Tag Archives: Arthur Kantrowitz

The Space Elevator Will Be Built About 50 Years After Everyone Stops Laughing

Arthur C. Clarke? Arthur Kantrowitz? Apocryphal?

Dear Quote Investigator: Science fiction luminary Arthur C. Clarke described the audacious idea of building an elevator from the surface of the Earth straight up into space and beyond geostationary orbit in his 1979 novel “The Fountains of Paradise”. The megaproject would require extremely strong lightweight material, and some engineers and scientists have questioned its feasibility. Clarke puckishly said that the space elevator would be built a few decades after people stopped laughing. Would you please help me to find a citation?

Quote Investigator: In 1979 Arthur C. Clarke addressed the 30th International Astronautical Congress and surveyed the concept of a “space elevator” which has also been called an “orbital tower” or “heavenly ladder”: 1

What I want to talk about today is a space transportation system so outrageous that many of you may consider it not even science-fiction, but pure fantasy. Perhaps it is; only the future will tell. Yet even if it is regarded as no more than a ‘thought-experiment’, it is one of the most fascinating and stimulating ideas in the history of astronautics.

Apparently, Clarke’s vivid quotation was modeled after an earlier remark made by Arthur Kantrowitz who was an influential proponent of an innovative idea for space transportation called laser propulsion. Clarke speculated about the time needed to develop the space elevator:

And when will we have that? I wouldn’t like to hazard a guess, so I’ll adapt the reply that Arthur Kantrowitz gave, when someone asked a similar question about his laser propulsion system:

The Space Elevator will be built about 50 years after everyone stops laughing.

QI has not yet located the earlier comment by Kantrowitz about laser propulsion.

There is some evidence that Clarke later endorsed a shorter time as indicated in the selected citations in chronological order listed below. Continue reading


  1. Website: Island One Society, Reprint Article: Year: 1981, Journal: Advances in Earth Oriented Applications of Space Technology (the website incorrectly used the words “applied” and “technologies” in the journal name), Volume 1, Article Title: The Space Elevator: ‘Thought Experiment’, or Key to the Universe?, Author: Arthur C. Clarke, Note: Address to the XXXth International Astronautical Congress, Munich, 20 September 1979, Start Page 49, Quote Near Final Page, Publisher: Pergamon Press Ltd., U.K. Website description: Island One Society website operated by Dale Amon. (Accessed islandone.org on June 8, 2017; QI has not verified the article in the original journal) Page 1 link Page 3 link