Push-ups, Pyramids, and You
The Great Pyramid of Giza was built around 2500 BC. Its individual stone blocks weigh up to 50 tons, and its base contains roughly 2,300,000 blocks, measuring 592,000 square feet. This combined with its height, 481 feet, would be enough to earn the pyramid a spot on the Seventh Wonders of the World, but it's even more impressive at second glance. The ancient Egyptians installed the pyramid's cornerstones in a special ball and socket configuration, allowing it to flex slightly in case of an earthquake. Indeed, the structure survived just such a quake in the 14th century, although the tremors loosened its smooth outer covering, which is mostly no longer with us. (Some believe the local population took advantage of the freed stones, carting them away for a variety of purposes. Who wouldn't want a pyramid souvenir?) When that limestone facade was intact and polished to a full shine, it would have been so bright that some have theorized it would be visible as a twinkly do...