Salvador Dali called himself the first painter of the atomic age. In Crucifixion (Corpus Hypercubus), Dali explores his obsession with nuclear science, mysticism, and sacred geometry of the Renaissance. Dali created his cross using a four dimension cube, called a hypercube or tesseract. Dali claimed his surrealism period was merely a stepping stone, and that in his nuclear phase, he would be able to solve the mysteries of the universe.

Carl Sagan's explanation of a hypercube is the best I've found:    • Cosmos - Carl Sagan - 4th Dimension  

Credits & References:
Salvador Dali Foundation
The Mystical Manifesto
The Secret Life of Salvador Dali
The Life and Masterworks of Salvador Dali
The Shameful Life of Salvador Dali
Salvador Dali by Robert Descharnes & Gilles Neret
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