Why it Would Be Impossible to Build a Billion Story Skyscraper

As part of their ongoingWhat If?"series,Randall MunroeofxkcdandHenry ReichofMinutePhysics looked at the possibility of constructing a skyscraper that had a billion stories. The short answer is that it is absolutely not possible, but reasons why are absolutely fascinating.

One is wind. The wind up high is very strong,and buildings have to be very strong to stand up against the wind. Another problem is, surprisingly, elevators. Tall buildings need elevators...If your building has lots of floors, you need lots of different elevators to get allthe people where they're trying to go atonce: some of our existing tall building have floors purely dedicated to letting people change from one elevator to another. If you make a building too tall, the whole thing gets taken up by elevators and there's no space for regular rooms.

A billion story mega-mega-MEGA skyscraper would also encounter another issue, which would rip the building outs by its roots and float off into space.

And it would introduce a new problem - centrifugal forces!... Our mega-mega-MEGA skyscraper is so muchtaller than geostationary orbit that most of itsmass is where the outwards-pulling centrifugal force is much, much, stronger than gravity. The engineering challenge of this skyscraper isn'tthat it will collapse down on itself like jello,but that it'll tear itself up by the roots and go into orbit near the moon. ...But the view from the roof would be incredible.