The when is a little harder to predict, but in
fifty
years for certain. It didn't take that long to get colonies established in the New World.
So what's it going to be like to live out there?
* * *
Well, first let's take the O'Neill Colony, which is a huge cylinder in space. NASA figures we could have the first one before the year 2000 if we wanted it, and there are good numbers to show that it would pay for itself within a few years after its establishment: it can sell power to Earth, as well as serve as a base for extensive space manufacturing—and there are plenty of things that you can manufacture
only
in space.
The colony will be quite large, say a cylinder three kilometers in diameter and ten to twenty kilometers long. Windows run the length of it to let in sunlight. Under the windows is land, ordinary dirt, with hills, streams, buildings, and such like. The whole thing rotates to give artificial gravity. Let's suppose the medical people have determined that a tenth of an Earth gravity is sufficient for long-term health; that means our cylinder rotates at .026 radians a second or .25 revolutions per minute.
A colonist standing on the ground and looking up through a window above will see the stars swinging past once each four minutes. He'll also see his neighbors' fields and houses hanging in space above his head, which can be disconcerting until he gets used to it, after which it won't seem any stranger than seeing mountains in the distance.
Life in the O'Neill colony may be a bit strange, but it has its compensations. If the colonist is a farmer, he'll never have to worry about the weather. There won't be any rain—he (or someone else) will have to irrigate—but on the other hand there won't be floods, storms, or droughts (so long as the engineers keep the watermakers going). He will be able to calculate
exactly
how many hours of daylight his crops will get for the entire growing season. The only weeds and insects he'll encounter will be those brought aboard by the ecology teams.
Actually, one suspects a few pests will come along as stowaways.
Imagine the town meeting after the sparrows have got loose. One faction wants them left alone. They're cute. Another advocates shotguns. Still another abhors guns, but is willing to send to Earth for a supply of sparrowhawks. After four hours of shouting the council sets the matter aside for another day. Personally, I'd vote for sparrowhawks. . . beautiful!
Machinists and mill workers will find their work little different from Earth, except that everything weighs only 10% as much. For production runs the colony probably has computer-controlled lathes and milling machines, but for one of a kind items the machinists will have to do the work. There will undoubtedly be doctors and storekeepers and librarians and tailors, and, alas, lawyers, none of whose business lives will be all that different from what they would be like on Earth.
But after working hours things get more exciting. No freeways; no cars. No subways, either. In 10% gravity the simplest means of transportation is to fly with artificial wings. There might not be any other form of transport besides walking. Why should there be? (Well, for heavy hauling you might want a few electric trucks, but surely there's no need for any individuals to own cars or trucks.)
If flying is the usual transport, grocery shopping will be like New York City, where you buy a few items a day as you need them, rather than like California where you buy bags and bags once a week and transport them in a car.
Flying also means that everyone in the colony is accessible to everyone else; every place is easily accessible to anyone wanting to get there. This can drastically change the sociology. Houses will probably have roofs, not to keep the rain out, but to keep the neighbors from looking in. The house need not be anything more than a visual screen: it doesn't have any weather to control.
What all this does to the colony's mores isn't really predictable. (Who, after all, could have prophesied drive-in movies from the first automobiles?) There's little privacy. Parents will know pretty well what their teen-age kids are doing. Whether this will make pre-marital sex more or less common isn't obvious, at least not to me. It depends partly on geography, I suppose: will there be any secluded places, dark and cozy? Dark comes when the windows are closed for the night, of course; the Sun only sets when the colony wants it to. Daylight saving time is silly in an O'Neill colony, because if you want more daylight, you simply program the window blinds to give it.
It may be that parents won't care much where their children are. There won't be any dangers in the colony; one presumes that airlocks to the outside and the like are controlled against accidental use, and also that there won't be many incompetents in the community—at least not
that
incompetent. There remains the problem of crime.
It's hard to imagine jails in a space colony, although I suppose they could be built. It's hard to imagine space muggers in the first place, or that the colonists would put up with them. They might be enslaved to the community. The cost of shipping an unwanted colonist back to Earth would be slightly colossal. On the other hand, the environment is fragile enough that you certainly don't want anyone wandering around harboring burning resentment against the colony—especially not if he has suicidal tendencies. It would be all too easy to take a number of others along in a spectacular suicide. If you couldn't send them back, what would
you
suggest?
We can presume, then, that the environment is
safe;
free of most of the dangers we live with here on Earth. Now in England the custom of dinner parties grew up only after Sir Robert Peel invented police; prior to that no one in his right mind went
anywhere
after dark, and when you visited friends you stayed at least for the night. When the London Police made the streets comparatively safe it became possible to visit for the evening and go back home for the night. Such factors will affect the colony patterns of friendship too.
