From the brains behind Iran’s Green Revolution to the economic Cassandra who actually did have a crystal ball, they had the big ideas that shaped our world in 2009. Read on to see the 100 minds that mattered most in the year that was.

71. Ray Kurzweil — for advancing the technology of eternal life.

FUTURIST | NORTH ANDOVER, MASS.

By 2045, the differences between men and machines will be negligible, or so Kurzweil believes. Humans will back up their memories and skill sets on hard drives, to the extent that they become virtually immortal, while robots will be endowed with consciousness — a turning point he refers to as “the Singularity.” Before he cemented his fame as a leading — and sometimes wacky — futurist, Kurzweil worked on artificial intelligence, including inventing the first text-to-speech software. Recently, Kurzweil has turned his attention to how software and medical technology could help people extend and ameliorate their lives. “The future is going to be a very exciting place, and that’s why I’d like to stick around to see it,” he says.

Reading list: One Hundred Years of Solitude, by Gabriel García Márquez; Cybernetics, by Norbert Wiener; Phantoms in the Brain, by V.S. Ramachandran and Sandra Blakeslee.

Wants to visit: China

Best idea: Ideas for applying nanotechnology to renewable-energy technologies, especially solar (given that we have 10,000 times more sunlight than we need to meet all of our energy needs).

Worst idea: That we are running out of resources — we in fact have plenty of energy, water, food, and space once we can apply emerging technologies to transform their availability, which will be soon.

Gadget: Twitter and BlackBerry.