Do you know how to tell at a glance whether the Moon is waxing or waning? Well, if you don’t, I’ll tell you how to do it — but first, an interlude:
So… I just need you to focus on two things: the Moon’s shadow, and the phrase ‘Wax on, wax off’.
As it’s read, ‘wax on’ is on the left, and ‘wax off’ (that is to say, ‘wane’) is on the right. So if the Moon’s shadow is on the left, that means ‘wax on’ — it’s waxing. And if the shadow is on the right, that means ‘wax off’ — it’s waning.
So simple, and yet it’s taken me a lifetime to realise it!
[A minor complication: The more astute of you who have actually watched the clip above may have noticed that when Daniel is doing ‘wax on’, he uses his right hand; and he uses his left hand for ‘wax off’. Which confuses things just a little bit; but if you think of the Man in the Moon as the one doing the Karate training, from that perspective the shadow when waxing is on the right (wax on) and it’s on the left when waning (wax off). So that works, too.]
Addendum: I had a sudden thought, wondering about whether this rule of thumb would work for those in the Southern hemisphere… a little digging revealed that it’s different ‘down under’; the sides are reversed, so it’s waxing when the shadow is on the right and waning when it’s on the left (and apparently the Moon itself looks upside down, too!).