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"Also: I've been to Giza. It's hot and dry as all hell. Humans are going to be far from perfect labor machines in that climate" The climate 4500 years ago was

by Balero 6y ago

"Also: I've been to Giza. It's hot and dry as all hell. Humans are going to be far from perfect labor machines in that climate" The climate 4500 years ago was very different in this area, and the world in general. For Egypt and the middle east it was generally a little cooler, but much wetter. When we are looking back into history, even only a couple of hundred years it is important to remember that the climate, and geography was different. Climate shifts, rivers and coastlines move etc.

close04 6y ago
The analysis is only about the effort to lift one cubic meter of stone to an arbitrary height a number of times until you reach the mathematical equivalent of a "pyramid's worth", and then divide this by the average human work capacity. That's it. No other theoretical or practical aspect was considered. No friction, no logistics, nothing else. The conclusion is that it took 900 men 20 years to lift one 2.6t cubic meter of stone to a specific height again and again. Does anyone considers this to be realistic for any construction project? Like estimating the Mona Lisa took 5s to paint based on the surface of 0.4 square meters. Or the Sistine Chapel ceiling took a couple of days and a really big brush. The fact that someone with such a CV [0] came up with this for the IEEE page as anything more than an exercise of imagination is very surprising for me. [0] https://spectrum.ieee.org/author/vaclav-smil https://spectrum.ieee.org/author/vaclav-smil
- scld 6y ago
  Well, the graph in the article says 3600 men for 20 years. 900 to lift the stones 900 to place and finish them (horizontal movement?) 1500 to cut the stone 3300 design/support (logistics?) The details are below the fold.
  - haihaibye 6y ago
    There's no accounting for inefficiencies applying human labor to moving massive stone blocks into a really high pile. Has the author ever done physical labor?
  - close04 6y ago
    I'm talking about the details of the real work. The details of his results are irrelevant since they're built from oversimplified assumptions. I mean the author didn't even include friction in his calculations. Or placing blocks with special shapes in exceptional positions. Or any setbacks, logistics, infrastructure, trial and error, design revisions, human inefficiency, illness, accidents, etc. His calculations just say it probably couldn't have taken less. But more? Just add a few more of those variables that he completely overlooked and the effort easily increases by one order of magnitude. The worst project managers I've met made better assumptions that this author. You make bad assumptions you get bad conclusions. And saying them "with certainty" just makes one sound even more ignorant. Imagine what his calculations would say about La Sagrada Familia. Certainly not 150 years.
  - peeters 6y ago
    Except everything besides the 900 estimate is made up out of thin air as far as the "details" go. The "appeal to simple physics" is useful as far as providing a reasonable lower bound ("it must by conservation of energy have been at least 900 workers"). But that's not the assertion of the author, the assertion is that all greater estimates are overestimates, but provides zero evidence for why.

by Balero 6y ago

close04 6y ago

The analysis is only about the effort to lift one cubic meter of stone to an arbitrary height a number of times until you reach the mathematical equivalent of a "pyramid's worth", and then divide this by the average human work capacity. That's it. No other theoretical or practical aspect was considered. No friction, no logistics, nothing else. The conclusion is that it took 900 men 20 years to lift one 2.6t cubic meter of stone to a specific height again and again. Does anyone considers this to be realistic for any construction project? Like estimating the Mona Lisa took 5s to paint based on the surface of 0.4 square meters. Or the Sistine Chapel ceiling took a couple of days and a really big brush. The fact that someone with such a CV [0] came up with this for the IEEE page as anything more than an exercise of imagination is very surprising for me. [0] https://spectrum.ieee.org/author/vaclav-smil https://spectrum.ieee.org/author/vaclav-smil

scld 6y ago
Well, the graph in the article says 3600 men for 20 years. 900 to lift the stones 900 to place and finish them (horizontal movement?) 1500 to cut the stone 3300 design/support (logistics?) The details are below the fold.
- haihaibye 6y ago
  There's no accounting for inefficiencies applying human labor to moving massive stone blocks into a really high pile. Has the author ever done physical labor?
- close04 6y ago
  I'm talking about the details of the real work. The details of his results are irrelevant since they're built from oversimplified assumptions. I mean the author didn't even include friction in his calculations. Or placing blocks with special shapes in exceptional positions. Or any setbacks, logistics, infrastructure, trial and error, design revisions, human inefficiency, illness, accidents, etc. His calculations just say it probably couldn't have taken less. But more? Just add a few more of those variables that he completely overlooked and the effort easily increases by one order of magnitude. The worst project managers I've met made better assumptions that this author. You make bad assumptions you get bad conclusions. And saying them "with certainty" just makes one sound even more ignorant. Imagine what his calculations would say about La Sagrada Familia. Certainly not 150 years.
- peeters 6y ago
  Except everything besides the 900 estimate is made up out of thin air as far as the "details" go. The "appeal to simple physics" is useful as far as providing a reasonable lower bound ("it must by conservation of energy have been at least 900 workers"). But that's not the assertion of the author, the assertion is that all greater estimates are overestimates, but provides zero evidence for why.