## 12

12 represents a fascinating number for engineers, particularly ones whose efforts provide electricity to our homes.

The average price of one kilowatt-hour (kWh) of electricity is 12 cents. Think about that. One can turn on a 100-watt light bulb and leave it on all day, for 10 hours, and it costs 12 cents. And with CFLs and LEDs, this cost will go way down. The engineer’s wife could dry her hair with a a 1000-watt hair dryer for an hour – if her hair is really wet – and it would cost 12 cents.

I realize that there are many factors that go into the cost of electricity and I certainly do not want to get involved in debates over subsidies, energy sources, environmental impacts, etc. (at least not now). What I wish to do is marvel at a system of creating and distributing electricity that engineers designed and built that contribute greatly to the ability for us to buy one kWh of electricity for 12 cents.

I am sure I don’t have to repeat it here, but engineers are amazing.

## Equilibrium

For an engineer, equilibrium is something to be attained – at home, at work, on travel. Equilibrium means things are equal. At peace. Not changing or frenzied. One equilibrium issue which is always running through my mind in winter is thermal equilibrium of our home.

Î”Heat = 0

Or, put another way,

Heat In = Heat Out

It seems simple enough. The more heat is transferred out of the house, the more the heating unit will need to transfer heat in to the house if equilibrium of the home temperature is to be maintained. I sit there and see the heat transfers take place and plot how I can affect this equation. How can I prevent heat from transferring out of the house, therefore reducing the need for more money being spent to add heat to the other side of the equation.

This is why we insulate our homes, seal the cracks around our windows, and yell at the kids to “Shut the door!”

Equilibrium.

## Quotes – What’s with them?

Where are all the inspirational quotes from engineers? I was reading an email newsletter from an engineering organization recently. They have a new quote in each day’s email. This particular day finally broke the camel’s back, adding that last non-engineering quote in an attempt to inspire the engineer readers. This was it:

People who lean on logic and philosophy and rational exposition end by starving the best part of the mind.”
–William Butler Yeats,
Irish poet and playwright

Another quote a few days before this one was as follows:

Birds sing after a storm; why shouldn’t people feel as free to delight in whatever remains to them.”

–Rose Kennedy,
American philanthropist

Who do these people think are reading this? It is a newsletter for ENGINEERS! We don’t want read about not leaning on logic and birds singing after storms. And we particularly don’t want hear from poets!

The publisher must give this part of the newsletter over to a non-engineer who has some dirt and is blackmailing the engineering organization that produces this newsletter. That is the only (logical and rational) explanation that would explain this behavior.

I may have to start producing some great inspirational engineering quotes for use in these newsletters. Look for them in future engineeringdaze posts.

## The Far End of the Bell Curve

I changed the lights in the entry way “chandelier” yesterday, with the help of a couple of my kids. I climbed the ladder, they took the burned out bulbs and handed me the new ones. It was a team effort.

It made me think of our previous house, where we had a similar setup with a chandelier in the entry way that had 7 or 9 or so light bulbs and the only way to access them is with a ladder. But with that one, all the lights were working when we moved in, and then, over the next few years, we saw the bulbs burn out, one by one, until there was only one of those 40W bulbs still working. This was the bulb at the far end of the bell curve of light bulb longevity. As an engineer, I appreciate a good bell curve.

My family whined and said it was too dim and we should replace the bulbs. But I didn’t want to replace all but one bulb and then have to go up there and replace that one before the others need replacing again, and then… well, you get the idea. Plus, this was a great experiment. I convinced them (my interpretation) of the need to find how far out that bell curve went, seeing that we had a 99.999 percentile bulb up there. We waited. We waited 2 or 3 years past the penultimate light bulb failing for that last bulb to finally burn out. We were exploring the very, very far end of the bell curve, and it was great. A little dim. But great.

I should have documented it.

## You Might Be an Engineer If…

– your New Year’s resolution involves improving the romantic relationship with your significant other by revisiting the romantic-relationship algorithm and improving it’s efficiency from feedback mechanisms.