### Gregorio Ricci-Curbastro (1853-1925)

Inventor of tensor calculus (1884).

*Azure, a fess Gules, accompanied, in chief, of a comet between two estoiles Or and, in base,*

of
an oak tree between two hedgehogs combattant Proper on a terrasse Vert.

*
Azzurro con una fascia rossa accompagnata in capo da una cometa posta tra due stelle d'oro,*

in punta una quercia al naturale terrazzata di verde accostata da due ricci al naturale e affrontati.

Those are canting arms: *Ricci* means hedgehog
in Italian and *Curbastro* is said to come from the latin name for the oak tree
(*quercus*).

The inventor of tensor calculus (1884) is from a family of
wine producers
based in Capriolo.
The Ricci-Curbastro
House (old Franchini House) is located
*Via San Vitale*, 31 (Bologna).
The traditional Ricci-Curbastro shield is the basis for the stylized
commercial logo
now used on the label of most Ricci-Curbastro wine bottles.
Fortunately, they have retained the unmodified shield for their
Franciacorta
Demi Sec (label at right) reproduced on the frontispiece of this page...

However, the colors used in the wine label depart significantly from the heraldic colors
which can be found elsewehere (example at left).
Strictly speaking, the composition of the shield violates the traditional heraldic
*rule of tinctures* which ordinarily forbids the juxtaposition of two
colors like gules and azure.

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In 1884, Gregorio Ricci-Curbastro
started the investigations of *quadratic differential forms* which led him
to invent tensor calculus
(1884-1894). The text he published about that with
Tullio Levi-Civita
in 1900 was entitled
*Méthodes de calcul différentiel absolu et leurs applications*.
*Ricci-Curbastro* signed this particular work with the abbreviated moniker
*Ricci* for the first and only time
(this is how he remains known to most scientists today).
That momentous treatise is what would enable A;bert Einstein
to formulate General Relativity in 1915.
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