So, I’ve installed a new anti-spam plugin on the blog. It should be completely transparent to the end-user, unless you aren’t using a java-script enabled browser, in which case it will tell you why you can’t post, but since just about everyone has java these days, I’m not guessing too many will run in to that.
Let me know if you run into any problems!
For the information of those who read these updates (a paltry demographic, I know) the following.
Sunday morning, at approximately 1630Z (8:30 local time) I completed my first solo flight. The weather was calm during taxi to the runway. During run-up the winds were picking up as well, and about the time I lifted off the runway it was blowing 15 knots, gusting to 20 (not very good for flying). Of course this also meant turbulence, so after the third touch-and-go I called it a day with about 12 minutes of time in the air.
On the up side, that’s about as bad as it gets around here, and the absence of 160lb of instructor plus the headwind made for fantastically quick takeoffs. On the down side, without all that weight and with the distraction of all the turbulence I ended up really high on all the approaches. Oh well, practice practice practice!
Recently, I have been helping to edit and clean up the Wikipedia project. I have been consistently surprised at the quality of information already present, and I rarely can find anything useful to add to the major articles. This is to say that I think the Wikipedia project, although clearly fallible, is often accurate and precise.
In contrast, I present for your approval this article about vacuum furnaces. Now, it is on the “international journal of thermal technology” website, by the “heat treat doctor” who even cites his sources. You don’t have to read the entire article to get to the good part, I’ll copy the important paragraph (in its entirety)
Now for a surprise and an important concept. At atmospheric pressure, one cubic centimeter of air contains approximately 2.69 x 1019 molecules all moving around in a random motion. As you might expect, this results in a fantastic number of collisions. In other words, the mean free path between molecules (or the average distance a molecule can travel before colliding with another molecule) is only about 2.6 x 10-6 inches. So if we pump a one-cubic-centimeter volume down to a micron (1 x 10-3 torr), which is a vacuum level commonly used in heat treating, we still have about 3.54 x 1013 molecules, or well over half of them remaining! You might be wondering how this can be an acceptable condition for heat treating, especially when about 20% of those remaining molecules are oxygen? The answer is that the mean free path increases dramatically, reducing the probability of molecular collision with the surface of the workpiece.
First, give him the benefit of the doubt that when he says 1019 he means 10^19, likewise with 1013 meaning 10^13. If not, then he just needs to ask a highschooler what avagadro’s number is. Okay, now someone tell me how a reduction of about 1,000,000 (yes, that’s one million) times can still leave “well over half” of the molecules? I’m still sitting here in astounded wonderment! That he goes on to spout about how “mean free path” is the reason heat treated surfaces don’t oxidize in the furnace shows that he really has no clue what he is talking about. To make matters worse, this was linked from the “Coatings and surface engineering” newsletter on GlobalSpec, a major engineering resource site. Did no one read what this guy is saying? The link from GlobalSpec says he “explains some of the basics” of what a vacuum is. This is the main point of his article! Did no one notice that he can’t read scientific notation, and compensates by making stuff up?
That people make mistakes is no surprise. What riles me is I could probably get away with citing this article in any engineering class, but if I cited Wikipedia I’d suddenly be on unfounded ground. The academics seem to have a penchant for the immutable, even if it is immutably wrong. Now, to be fair, I’ve just pitted a single errant example by a single man against an army of dedicated Wikipedians. On the other hand, if this article was on Wikipedia, I would have corrected it by now.
From Luke 16:10 and Mere Christianity.
There is never an action which does not shape our character. This is why I try (often unsucessfully, true) to do my homework, act honorably in computer games (especially when they don’t reward it), not cheat in meaningless games, and not exceed the speed limit. They are all trivial in the breach, but I would argue they are tremendous in a bind. For what you practice, you will do. Sure, no one cares if you kill the peasants, but it is the character that you engender that counts. This is why I hate it when people say “it’s just a game!” It is NOT “just” a game, it is a practice run. Every time you perform, you practice, you prepare for when it really counts. And he who is unrighteous in a very little thing…