Far out. On what basis do you predicate a Singularity as inevitable? And why would we need to muck about in LEO if we're due to be uploaded soon?

Forgive me for being skeptical. We have a historical record chock full of collapsed civilizations owing to overshoot, after all; also decades of predictions of inevitable breakthroughs in all manner of tech including Kurzweil's nano-based solar. Prudence is warranted when making decisions as to what directions mankind should head in to secure energy supplies sufficient for people to lead a comfortable lifestyle; should we spend $60 billion on SPS or a program for switching the OECD shipping fleet over to alternate fuels we can secure domestically?

As others have commented at present funding options are limited, and many believe the crude oil price runup/spike was a major factor in the present recession. If they are correct, bets are that, in the short term at the least, money will be thrown at solutions that are literally more mundane than SPS.

Where is Hirsch saying that he foresees dieoff? All I've ever heard him predict is that peak oil will lead to extreme hardship, economically and socially. This doesn't equate with mass starvation at all.

Hi BikeDave.

I have utterly no doubt he means well; most religious proselytizers do within their self-referential worldview. And I don't begrudge any of them their visions of paradise. One person's rapture is another person's laser ablation, space fleet, frozen head, and robotic upload.

That said, it does seem to evince a rather grotesque perspective on systems thinkers. A quote from the keyposter directly above says:

Hirsch, like yourself, has worked through the consequences of the data and concluded that a major die off is inevitable. He is hostile to any possibility that his world view might have a flaw in it. This strikes me as religious-like dogmatic thinking.
I can't fault him though, it's probably a more comforting world view than mine. Like Ray Kurzweil and Vernor Vinge I see the technological singularity as inevitable.

So Hirsch is the one being religious, and - ipso facto - his conclusions about an inevitable dieoff must be "comforting" to him, which explains why he's "hostile" to those who realize the technological singularity (another non-falsifiable afterlife claim) is inevitable.

By any reasonable criteria, this was a religion key post. "Not that there's anything wrong with it," as Seinfeld would say.

Thanks Dave but I actually just know folks who know a lot about fracing. But I agree with your point to a degree. Fracing gas shales isn't a solution to anything....it's just a way to get more NG out Of the ground. The only potential long term benefit is if we use NG as a buffer while we move onto real solutions. IMO we don't need new tech to save us. We have all the tech now to ease the problem significantly and allow us a more peaceful transition to a low use FF world.

But we won't IMO. And I see the single biggest obstacle is the focus on short term issues. Society is dominated by the 24 hour news cycle. Folks won't tolerate a discussion today about making choices that will affect us 10 or 15 years down the road. They want solutions to finding a job, paying the mortgage, filling up the car with gasoline, etc, etc, NEXT month. The solutions to our future are in the hands of the politicians...not the scientists, not the engineers, not the geologists, not the environmentalists. and certainly not the folks who participate at TOD. And the politicians are ruled by the average citizen. I know it’s old and worn out but it still fits well: “We have met the enemy and he is US.”

I am in complete agreement with you as far as attacking the overpop problem from the side of managing reduction (through family planning, of course and not forced attrition) and not assuming a growing head count. If for no other reason than to buy time for the more exotic and ego satisfying solutions to come to fruition, if at all.........
Now, as far as how to get people to be more conservative etc. All organisisms will always take "the path of least resistance". This observation is axiomatic and immutable so we must assume it will always hold in any new arrangements.

Our current spacial order is designed around a mode of transportation that allowed for a much more sprawled geography than transportation based on human power alone can provide. Don't expect anyone to be "talked into" using a bike to travel 5 miles to procure a gallon of milk when they can just hop into the family truckster and be back in a flash without even breaking a sweat.

No, this is about the patterns that people will establish based on the environment they live in and that environment is too spread out to do much more than improve the efficiency of the current transportation modes.

There is a lot of room to trim the fat for sure but I just don't see a replacing of fuel powered transportation until a more compact geography makes it feasible.
So I guess we need to plan our cities and towns differently or more like the good old days.
In the mean time keep working on those better condoms!

The problem is one of perspective. This post and the one on fracturing seem to imply that human population growth is a given and the only problem is how to accomodate that fact. The really simple solution to all of our problems is to get back into balance with the ecosphere. Basic math tells us that simple family planning measures could accomplish that by the end of the century. This obvious solution here is not to expend enormous amounts of natural resources to put gadgets in orbit, but to design better condums and birth control stuff.

I really think you're ignoring the fact that very rarely, if ever, do humans voluntarily limit their birth rate.

And I pose the question, if we have the energy and resources to grow in balance, why not? Why degenerate into an eventually doomed race limiting itself to one planet, if we can build cities in Langrange points, moon bases, terraform Mars, Niven rings, and eventually Dyson Spheres.

Sure there will be mistakes, but to do it long term, we will have to learn and incorporate deeper knowledge of ecological systems, and perhaps adapt somewhat to meet the large goals. But the future is NOT entirely calculated out, as Malthus proved, and no models have incorporated all the (currently unknownw) new ideas and new technologies into their calculations.

Might as well give up using fire.

You missed the main point.

I thought the point of the exercise was to find a way for renewable energy to cost-effectively replace fossil fuels? Given that, why insist on a demonstrably-more-expensive approach?

Given your assumptions, a ground-based system is cheaper; why insist on the space-based one, with all its unknowns and critical assumptions, unless your intent is "cool stuff in space" rather than "affordable renewable energy"?

The basic fact that you have to contend with is that you're proposing something enormously more complex than a ground-based installation, yet you're making the assumption that solar generation is extremely cheap. That means you have a fairly narrow range from which to pay for this additional complexity before simply installing solar generators on the ground is cheaper, and once all the costs you're ignoring are taken into account, your proposal does not appear to be in that range.

The first kg up cost ~$750/kg. But the cost of the Skylons comes down by 2/3rd, the life goes up reducing the cost by 2/5th and the amount go GEO goes up from 6 tons to 25 as more lasers take over more of the delta V.

That's an enormous chain of advances that have to go according to plan in order for your system to work. What if there are cost over-runs on building the spacecraft? What if costs don't fall as much as you hope? What if lifetime extension requires extensive maintenance? What if these things actually cost money to maintain and operate?

Moreover, you're ignoring an enormous number of details - practically all of them, in fact. Enough that it's not really possible to evaluate your proposal, unfortunately. How can we take seriously a proposal that has spacecraft flying twice daily but doesn't allocate a penny towards operating or maintaining those spacecraft? Or towards acquiring/creating fuel? Or towards ground station costs?

Of course your proposal looks cheap - you're ignoring almost all of the costs!

Power sat energy is fed into making fuel, so the only cost is the capital equipment.

Then why is there no capital cost entry for fuel synthesis plants? High-temperature electrolysis and LOH/LOX storage aren't free.

Moreover, ignoring operations and maintenance expenses for fuel synthesis, not to mention spacecraft that fly twice a day, seems...unrealistically optimistic. Suggesting that the only costs in existence are fuel and capital doesn't engender confidence in the thoroughness of the analysis.

There are too many details and too many numbers missing from your analysis. All we can conclude from it is (a) you're making a huge number of assumptions, and (b) ground-based installations would probably be cheaper and certainly have vastly lower startup costs.