this post was submitted on 12 Jan 2024
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[–] n0m4n@lemmy.world 2 points 10 months ago* (last edited 10 months ago) (1 children)

If you know the ancient unit of length, make a circle with the radius of that length, The various lengths of a line of stones on a side will introduce Pi. The slope would be determined by the height of the blocks and the number of revolutions marking the next run of stones. It is a simple and elegant geometry.

[–] krellor@kbin.social 1 points 10 months ago* (last edited 10 months ago) (1 children)

I don't know that I follow your illustration, but let me try an alternate explanation for my point.

One way pi appears is by taking the perimeter of the great pyramid and dividing by its height to get 2Pi. We can write this as

4L/h ~= 2Pi
2L/Pi ~= h

The great pyramid has a height of 280 cubits, and a base of 440. From this, using right triangles and Pythagorean identities we can find the long side and all angles.

Specifically, we look at the slope of the outer face, which we can express as rise over run. In our case, 280/220 = 1.27 or as 51.843 degrees.

As long as that ratio of rise over run holds you will preserve the above ratio with pi. You can fix that slope and vary either the base or the height, and the other value is predetermined. So how did the rise and run ratio come up? Not every pyramid had this relationship, and there is an infinite number of unit length combinations that wouldn't give rise to this ratio.

So let's look at the old units, in particular, the palm.

1 palm = 4 digits.
4 palms = 16 digits.
5 palms = 20 digits.

If for every 5 palms up, the block is 4 palms deep, you get the ratio of 1.25.

That gets us within the 4% agreement with our starting ratio.

Again, you could choose a unit length, and have the rise be 3 up for every 2 palms deep, and you now wouldn't have this ratio. There are an infinite number of ways to construct a pyramid with a unit measure that doesn't.

I hope that makes sense. Have a good day.

[–] n0m4n@lemmy.world 1 points 10 months ago (1 children)

We are talking about two separate things. You are correct in what you are writing. We both agree on this. What the article was referencing was the lengths of the various sides. It did not speak about height at any time. There is no rise, only runs.

The runs 'mysteriously' used a unit of length that used a multiple of their unit of measure * Pi. The Archeologist commented that the likely reason was that their wheel was their unit as part of the diameter or radius, hence introducing Pi as part of the measure of the sides. That's the SMH 'Doh' of the comment and the humor.

It is the same humor that poked fun at the engineering graduate who was hired by Edison. He was assigned the task of finding the volume of a new light bulb. After days of work and a long formula measuring it, he brought his results to Edison. Edison said that his was too complicated for him to figure. Edison filled the bulb with water and poured it into a measured beaker.

I have no idea if the Edison story is true, but always remembered it as a young engineering student, to not overcomplicate results. I worked with expert craftsmen who would chew me up and spit me out, if I were caught that way.

Have a good day, also.

[–] krellor@kbin.social 2 points 10 months ago

That makes sense, I honestly wasn't thinking in terms of the comment on the meme. Thanks for the clarification and have a great day!