from Hacker News

Egyptians may have moved massive pyramid stones on wet sand

by era86 on 5/2/14, 6:49 PM with 30 comments

• by AlexMuir on 5/2/14, 7:41 PM

  "[A team of eight researchers led by Daniel Bonn] placed a laboratory version of an Egyptian sledge in a bin of sand that had been dried in the oven. Then they threw down some water, and measured the grains’ stiffness."

  Surely the way to test this theory isn't to make a model of a sledge, and bake some wet sand in an oven in your lab in Amsterdam! Go to Cairo, build a wooden sledge, get some water and fifty men for an hour and see whether one can sledge two tons across wet sand. I quite fancy testing it out myself. Perhaps I could run a Kickstarter to build a pyramid.

• by junto on 5/2/14, 7:34 PM

  The picture is quite convincing indeed... once I was biased by the explanation!

  For those of you that haven't read the article yet, I suggest you study the picture with the hieroglyphics in detail first and then read the conclusion!

  Edit:

  Just to be clear, I wanted others to have the benefit of seeing the picture before the explanation, because after the fact I had no idea whether I had been biased by what I had read first! I wasn't trying to suggest it was biased per se! I have no idea whether I was biased or not. I can't undo history.

• by kabdib on 5/2/14, 8:22 PM

  In 3,000 years, I'd love to see what archeologists have to say about our code (assuming any of it survives, which IMHO is a long shot):

  "Ancient engineers used text editors to write machine language."

  "But how did they construct network packets?"

  "With Emacs macros. And purification rituals involving Python."

  "No way. It had to have been aliens."

• by te_platt on 5/2/14, 7:25 PM

  I love seeing how clever people figure out ways to solve problems with the tools they have. Also good to remember hacking didn't start with and doesn't only apply to computers.

• by amalag on 5/2/14, 7:34 PM

  Stephen Colbert tweeted:

  A new theory says wet sand was used to build the pyramids. But where did the aliens get all that wet sand???

• by maw on 5/2/14, 8:25 PM

  If the water had the appropriate level of wetness, something called “capillary bridges” — extremely small droplets of water that glue together individual grains of sand — would form.

  I wonder what happened when the water wasn't wet enough.

• by eurleif on 5/2/14, 7:31 PM

  I like this part, in reference to a painting that shows water being poured on the sand in front of a sled:

  >“In fact, Egyptologists had been interpreting the water as part of a purification ritual, and had never sought a scientific explanation. And friction is a terribly complicated problem; even if you realize that wet sand is harder – as in a sandcastle, you cannot build on dry sand — the consequences of that for friction are hard to predict.”

  Makes me wonder what other practical things we might be misinterpreting as rituals. Are we constantly ignoring ancient cultures' innovations because we assume they have no practical purpose?

• by alex_doom on 5/2/14, 7:52 PM

  Well technically, the slaves built the pyramids. They just don't get the credit in the README.

• by zyxley on 5/2/14, 7:43 PM

  > In all, the scientists say, “the Egyptians were probably aware of this handy trick.”

  Wheelwrights hate him! Use this one weird old trick to make your pyramid bigger!

• by mrbill on 5/2/14, 7:54 PM

  How many times is someone going to discover yet another way the Egyptians built the pyramids?

• by whoismua on 5/2/14, 7:46 PM

  OK, but how did they move the water? I can't load the Uni page to see how much water was needed but if we're talking miles or tens of miles, we should be talking about a lot of water. Water that dries very quickly so the path has to be wet again for the next load.