High-tech glass: scientists are discovering new uses for glass in schools, computers and even inside the human body.

Scientists are discovering new uses for glass in schools, computers, and even inside the human body.

Strange but true: The hottest high-tech substance in computers, medicine, and space flight is the same stuff that holds your orange juice and keeps the rain out of your house. That's right. Glass.

What's so great about glass? Its physical properties allow scientists to spin it into hair-thin fibers that may eventually turn TV sets into multiplex movie theaters and let students take classes from teachers halfway across the country. Glass already blasts into space as a protective coating on the space shuttle. One day soon it may even be molded into microscopic beads that zap cancer cells.

MESSY ATOMS

Glass has thousands of uses because scientists make it thousands of ways. The most common ingredient in glass is silica--a mixture of sand and oxygen. But scientists routinely create glass out of other ingredients. Even metal can be made into glass.

"Glass is a state of matter rather than a particular compound," or combination of specific chemical elements, explains researcher Alexis Clare of Alfred University. Almost all matter on Earth can be classified into one of three main states of matter solid, liquid or gas. But not glass. "Glass," says Clare, "is both a solid and a liquid."

Like other solids--say, ice or rocks--a piece of glass has a definite shape and a definite volume. But in most solids, the atoms, or tiny building blocks of matter, organize themselves in tidy, repeating patterns called crystals. Glass atoms, in contrast, are thrown together every which way, just like the free-flowing atoms in a liquid.

This messy arrangement of atoms gives glass some useful properties: It's easy to form into different shapes and it's good at dissolving other substances. "You can add any element in the periodic table to a basic glass recipe," says William LaCourse, co-director of the Glass Science Institute at Alfred University. "That means the properties you can generate and new materials you can make are almost unlimited."

And the glass cookbook is growing fast. Corning Inc., one of the world's largest glass manufacturers, has hundreds of thousands of glass "recipes" on file. Researchers there dream up about 100 new types of glass each week. Corning regularly manufactures 750 of them.

FIBER-OPTIC FRENZY

One of Corning's most valuable recipes is for the clearest glass now known. This superclear glass is rapidly changing how the world communicates, studies, and relaxes.

Workers use the perfectly clear glass to create optical fibers, bendable "wires" of glass the diameter of a human hair and miles long. Because the glass has no impurities, information can be sent through optical fibers as pulses of light, says Donna Cunningham of Bell Laboratories. That means information can zip around the globe at the speed of light (300,000 kilometers or 186,000 miles per second).

The superfast transfer of information has many cool uses. For example, a computer hooked up to optical fiber can deliver images from the World Wide Web 400 times faster than a computer hooked up to copper wires. Copper wires carry information as electrical pulses.

Scientists have developed ways to cram thousands of telephone conversations--or World Wide Web downloads or e-mail messages--onto a single pair of optical fibers. (Each fiber carries information in one direction.) A sophisticated computer "weaves" the conversations together so that the pauses in one are "filled" by chunks of another. Another computer unscrambles the information so each person hears or reads a message that makes sense.

Some schools in the United States are even being linked to one another with optical fiber. Students in one school can "attend" class in the other with two-way video hookups.

SPACE GLASS

If these advances in communications aren't enough to convince you that glass is a blast, the space shuttle should.

Tiles made from a special heat-resistant glass cover the shuttle's underside. These tiles protect astronauts and cargo even during re-entry into Earth's atmosphere, when friction warms the spacecraft's belly to a toasty 1,260[degrees]C (2,300[degrees]F).

How can glass get so hot without melting or cracking? The high-tech material takes advantage of the insulating property of air.

The tiles are formed by "cooking" glass fibers at 1,316[degrees]C (2,400[degreesd]F) until they stick together and form a block. The fibers trap tiny air bubbles between them. In fact, the finished glass is 93 percent air! Like the air pockets in a down jacket, the bubbles slow the movement of heat.

That high air content also means the super strong tiles are light-weight. A one-foot cube weighs only 4 kilograms (9 pounds). That's lighter than chalk! And being lightweight is an asset for a material that has to blast into space!

HEALING POWER

Researchers are also hoping to use glass for a more down-to-Earth problem: curing cancer.

"Doctors know that diseases like cancer respond to heating," reports glass scientist Clare. In fact, you can kill cancer cells at temperatures of about 43[degrees]C (109.4[degrees]F). Healthy cells don't begin to show signs of damage until about 46[degrees]C (114.8[degrees]F).

But there's a catch. Most human bodies maintain a temperature of only about 37[degrees]C (98.6[degrees]F). "Doctors have found that if you try to raise a person's entire body to those higher temperatures, the body works hard to cool itself down again," Clare says. For example, we sweat. So, it would be better to heat only the part of the body that has cancer.

Clare thinks a special kind of glass can help. She's still putting the finishing touches on the glass "recipe." But she's already picked the key ingredient: magnetic crystals. Clare traps these microscopic crystals inside glass "beads." Doctors would then inject the beads into the tumors. To heat the beads, the patients would enter an oscillating, or moving, magnetic field. The field would cause the magnetic crystals to spin, creating friction, and therefore heat.

