Mark Heaton Wrote:
-------------------------------------------------------
> Hi Pistol,
>
> Interestingly, a stone ball was discovered in one
> of the QC shafts which inevitably has a mass equal
> to the volume of a sphere of radius 'r' (with 'r'
> calculated for a sphere with the same density as
> the ball so as to have the same volume).

Why would this be significant to the Egyptians?

> The mass of the ball was published in Nature
> shortly after discovery (and the approximate
> diameter), and it seemed to me that the radius
> might be significant.

Ah -- the Dixon relics, I presume? That's a granite pounder and it's "round-ish"... not round.

> It would be necessary to determine the density of
> the ball, and fortunately the igneous stone ball
> is impervious, so its volume could be determined
> by immersion in water, from which the volume and
> density could be determined. The volume could then
> be used to calculate the radius of a hypothetical
> sphere, and the density would help classify the
> type of rock.

Not sure why you'd do that. It's dolorite. And here it is in the British Museum catalog: [www.britishmuseum.org]

Diameter: Diameter: 6.50 - 7.60 centimetres
Weight: Weight: 540 grammes

It's mentioned in at least two papers:
2004, 30 Apr-1 Nov, Schallaburg,---- 'Die Pyramiden Agyptens'
2013, 22 Jan - 20 May, Kunsthistorisches Museum, Vienna , 'In the Shadows of the Pyramids: The Austrian excavations at Giza (1912 – 1929)'

It's not the only roughly spherical pounder found in/around Giza.

> I didn't find anything related to a sphere in the
> Bent Pyramid or the Red Pyramid, but I thought
> both had geometric features based on a circle.

If you look for "pounders"/diorite pounders (or similar) you'll find some examples.

-- Byrd
Moderator, Hall of Ma'at