Tuesday, February 24, 2009

Comet Lulin Appears

Comet Lulin (C/2007 N3) is a comet discovered by Quanzhi Ye, a student at Sun Yat Sen Universty from sky photos taken at Taiwan's Lulin Observatory. About 20 hours ago around 0300 ET in the early morning of Feb 24, the comet made its closest approach to Earth at a distance of 0.41 AU.

The comet appears to be a first time visitor to the inner solar system. The NASA Swift Ultraviolet and X-Ray Explorer has been used to get images of the comet at ultraviolet and x-ray wavelengths. The data from Swift shows that it is shedding water at a rate of 3,000 litres per second (enough to fill an Olympic-sized swimming pool in about 15 minutes), and surrounded by a Jupiter-sized cloud of cyanogen and diatomic carbon, glowing green as these compounds fluoresces in sunlight.

This amazing photo was taken by Joe Wheelock of Fort Davis, Texas, USA, a couple of hours before the closest approach. He has the following notes:

I think I caught a tumbling satellite in between Comet Lulin and Saturn in this picture. Photo Details: Comet Lulin and Saturn Taken on Feb. 24, 2009 (12:05 A.M. CST) with 105mm Sigma telephoto piggybacked on my 16inch F/4.5 Newtonian Telescope Canon XSi DSLR 120sec. exp @ISO 1600 f/3.5. Image processed with Adobe Photoshop CS3, Digital Photo Professional, Blackframe Noise Reduction and Neat Image. In between Saturn and the comet appears to be a tumbling satellite?

The orbital path of Comet Lulin can also be visualized using the small body database maintained by JPL.

Comet Lulin currently has a brightness of visual magnitude +5.5. This level of brightness will drop over time for two reasons - first, due to increasing distance as the comet gets farther away from us. The second reason for a drop in brightness is a change in the amount of light reflected by the comet. As the comet reaches perihelion and starts moving farther from the sun, the amount of material blown off by heat and solar radiation will decrease, and the comet's extended halo and tail will decrease in size resulting in less light being reflected.

At +5.5, Comet Lulin will be difficult to spot in Toronto with the naked eye, although it should be fairly easy to see with binoculars for the next few days. Darker locations away from the middle of a city, like Lake Herridge, or Almonte, or the middle of Saskatchewan will be more ideal.

Monday, February 23, 2009

Feedback Controls

A big chunk of my work life has been in the automotive finance industry, but I can't really say that I am a car guy. A car is a necessary evil, not the raison d'etre of existence.

So it was that in early January, after delivering our friend Annalee to the airport, I noticed an instrument panel light that I had never seen before. A quick check showed no flames or smoke or other serious issues, so I continued driving, and got the car home before I hauled out the manual.

This particular problem, it said, was related to the exhaust system, prompting dark thoughts about the expense of replacing a catalytic converter. According to the manual, this problem was serious and needed fixing. Or Bad Things Would Happen.

The mechanic at our favourite garage was more enlightening. It wasn't the catalytic converter -- instead, it was an oxygen sensor. Of which there were three -- two in the engine itself, one in the exhaust. Our failure was the one in the exhaust.

At which point a light came on over my head. The oxygen sensor in the exhaust is the last part of a feedback loop providing information to the car's onboard computer. The computer adjusts the fuel mix until it achieves a preset level of oxygen in the exhaust, indicating that a predesgned fuel to air ratio had been achieved. The system is designed to monitor the output so that the input can be tweaked. Leaving this uncorrected would have meant that the car would have been doing strange things to the fuel mixture -- potentially damaging the engine, but certainly not optimizing for fuel consumption efficiency.

So, a feedback loop. A useful idea -- one could imagine monitoring the activity of, say, a financial institution and its effect on the economy. Then tweaking the government bailout money going in until the required output goals were achieved. Or one could imagine feeding bailout money into the auto industry based on what kind of vehicles it was producing -- set the feedback loop to optimize for fuel efficiency and low carbon emissions.

Saturday, February 21, 2009

The Avro Arrow

Fifty years ago yesterday, on February 20, 1959, the Canadian government of Prime Minister John Diefenbaker cancelled the development of the CF-105 fighter plane -- the aircraft known as the Avro Arrow.

In hindsight, the Arrow was just another 1950s era fighter plane, although for its time, it was the fastest and most advanced. And while it is possible to debate the upsides and downsides of the aircraft (fast, great climb rate, potentially capable of Mach 3+ on the upside versus heavy, high drag, low manueverability on the downside) it is the cancellation of the aircraft that results in one of the "might-have-been" myths of our shared Canadian experience. What might it have been, what could we have achieved, if the Arrow had gone forward to full production?

Cancellation of the Arrow project led to a lot of engineering talent moving south, and enormously benefiting the American space program. It also ensured the loss of an entire industrial sector -- Canada never again produced its own domestic military aircraft.

The lesson is an outsourcing lesson -- the country gave up some existing capability to save money. In doing so, it also shut down some future possibilities. In just the same way, a company which outsources its IT, or its manufacturing, or its marketing in order to realize some immediate bvenefits will give up some future capabilities -- and in fact will make it impossible to travel down some possible paths.

Wednesday, February 18, 2009

More on Tesseracts Twelve

From Claude Lalumiere's page on Facebook, a most interesting essay by Matthew David Surridge on Tesseracts Twelve, and how it avoids or sidesteps the traditional themes of Can Lit.

I read Margaret Atwood's Survival more than three decades ago for an English class. I was sufficiently impressed with it to go out and buy my own copy. But you'll note (he said, with wry understatement) that English Lit didn't end up being my field of study or the focus of my work life. However, this essay has inspired me to go find and re-read Survival.

Surridge has a much wider knowledge of Canadian literary criticism than I do, and observes that the stories in Tesseracts Twelve largely avoid the recurrent Man-Versus-Nature theme of traditional Can Lit, as extensively documented by Atwood and others, although

... nature is strongly present in the anthology in the form of animals; but these are animals which in one way or another blend into the human. “Intersections” is probably the only story without an animal presence. Humans and mammoths share mentalities in Derryl Murphy’s “Ancients of the Earth”, Michael Skeet and Jill Snyder Lum give us fox spirits and a surprisingly talkative tanuki in “Beneath the Skin”, Chen has men and women changing into dogs and goldfish, Randy McCharles’ story “Ringing the Changes in Okotoks, Alberta” has witchcraft linking a man and a goat, Gord Sellar’s super-hero tale “Wonjjang and the Madman of Pyongyang” includes a Japanese cat-woman, and “Wylde’s Kingdom” is the story of a man hunting and being hunted by a giant squid — with, inevitably, a hint of empathy between hunter and hunted towards the end. So perhaps this anthology represents a new Canadian mentality; no more of the garrison, no more of the conflict between man and wilderness, now our stories are those of man and nature merging.

Surridge goes on to this conclusion:

...Tesseracts Twelve may signal, ultimately, a change in Canadian literature to mirror the changes in the country itself. Where the country has seen its demography shift, has managed with surprisingly little strain to incorporate a wealth of voices and cultures within itself, has changed its traditional narrative of its own founding and development, the book suggests new themes for Canadian writing, new models for its story. Hints of the old are still there, certainly, as they should be, but not given the stress they might have carried in the past...

I like this idea -- that the collective narrative changes as culture and demographics change, each driving the other but also rooted in the past.