Category Archives: Technology and Society

Space, Technology and Society, Weird

Moving Day

17 Comments

Some thoughts on solar-system engineering:

One idea out there is to change the orbit of a good-sized asteroid or comet — about 100 kilometers in diameter — so that it swings by one of the inner planets and then back out to, say, Jupiter. As the cosmic tow truck passes our target planet, it uses its gravitational attraction to tug the planet in the desired direction, then hurtles back to slingshot around Jupiter, picking up more energy in the process. Repeat a few thousand times with a few score asteroids and there you go: Mars in your backyard.

This technique has been proposed as a way to drag Earth away from the ever-brightening sun that otherwise will eventually snuff out life on our planet. It has some downsides, though. One is that each time the asteroid comes by it’ll exert a tidal force ten times greater than the moon’s, wreaking havoc on the oceans and weather. Another is that some Poindexter on the relocation team is bound to make a unit conversion error along the way, and when the asteroid slams into the Earth — well, that’ll be a real pisser. Luckily, we don’t need to worry about things like that if we’re moving Mars or Venus: if we make one planet go boom, we’ve still got a spare.

Once we get the planet where we want it, though, we’ve still got our hands full. However bad the environment on Earth is, Venus’s is worse. Atmospheric pressure is roughly 92 times ours, the planet has no free oxygen or water to speak of, and the surface temp is hot enough to melt lead. Mars has an extremely thin atmosphere but its temperature, while chilly, isn’t so bad, and it’ll get warmer when it’s closer to the sun. That alone might cause enough melting at the Martian poles to release ice-bound CO2 and create a greenhouse effect. If not, we can always try focusing the sun’s rays with orbital mirrors or crashing (smaller) asteroids into the ice.

I don’t see a calculation of what would happen to Venus’ surface temp if it were farther out. Most terraforming plans of either planet don’t generally include moving them to a better location, but it’s worth thinking about — it is, after all, the first three rules of real estate.

Business, Economics, Media Criticism, Political Commentary, Technology and Society

Show Us How It Works

31 Comments

Virginia Postrel says do Medicare first:

Think about this for a moment. Medicare is a huge, single-payer, government-run program. It ought to provide the perfect environment for experimentation. If more-efficient government management can slash health-care costs by addressing all these problems, why not start with Medicare? Let’s see what “better management” looks like applied to Medicare before we roll it out to the rest of the country.

This is not a completely cynical suggestion. Medicare is, for instance, a logical place to start to design better electronic records systems and the incentives to use them. But you do have to wonder why a report that claims that Medicare is wasting 30 percent of its spending thinks it’s making a case for making the rest of the health care system more like Medicare.

Because they think we’re rubes. And judging by the voting results last fall, many of us are.

This reminds me of the old Soviet joke (that I’m sure I’ve related at this blog, perhaps more than once, but it remains appropriate). A teacher is lecturing schoolchildren on the brilliance of Karl Marx. A kid raises his hand, and says, “Teacher, was Marx truly a great scientist?” She beams and nods, and declares him the greatest scientist in the history of mankind. “Well,” he went on, “then why didn’t he try this crap on rats first?”

[Saturday afternoon update]

Peter Orszag has responded to Virginia’s question. Hail the blogosphere.

I find this quite telling:

Medicare First–changing Medicare and waiting to see how it works before messing around with the rest of the health care system–won’t work politically.

You don’t say…

Some people might think that cause to rethink. But not these people.

[Bumped]

Space, Technology and Society

Space Solar Powerballs

10 Comments

Trevor Brown proposes spherical solar power satellites.

This isn’t a new idea. I wrote a paper on it back in the early nineties for an SPS conference, and I think that Geoff Landis has done some work on it as well (for instance, here’s a report of a talk that he gave on it at the 1996 ISDC, which was the last one that I attended prior to by going to Dallas two years ago — ctrl-F for “spherical”). It does vastly simplify the design issues, because it is no longer necessary to point the panels at the sun. One of the comments there needs some elaboration:

While the surface area of the sphere facing the Sun matches your calculations, the whole side would not be available for power generation. The so-called Beta angle, or the Sun angle, affects the total amount of power converted. Also, while a sphere would not need rigid station-keeping and attitude control to collect solar energy, the transmitter back to Earth certainly will. Also, a large spherical structure would be more taxing on a station-keeping/attitude control system than a more planar design. These caveats in mind, this is a creative alternative.

With regard to the needed area, the beta-angle effect means that at any orientation, you’re only getting the effective solar panel area of the cross-section of the sphere. That is, while the hemisphere has twice the area of the circular cross section, the non-zero beta angle of all points except that at the center of the illuminated area means that you need twice the solar panel that would be necessary if it were a flat circle. Add to this the fact that you have just as much area on the side in shadow, and it means that you need four times the total solar panel area to get the equivalent collection capacity of a pointed flat plate. So you have to postulate very cheap panels for this to make economic sense. But if you can get them, the simplification of the design is worth a lot.

As for pointing the transmitter, that’s actually not so tough a job. You hang it down below the sphere, and it will remain vertical, due to gravity gradient restoring torques. You could point it with control cables all around its circumference, attached to the sphere. In addition to inflating it, I also considered putting a charge on its surface to keep it spherical, but it would take a lot of ions, particularly for a big one, and inflating is probably a better solution, though subject to leaks, and the need for gas resupply.

One other point. I actually considered a fleet of them in MEO, continuously switching from one rectenna to the next as they orbit, to reduce the size of the transmitter antenna, which gets kind of humungous out at GEO.

Political Commentary, Technology and Society

Fusion News

22 Comments

There’s an interesting question at the end of the post about the progress of ITER versus polywell:

Why hasn’t Polywell Fusion been fully funded by the Obama administration?

I suspect it’s not “green” enough. And by that, I don’t mean that it has too high a carbon footprint — it obviously has none. No, the problem is that it doesn’t force us to tighten up the hair shirts, and force us to live the politically correct lifestyles that our betters demand of us.