George Dantzig, 1914-2005
Markus Registrada writes "George Dantzig, the inventor of the Simplex method for solving Linear Programming problems, died on May 13. He was also the now-legendary student who turned in solutions for what he had taken to be a homework assignment, only to find out they had been posted as examples of what were suspected to be unsolvable problems."
If something is unsolvable, coming up a solution is definately impossible. If now we see a solution, that means the person should not have claimed unsolvable. It is at most "no solution to date", like P=?NP.