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FW: [SERMLIST] Of interest? (Why The Pyramids Crumble)

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  • Dianne C
    Date: Sat, 11 May 2013 13:48:50 -0400 From: parcels@GEORGIASOUTHERN.EDU Subject: [SERMLIST] Of interest? (Why The Pyramids Crumble) To:
    Message 1 of 2 , May 22, 2013
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      Date: Sat, 11 May 2013 13:48:50 -0400
      From: parcels@...
      Subject: [SERMLIST] Of interest? (Why The Pyramids Crumble)
      To: SERMLIST@...






      Just passing this on for anyone interested. --John



      The Atlantic, May 10, 2013

      Mystery Solved? A New Theory About Why Egypt Stopped Building
      Pyramids

      Is it possible they were too perfect?

      Rebecca J. Rosen







      When structural engineer Peter James arrived at the Bent Pyramid, 25
      miles south of Cairo, his task was to secure the structure's
      remaining "cladding" -- its smooth exterior envelope. But why was it
      crumbling in the first place?



      The foundation seemed completely stable. The prevailing theory--that
      "the missing cladding was removed by local opportunist thieves" --
      didn't inspire confidence: That could explain the destruction at the
      lower levels, but the damage extended far up the pyramid and "in an
      apparently random manner, with no signs of indentations from
      temporary scaffolding or of any symmetrical cutting of the blocks to
      aid removal," James writes in STRUCTURE, a structural engineering
      trade publication. The damage just did not look like the result of
      thieves. Rather, as James puts it, it "appears to be caused by a
      giant whose hand has swept across the face of the pyramid with
      enormous energy, sucking out the facing and leaving the ragged empty
      sockets.?"



      So what was causing the crumbling? James presents a new explanation:
      thermal movement--that is to say the expansion and contraction of
      the limestone with temperature fluctuations--has ground down the
      rocks and shifted their positions.



      During the day, the temperature rises to 40̊C (104̊F)
      across the face of the outer casing, then at night cools to 3^(0)C
      (37^(0)F) because of the lack of cover and exposure to the
      prevailing winds. This gives an average daily temperature
      fluctuation of 37̊C (67̊F). The photographs of the Bent Pyramid
      show how thermal expansion has caused the blocks to move to the
      edges, where they have detached. It also shows how individual
      stones, unsupported, can cantilever and snap off and subsequently
      fall to the ground.?




      He estimates that the motion can amount to 1¼ inches per 328 feet.
      As the stones move, dust and sand would fall from the stones and
      fill in the spaces between them. The spaces into which they could
      contract at night would shrink, and over time they would be pushed
      out of position. "Multiply this endless movement by the number of
      days that the pyramid has been erected and you have the reason why
      all the outer casing has moved to the extremities, where it has
      buckled or displaced against blocks moving in the opposite direction
      and then fallen off," James writes. "It may then have been picked up
      by opportunists and removed from the site.?"



      The Bent Pyramid is one of the best preserved and, as a result, it
      provides a unique opportunity for studying how the crumbling is
      happening. James theorizes that the reason the Bent Pyramid retains
      its casing, while the Red Pyramid and the Great Pyramid "have
      virtually none" is that, ironically, the Bent Pyramid had worse
      construction to begin with. As the Egyptians became more skilled,
      and developed more accurate construction techniques, the voids
      between the stones disappeared, and the structures were less able to
      absorb the ebbs and flows of the limestone. The other, more perfect
      pyramids may have developed exterior cracks rather quickly, and,
      James hypothesizes, may be why eventually they Egyptians moved their
      burial grounds to the Valley of the Kings. The pyramids' perfection
      became their imperfection; their smooth facades broken by the
      precision of their construction.



      http://www.theatlantic.com/technology/archive/2013/05/mystery-solved-a-new-theory-about-why-egypt-stopped-building-pyramids/275738/


      [Non-text portions of this message have been removed]
    • Anthropmor
      this is interesting, and I can t help but be reminded of my school - University if ZIllinois, Chicago, which had a really cool series of walk ways, on the
      Message 2 of 2 , May 22, 2013
      • 0 Attachment
        this is interesting, and I can't help but be reminded of my school - University if ZIllinois, Chicago, which had a really cool series of walk ways, on the second story level, connecting most of the buildings.
        There were beautiful granite slabs and concrete slabs- and someone had the bright idea of instilling heating coils in the cement covered concrete, to melt the snow and keep the walk ways clear in winter.
        O f course, the heating and cooling, provided both by Chicagos crazy weather patterns, and augmented by localized heating, lead to a lot of damage.
        Those walkways ( which I loved- it really brought out the "Planet of the Apes" motif) are now gone - some of the granite slabs are Lake Michigan, where mostly the cement and concrete are faighting erosion, and the better preserved of the granite slabs went off for resail, to line the pockets of the (connected) construction company.
        To live in Chicago is to know mother nature in her foulest moods, and government at its most Byzantine levels of corruption.
        Mike Pavlik



