Silicon Valley billionaire Peter Thiel is convening an unusual philanthropic summit Tuesday night at which he will introduce other wealthy tech figures to nonprofit groups exploring  such futuristic ideas as artificial intelligence, the use of “rejuvenation biotechnologies” to extend human life, and the creation of free-floating communities on the high seas.

Eight nonprofits that will be making brief presentations to Thiel’s audience, including Seasteading Institute, Humanity Plus, Foresight Institute,  SENS Foundation, X Prize Foundation, and Singularity Institute for Artificial Intelligence.