I used to be a space colony proponent, years ago, when Gerard O’Neill was in his heyday. There were attractive images of what these cities of the future might look like, as idealized and unreal as any other grandiose project. I was recently reminded of this when SF author Charles Stross pointed out an article by a professor at UCSD that concluded that they were not likely to be viable, at least in the near term, and the considerable outcry that came from those who still hold to the posibility.

Space colonies seemed to be a natural extension of the program of venturing into space in the 60s and 70s. Astronauts led the way, and the rest of us would follow in a few decades. Maybe there was some good rationale for having thousands of people living in space. New manufacturing processes were one concept. But what can you make better in space than you can elsewhere? And where would you get the materials to make it with?

The same thing is going on with vertical farming. A lovely rendering seems full of possibility and allure, but the fundamental reality is that it would be enormously expensive way of providing a very tiny fraction of the farming space needed.

I still love space colonies and vertical farms, but in the same way that I love science fiction movies, not as something I think has a serious place in policy discussion, as much as I might love for it to be otherwise.