Identified Hovering Objects

Just pretty pictures today; the post I had been planning on for today is turning out a bit more complicated than I had figured. This will probably happen again. That's the thing about learning new stuff... it always takes longer than you think it will.

Sao Paolo



There's nothing quite like standing on top of a tank in the hot summer sun, surrounded by other tanks all reflecting the heat back up at you. Except, maybe, if you're wearing a full face gas mask and taking samples of a gas that is just about everything bad you can call a chemical.

Toxic, corrosive, flammable, explosive, carcinogenic… The whole system ran at a slight negative pressure, so that if there were any leaks air would go in instead of toxic gas leaking out, and they monitored it carefully to keep the concentration out of the explosive range.

I was testing the performance of a new scrubber which was taking the gas in question out of the exhaust, so I had to climb up to the top of the tanks then up on a scaffold, carrying a vacuum flask, to stand next to the exhaust stack and suck a sample out of the flow. All around me were explosion hatches; small explosions ("puffs") were undesirable but routine, and there was a well-established procedure for re-starting the system after it shut itself down following a puff.

For all that, it was pretty safe: as safe as it could be, considering the material. One day when I was taking a sample, a puff happened while I was on top, and I barely noticed it. I think I heard a bang as the explosion hatches jumped, but by the time I turned to look they had fallen back into place and re-sealed the tank, exactly as they were designed to do.

The gas mask was uncomfortable, but I was happy to be wearing it. It sealed all around my face, forehead to chin, and the sweat it generated improved the seal. I couldn't wipe the sweat off my face however, and it's no fun to get sweat in your eyes while you're climbing around a scaffolding system.

After a couple of weeks of this (I could only take one in/out sample set per day, and if there was a process upset that day I had to throw my results out) I noticed that my hair smelled … strange. For all it was a treated gas stream, with low levels of the toxic chemical, I had been spending enough time exposed to it that the gas had started doing something to my hair. The smell was that sickly-sweet smell of rotting fruit, and it lingered for a week or so after I finished that particular project. It took a few washes before the smell finally went away.

That smell in my hair was the only effect the gas had on me. Gas masks are wonderful things.

Getting lost in the stacks

I'm in trouble now…

I recently discovered a black hole as deep as the internet for losing time in, but which is much more edifying - so I don't feel so bad about all the time spent there because I'm learning stuff.

How useful that stuff is has yet to be determined.

We begin with Google Scholar. This is a corner of google's search engine that is focussed exclusively on technical journals and peer-reviewed publications. It's fantastic if you're looking for technical information about something that is also for sale; regular Google would be massively polluted by people selling that something, or asking for help about that something, or reviews of that something, or blogging about that something. There's just one catch, and it's a big one: the journals are almost all pay sites.

Oh, they let you read the abstract, and sometimes you're just doing an overview and that's enough. But at $30 per article or more, it can get expensive really fast if you're actually trying to dig into a subject. On top of that, if you're looking for something specific like the solubility of a relatively obscure compound (by 'obscure' I mean it's not on wikipedia), the information may not be in the abstract.

Then I remembered from my student days that the university library had a proxy which students could log in with and which would give full, free, institutional access to most of these pay sites. Of course the university would have a subscription! Of course, I'm not a student anymore.

After a bit of investigating, I discovered that my old student number was still in the university's system, and I successfully logged in to the proxy and downloaded a few papers that I'd put on my "to get" list.

Next thing I knew, it was three hours later, I'd downloaded a dozen related papers, was having a grand time reading them and following references—and I was still at work.

Fortunately, I was looking up information related to one of my projects at work and some of the interesting stuff I'd read might help the project, so I knew the boss wouldn't mind. Too much.

Now I have a bookmark to Google Scholar via the library proxy in my browser's bookmark bar which takes me to the proxy login page then to the search engine, so that every link I click on in the results goes straight to the full article.

I think I'm in love.

Snow eater

The Chinook wind is a warm dry wind that comes down from the Rocky Mountains into Alberta, and can turn a winter day into short-sleeve weather in the space of hours. But what heats up the air? It wasn’t that warm on the BC side of the rockies, before it crossed the mountain range. Well, I decided that I was going to calculate it. Let's see if this works.

Let’s say the air comes off the ocean at about 10 degrees Centigrade and 90% relative humidity, which isn't actually typical for a dreary Vancouver winter day—but that's because the Chinook is powered by the Pineapple Express, which is warm, wet air coming inland from Hawaii. It travels inland, raining on Vancouver as it goes, until it hits the coast mountain range, and is forced to rise.

You’ve probably noticed, if you’ve ever changed altitude quickly, that it gets colder the higher you are. Well, that wind from the ocean is going to do exactly that.

To do the math, we’ll look at a small piece of the wind, pretend it stays together to simplify things, and follow it over the mountains.