The Ringworld Engineers

Dedication

Ringworld is ten years old; and I have never stopped getting letters about it. People have been commenting on the assumptions, overt and hidden, and the mathematics and the ecology and the philosophical implications, precisely as if the Ringworld were a proposed engineering project and they were being paid for the work.

A man in Washington, D.C., sent me a full proofreading job on the first edition of Ringworld, with the title “The Niven-McArthur Papers, Vol. I.” It was of enormous help to me. (If you own a first paperback edition of Ringworld, it’s the one with the mistakes in it. It’s worth money.)

A Florida high school class determined the need for the spillpipe system.

From a Cambridge professor came an estimate for the minimum tensile strength of scrith.

Freeman Dyson (Freeman Dyson!) has no trouble believing in the Ringworld (!), but can’t see why the engineers wouldn’t have built a lot of little ones instead. Wouldn’t it be safer. I hope the answer I’ve given in this book is satisfactory.

Of course there are no petrochemicals on the Ringworld. Frank Gasperik pointed out that any civilization at our level would be based on alcohol. The Machine People would be able to use the vegetable sludge for other purposes, up to and including a plastics industry.

During a speech in Boston someone in the audience pointed out that, mathematically, the Ringworld can be treated as a suspension bridge with no endpoints. Simple in concept; harder to build.

From all directions came news of the need for attitude jets. (During the 1971 World Science Fiction Convention, MIT students were chanting in the hotel hallways: THE RINGWORLD IS UNSTABLE!) but it took Ctein and Dan Alderson, working independently, several years to quantify the instability. Ctein also worked out data on moving the Ringworld.

Dan Alderson was kind enough to work out the parameters for the Ringworld meteor defense for me… and that was the only piece of information I actually solicited.

You who did all that work and wrote all those letters: be warned that this book would not exist without your unsolicited help. I hadn’t the slightest intention of writing a sequel to Ringworld. I dedicate this book to you.