Reflection v. Refraction
It was late afternoon on Christmas and I was driving west into the setting sun. It had been wet most of the day, but the rain machine had turned off for a bit, the sun was shining brightly through breaking clouds, and a brilliant rainbow dazzled in the rear-view mirror. I put down the visor so I could see which way I was heading, but it didn’t do much good: sunlight also reflected off the water on the roadway, as well as the wet hood of the car. The trio of searchlights made it pretty tough to see where I was going!
Along with the rainbow (which I studiously tried to ignore), they also made me begin to consider reflection, and how it differs from refraction.
Fast forward to this weekend. Susie and I headed to the coast for a couple nights, and to cheer on our granddaughter at her basketball game against Brookings High School (not to mention a lemon-drop martini for Susie at Superfly, and another excellent dinner at Pacific Sushi).
We also had some lovely weather! Warm and sunny, with temperatures in the 70s — not bad for mid-January. (But of course, since we all know that climate change is a hoax, this must have just been a one-off, with karma repaying Susie for all her clean living, and lucky me along for the ride.)
Anyway, I was sitting on the deck yesterday morning and looking at the ocean, and realized that there was nearly as much light bouncing off the water as there was coming out of the sky. “There’s that damn reflection again,” I groused to myself. Upon further reflection, I decided that it was time I got off my butt, attempt to find a few deep thoughts, and then share them with whomever might care to partake of the epiphanies (tune out now if this doesn’t include you).
Reflection is easy — anybody who’s ever looked in a mirror or played pool knows all about reflection.
Or indoor soccer. We were in Colorado in early December and had a chance to see two of our other grandkids playing soccer inside a converted warehouse, and it struck me that, even after forty years of coaching, refereeing, and watching the sport, I had never been involved with the indoor version.
What a difference from traditional, outdoor football! It struck me just how important it is for the players to understand how reflection works, and made me realize that if I was coaching soccer today, I would have a whole new technique to teach the kids. Which would be a good thing — none of us are ever too young (or too old) to explore how The Rules of Reality impact all aspects of our lives, even if we chose to believe that science is fake, too.
(As an aside: if I could return to any time in my past, coaching youth sports would be near the top of the list. Talk about rewarding! Other than American football, I did pretty much all of them, and have to say that soccer was my favorite: it’s fast-paced with no time-outs, and — back in the day, at least — most of the adults had absolutely no idea whatsoever what was going on. It was so unlike basketball, or especially baseball, where every parent with exterior plumbing was sure they knew more than the players, coaches, and umpires combined, and were never hesitant to shout out their wisdom.)
But I (again) digress.
There are even mathematical formulas that describe and control how reflection works. The big one is that the “angle of incidence” equals the “angle of reflection.” Again, anyone who has played billiards, or used a signal mirror to alert the troops that the bad guys were coming, understand all about this one. I’m sure there are other formulas to complicate the issue, but this is the important one and gets us through what we need for today.
Which brings us to refraction.
Speaking only for myself, I find refraction much more difficult to wrap my head around. It probably has something to do with the official definition. To paraphrase: Refraction is the bending of waves, especially light, as they pass from one transparent medium to another (like air to water). This happens because the wave changes speed, causing it to move in a different direction.
(BTW: I was always taught — and always taught — that the speed of light is constant. Even Einstein agreed with this, and came up with his famous formula (E=MC2) that celebrates this constancy and allows us to make atomic bombs. Maybe this is another issue with refraction that gives me pause. There is clearly something I don’t understand, but that’s probably only my shortcoming.)
Refraction is bound by something called “Snell’s Law” which is itself dependent upon the “refractive indices” of the two “transparent mediums,” but the simplified formula is fairly straightforward. It even uses some of the same terms as reflection, although in this case, the angle of incidence definitely does NOT equal the angle of refraction.
We’ve all seen the pictures of how a straw inserted into a glass of water looks like it’s bent (or otherwise offset) where it goes from the air into the water. This seems like it should be illegal, but there you go. “Tough titty, said the kitty.”
And there are practical effects. I’ve got to be honest with you, I have never tried to spear a fish, but imagine that the reality of refraction would seriously dictate where you aim your spear if you hope to have dinner that night.
And yet, I’m going to choose to like refraction, even if I don’t completely understand it. It is, after all, what makes a rainbow.
But given a choice, I’ll take mirrors and indoor soccer anytime over a fish that’s six inches away from where it’s supposed to be (with or without a rainbow).
One request: If you haven’t yet got your copy of Marker Bed, please click the link, check it out, and order your copy if it sounds like a fit. And tell your friends if you find it has value — word-of-mouth remains my marketing strategy. Thanks.
