred at 2:27am (PT) and 5:27 (EST), then it was no longer full by the time that it rose later that day as the sun was setting, it was already in its waning gibbous stage.   The previous night would be considered the night of the full moon and the moon-rise that could be witnessed on that night would more appropriately be the rising of the full moon. 

As for what night will be called and accepted to be the "harvest moon" I will leave it to the farmers to figure out.  Do not look to ABC, or any other news agency, for information about full moons. They admittedly used the farmer's almanac as a source of information.  The agency to rely upon for the Universal Time of moon phases would be NASA, the people who actually put men on the moon.  They are a more reliable source of information concerning our solar system and beyond.

For this last full moon it did occur at the times that I listed earlier. If you look at the NASA page that I linked it will seem to be off by an hour, that's because of daylight saving time. If you use the UT or UTC standard and the NASA list of full moon times it's easy to see that the night of the full moon was the night that spanned the 11th and the 12th of September, not the 12th and the 13th, though many would lead you to believe otherwise, and cite the general assumption of fallacy as proof.

Even though a full moon actually only occurs at a specific moment it is generally accepted to precede that moment by 12 hours and to continue for 12 hours afterwards, making up the "day" of the full moon.  Even by this general acceptance the moon that many witnessed rising on the evening of the 12th was not in fact a full moon, nor would it correctly be called the harvest moon, though the colloquial terms applied to the event don't really matter that much to me.  They are mainly for use by farmers, hippies, and bloggers.

I've linked a video of the harvest moon here, which documents the moon in all of its "fullness" on the night of Sept. 12, 2011.... Notice how full it looks in the beginning of the video...?  It's astonishing that the full moon, recorded on the night of Sept. 12th, would be missing a portion of its complete roundness on the right side, towards the bottom.  It might be because the moon was full the night before, a night that many people questioned me on, presumably because the calendar listed it as happening the following day, at 9:27am (UT), which used to be called Greenwich Mean Time (GMT)....

Now, Neil Young wrote a lovely song called Harvest Moon. I don't know if he's ever been to the moon or not, or if he knows or cares about the phases of the moon.  But one thing I do know, that if he looked at the image of the moon at the beginning of his video he'd agree that that moon isn't full.

No, I kid... the video was shot long ago and doesn't actually show a harvest moon because it isn't full. I can only assume that Neil Young's producer made the same mistake that many people make. About half of all full moons are celebrated and witnessed on the wrong day, the day after a full moon. It's simple math, half of them occur in the early a.m. and by just glancing at a calendar people suppose the moon that rises that evening is the full moon.  I'm assuming that's what happened to Neil Young.  As for my science teacher... I have tried and tried to reason with him on this issue.  Some people you just can't reach...

If nothing else we'll have more to argue about later if he continues in his willful errant ways.  By my reckoning we'll disagree exactly half of the time.  But at least he won't be alone, he'll have ABC's team of journalists to back him up.  I'll be forced to rely on science as a meager crutch for understanding.

I expect him to publish a retraction and full apology tomorrow morning.  I accept his apology in advance.