NPR. The saying goes, don't reinvent the wheel. But the wheel has been reinvented many times.

And that's a good thing, according to structural engineer and author Roma Agruwa.

I find this expression that we shouldn't reinvent the wheel really annoying.

Because the fact is that ever since we didn't invent the wheel,

we have been reinventing it.

This is the indicator from Planet Money. I'm Darien Woods.

On today's show reinterpreting the wheel,

how the wheel has cycled through change after change, and just how crucial that innovation

has been to the modern economy. Roeba Argyrell, structural engineer, and author of the book, Nuts and Bolts, seven small inventions

that changed the world in a big way. Welcome to the show. Thank you so much for having me. So obviously

wheels are important in the modern economy for driving, for trains, for planes, but

where else do we use wheels going through a typical day?

If you ask somebody what the most important inventions in human history is, I think a lot of people

would say the wheel and axle because it is so important and you've mentioned the kind of the

obvious ones that we can see but if you think about the fact that you might have a toothbrush with a rotating

head like an electric toothbrush I often have a breakfast smoothie which requires some

spinny sharp things to break my fruit down. So these are the kind of very

everyday objects that need that spinning action. So there is an absolutely

enormous range of applications of the wheels that might not be

immediately obvious when you think about it. So let's start with how the wheel was actually invented. I think the collective memory has some

kind of image of like a stone wheel carved in a cave, maybe some kind of Fred Flintstone style

carriage.

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