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.