Today’s Wonder of the Day was inspired by james from Bend, OR. james Wonders, “who made pyramids?” Thanks for WONDERing with us, james!
Have you ever tried to make a human pyramid? Climbing on your friends' backs is tricky work. It's even worse if you are on the bottom!
Want to know what is more challenging, though? Try building a real pyramid! If you've ever been to Giza, which is not far from Cairo in Egypt, then you've probably seen those massive structures the Egyptians are famous for. What are we talking about? The Great Pyramids, of course!
Although more than 130 pyramids have been discovered throughout Egypt, the most famous ones stand at Giza near Cairo. The tallest of these, the Great Pyramid of Khufu, is the tallest pyramid in the world and the only one of the Seven Wonders of the Ancient World that has survived the test of time.
The Great Pyramid of Khufu was originally 488 feet tall. It consists of over 1.3 million massive limestone blocks that can weigh anywhere from 5,000 to over 30,000 pounds. The Great Pyramids at Giza continue to amaze scientists to this day.
How were these massive structures built over 4,500 years ago without the help of modern technology and construction methods? Some people have suggested that the Great Pyramids must have been built by aliens. Researchers, however, now believe that a dedicated workforce of 20,000-30,000 Egyptian laborers built the Great Pyramids over the course of several decades for three different Pharaohs.
Although Greek historian Herodotus believed that it must have taken at least 100,000 workers to build the Great Pyramids, Egyptologists now believe the actual number was just a fraction of that. They believe that Giza was home to a small crew that worked on the Great Pyramids all year long.
Late in the summer and early in the fall, however, the nearby Nile River would often flood, leaving many fields underwater. At these times, researchers believe that thousands of farmers and villagers would come to Giza to work on the Great Pyramids when they couldn't farm their lands.
Even if laborers were plentiful, however, researchers have remained puzzled about how such massive stones could be moved and put into place on such an enormous structure. They do know the ancient Egyptians made use of basic tools, such as inclined planes (ramps) and levers, to help move the stones into place.
Recent research has also uncovered evidence that most of the stone came from local quarries and could have easily been pulled to the building site on giant sleds. If you're thinking that it must have been grueling work dragging huge stones weighing several tons across sand, you're right.
However, ancient Egyptians may have used a technique that made their work much easier. An ancient wall mural was found that appeared to show a large object being pulled by ropes attached to a sled. A worker at the front of the sled appeared to be pouring water on the sand in front of the sled.
Researchers discovered that wetting the sand in front of a sled does indeed reduce friction and make it much easier to pull. Thus, the huge stones that make up the Great Pyramids could have been moved the short distance from the quarry to the building site with fewer laborers than had originally been imagined.