Sometimes the most ordinary things are the most interesting. This month we’ll take a look at something we see and use every day. It can be clear or rainbow-colored, round or flat, thick or thin. It almost sounds magical, doesn’t it?
Can you guess what it is? It’s amazing stuff—it’s GLASS!
What Is Glass?
Glass is mostly made of melted sand! To make glass, people mix pure white sand with other things, such as soda ash and limestone. Then the ingredients go into a furnace at about 3,600º F (almost 2,000º C) for several hours. After the mixture melts, people or machines can press it, roll it, put it into molds, or blow it with a tube to make thousands of different things.
Adding minerals to glass can turn it different colors. For example, cobalt oxide makes bright blue glass. Gold chloride makes cranberry-colored glass. Iron oxide makes green or brown glass.
KaPow! It’s a Fulgurite!
Did you know that lightning can make glass? Lightning is about 54,000º F (about 30,000º C). That’s nearly six times hotter than the sun. If lightning strikes sand that’s made up of just the right stuff, the heat from the lightning can turn the sand to glass! These pieces of lightning glass are called “fulgurites.” The name comes from the Latin word fulgur (lightning). Fulgurites are usually tube-shaped and bumpy. Check out some more pictures of fulgurites at http://www.minresco.com/fulgurites/fulgurites.htm.
Spears and Scalpels
Obsidian (ob-SID-ee-un) is a natural black glass that forms when lava from a volcano cools quickly. Ancient people discovered that sharpened obsidian made excellent arrowheads and spear points.
Today some surgeons use obsidian scalpels (surgical knives) because they’re many times sharper than steel scalpels. Obsidian scalpels have such fine edges that they can cut between cells.
Good News and Bad News
Here’s some bad news: If you throw away a glass jelly jar, it goes to a landfill (a huge dump for garbage). Once it’s there, it stays there forever, because glass isn’t biodegradable—it can’t rot or break down like paper or food garbage.
But the good news is that glass can be recycled, and that’s great for the environment! People can recycle glass over and over and over. That means that when you recycle your jelly jar, poof!—in less than a month it could be back on the store shelf holding a different type of food!
More bad news, though: People only recycle 25% of the glass bottles and jars they use. That means that only one of every four glass containers gets to be recycled, and three out of four don’t.
So if your community has a recycling program, use it! It’s a no-brainer, and it’s an easy way to help take care of God’s creation.
HisTorY
5000 B.C. According to an old story, one day Syrian merchants rested cooking pots on blocks of nitrate placed by their fire. The heat of the fire melted the blocks, and they mixed with sand to form dark-colored glass.
3500 B.C. Mesopotamian people discover how to make glass beads and glaze pots with the raw materials of glass.
1500 B.C. Egyptians make glass pots by dipping molds made from compacted sand into molten glass.
27 B.C. - A.D. 14 Syrian craftsmen discover the art of glassblowing.
A.D. 100 Romans discover how to make clear glass windows in molds. They start putting glass windows in important buildings.
A.D. 1200 German glassmakers discover how to make sheet glass, making it possible for people to make stained-glass windows.
A.D. 1268-1289 An unknown European
inventor makes the first pair of eyeglasses.
A.D. 1688 French glassmakers discover how to make high-quality mirrors.
A.D. 1900 American engineer Michael Owen invents a machine to make glass bottles and jars.
Glassmaker Gone Wild
Glass artist Dale Chihuly is famous for his wild and crazy glass sculptures. Sometimes they look like flowers, sea creatures, or vegetables—sometimes they’re just for fun! Sometimes they float in water, “grow” in gardens, or hang from ceilings. Mr. Chihuly created the world’s largest glass sculpture, which is in a hotel in Las Vegas, Nevada. To see examples of his work, visit www.chihuly.com.
Magical, Musical Glass
Another amazing thing about glass is that it makes a musical sound. If you tap a water glass gently with a knife, it sounds like a ringing bell.
Or try this: Take a wine glass and fill it half full with water. Wet your middle finger, then run it quickly around and around the top edge of the glass while you hold the bottom of the glass on a table with your other hand. It takes some practice, but soon you’ll hear a beautiful musical sound.
Benjamin Franklin actually invented a musical instrument from glass bowls. It was called an “armonica.” It looked sort of like a small piano, only instead of keys there were bowls that turned when you pumped a foot pedal. When you played the turning bowls with wet fingers, they made a sound that was different from any other instrument.
Online Kaleidoscope
Kaleidoscopes are tubes with mirrors inside and pieces of glass or other stuff in the bottom. When you turn the kaleidoscope, you get patterns that change all the time.
Here’s a way to make your own kaleidoscope without any supplies! First, ask an adult for permission to go online. Then go to this site: http://www.vam.ac.uk/vastatic/microsites/moc_kaleidoscope/. Follow the instructions to make your own online kaleidoscope. (Warning: once you start it’s hard to stop, so tell adults NOT to do this at work!)
About the Author
Sandy Swartzentruber serves as the resource coordinator for Faith Formation Ministries and is a member of Sherman Street CRC in Grand Rapids, Mich.
