How old were the actors in Flubber (1997)?

Professor Phillip Brainard, an absent minded professor, works with his assistant Weebo, trying to create a substance that's a new source of energy and that will save Medfield College where his sweetheart Sara is the president. He has missed his wedding twice, and on the afternoon of his third wedding, Professor Brainard creates flubber, which allows objects to fly through the air.