Menus Subscribe Search

Quick Studies

pyramids1.jpg

(Photo: Ricardo Liberato/Wikimedia Commons)

To Haul Pyramid Stones Over Egyptian Sands, Just Add Water

• May 05, 2014 • 10:04 AM

(Photo: Ricardo Liberato/Wikimedia Commons)

A clue from an Egyptian tomb has provided scientists with a new explanation of how stones were transported for the construction of pyramids.

If a new scientific validation of one interpretation of a painting in Djehutihotep‘s elaborately decorated tomb is correct, then ancient Egyptians understood the key to king-sized desert Slip’N Slides.

The artistic commemoration that followed the Egyptian leader’s death is offering up clues, more than 4,000 years later, about how armies of men hauled hulking stones that were used to build the ancient pyramids.

Scientists who investigated the effect of potentially wetting sand in front of large Egyptian sleds—a process that may have been depicted on a painting in the nomarch’s tomb—say their discovery could have implications for how modern society can most efficiently transport everything from sand and cement to flour.

Check out this painting discovered more than a century ago in Djehutihotep’s tomb. It shows a giant statue of the leader being dragged on a sled, which was the same strategy taken for moving stones and other heavy payloads. Sometimes these sleds were dragged over wooden sleepers. But this scene might show something slightly different.

Painting from Djehoetihotep's tomb(Photo: P. E. Newberry, El Bersheh, The Tomb of Tehuti-Hetep, Vol. 1.)

Now, in this close-up, note the dude pouring what appears to be water over the sand ahead of the sled.

Pouring water ahead of Egyptian sled

What’s he up to?

Some say the pouring was purely ceremonial. But after simulating the effect of moistening sand in front of an Egyptian sled in a laboratory, an international team of scientists has rejected that explanation. They say the water could have reduced the amount of friction between the wooden sled and the sand beneath it—a process they concluded may have halved the amount of horsepower required, which, back then, was measured as manpower.

“[I]n some cases the Egyptians built roads for the sleds out of wooden sleepers,” the scientists write in a letter published last week in Physical Review Letters. “The possibility of dragging the sled through desert sand is often precluded because it is believed to be too difficult. However, in view of our results, it seems very possible to drag the sleds over wet sand with the manpower available to the Egyptians.”

The scientists measured how much force was required to drag a weight-laden sled over miniature deserts, some of them damp and some of them dry. By adding a “small amount” of moisture to the sand that most closely replicated the Egyptian variety, the scientists hit a sweet spot: a friction coefficient for wood-on-sand that’s similar to that of wood-on-wood.

The scientists say that isn’t just fascinating from a historical perspective—it has ramifications for bulk commodity handling today.

“Most of civil engineering deals with the handling and transport of granular materials—sand, concrete, cement and so forth,” says Daniel Bonn, a University of Amsterdam professor who co-authored the new paper. “Slightly wet sand is transported more easily through pipes than dry sand. This is counter-intuitive, since the wet sand is harder.”

John Upton
John Upton is a science journalist with an ecology background. He has written recently for VICE, Slate, Nautilus, Modern Farmer, Grist, and Audubon magazine. He blogs at Wonk on the Wildlife. Upton's favorite eukaryotes are fungi, but he won't fault you for being human. Follow him on Twitter @johnupton.

More From John Upton

A weekly roundup of the best of Pacific Standard and PSmag.com, delivered straight to your inbox.

Recent Posts

September 19 • 9:03 AM

Why Science Won’t Defeat Ebola

While science will certainly help, winning the battle against Ebola is a social challenge.


September 19 • 8:00 AM

Burrito Treason in the Lone Star State

Did Meatless Mondays bring down Texas Agriculture Commissioner Todd Staples?


September 19 • 7:31 AM

Savor Good Times, Get Through the Bad Ones—With Categories

Ticking off a category of things to do can feel like progress or a fun time coming to an end.


September 19 • 6:00 AM

The Most Untouchable Man in Sports

How the head of the governing body for the world’s most popular sport freely wields his wildly incompetent power.


