Save on Gas. Drive the Speed Limit

I stopped at the gas station on the way home from work today. With gas prices at $1.034/L, the $40 worth that I purchased barely filled 3/4 of my tank. Being the cheap bastard that I am, I was immediately reminded of an article I recently came across on Treehugger that recommends conserving gas by driving the speed limit. It’s good advice but, as an engineer, I found their expanation somewhat lacking. So here is my best attempt at explaining, in the language of high-school physics, why driving slower uses less gas.

There are two parts of driving that are worth considering. First, how much energy is spent getting a vehicle up to speed, and second, how much is used to sustain that speed.

Let’s consider the first: accelerating to full speed. If you remember from your high school physics classes, the kinetic energy of a moving object is proportional to the square of its velocity, or e=mv2/2. What this means is that to go twice as fast requires four times as much energy. For example, to accelerate from 0-100km/h requires in your car requires four times as much energy, and therefore four times as much gasoline, as accelerating from 0-50km/h.

And that’s just the energy to get up to speed. In a frictionless and air-resistanceless world, you wouldn’t need any more energy, the car would just coast forever. But we don’t live in such a world, which brings us to the second point, sustaining the velocity.

Air resistance and internal friction increase propotionally with the speed that you drive. If you drive twice as fast, the air pushes twice as hard against you. This shouldn’t come as a shock to anybody who has held their hand out the window of a moving vehicle. So how does that translate into fuel consumption?

If you followed the link to the Treehugger article, you’d already know that fuel consumption is proportional to the speed you drive. But how? Think back again to your high school physics class: work is equal to force times distance, or w=fd. You’ll also remember that work and energy are the same thing. So if you drive faster, you’ll have to apply a force against a higher air resistance. Over the same distance, driving faster will require more work, which is energy, which is gasoline, which is dollars at the gas station. Driving twice as fast requires twice as much gasoline over the same distance.

So there you have the basic physics of how it’s cheaper to drive the speed limit (or less) from a cheap bastard of an engineer.

Spray paint your chips

Ars Technica is reporting on a new technique that researchers at Epson have developed to manufacture semiconductors. They liken it to spray painting chips:

Their approach is to use either a “spray painting” technique or ink jet deposition to grow features. They have designed an organo-silicon molecule, which readily dissolves in common solvents. This molecule is then deposited by either a spraying or ink jet technique on a silicon substrate to form the semiconductor features. The whole wafer is then heated causing the organic molecules to decompose and form amorphous silicon. The amorphous silicon can then be converted to crystalline silicon by irradiation with standard UV lasers. So far, researchers have managed to demonstrate a proof-of-concept by growing thin film transistors used for controlling the pixels on LCD displays.

They are currently able to produce chips at feature size of 250nm. Not bad for a first shot. And that number is bound to come down with more research. It’ll be interesting to see if anything comes of it.

I Suck at Texas Hold’em

On Friday night, Mandy’s office held a small poker tournament. Considering what life lessons Steve Pavlina learned from playing poker and blackjack, I figured I’d give it a try.

I didn’t expect to do very well, despite skipping my Friday workout to practice at home on our PS2 with World Championship Poker, but I was shocked a just how hard I sucked at it. I finished 20th or 21st out of 24.

So being the kind of person who just can’t stand to suck at something that rests so firmly on one’s mathematical and analytical abilities, and knowing that assessing risks and capitalizing on opportunities is something that I’ll need to learn if I’m ever going to start a company, I’ve downloaded the client to get some more practice.

We’ll see if it helps any at the next tournament.

Aside: Something tells me that gambling is one of the two things Dave Pollard chose to leave off his list things to do when you’re blue.

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Why is home ownership so popular?

I was out dethatching the front yard this morning, taking advantage of the unusually sunny weather that has come our way, and, as is often the case when I’m left alone with my thoughts and a witless task, my mind wandered to the obvious place, wondering why on earth I ever agreed to buy this house that consumes so much of my time and energy.

When you consider all the costs of owning a house (taxes, interest on a mortgage, gas, electricity, renovations, maintenance, time, etc), there’s no way that it could possibly be a better investment than renting an apartment and investing the difference in mutual funds. It’s like having a second job, except instead of being paid to work, you pay to do it. So why do so many people own houses?

The answer is obvious to anybody whose ever given a few moments of consideration: control.

In his talk at EclipseCon, Joel Spolsky touched on Martin E. P. Seligman’s theory of learned helplessness, which as I undertstand it states that depression is a result of a lack of control over one’s environment. When you feel that you can’t influence the world around you, you tend to feel depressed.

In today’s society, what better way of exerting control over your environment is there than owning a house? Unlike a rented apartment, you can paint the walls whatever colour you like; plant a garden if you have the thumb for it, or as in my case, rip one out because you haven’t; change the floors; fill it with furniture; etc. Apparently, for most people that sense of control is worth all the afternoons mowing lawns; raking leaves; shoveling driveways; wiring basements; etc.

Thoreau, when he left Concord for a simple life in a hand-built shed on Walden pond, noted that “Men do not own their homes, but rather the homes own the men.” Maybe so, but it seems to be a type of slavery most are willing settle for.

Eating my words on William Gibson’s Pattern Recognition

Last week, I beat up William Gibson’s Pattern Recognition, calling it “terribly contrived” story, and suggested that it was a mediocre novel.

I’ve since finished reading it and I have to say I’ve had a change of heart. In all fairness, it finishes better than I expected. By the time I reached the end, I’d even say that I was, gasp, enjoying it.

I still wouldn’t consider it to be a great novel, but it was certainly better than mediocre, and not at all deserving of my initial comments.

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Power hikes could hit 16 per cent: analyst

CBC Toronto is reporting that power hikes could hit 16%:

An energy expert is predicting an electricity rate increase of up to 16 per cent per cent May 1, though the bump in price will vary across the province.

Tom Adams from Energy Probe said rates will increase by at least five per cent to allow the province to recover money it lost because last year because [sic] the wholesale or commodity price of electricity was higher than expected.

No need to worry, though. Just inform your boss that your hourly rates will increase at least five percent to allow you to recover money you lost because last year the wholesale price of beer was higher than expected.

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