Long distance butterflies

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Engineers do a lot of cool and useful stuff. But there are a few things Mother Nature still does better. We’ll look at one, today on Engineering Works!

Just about everybody knows about the global positioning system, or GPS. It’s a network of satellites that let us know almost exactly where we are. GPS can help us find our way – across town, or across the mountains.

Now, let’s look at butterflies — monarch butterflies in particular. Monarchs fly really long distances. Each fall they find their way south from their summer homes in Canada to their winter homes in central Mexico. And each spring they go north, back to Canada. About 3,000 miles each way. And they never get lost.

Two things are important here. First, butterflies don’t have GPS receivers. And second, none of them lives long enough to make the trip both ways. They don’t remember where they came from. They start over again, every time. And they still get there. How does this work?

It has to do with the way butterflies see ultraviolet light from the sun. That’s a part of sunlight humans can’t see. Monarchs see the direction this light comes from and use it to set a course for their trips north or south. How long they see it each day tells them when it’s time to go.

So, no engineers here today. Just a little reminder that there are still some things engineers can’t do. Yet. See you next time.

Landscapes that work

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You probably don’t see much engineering in a rainstorm. Engineers do. We will, too, today on Engineering Works!

Rain is water, and water is wet. Nobody has to think much to figure that out. But figuring out what to do with all that wet can be a challenge for the folks that design things that spend all their time out in the rain — like big shopping malls or convention centers. Some have several acres of roof, and that roof collects a lot of water.

The first thing that has to happen is the rain has to get off the roof. This isn’t too hard. Make sure the roof slopes in the right direction, and put in drains to take the water away. Easy.

Now what? The water isn’t on the roof any more, but it’s still got to go somewhere. Running it out into the parking lot just moves the problem from one place to another.

Engineers and landscape architects have figured out how to combine natural stuff like rocks and soil with the shape of the ground so rainwater collects out of the way and then soaks in instead of just running into storm drains.

One of the best things about this approach to dealing with rain is that plants and soil filter the water as it goes back into the ground. Then it’s something we can use, not just something to get rid of.

It sounds like we’re about to get rained on ourselves. See you later.

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Personal fabrication

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It’s almost like the fairy tale of the genie in the lamp. But you get more than three wishes — personal fabrication, today on Engineering Works!

All of us have wanted things that we couldn’t find. Not big or expensive, but we couldn’t find it anywhere — spent hours Googling. It didn’t exist.

Now information technology experts and engineers are working on an idea that may make our wishes come true. They call it fabrication laboratories, or fab labs. Your own personal genie in the lamp — with unlimited wishes. Almost.

Fab labs put together easy-to-use design software and computer-controlled tools so people can design and make – themselves – things that they want, but nobody makes. It sounds like it ought to be science fiction, but it’s already fact. In a small way.

How about this one? A farmer in far northern Norway kept losing some of his sheep as they grazed in the rugged hills around his farm. He used a fab lab in one of his barns to design and build little devices based on cell phones and GPS locators that the sheep wear on collars. When he couldn’t find one, he’d call its locator and it would tell him where the sheep was. Pretty slick.

This kind of personal fab lab is still mostly experimental, but the engineers working on them say they should be getting more common.

Our time is up for now, so we’re going to fabricate our way out of here. See you next time.

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