Why couldn’t I just say Two Forward and Two Back?
The words: a couple, a few, came in handy back in 2004 when I had to teach significant digits to my high school physics class.
While I’m pretty good in physics, meteorology really just being mostly math and physics, with a few fluid dynamics classes thrown in, I had to refresh myself (learn) about significant digits to teach it. As it turned out, it was the last year in was in the New York State high school physics curriculum, but I thought it important, so I taught it.
At the time I wondered why I didn’t it didn’t come quickly to mind as the other important concepts of physics did. Later, I realized because during my high school and university, I was using a slide rule and understanding how many digits were significant in any calculation was an integral part of it’s effective use.
Thus, I “knew” it, without knowing what I knew.
So, when thinking about this blog post today, I debated titles: Two steps forward, three back, no, I have made some progress, two forward one back, let’s not get carried away on the amount of progress, two steps forward, one and a half back, sounds awkward.
Two Steps Forward, a Couple Back about sums it up. Of my 6-item list I of last week, one, moving the fresh water selector valve is done, but now instead of 5 things left to do, I’ve already discovered a dozen more. I’ve already taken care of a few, like the hole I found in my stainless-steel sink (how does that happen??), but that still leaves me with half-a-dozen more.
Therefore, the ambiguity of “a couple” is perfect.
My re-positioning of the fresh water tank selector valve is done. Finally, with only a few missteps. In the process, I may also have found the problem with my fresh water pump. I had to replace the pressure switch back in the fall and at first, I taught all was OK, but then I noticed decreasing water pressure as the pump ran. For most of the winter, I assumed I had to adjust the pressure switch, but now I think I had a very small air leak in one of my older water hoses where it connected to the copper hose (and I put new hose from the output of the selector valve to that copper fitting).
I’ll know once everything is up and running and no matter where you live you will probably hear me laughing or crying in my shower depending upon the outcome.
I’ve also been working on a number of electrical/mechanical improvements:
- Repositioning the Maretron instruments on my mast, including running a new Maretron cable and re-conditioning all the connectors,
- Moving my Groove Wi-fi extender to the mast also and running its antenna cable thru a new route from fly bridge to pilot house, as the old wire race is full to capacity.
- Adding switches, replacing a fuse box, adding a voltmeter and rewriting my AM/FF radio in the salon.
- Adding some LED lighting to the side decks (more robust and waterproof than my initial effort 5 years ago.
Pictures and results to follow.
Moving the mast instruments has been a drama. After finally realizing I needed to tap and die the bolts for the spreader since the aluminum is so thick, 3/16th, to ¼”, I was “pleased” to discover that while I have two metric tap and die kits, I have virtually no metric bolts or machine screws, at least none that were stainless steel.
So, I spent some days, just sorting my stainless steel and figuring out what was metric and what wasn’t. It’s amazing the amount of stuff I’ve accumulated that really isn’t suited for boat life, but I don’t want to get rid of any of it, because you never know what you may need in the middle of the ocean.
Having said that, it’s so strange to get my mind around that fact that for the foreseeable future I will be in range of Boat US or Sea Tow. More so because in my first year, going up and down the ICW, I had Boat US on speed dial. But now, having spent so much time and miles being totally independent, it’s a mindset that is not easily turned off.
Now for those of still waiting anticipation of learning about significant digits.
It means that no matter how many digits your calculator displays, you need to use your common sense.
e.g. I walked 2 miles (a couple) today. There are 5280 feet in a mile, therefore, my calculator tells me I walked 10,560 feet. But did I walk exactly two miles? Or was it 2.1 or 1.8 mile, one cannot know from the information
given.
5280 has 3 significant digits, 2 has 1 significant digit, when multiplied you take the minimum, therefore the answer will have one significant digit. So, even though the calculator says 10,560 feet, the answer with significant digits in mind is 10,000 feet (rounded off to the one significant digit).
You can get a very nice definition and explanation here:
http://limestone.k12.il.us/teachers/rhebron/Chem_HO/c05_Sig_Figs_Help.html
Dauntless at Sea 