On the other hand, there are dangers that we don't worry about here. The most significant would be leaks. It would take a very large leak to affect the colony, of course. Small ones would be costly (air isn't cheap when it has to be taken to orbit) but easily repaired before anyone felt their effects. Still, it seems reasonable that there would be a few major airtight structures, shelters into which the colonists could crowd in the event of a major break in the pressure hull.
An interesting life, with kids learning to fly at an early age. I suppose when a parent tells a teenager he's grounded, he'll mean that quite literally.
* * *
So what do you do in such a colony? Well, what do you do now? It's simple enough to sit at home and watch TV whether you're in New York or Earth orbit. Some recreations won't be possible. No backpacking trip through the wilderness. Probably no sailboating: no wind, even if there's a lake. There may be fishing, but certainly no hunting.
On the other hand, there'll be cultural activities not available on Earth. Flying, of course; real flying, not dangling from an oversized kite, but man's ancient dream of flying like a bird. Aerial acts will probably become an art form, possibly involving a large portion of the colony population. There can also be aerial ballet, with and without wings. Up in the center of the cylinder there's no gravity. Zero-g areas are easily accessible.
Games can be strange. With that large radius and slow rotation rate, the colonists won't easily be able to tell the difference between their artificial spin gravity and the real thing: not, that is, until they begin throwing things. As soon as you throw something, say a baseball, you'll know you don't have normal gravity. The ball's trajectory will be strange, and it will depend on which direction you threw it in. You'll also be able to throw the ball a very long way, so far that baseball may require much larger teams to cover the huge playing field.
In fact, any projectile motion is affected. Obviously, in one-tenth gravity you can throw a ball (or a javelin or a wrestling opponent) ten times as far as you could on Earth. A javelin-throwing athlete who can manage 285 feet on Earth would get 2,850 feet, over half a mile, in the O'Neill colony gravity. Broad jumpers would also do well.
However, there's a problem. When you loft a thrown object in centrifugal gravity, you increase the time of flight; and the ballistics become strange indeed, due to an effect called the Coriolis Force. What happens is this: from the viewpoint of an observer inside the spinning object, the "gravity" is radial. Objects dropped tend to fly directly away from the center. They fall toward the "floor," and in 10% gravity as we have here, they fall rather slowly. It takes two full seconds for something to drop two meters.
While the object is falling, the "floor" is moving, so that the dropped object does
not
strike the spot directly under it. The discrepancy is related to the rate of spin and the radius of the spinning craft, and for something as large as an O'Neill colony you'd never notice it under normal circumstances; but if you throw the ball up, or loft it into an arching trajectory, the effect can be
very
noticeable.
(I know: it isn't
really
that way at all. To an observer watching from outside there is no such thing as "centrifugal force," and the Coriolis effect I described in the last paragraph is also a pseudo-force. What happens is that the released object tends to fly along in a straight line tangent to the circle of motion; but the effect, as far as someone inside the colony is concerned, is as I described it. I've diagrammed the situation below.)
The result is that if we did have baseball in an O'Neill colony, the batted ball would follow an abnormal trajectory.
__________
Coriolis "Force" displaces dropped or thrown object; view as seen by observer rotating with system.
__________
Cause of the Coriolis Effect: true situation as seen by non-rotating observer.
__________
The fielders could jump fifty feet into the air in an attempt to catch it. If the ball nevertheless falls into the outfield and a player snags it, he'll have to be careful not to aim his throw at the catcher. Exactly what his point of aim should be if he wishes to get the ball to home plate will depend on where the player's standing when he makes his throw. If the axis of the field is along the axis of the cylinder it could make quite a difference whether you threw from right or left field!
* * *
Conditions in a lunar colony would be rather different While it's only one-sixth Earth's, the gravity on the Moon is real, not artificial. Also, O'Neill colonies have to be built with a lot of open space. A Lunar base doesn't, and most models have the colony carved out of caves. It's certainly possible to roof over a large crater, and it will probably be done: but I doubt that there will be any larger surface cities.
Lunar farmers have a problem. The Sun doesn't shine all the time. During the long Lunar night there's got to be heat and light for their plants. There are a lot of schemes to provide that, from full-time artificial light to Mylar-roofed craters with an opaque roof that can be put on over it (and artificial lights, of course). You certainly have to cover any transparencies (large ones, anyway) during the night cycle. If you didn't you'd lose all heat to radiation. The effective temperature of outer space is about -200° C (73° K) and heat radiates proportional to the fourth power of the temperature difference. Even here with Earth's atmosphere to catch some of that outgoing heat it's always
much
colder on a clear than a cloudy night, and in fact the Romans used the night sky to make ice cream in the Sahara. Maybe I'd better explain that.
Take one large pit, and fill it with straw. The idea is to insulate it as thoroughly as possible. Put a small container in the middle of the straw. At night you expose the pit to space. It radiates heat. In the daytime you keep it covered with more straw and on top of it all place highly polished shields or other reflective surfaces. Ice will form in a few days (provided that the night sky is clear, as it is in the desert). Enough for the Romans. Back to space.