Placeholder Image

字幕表 動画を再生する

  • This video was made possible by Assassin’s Creed Origins, which is out today.

  • When we think of ancient Egypt, most imagine sand swept plains with giant pyramids jousting

  • up from a barren desert, juxtaposed next to the lush meandering Nile spilling nutrients

  • to into the surrounding floodplains to feed this burgeoning empire.

  • But all we have for reference for this vision of the past are the ancient monuments and

  • artifacts that remain and ancient hieroglyphs, that puzzled linguists for centuries.

  • The ways of this ancient world is shrouded in mystery, so when I was invited out by Ubisoft

  • to get a private tour of the British Museum, speak with historians and get hands on experience

  • with their 3D explorable vision of ancient Egypt in Assassin's Creed Origins to learn

  • more, I jumped at the opportunity.

  • Today we are going to explore this ancient world and try to uncover one it’s greatest

  • secrets, how a civilisation without power machinery managed to build those gigantic

  • godly structure.

  • In our modern world, these structures may seem to some as just huge piles of rock.

  • With modern machinery, like cranes, it may be easy to take for granted the monumental

  • task of moving and lifting this much material.

  • So let’s put this problem in context to understand why it has baffled historians for

  • centuries.

  • The largest of the Great Pyramids, Pyramid Khufu, was the tallest man made structure

  • on earth for almost four thousands years.

  • Pyramid Khufu contains over 2.3 million limestone blocks, each weighing an average of 2.5 tonnes,

  • which form the interior structure of the pyramid and an additional 200,000 blocks were used

  • for the smooth white stone casing, which now only exists on the upper cap.

  • but the Pyramids aren’t simply giant piles of limestone arranged nicely, Pyramid Khufu,

  • incredibly, contains massive interior chambers, like the king’s chamber, which is supported

  • by massive granite beams, with the heaviest weighing about 40 tonnes, that’s about the

  • same as the maximum allowable weight of a fully laden articulated truck.

  • These stones are located between 43 metres and 65 metres up the pyramid.

  • Just transporting the massive stones to the site from the quarries was a massive undertaking,

  • but other civilisations that predate the Egyptians have achieved similar feats, like stonehenge,

  • or the even more ancient Irish building of Newgrange.

  • The limestone for the Pyramids was quarried nearby, much of it quarried directly next

  • to the pyramids, while the granite was likely taken from Aswan and transported to the site

  • on boats.

  • We know from hieroglyphs that the egyptians used wooden sleds to transport heavy objects,

  • while workers lubricated it’s movement with water.

  • This was simply a problem of manpower, which the wealthy Egyptian empire was not short

  • on.

  • What has fascinated me is the logistic challenge of building a structure like this, the sequence

  • of events and mechanisms that these ancient engineers used to lift these immense weights

  • into place are a mystery, a mystery that many have tried to solve, but many theories come

  • up short.

  • To solve this riddle, let’s start with what we do know.

  • First things first, unless the Pyramids were truly built by aliens with anti-gravity machines,

  • the pyramids were built from the bottom.

  • Next, because of the precise geometric shape of the pyramids, with each side of the Great

  • Pyramid being 230.3 metres long, with the largest difference in lengths, between the

  • Northern and Southern edge, at only 4.4 centimetres.

  • This level of accuracy could only have been possible if the external casing stones were

  • laid first, allowing any deviations to be caught early and corrected, before the internal

  • structure was filled in.

  • This makes any theories for external ramps or cranes unlikely, as they would have been

  • extremely difficult to attach to the smooth external wall, which was inclined at 52 degrees.

  • Instead, the most prevalent theory suggests a ramp on one side of the pyramid that would

  • raise with pyramid, but this has it’s limit.

  • When pulling a weight like this uphill, the force required is given by this equation.

  • The average mass of blocks was 2.5 tonnes, or about 24,500 Newton's, there were heavier

  • blocks, but these were mainly used in the lower levels.

  • Let’s set our slope angle alpha, at 7 degrees, and the coefficient of friction between two

  • pieces of wet wood is about 0.1, using these figures we can calculate the force needed

  • to pull this weight uphill at 5418 Newtons.

  • Modern safety guidelines say the maximum any worker should pull is 225 Newtons [1], but

  • since this is a prolonged track and stopping is not an option, most calculate the max each

  • worker would pull at 150 Newtons or about 15.3 kg.

  • So that means we would need around 36 workers would be needed to haul this weight.

  • This figure is reasonable, but for every additional degree of slope at least an extra 3 workers

  • will be needed, which would soon become extremely impractical.

  • The other option, of simply elongating the ramp and maintaining the angle is completely

  • unfeasible, as constructing the ramp would be bigger project than the great pyramid itself.

  • Like any modern construction project, these are all logistical issues the Egyptians would

  • have had to overcome.

  • This is the core of engineering.

  • Trying to solve problems with the tools at hand, and now we have to reverse engineer

  • this problem without knowing exactly what tools the Egyptians had.

  • One of the most convincing theories I have seen, from French architect, Jean-Pierre Houdin,

  • may hold the truth of the Pyramids construction.

  • Jean-Pierre theorised that this external ramp was used to construct up to the height of

  • the King's Chamber at around 43 metres, allowing the heaviest granite stones used to be hauled

  • up this ramp.

  • Granite has often been used in grand historic buildings for it’s superior compressive

  • strength, allowing the buildings to grow in size, here the granite was tasked with supporting

  • the immense weight of the pyramid above the King’s Chamber.

  • At this height the majority of the volume of the pyramid is completed, but we still

  • need a way of transporting those final blocks into place.

  • This is where the innovative part of Jean-Pierre’s theory comes in.

  • He proposes that while the first 43 metres was being constructed, the workers also built

  • an internal ramp, which would transport material recycled from the exterior ramp to the top

  • of the pyramid.

  • Now this theory should be easy to prove, the interior ramp should still exist, but the

  • Pyramid is a protected structure, we can’t just take it apart to see what’s inside.

  • But we do have tools that can peer into the internal structure without damaging it, one

  • team used microgravimetry in 1986 to measure the density of different sections of the pyramid.

  • This research produced this image image, showing a strange pattern where the green indicates

  • lower density, which closely matches the pattern of Jean Piere’s predicted internal ramp.

  • I believe this is the most convincing theory to date, but it is yet to be confirmed or

  • disproven.

  • The mystery of the pyramids construction may remain a mystery forever, but you can explore

  • this mysterious world in Assassin’s Creed Origins, which is out today.

  • I fell in love with the Assassin’s Creed franchise when I got to explore Florence in

  • Assassin’s Creed 2.

  • It gave me a unique insight into this distant world, and I got the exact same feeling exploring

  • Egypt in Assassin’s Creed Origins.

  • They are even including a mode called Discovery Tour to turn off the hippo violence, and give

  • you guided tours around this beautiful recreation of the past.

  • I really enjoyed the game, if it sounds like something you are into, check it out with

  • the link in the description.

  • As always, thanks for watching and thank you to my Patreon Supporters for helping to make

  • this channel possible.

  • If you want to see more content from Real Engineering, the links to my social media

  • accounts are in the description.

  • I just gave a sneak peek for next weeks video on Instagram, so if you are interested check

  • that out.

This video was made possible by Assassin’s Creed Origins, which is out today.

字幕と単語

動画の操作 ここで「動画」の調整と「字幕」の表示を設定することができます

B2 中上級

The Mystery of the Pyramids' Construction

  • 12 2
    joey joey に公開 2021 年 06 月 11 日
動画の中の単語