Archive for July, 2004

Food irradiation

July 30th, 2004 by dstmartin
 

Listen to the episode

Everybody does it. Nuke it! Today on Engineering Works, we’ll find out how the biggest microwave oven you ever thought of makes food and other things safer.

Microwave ovens and food just seem to go together. They’re pretty handy. A minute or so and last night’s leftover fried rice turns into a tasty lunch today.

Food engineers are using a device sort of like a microwave on steroids to rid all kinds of food of unpleasant bacteria like salmonella and E-coli that can make us sick. It’s called irradiation.

Irradiation is causing quite a stir in the world of food. Some people think it’s a great idea. In one simple process, they say, food can be made safe from contamination by bacteria. And you can store irradiated food almost forever.

Other people think it’s scary. As soon as you say irradiation, they start thinking about things that glow in the dark.

Actually, we’ve been irradiating food for a long time; more than 90 years, in fact. And no one’s been contaminated yet by irradiated food. All the food the astronauts eat while flying the space shuttle or circling the globe on the international space station has been irradiated. And you’ve been using irradiated spices and cosmetics for years.

So the next time someone mentions irradiated food think of fried rice and astronauts and dig in. You’re in good company.

Play

Tour de WOW!

July 28th, 2004 by dstmartin
 

Listen to the episode

We’ll look into the technology that helped Lance Armstrong to his unprecedented sixth win in the Tour de France bicycle race, today on Engineering Works!

Winning the world’s best-known bicycle race once is tough. Winning it six times in a row is tougher. Tour cyclists pedaled more than 2,100 miles from one end of France to the other — often more than 100 miles a day.

Most of the credit for Armstrong’s win goes to strength and training and guts. But behind it was more than $1 million worth of engineering research and technology.

How about a carbon fiber bike frame designed especially for the race’s sprint-like time trials and another new frame, especially for the long road stages. Then there’s a narrower-than-usual bottom bracket – the hub the pedals spin around. Placing the pedals closer to the frame reduces drag as the pedals move through the air. And new handlebars, to pull Armstrong’s body into a more-aerodynamic crouch.

Then there were slick new time-trial helmets, shaped to slip through the wind more easily, a slippery body suit that saves weight by refusing to absorb sweat and special cycling shoes that weighed less than 12 ounces a pair.

Then there was hours of wind-tunnel testing they worked out the combinations of equipment that produced the least drag, the most power to the pedals – and the most speed.

We’re going to hop on our bike and pedal on out of here, but not like Lance.

Play

Big Things!

July 21st, 2004 by dstmartin
 

Listen to the episode

Everybody knows about big. But what is big? We’re going to talk about really big, today on Engineering Works!

Humans like to build big things. And we’ve built some things really big.

The biggest thing ever built is also one of the oldest – the Great Wall of China. It’s built of stone and brick and stretches for more than 4,000 miles across northern China. That’s long enough to stretch from New York City to San Francisco and splash out into the ocean on both ends. The Great Wall is so big, astronauts can see it from orbit.

Then there’s the Great Pyramid of Khufu, in Egypt. We’ve all seen pictures of it, but in person it’s really big – 482 feet tall; 754 feet on each side. Ancient Egyptian engineers used about two million big stone blocks to build it – enough stone that you could build a stone wall 10 feet tall around Colorado and Wyoming.

Until about 200 years ago, it was the tallest human-built structure on the planet.

Today, the tallest building we have is a skyscraper called the Taipei 101 tower, in Taipei, Taiwan. It’s more than 1,600 feet tall and has 101 floors. The Taipei 101 Tower may be the tallest now, but one planned in India should be taller yet. The Center of India tower in Katangi should be more than 2,200 feet tall and have 224 floors.

Play

Radar!

July 14th, 2004 by dstmartin
 

Listen to the episode

Traffic cops use it to catch you speeding. It’s a lot of other things, too. You got it — radar. Today, on Engineering Works!

Radar — radio detection and ranging — has been around since the 1930s. Radar helped protect English cities against German bombers during World War 2. Now, air traffic controllers use it to keep airliners from colliding. Radar images help predict the weather and find tornadoes.

Radar’s name describes how it works. A radio transmitter sends out a beam of radio waves. When they hit something, some are reflected back to a special receiver. The receiver turns the reflected beam into information about direction and distance.

Early radar images were awful — smears of light on a screen. You had to know what you were looking for to make sense out of them. But during World War 2, they seemed almost magical. Radar today is different — a lot better. One kind, synthetic aperture radar, or SAR, produces images that are almost like photos. Even non-experts can tell the difference between SAR images of a car and a truck. And this is only the beginning.

Engineers are working on ways to make radar so small it can fit into unmanned aerial vehicles only a little bigger than model airplanes. And automakers are working on even smaller radars that will warn us if someone is driving in our blind spot on the highway.

Someone must be in our blind spot. We’ll get out of the way.

Play

Pop culture

July 7th, 2004 by dstmartin
 

Listen to the episode

You’ve heard that sound in a thousand commercials – pop tops. Today on Engineering Works!

Nobody thinks much about poptops. They’re just there. But putting that fizzy drink into that can and getting it out again was harder than you think. Took longer, too.

It all started with a bottle and a cork. That didn’t work too well. The fizz in drinks creates pressure. Pressure that tends to pop the cork before you’re ready for it. In 1892, engineers invented the crown cap. Crown caps had metal ridges that gripped the bottletop and held on against the pressure inside. About the only place you see crown caps these days is on longneck beer bottles

Bottles were all we had until the 1950s, when engineers came up with a way to seal soft drinks into metal cans. These cans were made of steel and you used a can opener to punch triangular holes in the tops.

In 1962, along came the pull tab. This was closer to today’s poptops. Pull on the ring and a keyhole-shaped opening appeared in the top of the can.

Cut to 1990. That’s when the poptops we all know came to be. This time, engineers combined the ring with a lever that pushed a hole into the top of the can. Everything stayed attached. No can opener, nothing to litter. Just fizzy soft drinks in your hand.

Talking is dry work. Hey! There’s a can of something cold and wet. Aahh!

Play