I think that's a moiré pattern.

About five minutes ago, just before starting to write the text for this post, I looked up 'retirement quotes' in Google. I was hoping to find an appropriate one. After I read through the 30 Best Retirement Quotes without finding one that really impressed me, I decided against continuing my research with the next item down on the page, the 500 Best Retirement Quotes. Way too much work. And if the top 30 hadn't done it, well, what were the chances? 

I decided then to just wing it, and tell you what I've been thinking about of late.  

The subject for today begins with retirement of course, but is really (yes, again) about appreciating the world we've been given.  I've talked several times in past posts about how I now have time to really see the wonder of the world around me.  I've admired a bee's wing^, and been awestruck by seeing the Alpha Centauri binary separated into its A and B stars*.  I have continued to be amazed by our world, even when I am doing nothing more than sitting on our sofa and looking out our balcony door. That's what you'll learn about today if you continue to read.    

This was my view as I sat and looked. 

("Okay," you say to yourself.  "Big deal. What's he going to be amazed at this time?") 

Well, I'll tell you. 

The picture below is a close-up of the fabric that makes up the sheer curtains you just saw.  

("So what?," you might say. "The curtain hangs there in the window to provide a bit of privacy while still allowing plenty of light into a room. What's there to talk about?" )   

Well, I think there is plenty.  I might start off by wondering about the machinery that weaves something so fine, but that's not what I want to talk about right now. I prefer to point out the weird patterns that are visible on the folds of the fabric that you see over on the left side of the sheer curtain.  Go back up and look again if you didn't notice them during your first viewing.  

As I said in the title of this post, I think they're showing a moiré pattern.

A moiré pattern (I looked it up) can be produced by overlaying two identical (or even similar) pieces of a mesh (or other things) and moving them in relation to one another, or by having the observer move while they stand still.   (Wikipedia) 

In this case, the sheer behind the heavy drapes in front of our balcony door is constantly moving in the breeze and as it folds back on itself, sometimes several times, diffraction of the light coming through the weave of the fabric results in an interference pattern. This pattern takes all sorts of shapes, as you can see in the picture below and is of course, constantly changing. (This is a close up of the first picture. I think this looks a little like a display of weird neckties.)    

Diffraction simply means that some of the light at any given point bends a little if it passes the edge of something or if it goes through a slit. When there are lots of these slits or holes, as there are in this sheer mesh, the bent light from each of the tiny holes interferes with the bent light coming from other holes, and produces alternating dark and light bands, depending on whether the wavelengths of the bent light are adding to each other or diminishing one another. 

This effect is very common phenomenon, but still wondrous.  We are seeing a demonstration of how a component of the universe functions, and on our curtains of all places!  If that isn't worth appreciating, I don't know what is.  

Now, if you're in the dark at all about how wave lengths of light add together or diminish one another, think about this next explanation. It's something that I had forgotten, but that Jeanne had remembered as we talked about this post.   

Out at Bethell Beach one day, we watched the Waitakere River (only about a foot deep at that point) flow into the Tasman Sea. We noticed that the waves coming together from the two sources sometimes came together and formed an even bigger bit of wave, or they came together and cancelled each other out, or even disappeared. At certain areas, we could actually see patterns of standing waves. It all depended on what part of the waves, the high part or the low part, met the other waves.  

When the two high parts met, the new wave got larger, a high part and a low part evened each other out, and two low parts meant little or no water at all.  

The very same thing happens with light, but we see the result as either bright or dark bands instead. I could sit on the sofa and see physics revealed, just like at Bethells. But my feet didn't get wet nor was there sand between my toes. Does it get any better?

I hope that you now agree that this was worth reading. And it wasn't that long, after all.  

I said at the beginning of this post that I had been unsuccessful in finding an appropriate quote with which to start. If those 30 were the best there are, well then, it seems to me that almost anyone should be able to come up with a reasonably good one.  So, I thought about it and came up with my own quotes. Here they are. They're about acknowledging, and about giving thanks. 

During retirement, contemplate your own personal moiré effect.  Consider and acknowledge how the highs and lows of your life experiences have patterned your soul.  

And its corollary, (Okay, you're right, it doesn't precisely fit the definition of a corollary, but it sort of follows.)  

During retirement, if your life has been great, be thankful because you ought to be, and if your life has been tough, be thankful because it's almost over.  

I don't care if my quotes ever make it into the top 500 retirement quotes, much less the top 30, but that's okay. I have said since I was a kid that I would never, ever, ever, want to be a famous person, and in that, I have succeeded spectacularly.   -djf

-Just in case you're interested, here are the sites I referenced above:

^ https://fostersoe.blogspot.com/2021/01/gee-bees.html

*https://fostersoe.blogspot.com/2022/08/wonders-in-night-sky.html