The above is an artists’ rendering of Burj Dubai, a tower that will measure 700 - 900m in height (the tallest on Earth) upon its completion in 2008. Its location is the city of Dubai in United Arab Emirates, home to several other artificial wonders. Construction began only recently, with around 20 floors completed so far. The exact height is being kept a secret by developers. The cost is approximately $8 billion.

Why build towers so tall? Because we have the technology! The top will sway back and forth up to about a dozen feet, which is typical for buildings of this size, but unnoticeable because it’s so gradual. Not only will Burj Dubai will be the tallest occupied building on Earth, it will be the tallest manmade structure of any kind (including radio towers). It will not even be beaten by the proposal for a Solar Tower in Australia, because recent developments have reduced its planned height from 1000m to 650m.

700m above the ground, the distance to the horizon is approximately 65 miles, compared to 3 miles to the horizon at ground level. The field of view increases from 5 square miles to 100 square miles.

Skyscrapers have appeal besides the wow factor. Making use of vertical expansion allows us to condense a lot of activity, services, and interactions within a smaller space. China has considered building a 1228m “Bionic Tower” to house 100,000 people. The cost estimates for such a structure are in the range of $20 billion.

A Space Elevator, the type that would lift packages and passengers to geosynchronous orbit, would be about 100,000 km in height. Liftport ambitiously claims one could be built by 2018, through the use of automated robotic builders using buckytubes (buckminsterfullene) as a building material. (A buckytube is a molecule made of long chains of covalently bonded carbon atoms.) Buckytube towers would be able to easily withstand airplane impacts, or even indirect nuclear attacks.

It could take a while, but once the first orbit-reaching structure is created, there will be more to follow. The convenience of reaching space by climbing rather than launching independently will bring the cost of space travel down to affordability. The political and economic reasons for building such towers will be pursuasive to many countries and groups in the years after they become technologically feasible. We’d better get used to these towers, because we’ll be seeing a lot of them!