There is nothing particularly new about this idea and it has most likely been tried already. On some airlines now each person can have a small flatscreen display located just in front of them. They could watch the ads or the flight progress or choose the movie they want to see. Nothing new about that.
It would probably not be relevant for cars on the road or for planes as they are today, but if you could use flatscreen displays on the inner walls of a vehicle and show live video from cameras looking out from the side of the vehicle, then you could have thick solid walls for the vehicle and the semblance of windows along the inner walls. The pretend window/screens could be quite large too. You might be able to make it look as if the vehicle had glass walls and a glass roof, even while there were solid walls protecting the inside from whatever was outside of the vessel. With such pretend windows you could also have labels next to relevant objects if you wanted to.
Another thing you could do in a place like space is to give the occupants the semblance that the vessel is stationary with regard to its surrounds, while in fact it may be spinning to create an artificial gravity for the people inside. People could walk around in such a space station or spinning spaceship and look out these pretend windows and see the view as if they were looking at them from a stationary place in space – the constellations would appear to remain stationary. The cameras and screens will also be able to filter the image and show things that a person could not directly look at if they were seeing in analog, such as the sun for example. After being in such an environment for a while, people would get used to it and there would be conventions about how things are presented. You could have spacecraft with strong, thick walls and without windows, much like a submarine I suppose, while for the people inside the view on these pretend windows could be spectacular if they were traveling near some place like the moon’s surface. It isn’t that much of a stretch of the imagination.
You could also imagine building a spaceship with a spinning living quarters inside – like a large washing machine in a spin cycle (don’t you love those clumsy hand waving analogies). When the spaceship is traveling (as if weightless) in space the inner tub could be set to spin to provide a semblance of gravity with the rounded walls of the inner tub being like the floor – it might be better to have a number of flat surfaces like a polygon to walk on. It would still be useful to have a fraction of the acceleration due to gravity as experienced on earth in a spacecraft to make life easier – so liquids flow in a downwards direction. You could cook, go the toilet, have a shower, sleep without being strapped into a bunk, walk around and exercise on a treadmill, and so on.
When the spaceship is somewhere where gravity is experienced, close to a planet or moon for instance, the spinning of the inner tub would be stopped and one of the flat WALLs in the tub while it was spinning would become the FLOOR and the erstwhile curved (or polygon) FLOOR while it was spinning becomes the WALL – the axis for up and down shifts by 90 degrees, if you know what I mean… Anyway, the people traveling in a spaceship with a spinning inner living quarters would need to be fastened to their seats as the inner tub (for want of a better term) is accelerated or decelerated. One challenge would be to dynamically adjust the moment of inertia for the inner tub as a whole for slight changes in the centre of mass as people move around while it is spinning. The angular velocity would have to be constant while people are walking around in the spinning living quarters. You wonder what radius and speed would be naturally comfortable for people to live in. Camera and screen systems as mentioned above could be used to give the people traveling in a spinning living quarters the feeling that they are moving linearly through space. A disc or saucer shaped spacecraft does make sense (but not when they are propelled by rockets).
12 November 2008
You might be able to have a spacestation with a number of these rotating living quarters connected at leaf nodes off central branches. You could then have all the possibilities of modular design and for adding extensions with tree, lattice or ring-like structures that connect the branches in a particular spacestation. For large extended branches you could imagine something like rails on either side of the walls so that very small vehicles using those rails could convey people too and fro along a branch, given that it is in zero gravity. The branches and spacecraft docking facilities would all be stationary with regard to the space around the station and these places would be weightless. Large spacestations would definitely not be suitable for low earth orbits where the ISS currently is.
There would need to be an equivalent of a lift in a building on earth for each of these living quarters such that a person would walk into one of these -rotation or frame changing- lifts in a rotating living quarter and that ‘lift’ would move from the edge of the rotating hub to the axis of rotation for that hub in such a way that when it did arrive at the axis of rotation for the hub it wouldn’t be rotating at all.
