Archive for September, 2003

What a wonderful world

September 24th, 2003 by dstmartin

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Take this, David Letterman and your top 10 lists. We can do our list in seven: the Seven Wonders of the Ancient World. So fire up your imagination and we’ll check it out today on Engineering Works!

In any list of lists, the Seven Wonders of the Ancient World stand pretty near the top. These marvels were all built thousands of years ago, but engineers today would be proud of them.

Let’s start with the Great Pyramid of Cheops. It is great, as in big; tall as a 40-story building; two-and-a-half football fields on each side, it covers 350 city blocks. And get this: all four sides are within half an inch of being exactly the same length. And it was built more than 4,500 years ago.

The Colossus of Rhodes: 110 feet of bronze on the Greek island of Rhodes. An earthquake knocked the statue down 50 years after it was built, but tourists kept coming to see the wreckage for a thousand years.

King Mausollos of Halicarnassus built a huge fancy tomb for himself. He’s gone and so is his tomb, but he added a word to our language – mausoleum.

The Lighthouse of Alexandria on Pharos Island stood for more than 1,500 years, until late in the 1600s. It was so wonderful that the name of the island came to mean lighthouse in French, Italian and Spanish. You can look it up.

The other wonders? Well, there’s the Hanging Gardens of Babylon, built about 800 BC in what’s now Iraq. The statue of Zeus presided over the early Olympic games in Greece. And the Temple of Artemis at Ephesus in today’s Turkey.

Who knows what folks 5,000 years from now will call our seven wonders? Write and let us know.


Conversations with my computer

September 17th, 2003 by dstmartin

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Recognize that sound? You should. Today, we’re going to join the revolution. Make computer keyboards a thing of the past. On Engineering Works!

Everybody knows what a set of busy fingers on a computer keyboard sounds like. More than half of us use computers at work. Almost that many use them at home, too. That’s a lot of keyboard time.

Here’s the good news. Someday you may be able to quit typing everything into your computer. Speech recognition systems that recognize what you say and store it in you computer are available, now. The bad news is that they don’t work that well yet.

Dictation is like me speaking into the microphone in front of me, except that instead of you hearing what I say, the idea is that the words go directly into a digital file in my computer. No typing. Then I could print it out on paper or send it in an e-mail.

Dictation still has some bugs in it. Sometimes it has trouble figuring out the difference between words that sound alike. Or understanding people with accents. Get your buddy from San Angelo to say the word – e-g-g – and you’ll hear the problem.

You’ve probably seen ads for cell phones that you can talk to. Tell it to “Call Momâ€? and it does. That’s the command and control system. It works better than dictation right now because it doesn’t need to recognize many words to carry out commands. Software engineers are working hard at getting these systems to work better. They’re getting better all the time.

Computer! Bring up theme music.


Engineering is music to your ears

September 10th, 2003 by dstmartin

Just about anything can make a sound. It takes skill – and engineering – to turn sound into music. Find out how engineers do that, today on Engineering Works!

You’ve probably blown across the top of an empty bottle. The bottle vibrates, creating sound waves. Add water to the bottle and blow again. Hear the difference? You’ve changed the bottle’s pitch – how high or low it sounds.

Things like valves, pistons and springs change pitch in many musical instruments. That’s right: those parts you find in engines and machines also help musicians play mellow tones and reach high notes.

You’re catching jazz legend Miles Davis on trumpet right now. Trumpets and horns were simply long tubes until around 1815. Two musicians in Germany developed a spring-controlled sliding valve that increased the range of notes those instruments could play. They based the idea on valves used to control air, water and steam in blast furnaces and steam engines, the high tech of their time.

This really big machine – the pipe organ – got its start thanks to an engineer in Egypt more than two-thousand years ago. We even know his name: Ktesibios of Alexandria, inventor of the water clock. He used water pressure to pump air to lots of pipes at the same time. Most organs built today use electric air pumps to power their pipes.

Oh-oh, is that a Martian behind you? Fans of old science fiction movies probably recognize these eerie sounds, although you may not know the instrument that makes them. The theremin – named for its inventor, physicist Leon Theremin, in 1919 – doesn’t have any keys or valves at all. Instead, you play it by moving your hands to control radio frequency sound waves.

Got that? Okay. Let’s take it from the top!

Slinky: an engineering marvel

September 3rd, 2003 by dstmartin

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Listen close. If you’re a kid, or you’ve ever been one, chances are you know what this sound belongs to. Do you know? We’ll find out if you’re right, today on Engineering Works!

Did you guess? You’re right, of course. It’s that silly engineering marvel, the Slinky.

The toy generations of kids know as the Slinky was born by accident on a U-S Navy ship during World War II. Naval engineer Richard James was trying to design a way to use springs to insulate fragile shipboard instruments from shocks and vibration. He got the idea for the Slinky when one of his experimental springs walked off a shelf and down onto the deck. As it turned out, the Navy never used James’ idea. But when he got home after the war, he and his wife perfected the steel ribbon spring toy we all know today.

The Slinky was an instant success. The Jameses sold their first four-hundred Slinkys within an hour and a half of when they offered the springy toys for sale.

Most of us still think of Slinkys as toys. But they have their serious side, too. The springy steel spirals have been used to build everything from radio antennas to light fixtures and pecan pickers. Physics teachers use them in class to demonstrate cool stuff like – wave properties – forces – and – energy states.

The Slinky has even made it to the big screen, in the “Toy Story� movie series.

Time’s up. It’s time for us to slink away.