N'afọ 1924, afọ anọ tupu van der Laan emee baptism nke aha nọmba ahụ, onye injinia French bụ Gérard Cordonnier achọpụtalarị nọmba ahụ ma kpọọ ya dị ka ọnụ ọgụgụ radiant (French: le nombre radiant). N'adịghị ka aha nke ọla edo na ọlaọcha, okwu plastik abụghị nke van der Laan bu n'obi na-ezo aka na ihe a kapịrị ọnụ, kama ọ bụ n'echiche ya, nke pụtara ihe nwere ike inye ya akụkụ atọ. Nke a, dị ka Richard Knovan si kwuo, bụ n'ihi na ọnụọgụ nke ọnụọgụ ahụ, 3/4 na 1/7, metụtara njedebe nke nghọta mmadụ n'otu ụdị anụ ahụ ọzọ.
Dom Hans van der Laan