October 2010

Exploding telescope!

If, like me, you were bemused by the warning on Orion’s giant telescopes that pointing said telescopes at the sun could set their surroundings on fire, here’s some evidence that they’re really not kidding. Mike Lynch’s 14½-inch Dobsonian telescope exploded — that’s right, exploded — when the wind blew the cover off it and the primary mirror briefly caught the Sun’s rays.

“The wind blew the cover off,” he explains. “The scope was locked horizontally but the wind blew it out of gear and lifted it skyward — toward the southeast, unfortunately! Later that the morning the Sun just happened to pass in front of the mirror. What are the chances of that! When that happened, all hell broke loose: the eyepiece mount cap caught fire, and soon the entire upper half of the scope exploded in flame. The hand controller, eyepiece mount, and Telrad finder totally disintegrated!”

So, don’t point your telescope at the fucking Sun, okay? Especially if it’s a big Dob.

Do the Mythbusters know about this yet?

Building a snake hibernaculum

In my last post, I mentioned that one way to encourage snakes on your property is to build a hibernation den. Naturally the question followed: how does one go about doing that? Personally, I have no idea, but here are a couple of pages about building a snake hibernaculum: this one from the Toronto Zoo’s Adopt-a-Pond program; and this one from Respect the Snake, a website about conserving the Lake Erie Water Snake.

Releasing snakes as rodent control

Mildred from New Mexico writes with a question I’ve received on several occasions:

I was told that the most effective way to combat gophers is with snakes. Is it possible to introduce garter snakes into my back yard? Have you ever heard of this solution to the gopher problem and do you have an opinion on this matter? Is there a way to “direct” the snakes to the gophers? Where does one obtain a garter snake?

Mildred goes on to say that she isn’t sure that New Mexico’s climate can support garter snakes, but in fact there are eight species of garter snake in that state — New Mexico is actually tied with California for the most garter snake species in the U.S. Now that doesn’t mean that every spot in New Mexico is ideal for garter snakes, nor that Mildred’s back yard is suitable garter snake habitat.

And garter snakes are not the best predators on gophers. While several garter snake species can and do hunt rodents, gophers are more than a little on the large side. A lot of people use “garter snake” to refer to harmless snakes in general, but the common striped snakes we know and love won’t do any good against gophers. What Mildred really wants is a bullsnake or a gopher snake, which specifically target pocket gophers. Bullsnakes and gopher snakes are essentially the same snake: the bullsnake is the large subspecies of gopher snake found east of the Rockies. They’re found all over New Mexico.

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First impressions: Apple TV

Apple TV (courtesy Apple)

What the Apple TV does:

  • It connects to your high-definition television via HDMI (and only HDMI; cable sold separately).
  • It connects to your computer’s iTunes library, allowing you to play music, audio and video through your HDTV and home theatre system.
  • It connects certain Internet video and photo services to your HDTV (Flickr, MobileMe, Netflix, YouTube).
  • When iOS 4.2 comes out next month, you’ll be able to stream audio and video wirelessly from your iPad, iPhone and iPod touch on your HDTV and home theatre system, and not just from the default iPod or video apps. (This alone will save you the cost of a connector cable.)
  • It lets you rent and stream movies (and, in the U.S., TV episodes).

At $119 Canadian ($99 U.S.), that’s not a bad set of features, even if you have no plans to rent movies from Apple, so long as you already have a heavy investment in the Apple ecosystem. Adding a TV to that system for a hundred bucks or so does not seem unreasonable. A video-out cable for the iPad, iPhone or iPod costs $55 in Canada, $49 in the U.S., which is half the cost of an Apple TV that does the same thing wirelessly.

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Women and amateur science

Last month, Reptile Channel’s Russ Case posted a blog entry on women and reptiles — specifically, on the growing presence of women in the amateur herpetocultural community. Whereas once reptiles were “usually considered a guy thing,” Case argues,

Somewhere along the way, things changed. The next time you’re at a reptile expo, pay attention and you’ll notice just as many women wandering the aisles and enthusiastically examining the reptiles on display as there are men. And they’re not just in the aisles — you’ll see plenty of women vendors selling reptiles and amphibians, too.

It’s something I’ve noticed as well — not the trend, because even after 11 years, I haven’t been in the community long enough, or paying attention to it enough, to be aware of the trend — but the presence of women in the herp community, wrangling frogs, snakes, and lizards with the best of them, and I was aware that it was counterintuitive insofar as common sense or received wisdom was concerned. I’ve also met women who were bolder and less afraid of snakes than their male partners (which I found very interesting).