… the lift door would close, the person would experience acceleration to one side of the lift until it was stationary again, the door on the opposite side of the lift would open and the person could float out into the weightless branch section of the spacestation. Perhaps the ‘rotational lift’ could simply be an interface between a weightless branch section of a spacestation and a rotating living quarter which would have the semblance of gravity. The radius wouldn’t have to change as the rotational lift’s angular velocity accelerates and decelerates. One door for the lift would open up to the branch section when it is not rotating and the door on the opposite side of the lift could open on to the living quarters when the lift’s rotation matches that of the living quarters and the rotational lift is locked to the lift door point in that living quarter. Instead of the experience we feel in a linear lift of being slightly lighter or heavier as a lift goes up or down, on these rotational lifts the acceleration is to the side so we would naturally lean or sit against the relevant wall as the rotational lift is accelerated or decelerated – it would feel like being in a car that is turning through a corner and just keeps on turning until it eventually straightens out again [13 November 2008] …
The person in the ‘lift’ could then leave the lift and move weightlessly through the spacestation branch, perhaps to another rotating living quarter or to a dock for spacecraft, or where ever. A ‘lift’ for these rotating living quarters would similarly take a person from the weightless branch area of the station to the floor of a rotating living quarter where the person would experience the artificial gravity due to rotation.
For a spacecraft built around only the one rotating living quarters the direction of movement in space would best be in the same direction as the angular momentum vector L for the spinning living quarters (or tub as expressed above). Even while the living quarters for such a spaceship is spinning, the direction of the spacecraft as a whole would appear to be parallel to the line of sight for people standing in the spaceship with one ‘wall’ while spinning being behind and one ‘wall’ while spinning being in front or ahead. Maybe nautical terms could be adapted for use in these novel frames of reference. When the spinning is stopped and the spacecraft moves near a large object like a planet or moon, it would move relative to the planet or moon flat like a frisbee and what was the behind ‘wall’ while spinning would now be the floor. People who have studied basic physics should be able to understand these ideas, even if I am not expressing them very well. A few diagrams would probably go a long way in descibing these ideas.
14 November 2008
Back to the more mundane: large space stations as described above could earn their keep in space as industrial manufacturing and processing centres. The range of environments available for processing metals, crystals or glasses is much more varied than what is available on earth. There is the range from zero gravity to custom and manifold fields to grow crystals or set glass in. There are temperature ranges from the ambient temperature in space to very high temperatures available by focusing solar energy through reflective solar collectors onto a point. That energy is clean and constant in space. The pressures available range from the vacuum of space through to as high a pressure that machinery with an endless supply of solar energy could produce. It could be a place to process mineral ores. You could also grow plants in large rotational living quarters. You might be able to create water and oxygen from minerals that could be sourced in space. Soil, however, can not be manufactured. There’d be plenty to do out there beyond the clouds!
A large space station could sustain itself and include the industrial infrastructure to build and extend its own structures. Spacestations might start out as small villages in space, grow to the size of towns and eventually become as large as cities if they are suitably located. It is important that they are organised as civil and public spaces with elected democratic representatives to take responsibility for public decisions. It is also important that what happens in space is transparent and open to public scrutiny. There is a sense that space is international and demilitarised.
16 Nov 08
On a large space station, eventually, you could imagine large cylinders built like apartment blocks with the angular velocity being such that the centrifugal acceleration for the living quarters on the outer edge of the cylinder comes close to the acceleration due to gravity on earth or that would be felt to be a comfortable fraction of g. There could be a few radial floors closer to the axis of rotation of the cylinder, and these places would have a centrifugal acceleration less than those below them with a larger radius. You could perhaps use the innermost radial floors of a large cylinder for growing plants. That way the cylinder could be filled and used productively. I would assume that there are some plants (or algae) that would do alright in such an environment and that could adapt to space but that is something that would need to be researched. I do not support genetic engineering.
A lift for such a cylinder might accelerate and decelerate at the outermost radius and once the lift is spinning at the same speed as the cylinder perhaps the lift could move closer to the axis of rotation for the cylinder by reducing the radius for the lift, obviously. A lift for these large cylinders would need to have a balancing counterweight. Most of these things have been thought of before and these ideas aren’t new.