Monday, May 11, 2009

Final Frontier 2: Cities in Space

I'm spending this week looking at the future of humanity, and of the need to secure that future by becoming a space faring race.

The future of humanity requires that we not have all of our eggs in one planetary basked – that we spread out. Parents, teachers, politicians, writers and producers can all help to point the dreams and ambitious of children to space as a potential future home.

As for what that future will look like, I sincerely doubt that we are going to live in a universe where people can zip from one solar system to another in hours or days like travelling between cities in the real world. The planets are a long ways off.

The future that we should direct children’s attention to is one in which humanity has moved off of earth and onto cities in space. Our future is in cities built to orbit the sun as we do – large cylinders where we live on the inside and the centrifugal force of rotation gives us the impression of gravity.

Once we get into space, it would be foolish just to crawl back down into the gravity well of another planet.

It takes 2000 cubic kilometers of material to create one square kilometer of surface area to live on – and much of that is under water. It takes 0.002 cubic kilometers of material to build a square kilometer of surface area on the inside of a space station. That is a ratio of 1 million to 1.

If we add all of the asteroids together, they will still come out to only three percent of the mass of the earth. However, that would be enough to build space cities equivalent to 30,000 times the surface area of Earth (and around 1 million times the land surface area).

Just for fun, let's look at some of the numbers.

In speaking about 30,000 times the surface of the earth is not the same as 30,000 stations in space. Just for fun, let us assume that each station has a surface area of 25 square kilometers of surface area on the inside. The surface area of the earth would require 20,000,000 stations. The asteroid belt could be used to create 600 billion stations – or 100 space cities for every person alive today.

It seems quite obvious that the future population of humanity (assuming we do not kill ourselves and nature gives us enough time) will be living in space, not on the surface of a planet.

This is not (the equivalent of) 30,000 earths spread out across the whole 'Alpha Quadrant'. But (the equivalent of) 30,000 earths orbiting the same sun and capable of talking to each other, where ships can travel from one to the other. A space ship would, in fact, be able to travel from city to city over the course of hours or days (or weeks).

Each city will be surrounded by a vacuum filled irradiated moat that will isolate each city geographically. Each city would have the opportunity to develop its own rules and culture. I suspect, over time, we will be able to see a rich variety of cultures as each station becomes its own social experiment. Some will obviously work better than others, which will provide important lessons to future generations.

The value of living in a city in space brings to mind the possibility of predicting where humans will move to first in leaving this solar system – assuming we survive. If all we need is bunch of orbiting debris and a huge supply of energy (as if from the sun), the nearest neighbor that meets these qualifications is Proxima Centauri. There is no need to look for a planet with life. We could, in fact, leave those planets as wildlife refuges to grow along their own course of evolution without our intrusion.

This represents that future that we should be teaching children to value and to want to build. It is a future with space cities – a cloud of them built around Earth and along Earth’s orbit. Others, however, will be content to put some distance between their social experiment – their “beacon on the hill” – and the rest of humanity.

This is the future to aim for.

Emu Sam said...

For those interested, here's a reference: some of NASA's research into a colonizable space station.

http://www.nas.nasa.gov/Services/Education/SpaceSettlement/75SummerStudy/Table_of_Contents1.html