Petrie writes in The Wisdom of the Egyptians, pp10-11:
I tried to verify this statement by leveraging the Pendulum equation (T = 2π * √(L/g)). T= period, L = length, g = gravity Note: this equation is for metric units. I arrived at approximately 50,000 periods of this sized pendulum. It is possible to get an exact 50,000 only through variation of gravity which isn't constant over earth but we generally use a constant of 9.81 m per second squared to approximate it. 50,000 periods would equate to 100,000 swings back and forth in a day.
Quite remarkable but not generally accepted. Why is this?
Quote
Petrie
14. Plumb-line pendulum. Whether the Egyptian treated the well-known plumb-line as a pendulum is not indicated by any remains, though the plumb-line was commonly in use from very early times. But the notable fact is that 29·157 ins. (the diagonal of the 20·62 ins. cubit), which was the basis of all land measure, is the length which would swing 100,000 times in 24 hours, exactly true at Memphis latitude. This is so remarkable that it suggests that it may have been derived from that observed length, and the source entirely forgotten after the scientific age of the pyramid builders.
I tried to verify this statement by leveraging the Pendulum equation (T = 2π * √(L/g)). T= period, L = length, g = gravity Note: this equation is for metric units. I arrived at approximately 50,000 periods of this sized pendulum. It is possible to get an exact 50,000 only through variation of gravity which isn't constant over earth but we generally use a constant of 9.81 m per second squared to approximate it. 50,000 periods would equate to 100,000 swings back and forth in a day.
Quite remarkable but not generally accepted. Why is this?