Pyramid Construction | By Naked Science

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Its sides climb at an angle of slightly less than 52 degrees rising to a summit of 480 feet. But how did they manage to maneuver two and a half-ton blocks to such an incredible height without the crane or the block and tackle? It was a challenge to the ancient Egyptians and still remains a mystery to modern archaeologists. Egyptologist Mark Lehner has spent 30 years studying the pyramids hands-on. 
"My approach to the question was where are the quarries? what kind of a ramp can you get from the quarry to the pyramid in a functional slope". 
Lehner and almost all Egyptologists believe that some kind of ramp was used to raise the stone blocks. The type of ramp remains a mystery. Did they approach the pyramid straight on; zigzag up one side or spiral around it. 
"It's not a problem that's been totally solved and you know I've given my suggestions, I've tried to base them in the landscape, but you know a lot of it is still inference". 
Because the ramps were dismantled once the pyramid was complete, only fragments of evidence are available to archaeologists but it was ramps and sheer muscle power that allowed millions of blocks to reach the summit. Once in position, the builders faced a new task. The blocks had to be fitted together. Surprisingly in such a precise build, a large proportion of the internal stones were just roughly finished. The gaps between them were filled with rubble and gypsum mortar. 
"In between the blocks were stuff, lots of limestone chippings mixed with huge dollops of mortar, and it says just like modern concrete." 
But every stone that would be visible when the build was completed was placed with amazing precision. In the Great Pyramid, the blocks of the burial chamber fit precisely. The sides of these blocks had to be almost perfectly flat to make these astonishing joins. This precision engineering was achieved using the most rudimentary of tools.
"We'll use this rod spring tool in order to find out what the surface is truly flat and by using a third rod which is the same length as the other two rods joined by the string which is now called very taut. We can see if it just slips under now we've got a bit of a high spot there now. In ancient times they would mark that simply by what is some red ochre on just to remind the workers where to go to and check along the length of the string". 
The ancient mason would use the rods and string to spot imperfections and then mark them with red ochre to show where more work was needed. 
"Using two further tools this one being a flint scraper and this one being a sandstone rubber. Now we can use the mount as a guide to scrape away the high point like so and it's obvious that as you scrape the mark disappears and with it, of course, the high spot".
This same technique was also used in the final stage of construction. The rough internal blocks were covered with an outer casing of perfectly smooth stone. This was carved from the highest-grade limestone and had to be carried across the Nile to the pyramid site. With this polished casing, the pyramid would have shown dazzling white in the Egyptian Sun.
"But when the pyramids were newly encased, in this special limestone they must have been blinding in the Sun like newly fallen snow". 
To achieve, this every casing stone was cut to sit perfectly with its neighbors. When complete, the Great Pyramid of Giza was covered with thousands of these facing stones. Sadly they have long vanished, taken to build the mosques and castles of Cairo but facing stones can still be seen on the cap of Khafre's pyramid. Even with all the Egyptian skills and tools, building the pyramids was still an incredibly hard task, requiring millions of man-hours to complete. Legend has long suggested that the pyramids were built by armies of slaves. The legends are wrong. Forensic archaeological discoveries are now putting a face on the people who really built the pyramids.

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✍ Vocabulary Review (find the word in the text that is suitable to each below description by your comment): 

1. a shape made up of curves, each one above or wider than the one before
2. A small part broken or separated off something.
3. anything that helps to prove that something is or is not true
4. Take (a machine or structure) to pieces.
5. The highest point of a hill or mountain
6. exact and accurate
7. the number or amount of a group or part of something when compared to the whole
8. the piles of broken stone and bricks, etc. that are left when a building falls down or is destroyed
9. to handle and move something carefully or with difficulty
10. a mechanism consisting of ropes and one or more pulley-blocks, used for lifting or pulling heavy objects.
11. used to emphasize how very great, important, or powerful a quality or feeling is; nothing except
12. a person who studies the language, history, and culture of ancient Egypt
13. a mixture of sand, water, and cement or lime that is used to fix bricks or stones to each other when building walls
14. Extremely surprising or impressive; amazing.
15. only basic, and not deep or detailed
16. tight or completely stretched
17. a yellowish-orange colour, or a substance obtained from earth that is used for giving this colour to paints
18. a very old story or set of stories from ancient times, or the stories, not always true, that people tell about a famous event or person
19. a person who is trained to work with bricks and stones used in buildings
20. a guess that you make or an opinion that you form based on the information that you have.
21. to remove an unwanted covering or a top layer from something, especially using a sharp edge or something rough
22. a covering that protects something
23. Cut (a hard material) in order to produce an object, design, or inscription.
24. Extremely bright, especially so as to blind the eyes temporarily.
25. to cover or enclose something completely
26. Shiny as a result of being rubbed.
27. Disappear suddenly and completely.
28. a building for Islamic religious activities and worship
29. a large strong building, built in the past by a ruler or important person to protect the people inside from attack
30. using the methods of science to provide information about a crime

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