Re: OK, great, we can get something to Alpha Centauri with a lightsail. Now what?
If you are going to be practical and talk about benefits for humanity, we would be far better off spending the money on eradicating poverty and addressing many of the other ills the planet has.
However, in terms of advancing humanity in terms of the larger universe, longer term projects and thinking are things we should consider, currently, most projects are determined by politics (so results before or by the next election), or ROI which is mostly determined by share price, patience of the stake/shareholders and the state of the markets.
Space researchers are probably the most forward looking people on the planet and I am sure you would have little problem getting space researchers to embrace and work on a 70+ year project.
Biting the hand that feeds IT