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Home reorganization update

Living room upgrade 1 Living room upgrade 2

An update on our summer plans to get the apartment into shape, execution of which plans has stretched into the fall.

I bought new shelves for the kitchen in August; they replaced a bunch of increasingly beat-up bookshelves that have since been redistributed to the basement and bedroom. For IKEA geeks, they were Bestå shelves, which are intended for living room entertainment systems, but they adapted well to kitchen use.

Living room upgrades are now done. Last month I splurged and bought a 40-inch LED high-definition TV set and a Blu-Ray player; it’s a profoundly better experience than the old 26-inch standard-def widescreen we’ve been using for the past five years. All old TVs have found new homes in places other than landfills.

Last week the new leather sofa bed showed up, sooner than expected: I ordered it online and it turned up after a week; I’d been led to expect three weeks when I asked at the Ottawa store. Unlike the TV, this was a necessary upgrade: the old futon (which now goes into the basement) was uncomfortable to sit on for long periods of time, and no other sofa bed in my price range, leather or fabric, was as comfortable as this one.

Jen also picked up an Apple TV last Thursday; I’ll have my first impressions of the gadget in a blog entry soon.

HDMI cables, which we needed to connect the Blu-Ray and the Apple TV to the television, are overpriced. It cost me $30 to grab one at Best Buy; I later ordered two more from Monoprice, which arrived in a week and a half and cost me all of $12, shipping included.

The basement is largely done. We’ve sent a lot of old crap to the dump, painted the floor (except for a spot or two) and washed the walls (which got rid of the musty — i.e., mouldy — smell), and put up new shelves. Still some sorting (and a little painting) left, but it’s already an order of magnitude more habitable than it was before.

All these purchases have emptied my bank account (or will when it comes time to pay the credit card bill), but that simply means that I’ve allocated the money I saved up while working on contract for the federal government. This was what it was for, you see.

Reflex or mirror lenses

Ken Rockwell reviews the Nikon Reflex-Nikkor 500mm f/8 lens, one of several mirror-based telephoto lenses Nikon once made. These are catadioptric lenses, which use a combination of mirrors and lenses. It’s an optical type familiar to astronomers: the popular Schmidt-Cassegrain and Maksutov telescopes are catadioptric systems. (It doesn’t look like Reflex-Nikkors are either Schmidts or Maksutovs, though.)

Catadioptrics achieve very long focal lengths in a compact space, and, because they use mirrors, there’s no chromatic aberration. But their focal ratio is fixed and, at those long focal lengths, depth of field is very shallow even at f/8 or f/11 — and because of the central obstruction, bokeh is horrible: out-of-focus elements appear as donuts. This isn’t a problem in astronomy, where focus is always at infinity — I’ve taken plenty of shots through my Schmidt-Cassegrain — but it’s distracting in terrestrial telephoto photography. (Three examples on Flickr here, here and here.)

This page compares a Tamron mirror lens with a Canon telephoto: the Canon is the clear winner in quality, but the mirror lens is considerably cheaper (another advantage). Only one reflex lens — Sony’s 500mm f/8, still available — has ever had autofocus; the rest are manual lenses.

There’s a mirror reflex lens group on Flickr, and an (inactive) blog about mirror lenses.

Books read: September 2010

Books read: September 2010 (covers)

The Lifecycle of Software Objects by Ted Chiang. I wrote about Ted Chiang’s new novella in July; our copy arrived in late August, and I read it in an easy Sunday afternoon on Labour Day weekend. If you like Chiang’s work as much as I do, this one won’t disappoint: as usual, a finely crafted work that blends a high concept with a powerful emotional punch. To explain what this book is about, imagine that we invented artificial intelligence. Now imagine that it only ran on the Amiga. That’s what this story is about: the struggle to keep artificial intelligences going when technology — and society — have largely left them behind.

HTML5 for Web Designers by Jeremy Keith. Slender book explaining the history of the development of the HTML5 specification and the changes in code from HTML 4/XHTML 1.1. Extremely concise and at least as effective as longer, more expensive books on the subject (e.g., HTML5: Up and Running by Mark Pilgrim). I read this one as an e-book, in which format it cost me all of $9.

Leviathan by Scott Westerfeld. Young-adult steampunk alternate history set during the outbreak of World War I, where Europe’s alliances are determined by their technologies: Germany and Austria-Hungary are Clankers, using machinery; Britain and France are Darwinists, using bioengineering. Readable, engaging and ultimately successful, but frustratingly reads as the first installment of a larger series, which it is.

The Lifecycle of Software Objects by Ted Chiang
Leviathan by Scott Westerfeld