Thursday, November 3, 2005

Fan Behavior

I’m working on an electronic design that includes a fan to exhaust warm air, and a filter on the air intake to keep the electronics from getting covered in dust. The finished project will be placed in a somewhat dirty room that is quite remote from where I will be monitoring the equipment. I want to sense whether the filter is dirty enough to restrict air flow. Of course I can (and will be) monitoring temperatures, but I’m looking for something that’s a more direct measure of air flow.

I had an idea: that there should be a difference in fan speed between a clean filter and a dirty filter. The fan speed should go down, I thought, if the filter was clogged up (as it would be working harder, kind of like a car going uphill). So I decided to test this thought out. I connected a small fan (an 80 mm “case fan") to 12 VDC, and monitored its RPM. Sitting on my desk, this fan rotated at just under 4,500 RPM. Then I put a piece of cardboard across the intake side of the fan, expecting the RPM to go down, though I didn’t know by how much. The RPM with the cardboard completely blocking the intake was 4,700 RPM — it went up! This effect was completely repeatable…

Does anyone know the explanation for this?

Flaming Paris

For the past seven nights in a row, Paris has been burning. You’d never know it from the MSM, but riots and other disturbances have been steadily escalating. Last night, over 100 cars were burned, a shopping center set ablaze and destroyed, people were injured, public and private property vandalized, and even a police station briefly taken over. French politicians are in full crisis mode, right up to Chirac. Gateway Pundit has been running a series of must-read posts on these events. The rioters are Islamic youths, primarily young men. The excuse: the deaths of two teenagers a week ago, electrocuted, we’re told, as they fled from police.

What’s really going on?

I have no personal knowledge of the situation in Paris, but I have researched several dozen sources over the past week. I was taken by surprise by the riots in Paris, so I wanted to understand how such a thing could happen. After all this research, I conclude there are two major factors underlying the explosion of violence in Paris:

1. French policies that discourage integration of immigrant communities, and encourage the development of “enclaves” of foreign culture. These policies almost certainly derive from widely held racist views, no matter how the French intellectuals dress them up. For example, European elites, in talking about the Islamic ghettos that dot the European scene, will pat themselves on the back and say things like: “We’re sooooo superior to the U.S. — we’re tolerant of the Islamic culture here, and we let them freely recreate these islands of Islamic culture within Europe.” Really? Here’s another view (mine): you’re all smug racists, convinced of your own superiority (over everybody, including Muslims and Americans), and the only way you’re going to tolerate alien cultures and ways of thinking is to bottle them all up in some place where they won’t offend your sense of propriety. Like a nice Islamic slum.

2. French economic policies, resulting in very few available jobs (which go first to the “real” Frenchmen, of course) and a massive public dole. The direct result of these policies is a large unemployed population in the isolated immigrant communities — people with no way up, no incentive to leave, and lots of anger. If you wanted to design a volatile situation, this might be what you end up with.

So what’s the answer? Darned if I know! I suppose it’s possible that somehow the French people will wake up some day, and take some concrete action to deal with the situation. But who knows what that action would be? I’m not sure we’d like it all that much. For instance, suppose their reaction was to throw all the Islamic people out of France? That’s millions of people at this point…we’d have a massive humanitarian problem then, and of course the anger and volatility of the situation would only increase. I can imagine good outcomes as well, though they don’t seem very likely: the French could vote out their entire corrupt government and replace it with an honest, pragmatic one. I don’t think I’ll live that long <smile>…

If there’s any good in this situation at all, it’s this: events like this are probably the only thing that could shock the European people and political structure into actually helping America in the war on terror…