But the crossdressing time traveler had the great benefit of reading this trenchant thread on
What if we put the shades into a geo stationary orbit hovering only over the deepest parts of the ocean.
As somebody else pointed out, that's not how GEOstationary orbits work. They are stationary with respect to the Earth, not the Sun moving across the sky. Rather, the notion is to place sunshades in orbits around the Earth-Sun L1 point (Lagrange worked out these specific solutions to the three-body problem) where the teeter-totter gravity of each body balances out. Google "Roger Angel".
Also, the atmosphere is well mixed, such that cooling the air over one place cools it everywhere. You might be able to enhance cooling in latitude bands relative to the six Hadley cells (3 north, 3 south). This could be handy for tweaking the North Atlantic Drift that keeps Europe happy and habitable. Of course, global warming is expected to affect the Hadley circulation itself, but as long as the equator remains warmer than the poles, the air that goes up must come down generating an odd number of cells. An interesting notion whether we could tweak the shading asymmetrically to result in differing numbers of cells north and south.
Whether we should pursue such a project is doubtful, but it would be good to work out the details before we find that we must pursue such a project.
A mathematical amusement causes people confusion and consternation. It's like asking someone why they appear reversed left-to-right in a mirror, but not top-to-bottom, and saying there's an inconsistency in the foundation of physics.
Mirrors reverse front-to-back, not left-to-right. This flips parity ("handedness"), but the rays still trace straight lines at the top, bottom, and sides.
Judging from the article and "50 Posts" web site, this group's definition of "Cyborg" is broad enough to be equivalent to Richard Dawkins' notion of the "Extended Phenotype" ( http://amzn.to/cbSmTo or many online hits ). Or perhaps to a second order recursion of the EP. The reach of our genes extends outside our somatic selves to the mechanisms we build with our tool-wielding hands. These mechanisms (perhaps themselves crypto-biological) are then candidates for tinkering within our soma - a prosthetic hand, for instance.
For another take, read Andrew Pickering's "The Cybernetic Brain: Sketches of Another Future" ( http://bit.ly/bTFrqb )
Consider that each object (in low Earth orbit) is in a separate orbit. Each pair of orbits crosses twice on opposite sides of the Earth. The eccentricity of each orbit causes the object to traverse a range of altitudes, defining the subset of all the LEO objects that are possible collision risks at any given time. The risk for two particular objects colliding is low, but each object has many other opportunities as it crosses thousands of other orbital tracks each time it circles the Earth. Then integrate over all the objects. The probability is a nested summation - integrated over time.
For example, assume there are about one hundred spacecraft (active and defunct) occupying a particular semimajor axis "zone". Each satellite orbits once every 90 minutes, ie, 16 orbits/day. Each satellite crosses the orbit of another about 200 times in that 90 minutes. Usually the other spacecraft is somewhere else entirely, but there are a lot of opportunities.
Establish a "comfort radius" - say, one kilometer. If Le Petit Prince is sitting on a satellite, he will get very nervous if another spacecraft zooms through this keyhole at 10 km/s. A typical low Earth orbit is about 42,000 of these comfort units long. So the odds (ignoring altitude for the moment) of finding a spacecraft within the same part of the orbit - during each passage - is 1/42,000. Multiply by the 200 opportunities makes this 1/210 (0.5%) per orbit or about 7.5%/day/spacecraft. There are 100 spacecraft in this zone, so that amounts to about 4 close encounters per day (divide in half since it takes two to tango) in which some spacecraft passes directly above or below another by a few kilometers.
Accounting for altitude requires a bit more physics (inverse square law and all that), but basically amounts to a similar argument of dividing the altitude range traversed by each satellite into comfort zones. The odds of passing through the keyhole drop, but not dramatically - and the orbit crossings keep piling up about a hundred thousand per day per altitude range. With each close encounter, the odds of an impact are basically very simple. What is the volume of a typical spacecraft divided by the 1 km^3 volume? (The second spacecraft either will or won't be occupying the same volume at the moment of closest approach.) Satellites can be surprisingly large - Hubble is about the size of a schoolbus - but figure a Volkswagen van or at least a Beetle.
Bear in mind that this is just one particular altitude range, the same thing is happening at different altitudes. Some spacecraft are in highly elliptical orbits and cross through several such zones. In short, what seems to be a three dimensional problem is really one dimensional. After the spacecraft collision a couple of years ago some of us were scribbling on a blackboard. A physical model would be needed to get the precise answers, but a ball park figure is that we can expect the apparently astronomically rare event of two LEO spacecraft colliding to happen about once per decade (in the absence of active station keeping). Then account for all the debris, not just complete spacecraft.
The underlying mechanism here is a way to record actions for later playback. Combine that with multithreading and it provides side-by-side scripting. Various shell environments provide different levels of keystroke recording for playback, for instance in a kiosk mode for demos. As somebody said, this is by no means new - I think there were teletype games with similar features.
How many levels of replication are possible? It would be pretty cool to clone an army of yourself through a few levels of binary replication. Can you save the recorded scripts to use under different circumstances?
Software production is assumed to be a line function, but it is run like a staff function. -- Paul Licker
