The Soddy page.

Frederick Soddy 1877-1960

Michael Fox, Adrian Oldknow, John Rigby and Sir Christopher Zeeman have submitted a two-part article to the Mathematical Gazett giving details on their discoveries and their proofs of the generalisation of results about Soddy circles of a triangle to Soddy spheres of 4-ball tetrahedra. In the meantime the key results are summarised in the note below:

The Soddy spheres of a 4-ball tetrahedron (3pp) (Word 139 Kb)

The Oldknow article giving the constructions for Cabri 3D:

Exploring 4-ball tetrahedra with Cabri 3D (5pp) (Word 1293 Kb)

A zip file of the Cabri 3D constructions (Zip 295 Kb)

(a) (b) (c)

 (a) The centres of 4 touching spheres form a 4-ball tetrahedron

(b) Four spherical fruit can lie inside a transparent spherical fruit bowl,

and touch a small spherical fruit in their middle!

(c) Three of the authors hard at work in the Hertford College SCR.





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