If I had that wealth I would still keep coding... just for fun and for the sake of coding! Probably I would focus on something extraordinary, like robotics or AI.
Usually these kind of goals are ones that are only realistic if you have already made it big and can fund something expensive without the need to see real returns for a long time. Like what Elon Musk has done with spacex, wouldn't have been possible without large personal wealth.
Robotics or AI, while respectable, are not extraordinary. To do extraordinary work, you'll probably have to go into biology, although I'm too uneducated to know which subfield. From afar, computational and synthetic biology look very promising. So if I got rich, that's probably where I'd put my efforts.
Wow, it seems a little presumptuous of you to believe you have the foresight to determine which fields are extraordinary and which are simply respectable, don't you think?
You're right. It is very presumptuous,almost to the point of pretension. I would change the post if I could.
I don't actually know what field will be extraordinary and which will be simply respectable. However, I can understand AI and robotics, and from what I've seen, there isn't extraordinary work being done (please feel free to prove otherwise). There are only incremental advances being made that improve our lives by small steps.
What I can't understand is biology; it is unimaginably complex, which is why is why now I'm kind of wishing I had majored in it rather than computer science.
There are many extraordinary things have been done in robotics in recent, and a lot many to be done yet. Just try to "teach" a self-balancing biped to run. In theory it's possible to run over walls and ceiling in your room (if you run fast enough), but damn hard to implement. I admire what Anybots and Big Dog guys do.
"What I can't understand is biology; it is unimaginably complex"
Not understanding it does not imply mean that extraordinary work is being done in biology, either. My guess would be that only "incremental" advances are happening in biology, too, just because that is true of most fields of human endeavor. It is only looking backwards at the cumulative progress of many incremental steps when you can see that an amazing amount of progress has occurred.
No idea what "extraordinary" means to you, but the scenarios reported in Peter Singer's recent book on military robotics, Wired for War, represent some potentially huge shifts. They may not "improve our lives" though.
Believe me.
Until then, keep coding...