I came here just to say that - if memory serves - this was mentioned in The Mote in God's Eye by Niven & Pournelle: humans have contacted an alien race, and the

I came here just to say that - if memory serves - this was mentioned in The Mote in God's Eye by Niven & Pournelle: humans have contacted an alien race, and the aliens suggest some improvements to the human technology on display on the spaceship. Among these, a "frictionless material" which one of the human engineers points out "will save lots of water on arid planets and also on the spaceships themselves". (During the exchange with the aliens who live there, one