        During the day, the temperature rises to 40̊C (104̊F)
        across the face of the outer casing, then at night cools to 3^(0)C
        (37^(0)F) because of the lack of cover and exposure to the
        prevailing winds. This gives an average daily temperature
        fluctuation of 37̊C (67̊F). The photographs of the Bent Pyramid
        show how thermal expansion has caused the blocks




        -----Original Message-----
        From: Dianne C <dianneky@...>
        To: sacc-l <sacc-l@yahoogroups.com>
        Sent: Wed, May 22, 2013 9:47 am
        Subject: [SACC-L] FW: [SERMLIST] Of interest? (Why The Pyramids Crumble)






        Date: Sat, 11 May 2013 13:48:50 -0400
        From: parcels@...
        Subject: [SERMLIST] Of interest? (Why The Pyramids Crumble)
        To: SERMLIST@...


        Just passing this on for anyone interested. --John



        The Atlantic, May 10, 2013

        Mystery Solved? A New Theory About Why Egypt Stopped Building
        Pyramids

        Is it possible they were too perfect?

        Rebecca J. Rosen







        When structural engineer Peter James arrived at the Bent Pyramid, 25
        miles south of Cairo, his task was to secure the structure's
        remaining "cladding" -- its smooth exterior envelope. But why was it
        crumbling in the first place?



        The foundation seemed completely stable. The prevailing theory--that
        "the missing cladding was removed by local opportunist thieves" --
        didn't inspire confidence: That could explain the destruction at the
        lower levels, but the damage extended far up the pyramid and "in an
        apparently random manner, with no signs of indentations from
        temporary scaffolding or of any symmetrical cutting of the blocks to
        aid removal," James writes in STRUCTURE, a structural engineering
        trade publication. The damage just did not look like the result of
        thieves. Rather, as James puts it, it "appears to be caused by a
        giant whose hand has swept across the face of the pyramid with
        enormous energy, sucking out the facing and leaving the ragged empty
        sockets.?"



        So what was causing the crumbling? James presents a new explanation:
        thermal movement--that is to say the expansion and contraction of
        the limestone with temperature fluctuations--has ground down the
        rocks and shifted their positions.



        During the day, the temperature rises to 40̊C (104̊F)
        across the face of the outer casing, then at night cools to 3^(0)C
        (37^(0)F) because of the lack of cover and exposure to the
        prevailing winds. This gives an average daily temperature
        fluctuation of 37̊C (67̊F). The photographs of the Bent Pyramid
        show how thermal expansion has caused the blocks to move to the
        edges, where they have detached. It also shows how individual
        stones, unsupported, can cantilever and snap off and subsequently
        fall to the ground.?



        He estimates that the motion can amount to 1¼ inches per 328 feet.
        As the stones move, dust and sand would fall from the stones and
        fill in the spaces between them. The spaces into which they could
        contract at night would shrink, and over time they would be pushed
        out of position. "Multiply this endless movement by the number of
        days that the pyramid has been erected and you have the reason why
        all the outer casing has moved to the extremities, where it has
        buckled or displaced against blocks moving in the opposite direction
        and then fallen off," James writes. "It may then have been picked up
        by opportunists and removed from the site.?"



        The Bent Pyramid is one of the best preserved and, as a result, it
        provides a unique opportunity for studying how the crumbling is
        happening. James theorizes that the reason the Bent Pyramid retains
        its casing, while the Red Pyramid and the Great Pyramid "have
        virtually none" is that, ironically, the Bent Pyramid had worse
        construction to begin with. As the Egyptians became more skilled,
        and developed more accurate construction techniques, the voids
        between the stones disappeared, and the structures were less able to
        absorb the ebbs and flows of the limestone. The other, more perfect
        pyramids may have developed exterior cracks rather quickly, and,
        James hypothesizes, may be why eventually they Egyptians moved their
        burial grounds to the Valley of the Kings. The pyramids' perfection
        became their imperfection; their smooth facades broken by the
        precision of their construction.



        http://www.theatlantic.com/technology/archive/2013/05/mystery-solved-a-new-theory-about-why-egypt-stopped-building-pyramids/275738/


        [Non-text portions of this message have been removed]







        [Non-text portions of this message have been removed]
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