There are gaping holes in my knowledge of the world. History is probably the biggest and the most important. In the course of human existence, many, many important things happen about which I know nothing at all. A bunch of other things happened, about which I know a paltry little. There are only a few historical events about which I can claim even a cocktail-party level of expertise.
I read a bit about the French Revolution, and can join that large cadre of people who thank Simon Schama for making them sound reasonably well-educated on that subject. I know a bit about the reign of Queen Victoria, since I’ve spent an unconscionable amount of time reading every single novel written during it. I’m sorry to say that my understanding of ancient Greece comes primarily from Mary Renault, and ancient Rome, from Robert Graves. About the history of that part of the world known as ‘Asia,’ I know nothing whatsoever, until you get to Mao, with whom I have a macabre fascination.
I do better with literature. I’ve read most of the notable stuff written in English, but don’t do as well with the French or the Russians. And, of course, about the literature of that part of the world known as ‘Asia,’ I know nothing whatsoever. My excuse: I don’t like reading in translation. Since I’m a pathetic monoglot, that limits me to the notable stuff written in English.
Math and science, I’m at least conversant. Numbers speak to me – they always have – so I have a good shot at understanding statistics and calculations. And I often find that I know just enough science to ask the people who know a great deal of science the right questions – that’ll take you a long way in this world, I’ve found.
There is, however, one scientific phenomenon that might as well be black magic, for all I understand about it. I just don’t get electricity. It’s that really cool stuff that comes out of the walls, that keeps the lights on and the refrigerator running, and that can kill you if you touch the wrong two wires. It has to do with sub-atomic particles going from one place to another, but how that translates to actual power is a mystery to me.
Which is why I cannot, for the life of me, give you an adequate explanation of a sacrificial zinc anode. This is unfortunate, because sacrificial zinc anodes are pretty interesting, and we should all understand them.
Although they’ve certainly been mentioned in my earshot, both by Kevin and by Billy, our boat mechanic, before today, today was the first time I paid any attention to them. I did this because I found Kevin lying on a tarp under the boat motor, wrench in hand.
“Whatcha doing, honey?”
“Replacing the sacrificial zinc anodes.”
Because I had hazy memories of sacrificial zinc anodes being mentioned, I was a little embarrassed to admit I had not the foggiest idea of what they were and what they did. So I left Kevin lying on his tarp, and went inside to Google them.
There are several cogent explanations, but none is comprehensive enough to compensate for my complete lack of electrical expertise. Those of you with both expertise and interest can go over and read this explanation. Those of you with neither may be content with my rudimentary, incomplete, and possibly incorrect explanation.
When you submerge metals in salt water, you make a battery of sorts. The salt water either is an electrolyte or contains electrolytes, I’m not sure which, but, in either case, it is a conductor of electricity. Electricity is, apparently, made up of electrons, and those electrons come from one of the metals. Losing your electrons, if you’re a metal, is not a good thing. You corrode. Metals differ in their willingness to give up their electrons, and it is the most willing which will corrode.
Boat engines have metal. Generally, several kinds. Unless you take corrective action, one of those metals – the most willing – will corrode in sea water. The way you prevent that is to take a metal that is even more willing — in this case, zinc — and attach a chunk of it to your engine. Its job is to corrode so that the other metals don’t. When it reduces down to about half its original size, you spread a tarp under your motor, get out your wrench, and replace it. Or you do nothing at all, and simply assume your husband will take care of it.
All this has made me think it’s high time I made an effort to understand electricity. Can anyone recommend a book? I’ll get to it just as soon as I finish The Brothers Karamazov.