Thursday, November 29, 2007

Things stop working

These days it seems to me that nothing is working.

Reminds me of a time almost 35 years ago when I had trouble with a particular computer. Back then, very few people owned a personal computer. I was an undergraduate in a new Computer Science department, and one of my professors owned a mini-computer, a PDP-8. It was available for student use, and we had to sign up in advance for 50 minute time slots.

Every time it was my turn, I would walk in, set my notebook on top of the console, and start to work. After just a few minutes, the machine would crash, and I would have to spend the rest of my time slot trying to get it working again.

I asked my fellow students, but no one else had that problem.

What was going on? It turns out, that you already know enough to figure it out, if you'd like to take a minute to think about it before reading on.

* * *

Yeah, it was the notebook on top of the console, causing it to overheat. Stopped putting the notebook on the console and never had the problem again.

It's not always quite so easy to figure out why something that always worked before doesn't work any more.

* * *

Recently, my email client software, Mozilla Thunderbird, has stopped doing its automatic updates. Here's what happens instead. Without telling me, it goes out to the network and downloads the latest version. Once that's all been received, it pops up this alert (interrupting whatever I happen to be doing at the time--ARGH!):

I've tried it both ways. Closing everything and giving it the go ahead, and clicking on Later. Choosing "Later" gives this response:

Okay, that's fine. Either way, I am always very careful to shut everything down before restarting Thunderbird.

Doesn't matter. It always fails. After a few moments, it lets me know that it didn't work. Again. I've lost track of how many times it has tried. The bottom line is that Mozilla Thunderbird update doesn't work.

The error message is not helpful. All other applications ARE closed. WHICH files do I need permission to modify? It doesn't say!

And, I have no confidence that restarting Thunderbird makes it actually try again. Because all future attempts to restart Thunderbird happen without incident. And yet, over and over again, it is downloading and readying the update. Only to put me through the same process and the same failure yet again.

Where can I turn for help with this kind of problem?

Wednesday, November 14, 2007

On being average

There's nothing wrong with being average. Most people are. Another word for average is "normal" and certainly there's nothing wrong with being normal.

I have recently heard a couple of jokes about "average" that bear repeating.

One claims that a national leader expressed dismay upon learning that half of all Americans are below average.

Another claims that 80% of university professors surveyed rated themselves above average as professors.

What makes these jokes funny is that, in any population, half are below average and half are above average. That's just what "average" means. In particular, 80% of the population cannot be above average; exactly 50% are.

Suppose you look at an entire population and measure any naturally occurring property (height, weight, intelligence, bank balance, etc.). Suppose you then count the number of people with each possible measurement. Now graph the values of the property across, from smallest to largest value. Finally, show the number of individuals at each measurement as the height of the graph. When you do this, the graph will look something like this:

Image courtesy Wikipedia.

This graph is called the "normal distribution" by statisticians. You may recognize it as the "bell curve," so called because of its shape.

The vertical line at the very center is labeled with the Greek letter mu, which is the symbol used for the "mean value" (which is what statisticians call the average measurement).

This is the highest point in the graph, which means that there are more people who have the average measurement than any other measurement. Fully 68% of the people are "close" to this average measurement. Most people will be close to normal.

And, as I have said, 50% of the people have measurements above average; the other 50% are below average.

To indicate how far a measurement is from average, statisticians use the term "standard deviation," indicated by the Greek letter sigma. Only about one in a thousand people will be more than three standard deviations above average.

More than 2/3 of the individuals in the population will be within one standard deviation of the average measurement. Only one in six will be abnormally above or below average. Of these, only one in fifty will be "way" above (or below) average. And, as mentioned earlier, only one in a thousand will be off the chart.

Almost everyone is average. That is normal. And being normal is nothing to be ashamed about.

Disclaimer: The statistics here are simplified, as this is just meant to be thought-provoking.

Saturday, November 3, 2007

Time travel

I have always been very much aware of time. Not that I am a good manager of time--that is a different matter.

This awareness is so much a part of my life that I chose this tagline: "traveling through time at the usual rate of one second per second," hoping for something pithy, memorable, and evocative.

Looking back at the past, and looking forward to the future, are both favorite passtimes. And I mean "passtime" in the more literal sense of something to do while time passes; for meanwhile, the world continues to move forward at the usual rate, etc.

There is nothing like a photo to plunge me into a state of nostalgia and reflection.

Pictured are four of my favorite people. I think I was the photographer. I was certainly present when the photo was taken. That was a wonderful moment that was captured; one of many that day, visiting my parents in Canada.

All of the people in the photo are gone now. My children's grandparents gone the way of all the world: dead and buried, but not forgotten. The children are still living, so they are not gone in the same sense of the word.

But the children are now adults. Of course, I love them just as much now as I did then.

It is them as they were then that I miss. Gone is the naiveté, the innocence, the simple delight in being alive. That moment, that day, those innocents, are gone forever.

And that is one of the consequences of traveling through time--not that I have any choice--at the usual rate of one second per second.