Understanding Relative Motion

A few weeks back, in a discussion regarding the effectiveness of whether ’tis better to alter course for large cargo ships far in advance, or to proceed boldly ahead until the ColRegs take hold, I noted that relative motion diagrams are not all that commonly understood. Whilst most will not have occasion to whip out a maneuvering board and hand-draw a plot, understanding relative motion is still a key part of interpreting motion on a radar screen.

Here is my initial attempt at a short slide deck explaining the basics of relative motion and how to use that in evaluating crossing situations at sea:


Metric Side Effects

A recent thread on Mountain Project caught my interest, when someone asked why US guidebooks give the length of rappels in feet but ropes are sold in metres.  At the time of writing the thread has just reached seven pages of debate on the merits of U.S. customary units vs. the SI units.  While the thread title mentioned “imperial units”, it’s worth noting that the imperial units are actually different from the U.S. units.  This is why the British pint of 20 fluid ounces is larger than the American pint of 16 fluid ounces.  (Of note, those fluid ounces also differ by about 4%.)  Just to kick a little more sand at the U.S. system, I’ll mention the odd bit of trivia that the international foot and the U.S. survey foot are also very slightly different.  (Only some U.S. states use the survey foot.)

But I digress… the argument online rather quickly diverted into a debate about the merits of decimalization, with at least one poster very much attached to inches divided into halves, quarters, and eighths.  While decimalization is not strictly the same as metrication (or “going metric”), it certainly is strongly associated with it!  It occurred to me that a few other concepts also come along with metrication, which is what this post is about.  I suspect many non-metric folk are largely unaware of these side benefits, so this post is for them. Continue reading

Sentence Structure

This weekend I was introduced to an essay by Edgar Allen Poe, titled The Philosophy of Composition. The essay itself is mildly interesting; the comparatively less well-written Wikipedia entry conjectures the essay may have been intended as satire and in the alternative quotes a biographer of Poe describing it as “a rather highly ingenious exercise in the art of rationalization than literary criticism”. Content aside, the writing itself is worthy of note both for stylistic as well as historical reasons.

Most of the text I encounter can be easily skimmed, assimilated, and comprehended with a pittance of effort. The sentences are short, the words mundane. In Composition Poe has constructed, like an ancient cathedral-builder, clauses that build one upon the other, mortared with m-dash and comma alike. To place it beside modern literature is to expose current authorship as little more than a rudimentary scraping of foundations, topped in the best of cases by a mean mud hut.

An Interesting Collection of Commentary

I turned off a movie (“Wrong Turn”) today because the level of stupidity exceeded my tolerance with a speed that surprised even myself. The last movie I recall doing that to was “The Ring 2”. Fortunately I was spending the time with much more interesting reading material.

I will admit to watching bad movies. Just because the movie is bad, does not mean it can’t be enjoyable; MST3K proved that. However, there is a difference between watching a video of a cat discovering how to flush a toilet (and now earnestly engaged in driving up its humans’ water bill), and watching a human displaying roughly the same level of reasoning ability. Especially over two hours.

Continue reading

Back To School

I was walking home from Saturday’s Cal game when I had the strangest idea. I’ve always assumed that I would go back to school, but even when I was in school I had a general idea of what direction I would go. My strange idea came from the realization that I hadn’t taken much in the way of science classes. Sure, there was one or two, but for the most part my work involved writing papers or programs.

This is why I’ve been browsing the biology offerings in the UC Berkeley Extension catalog. While typing this, I’ve signed up for an introductory biology course. I’ll try it out, and if all goes well, follow up with the offerings in chemistry, o-chem, and human physiology. In case you’re wondering, no, I have absolutely no idea what I’ll do with the classes. This is for fun!