4-amalgamation illustrated


Picture by Rami Grossberg, from John Baldwin, “ The complex numbers and complex exponentiation. Why Infinitary Logic is necessary!


Grothediecks scribings

Witch’s Kitchen 1971. Riemann-Roch Theorem: The ‘dernier cri’: The diagram is commutative! To give an approximate sense to the statement about f : X \rightarrow  Y, I had to abuse the listeners’ patience for almost two hours. Black on white (in Springer Lecture Notes) it probably takes about 400, 500 pages. A gripping example of how our thirst for knowledge and discovery indulges itself more and more in a logical delirium far removed from life, while life itself is going to Hell in a thousand ways—and is under the threat of final extermination. High time to change our course!


Grothendieck wrote this abstract into the colloquium book at the Universität Bielefeld when he spoke there in 1971, from “Comme Appelé du Néant — As If Summoned from the Void: The Life of Alexandre Grothendieck” by Allyn Jackson [1] [2].

Commutative arts

January 28, 2008

Big commutative diagramm

Suppose that, in Venet’s monumentally presented painting Related to the Homology Simplicial Complexes, in the place of H_{q-1}(L^{q-1}) the artist
had copied H^{q-1}(L^{q-1})


From “Commutative Diagrams in the Fine Arts” by Karl Heinrich Hofmann