September 19 • 4:00 AM

The Danger of Dining With an Overweight Companion

There’s a good chance you’ll eat more unhealthy food.



September 18 • 4:00 PM

Racial Disparity in Imprisonment Inspires White People to Be Even More Tough on Crime

White Americans are more comfortable with punitive and harsh policing and sentencing when they imagine that the people being policed and put in prison are black.



September 18 • 2:00 PM

The Wages of Millions Are Being Seized to Pay Past Debts

A new study provides the first-ever tally of how many employees lose up to a quarter of their paychecks over debts like unpaid credit card or medical bills and student loans.


September 18 • 12:00 PM

When Counterfeit and Contaminated Drugs Are Deadly

The cost and the crackdown, worldwide.


September 18 • 10:00 AM

How Do You Make a Living, Molly Crabapple?

Noah Davis talks to Molly Crapabble about Michelangelo, the Medicis, and the tension between making art and making money.


September 18 • 9:00 AM

Um, Why Are These Professors Creeping on My Facebook Page?

The ethics of student-teacher “intimacy”—on campus and on social media.


September 18 • 8:00 AM

Welcome to the Economy Economy

With the recent introduction of Apple Pay, the Silicon Valley giant is promising to remake how we interact with money. Could iCoin be next?



September 18 • 6:09 AM

How to Build a Better Election

Elimination-style voting is harder to fiddle with than majority rule.


September 18 • 6:00 AM

Homeless on Purpose

The latest entry in a series of interviews about subculture in America.


September 18 • 4:00 AM

Why Original Artworks Move Us More Than Reproductions

Researchers present evidence that hand-created artworks convey an almost magical sense of the artist’s essence.


September 17 • 4:00 PM

Why Gun Control Groups Have Moved Away From an Assault Weapons Ban

A decade after the ban expired, gun control groups say that focusing on other policies will save more American lives.


September 17 • 2:00 PM

Can You Make Two People Like Each Other Just By Telling Them That They Should?

OKCupid manipulates user data in an attempt to find out.


September 17 • 12:00 PM

Understanding ISIL Messaging Through Behavioral Science

By generating propaganda that taps into individuals’ emotional and cognitive states, ISIL is better able motivate people to join their jihad.


September 17 • 10:00 AM

Pulling Punches: Why Sports Leagues Treat Most Offenders With Leniency

There’s a psychological explanation for the weak punishment given to Ray Rice before a video surfaced that made a re-evaluation unavoidable.


September 17 • 9:44 AM

No Innovation Without Migration: Portlandia Is Dying

Build an emerald city. Attract the best and brightest with glorious amenities. They will come and do nothing.



September 17 • 8:00 AM

Why Don’t We Have Pay Toilets in America?

Forty years ago, thanks to an organization founded by four high school friends, human rights beat out the free market—and now we can all pee for free.


September 17 • 6:32 AM

Do Conspiracy Theorists Feed on Unsuspecting Internet Trolls?

Not literally, but debunkers and satirists do fuel conspiracy theorists’ appetites.


Follow us


Savor Good Times, Get Through the Bad Ones—With Categories

Ticking off a category of things to do can feel like progress or a fun time coming to an end.

How to Build a Better Election

Elimination-style voting is harder to fiddle with than majority rule.

Do Conspiracy Theorists Feed on Unsuspecting Internet Trolls?

Not literally, but debunkers and satirists do fuel conspiracy theorists' appetites.

3-D Movies Aren’t That Special

Psychologists find that 3-D doesn't have any extra emotional impact.

To Protect Against Meltdowns, Banks Must Map Financial Interconnections

A new model suggests looking beyond balance sheets, studying the network of investment as well.

The Big One

One in three drivers in Brooklyn's Park Slope—at certain times of day—is just looking for parking. The same goes for drivers in Manhattan's SoHo. September/October 2014 new-big-one-3

Copyright © 2014 by Pacific Standard and The Miller-McCune Center for Research, Media, and Public Policy. All Rights Reserved.