Found in 1 comment on Hacker News
adastra · 2012-11-15 · Original thread
He's wrong.

For starters, there's this assertion: "The far-fetched version is to use back holes as power sources [1] as this is, as far as I've read anyway, the only remotely viable method of providing propulsion without reaction mass to speak of and reaction mass is the death of any form of interstellar propulsion."

Not true. We can definitely build something with today's technology that allows for propulsion without reaction mass: light-sails pushed by lasers[1]. I can address some of his other points but it's not necessary. If you crunch the numbers, it should be doable to travel to another star in about 150 years.

[1] See Humble's canonical text on space propulsion design:

Fresh book recommendations delivered straight to your inbox every Thursday.