Ancient Egyptians Used Wooden Sleds to Move Pyramid Stones and Overcame Problem of Friction With a Simple But Clever Trick: Wet Sand.

Gizah Pyramids. Photo: Ricardo Liberato (CC)

Gizah Pyramids. Photo: Ricardo Liberato (CC)

The mystery of how the pyramids were built at Giza, Egypt, has fascinated generation after generation of visitors. A new study purports to reveal the simple truth of it, reports the Washington Post:

Few have traveled to the pyramids of Egypt and not wondered how an ancient civilization without modern technology could have constructed structures so large they can be viewed from space. Some have theorized they were built inside out.

On the flakier side, some say aliens did it.

Perhaps the most confounding mystery of all involves how incredibly large stones made their way to the middle of the desert without massive mechanical assistance. No camel, even the Egyptian kind, is that strong.

The truth, researchers at the University of Amsterdam announced this week in a study published in the journal Physical Review Letters, may actually be quite simple. It has long been believed that Egyptians used wooden sleds to haul the stone, but until now it hasn’t been entirely understood how they had overcome the problem of friction. It amounts to nothing more, scientists say, than a “clever trick.”

They likely wet the sand. ”For the construction of the pyramids, the ancient Egyptians had to transport heavy blocks of stone and large statues across the desert,” the university said. “The Egyptians therefore placed the heavy objects on a sledge that workers pulled over the sand. Research … revealed that the Egyptians probably made the desert sand in front of the sledge wet.”

It has to do with physics. The sort of sledges the Egyptians used to transport the two-ton loads of stone were pretty rudimentary. They were wooden planks with upturned edges. Dragging something that heavy through hot sand would — unsurprisingly — dig into the grains, creating a sand berm that would make progress nearly impossible. It “was perhaps observed by the Egyptians that in [a] dry case, a heap of sand forms in front of the sled before it can really start to move,” says the study, authored by a team of eight researchers led by Professor Daniel Bonn…

[continues at the Washington Post]


Majestic is gadfly emeritus.

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13 Comments on "Ancient Egyptians Used Wooden Sleds to Move Pyramid Stones and Overcame Problem of Friction With a Simple But Clever Trick: Wet Sand."

  1. Liam_McGonagle | May 2, 2014 at 1:08 pm |

    Wait a minute–you’re trying to suggest that a ruthless power elite p*ssed away a precious resource like water in the desert just so they could erect a monument to their piddling 30 years on the ageless earth?

    Okay, now I accept that humans built the pyramids and not aliens.

    • Simon Valentine | May 2, 2014 at 4:52 pm |

      who’s line is it anyway
      with the dead bodies under the sand tracks

  2. Kjvyn Koldt | May 2, 2014 at 2:00 pm |

    What’s “most confounding” actually is that we refuse to believe in an extra-terrestrial intelligence/presence. That to me is “pretty rudimentary”.

  3. Gjallarbru | May 2, 2014 at 2:51 pm |

    And I suppose they shoveled sand on placed stones to move that sledge on top of them? And then, just befor dropping a stone, they had to clear all that sand they put on top. Or is it that fiction of a sledge carrying a block of stone, on top of a stone block, is really easy to work against? And I have another quetion, about loading and unloading those stones that wheighed tons. Where’s the sand in that? How the F* did they load and unload those, when our modern cranes would have trouble doing the job?

    This “thoery” is incredibly “limited” in scope, and credibility. Just like much of the crap around the subject of old Egypt. Just try to get a wheeled vehicle out of wet sand, and tell me again how this works, never mind a sledge.

    • VaudeVillain | May 3, 2014 at 10:54 pm |

      Most theories I’ve seen involve wooden scaffolds and staggering amounts of human labor for moving the stones up. Since the pyramids are sloped themselves, this isn’t so infeasible. Logs are adequate for reducing friction between such surfaces. Sleds can be constructed and dismantled around the stones rather than loading.

      As for the wheeled vehicle thing… that’s exactly the point. Wheeled vehicles rely on friction in order to operate, wet sand has a lower coefficient of friction than dry sand, so your drive wheels can’t stick in it well enough to get you out. Sleds have literally the opposite problem, because they cannot transfer which surface experiences friction, they cannot operate unless the coefficient is low.

      For a real world, modern times example of the above, look at roller skates and ice skates. Roller skates work best on dry, firm, high friction surfaces where the wheels stick to the ground enough to allow a proper roll. They do not work well, if at all, on wet, soft, or low friction surfaces such as mud or ice. Conversely, ice skates work well on very slick surfaces (well, really just the one: ice), and do not work at all on tacky dry surfaces like asphalt or dirt. If you don’t believe me, take the wrong kind of skates out on the wrong kind of surface and bust your ass, you can get Youtube famous while you’re at it.

      • Gjallarbru | May 4, 2014 at 7:19 am |

        You have got to be kidding. Wood, doesn’t slide easily on sand, wet or otherwise. It slides even less with tons of weight on it. Second, it sure as hell grabs on stone (remember those skate of yours). Third, building a sled “around stones” would implie putting some support under the stone. How would that happen, knowing that the stones probably arrived on boats, without loading or unloading? Fourth, how do you dismantle the sled, and remove the support from under the stone, without lifting it. Lastly, how about the perfectly placed stones, how did they accomplish that? None of those questions are answered by the theory, and I have tons more to ask.

        Frankly, keeps your skates, I don’t believe you thought this through at all. If you had done any serious work with your hands, you would know that this sledge theory is total crap. I don’t know how Ancient Egyptiens did it, but it sure isn’t a damn sled.

        • VaudeVillain | May 4, 2014 at 7:26 pm |

          You must not have read either the article or my reply to you very carefully. you also must not be terribly creative, or have much experience in moving large or heavy objects, because nothing that I wrote was unorthodox or controversial.

          But whatever dude, if you want it to be space aliens, it can be space aliens.

          • Gjallarbru | May 4, 2014 at 9:55 pm |

            I never said aliens, as I find that even more ridiculous, although much more entertaining. Further, I wont answer your insults to my creativity with the same.

            As for my experience in moving heavy objects, I’m convinced it exceeds yours by a longshot. I have moved things around that were a couple of tons (large engines / transmissions, if you must know), and I swear a sledge wouldn’t have allowed those things to move on sand.

            As for your what you wrote being orthodox, yes it is. I just happen to not agree with it. So I have read your text, I understand its meaning, and I still reject the “sledge” concept as unfeasible. I’m not saying your position is “crazy”, just that there is too much missing to the process of placing those stones for me to agree with you.

            But as you have so eloquently said yourself, whatever dude…

  4. It wahz tuh sonik rayze

  5. InfvoCuernos | May 2, 2014 at 4:42 pm |

    Ya, because dragging heavy things is so much easier in mud than sand. I’m not saying aliens, I’m just saying probably not wet sand.

  6. Simon Valentine | May 2, 2014 at 4:55 pm |

    it’s like they always said
    you’re going to have to start thinking like a god

  7. DrDavidKelly | May 2, 2014 at 5:57 pm |

    Pharaohs hate this guy. You wont believe how easy it is to move MASSIVE stones with this one simple trick …

  8. It’s a compelling theory. It’s just too bad that those in the mainstream are too dogmatic to consider any evidence that questions their “ancient aliens” paradigm.

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