conjecture
in his Nobel Lecture http://nobelprize.org/nobel_prizes/chemistry/laureates/1996/curl-lecture.html, December 7, 1996, Dawn of the Fullerenes: Experiment and Conjecture
Robert Floyd Curl Jr. is a University Professor Emeritus, Pitzer–Schlumberger Professor of Natural Sciences Emeritus, and Professor of Chemistry Emeritus at Rice University. He was awarded the Nobel Prize in Chemistry in 1996 for the discovery of the nanomaterial buckminsterfullerene, along with Richard Smalley and Harold Kroto of the University of Sussex. Wikipedia
conjecture
in his Nobel Lecture http://nobelprize.org/nobel_prizes/chemistry/laureates/1996/curl-lecture.html, December 7, 1996, Dawn of the Fullerenes: Experiment and Conjecture