How did Tom in the future get his ring just as the star in the nebula exploded?
Tom at the very end of the movie in 2500 as he is floating up towards the star seems to be existing in all three of his lifetimes at once, as he has been taken backwards in time by Izzy, who is then the tree. He is shown to come before the Mayan king just before he kills the Conquistador, or him in 1500. The Conquistador then goes to drink the sap of the tree, dying by becoming a patch of flowers and dropping the ring. Tom in 2000 also loses his ring. If Tom in 2500 exists in all these times at the same time, it can be assumed he took them from his Conquistador self and his year 2000 self to have it at the end of the movie.
