[duyvh0309 (OP)]

all three Great Pyramids were constructed within a century.  Assuming very low numbers, the pyramids consist of 2.5 million stone blocks for each of the large 2 pyramids, and 1.0 million stone blocks for the small one giving 6.0 million stones to be cut, hauled, shaped, lifted and postioned in 100 years.

6,000,000 blocks / 1200 months = 5000 blocks laid per month

5000 blocks / 30 days per month = 166.6 blocks laid per day

166.6 blocks / 24 hour working day = 6.9 blocks laid per hour

So given very generous figures, the Egyptologists want you to believe that the Egyptions were able to complete (at a bare minimum) 7 stone blocks weighing 2.0-2.5 Tons every hour of every day for 100 years without days off for accidents or bad weather etc, using only primitive stone and copper tools, plant-fiber ropes and wooden sledges.

[Kryptid]

There's a missing part of the equation here: how many workers were there? If there are enough, you can get a large amount of work done in a short period of time (no need to use all 24 hours of each day). It's not like you have to wait until one block is in place before you can go and start cutting the next one. Ideally, you'd have a long line of blocks being transported to the construction site all at once. Then it may only be a matter of minutes after one block is placed before the next one can be put into place and so on.

[alancalverd]

Technology has steadily retreated in the face of lawyers, accountants and idiots in high places.

The simple act of building a railway from London to Birmingham is already 5 years behind schedule and 300% over budget without a single piece of track actually laid.

Back in the 1940s the Ministry of Works decided that one of the bits of Stonehenge had fallen over. They tried to erect it, broke it, then decided it was supposed to be horizontal anyway.

How anyone ever did anything in the past is now completely shrouded in mystery. But we have 5G, so there's no need to do anything, and COVID, so it would probably kill you to try.

[Petrochemicals]

Where is it estimated that its 6 million blocks of stone?, at a block of 1m sq or 2.2 tonnes, thats  6 square kilometers,  or 0.08 km3 of material, where as the pyramids are only 0.003km3 volume.

Also at the same time of the pyramids they constructed many smaller buildings, sphinx around the complex, but really thats only 0.01km3 total in 100 years.

The third pyramid is theorised to have been so small as the 2nd pyramid was not finished and two had to be completed at the same time. Or perhaps even later.

[Bored chemist]

Where is it estimated that its 6 million blocks of stone?,

Well, the wiki page says " It is estimated that the pyramid weighs approximately 6 million tonnes, and consists of 2.3 million blocks of limestone and granite, some weighing as much as 80 tonnes"
https://en.wikipedia.org/wiki/Great_Pyramid_of_Giza

at a block of 1m sq or 2.2 tonnes, thats  6 square kilometers

Wrong units.

[Bored chemist]

The simple act of building a railway from London to Birmingham

It's plainly not simple, is it?

[alancalverd]

It was easy enough for the Victorians, who did it all with pick and shovel. The trans-Canada railway was built from coast to coast in 5 years through virgin forest and mountains. Very few lawyers or accountants were involved.

[Bored chemist]

It was easy enough for the Victorians, who did it all with pick and shovel. The trans-Canada railway was built from coast to coast in 5 years through virgin forest and mountains. Very few lawyers or accountants were involved.

I'm afraid I have bad news for you.
Things have changed.

[Petrochemicals]

It was easy enough for the Victorians, who did it all with pick and shovel. The trans-Canada railway was built from coast to coast in 5 years through virgin forest and mountains. Very few lawyers or accountants were involved.

But lots of dead people, soow trains, lots of curves poor standards of life,

That being said, 800,000 quid a sleeper .........

[alancalverd]

I'm afraid I have bad news for you.
Things have changed.

And they can change again, surely?

[Bored chemist]

I'm afraid I have bad news for you.
Things have changed.

And they can change again, surely?

I seem to recall a government that was looking for a return to "Victorian Values".

[Petrochemicals]

5000 blocks / 30 days per month = 166.6 blocks laid per day

Also another thought, this is perfectly feasable at the beginning, a 2 tonne block of stone on the back of a cart pulled on the flat over a work area of the size of the pyramid footprint, 200 per day means only 200 trips to the quarry for as many of the pharoes army as were needed. But as the pyramid rises the work area gets smaller and the gradient steeper , sort of like a ponzy scheme in reverse, far too many resources at the top to be beneficial. It doesnt matter how many people you have, the area is finite and gravity is constant.

[Bored chemist]

But as the pyramid rises the work area gets smaller and the gradient steeper ,

The work area gets smaller, roughly in proportion to the square of the height.
The gradient gets steeper  roughly in proportion to the height.
So, overall,  the job gets easier from that perspective.

[alexriderr]

The Giza Pyramids, built to endure an eternity, have done just that. The monumental tombs are relics of Egypt's Old Kingdom era and were constructed some 4,500 years ago.

[alancalverd]

Not as old as Stonehenge, then. But 4500 years is not an eternity.

[Spam160920]

From left to right, the three largest are: the Pyramid of Menkaure, the Pyramid of Khafre and the Great Pyramid of Khufu