Very few constructions proposed by scientists are nearly as ambitious as one project designed by a Physicist utilizing the help of his students. Gerard K. O’Neill’s proposal suggests something so large and so monumental that many scientists can’t imagine ever accomplishing it. Of course it should be noted that “impossible” is a word that scientists have a way of reinterpreting as time goes on.
The moon was seen as impossible once right up until the point when human footprints were first seen upon it. The O’Neill Cylinder, humanity’s home away from home is seen as impossible today… at least for now.
The idea is simple enough – build an island in space that is completely enclosed. The cylinder design is augmented by having three islands running long way along the sides with windows to allow heat and light to come in as the cylinder rotates. Mirrors stationed along the outside operate as blinds to simulate night at regular intervals. But it is the artificial gravity that is likely the O’Neill Cylinder’s most promising feature.
In the space operas of the 1960’s leading all the way up to now, the concept of artificial gravity is generally glossed over as the physics behind it is far beyond current levels of understanding. The closest thing we would have in space to artificial gravity would have to come from the centrifugal force of an object rotating in an enclosed environment. This was most famously seen in Arthur C. Clarke’s 2001: A Space Odyssey.
By rotating the several mile long cylinder, the land masses on the inside would be pulled outward, and increasing and decreasing the speed of the cylinder’s rotation could increase and decrease the relative weight of those living within.
Waterfalls, flocks of birds, mountains, trees, and most other features you can imagine on Earth could theoretically work inside one of these cylinders. Additionally, the controlled environment would make it far easier to alter.
Even seasons could be influenced by the increased or decreased use of mirrors on the windows lining the exterior. Increased time of the windows being closed would result in cooler temperatures, and a decrease in the amount of time the “blinds” were shut would inversely close it.
But the trick would be to actually get enough “stuff” into space to build it. Fortunately, if building the device were ever seriously considered, most of the materials required exist in massive quantities already orbiting Earth in the form of asteroids.
Mining operations could extract the materials from ore rich asteroids and a space based processing center, itself quite ambitious a task, would be able to process the material into strips for assembly of the outer shell.
Of course accomplishing a feat such as this would be an engineering nightmare – but once the infrastructure was put in orbit it would become no more difficult than building the nearly 70 million kilometers of road on Earth.