I thought of what I think is a good experiment today that could help prove the Multiple Worlds Interpretation of Quantum Mechanics - or at least improve our chances of understanding and utilizing it.

I'm going to buy a lottery ticket. I'm going to pick my numbers using a quantum random number generator. If MWI is true, then there should be a version of me that gets rich really quick and many versions that don't.

If I win the lottery, I'm going to go and buy another ticket and use the same method to pick the numbers. If I continue to win, I'll continue to buy tickets, stopping only when I'm the richest man in the world, or the authorities decide I must be cheating somehow and stop me.

Using this method I should be guaranteed that in at least one of the possible worlds I become very rich and powerful, with a near limitless supply of funds. (For the sake of those versions of me that win the lottery but not to the point of becoming the richest man in the world, I'll consider them exempt), I can pour these into quantum research, with a goal of finding some way of communicating across worlds (likely impossible, but let's continue to hope) and letting the non-lottery-winning versions of myself know how it's done.

If this works I should expect to receive a message from the super rich and powerful version of myself with information that will make me super rich and powerful as well.

The main problem being that I'm not sure my super-rich self would have a "handle" by which to contact the other versions. Maybe by some clever use of quantum entanglement?