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## Think of a number …

December 22nd, 2010 by Gene

Today’s trick question: show us a number. Better yet, show us an imaginary number. We’ll use our imagination and see what they’re good for. Today, on Engineering Works!

Engineers love numbers. They’re at the center of everything engineers do. Measure and calculate and predict. Numbers let engineers decide how strong that bridge needs to be. They make sure the thousands of parts in a jet engine fit together and do what they’re supposed to. They’re real numbers.

Imaginary numbers are something else. Technically, an imaginary number is the square root of a negative number. Ask your math teacher how that works. He or she will probably tell you it doesn’t. You’re not supposed to be able to do a square root of a negative number. But imaginary numbers are very real.

If you find this confusing, you’ve got company. The 16th-century mathematician who discovered imaginary numbers thought they were pretty cool, but he couldn’t see that they were good for anything. Over the next several hundred years, other mathematicians agreed with him. Now, close to 500 years later, we’ve figured out that imaginary numbers are crucial to the weird branch of physics called quantum mechanics. And quantum mechanics helped engineers develop a lot of technology we take for granted. Stuff like computer data compression and MP3 players and most of the high-tech electronics we take for granted.

We don’t know if our numbers are imaginary, but we’re running out of them for this time. See you later.

Engineering Works! is made possible by Texas A&M Engineering and produced by KAMU-FM in College Station. Learn more about engineering. Visit us on the World Wide Web.

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Start the discussion: Numbers play important roles in each of our lives, yet most of us are profoundly uncomfortable dealing with them. How can we change this?

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