Skyscrapers are the tallest buildings on the planet. If you were an ancient Egyptian time traveller, you would be in complete awe of these buildings, which tower over the pyramids in height and stay upright even in hurricane winds! The big question is how do they do it? What design makes the strongest skyscraper, one that can resist winds and the force of gravity?

The real key to a skyscraper’s stability is its steel frame. It holds the weight of the building entirely. Before skyscraper technology, there were many tall buildings, but they were pretty wobbly because the walls supported the weight of the building—and too much weight on a wall could make it, and the whole building, collapse. The ancient Romans actually built many really tall buildings, some ten floors or more tall. But without a steel frame, they were rather unsafe!

So what’s the latest in skyscraper design? It’s being built right now in Chicago, the first true home of skyscrapers! What’s so special about this new building? It’s shape! It’s shaped like, would you believe it, a cork screw?! Yup, it’s called the Chicago Spire. Why spiral? The unique shape actually reduces wind down drafts that can rock skyscrapers and, thus, makes the building more stable! It’s got a lot of other eco-cool features too, like recycled rainwater and a cooling system that runs off the cold water from the Chicago River!

20 buildings on the Chicago skyline are over 200 meters tall. One is the tallest in North America—the Sears Tower, which measures in at a sky-scraping 442 meters. Currently, the tallest skyscraper in the world is the Taipei Towers in Taipei. It is 509.2 meters tall. But it will soon be the second tallest building in the world! A new skyscraper is being built in the United Arab Emerates that will be 643.3 meters tall. It should be ready to move into in 2009. The Chicago Spire will be 609.6 meters tall, just a little shorter. To see what it will look like, go to http://en.wikipedia.org/wiki/Chicago_Spire As you can see, the race to be the tallest in the world is still going strong!