He was such an amazing guy. We got to interview him on our tiny podcast[1] after we reached out and he so happily joined us for half an hour. His book, Manna (which is $0.99 to download from Amazon[2] or free on his website[3]) is still one of the most fascinating and interesting visions of the future that I've come across (although I don't totally agree it's the only reasonable option).

What a loss.

[1] https://www.youtube.com/watch?v=BA5v2cfJp1o

[2] https://www.amazon.co.uk/Manna-Two-Visions-Humanitys-Future-...

[3] https://marshallbrain.com/manna

Edit: Fixed "free to download from Amazon" - it's not