Since the beads are made of elements found naturally in the body, like iron and phosphate, the doctors won't have to figure out a way to remove them. Clare explains, "After the beads have done their job, they'll dissolve without doing any harm."

That's the latest news flash on glass. Where will this high-tech material make its next appearance? Stay tuned.

RELATED ARTICLE: GLASS HOUSES

Robert Du Grenier is a New York City artist who is also a homemaker for hermit crabs!

The crabs homes start out as glass scraps, which Du Grenier throws into a 1,260[degrees]C (2,300[degrees]F) furnace to melt for day. Then, with a heated iron tube called a blow pipe. Du Grenier grabs a hunk of molten glass and blows it to form a cone shape.

A helper brings the artist another lump of hot glass--this one about the size of a chewing gum wad. Du Grenier attaches it to the tip of the cone and rolls the tip toward the pipe to create the shell's spiral shape. Constantly turning the hot glass is critical. Stop and gravity makes the glass drip out a shape.

When he's finished, Du Grenier removes the shell from the pipe and places it in an annealing oven. The temperature in the oven drops slowly, allowing the glass to cool, the without breaking. When the glass is cool, the artist carves the shell's opening and decorates the outside.

Du Grenier has found hermit crabs quite willing to make their homes inside blown glass, but they are finicky about its shape. He learned that the hard way.

The spiral he created inside his first shells twisted the wrong way. Crabs that crawled in made a quick exit. When Du Grenier reversed the spiral, the crabs became happy tenants.

"Observation is the key to my art," Du Grenier notes. Sounds a lot like science!

RELATED ARTICLE: EDIBLE GLASS

You can make glass with thousands of recipes, including this delicious one.

WHAT YOU NEED:

* an adult helper

* stove

* heavy pot with lid

* water

* candy thermometer 

* oven mitts

* 2 cups sugar

* 3/4 cup light corn

syrup

* 1 tablespoon 

unsalted butter

* plate

* long wooden spoon

* drinking glass

* food coloring

* flavoring

* cookie sheet greased

with vegetable oil

* sturdy sandwich

toothpicks

* paper and pencil

WHAT TO DO:

Before you start, check the accuracy of your thermometer: Bring half a pot of water to a boil. Hold thermometer in center of boiling water for 2 minutes. Be careful: Steam burns! Use a mitt. Check temperature with thermometer still in boiling water. What does it read? What should it read? How many degrees do you need to add or subtract to correct the thermometer's reading? Write that number down. When you do the experiment, add or subtract it to the temperatures given to determine what your thermometer should read at each step.

1. Add the sugar, corn syrup, and butter to 1 cup of boiling water. Stir until ingredients dissolve. 2. Heat mixture to a boil without stirring. Cover and cook for 3 minutes. 3. Hold thermometer in syrup. Caution: Syrup will be very hot! Continue to heat without stirring until temperature reaches 110[degrees]C (230[degrees]F). 4. Remove syrup from heat. Scoop up a spoonful of syrup and pour it onto the plate. What happens? Record your observations. 5. Scoop another spoonful of hot syrup into a glass of cool water. Record your observations. 6. Return syrup to heat without stirring and repeat Steps 4 and 5 at the Following temperatures: 112[degrees]C (234[degrees]F); 118[degrees]C (244[degrees]F); 121[degrees]C (250[degrees]F); and 132[degrees]C (270[degrees]F). 7. When syrup reaches 149[degrees]C (300[degrees]F), remove from heat. Cool to 71[degrees]C (160[degrees]F). This will take about 15 minutes. To speed the process, place pot in a container of cold water. 8. Stir in color and flavor. 9. Set toothpicks on oiled cookie sheet. Pour a small amount of syrup around each. Remove lollipops from cookie sheet as soon as they are firm.

Congratulations. You've just made glass! Though your candy looks solid, its atoms are free-flowing, just like those in window glass.

CONCLUSIONS:

Your syrup should change as heat rearranges its atoms. Describe these changes. At what temperature would it be easiest to make candy optical fibers? What physical properties does your glass share with window glass?

DON'T STOP NOW!

Research how candy makers form their glass into balls, cotton candy, and hollow lollipops for Tootsie Pops.

RELATED ARTICLE: TOTALLY COOL CAREER

Alexis Clare whips up cancer-curing glass--between classes.

Hectic!" is how Alexis Clare, 36, describes her day. As a researcher and college professor, Clare races from blackboards to beakers to meetings from before 8 a. m. until nearly midnight. "Doing research is like being a big a kid, playing with toys--and getting paid for it!" she says. Still, her greatest kick is teaching. But becoming a professor takes time. To earn her doctorate and "postdoc" research degrees, Clare studied for seven years after college. New professors earn about $30,000 a year. Scientists who work in industry start at twice that. For more info about careers in materials research, write:

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