Will The End Of Oil See The End Of My Town?

[Darth Raptor]

People who think the 21st Century will see the complete extinction of the human race are just as delusional as those who think we'll be just fine. Worst case scenario: We suffer a huge dieoff via starvation and nuclear war and civilization makes a complete reboot. Even that won't happen. We have six thousand years of science and technology written in books that will give the survivors of the Second Dark Ages that much of a head start. This hypothetical successor civilization will have an even better shot at reaching the stars than we did, because their economy won't be driven by limitless consumption and dependent on equally limitless growth. It's absolutely tragic that we've squandered the planet's most precious gifts to civilization. But while the humanity of a hundred years from now will curse us for it, they'll have us to thank for their swift recovery.

[Admiral Valdemar]

Punch a small hole in a phased area antenna and at worst you knock out one element, for a tiny drop in efficiency. Punch a small hole in a laser and it's broken. Microwaves are the robust solution.

That same tiny chance of the laser being hit can apply to the generator on the microwave station. It's nothing like the same.

Please provide an inertial confinement fusion design that produces better than 1:1 thrust to weight, or failing that even a rough study that shows that this is possible.

Hydrogen-boron, MC fusion and a couple of other concepts are considered to give far better thrust in low gear, as it were. It depends a lot on the technology and how far it can be reduced in mass for starters, which is way off in the future given fusion for power production is a dream right now.

Because any tech you can image can be built if you throw money at it. Might as well throw money at anti-gravity then, since you don't seem to think that a plan or even an empirical theory for how to build that either. I'd tolerate 'maybe one day we will have pure fusion bombs' as a speculative what-if, but I won't tolerate 'we shouldn't build Orion now because we'll eventually invent pure fusion bombs', when you have no evidence that this is possible.

Point out where I said we shouldn't build Orion. I think you'll find I said no such thing. There's nothing saying AM or NTR based systems cannot be used instead or to complement larger pulse craft, or even skipping rockets and use large Skylon systems for taking smaller items to space too and being reusable with faster turnaround times.

By the same logic we should scrap all current spaceflight efforts because we should wait for imaginary ultratech to be developed.

Again with the assumptions.

Synonym for 'I was throwing out cool-sounding buzzwords without bothering to check whether they're actually plausible'.

Which is rich coming from someone proposing Orion based ships when the planet is facing a crisis that might make such a thing fantasy for centuries.

Trying to counter concrete proposals backed up by detailed design studies and in some cases working prototypes (i.e. Orion subscale model, microwave powered UAVs) with imaginary ultratech pulled out of your ass just looks stupid. Neither of us are qualified or employed to do professional grade analysis of space technology, but at least I do minimal research and read papers by people who are, whereas you're just grab for words and vague concepts that sound cool.

Just as well that I did then, because I certainly don't see how impossible pure fusion via an AM component is to replace the fission trigger. When I mention Daedalus, I mean fusion drives in general and the idea of such drives using AM as a more compact source should MC or IC prove inadequate is not fantastical anymore than what you propose. Afterall, we've not even entered the energy crisis and we're now debating the relative merits of giant expansion programmes into space. Does not that seem a tad beside the point to you?

You don't get to ignore basic physics and engineering limitations with 'oh, someday we'll discover magic and use that instead'. This isn't sci-fi, this is a question of what's actually possible in the real world, and quantitative analysis wins over fuzzy wishful thinking every time.

I was unaware AM initiated fusion was magical. My mistake.

People who think the 21st Century will see the complete extinction of the human race are just as delusional as those who think we'll be just fine. Worst case scenario: We suffer a huge dieoff via starvation and nuclear war and civilization makes a complete reboot. Even that won't happen. We have six thousand years of science and technology written in books that will give the survivors of the Second Dark Ages that much of a head start. This hypothetical successor civilization will have an even better shot at reaching the stars than we did, because their economy won't be driven by limitless consumption and dependent on equally limitless growth. It's absolutely tragic that we've squandered the planet's most precious gifts to civilization. But while the humanity of a hundred years from now will curse us for it, they'll have us to thank for their swift recovery.

I think Pat Robertson is trying to see PO as one of many events that will kill us all off in the near future. Naturally, him and his ilk pray for that every damn day, so those kinds of nuts can be ignored quite happily. They only allow everyone else to dismiss any real threats by coming off as lunatics, which doesn't help us in the least.

[Starglider]

People who think the 21st Century will see the complete extinction of the human race are just as delusional as those who think we'll be just fine. Worst case scenario: We suffer a huge dieoff via starvation and nuclear war and civilization makes a complete reboot. Even that won't happen.

Certainly some people are worrying about the wrong risks, crying doom about the wrong issues. However there are genuine existential risks. For example a bioweapon that kills humans but which birds act as non-symptomatic carriers for. Grey goo often gets overhyped into physical implausibility, but biology is inefficient in many respects, and dry-nanotech universal assemblers that easily outcompete all species of bacteria are at least plausible (we're still working out the details, possible/impossible verdict coming soon). Wipe out all the bacteria and the rest of the food chain falls even if the assemblers aren't actively eating all other biomass. Runaway climate change is a real risk, though the earth's biosphere seems to have survived worse than what we've done to it so far in the past (albeit with massive dieoff - not just global warming, see the 'snowball earth' theory as well). Nuclear war with current arsenals is very unlikely to kill everyone, but enough dirty bombs will get the job done, and we can't predict future arms races. A big enough asteroid/comet impact will do the trick if we can't deflect it. On the more esoteric side, maybe we'll create 'true vacuum' in a particle accelerator and wipe out all matter in the solar system - it doesn't seem likely right now, but this has been seriously proposed and studied by particle physicists. Finally there's my favourite, the one risk we can't really dodge, the creation of greater-than-human (and possibly very alien) intelligence and its consequences. This is a domain where the metaphors start at 'as intelligent compared to a human as a human is compared to a rabbit, and thinking thousands of times faster to boot' and go up from there.

This hypothetical successor civilization will have an even better shot at reaching the stars than we did, because their economy won't be driven by limitless consumption and dependent on equally limitless growth.

Humanity has a very poor track record at learning the lessons of history. The problem we're in now is due to short-sightedness and wishful thinking. The basic cognitive flaws behind it aren't going to go away in a few thousand years. I'm pessimistic at the chances of future humans actually avoiding the general class of mistake we made. Not having fossil fuels available should prevent them from getting into the exact mess we're in, but it'll slow down their technical/industrial progress a lot too.

[Admiral Valdemar]

I wouldn't worry about grey goo. For anything to work at that size, bacteria, which have evolved over billions of years anyway, will likely deal with them in no time flat. No single bacterial species has ever converted the planet to a mass of itself and nor will any human nanomachine. The nanowankers out there simply don't understand that the vast majority of what they propose already exists and has done so for far longer and doing far better than any dream they came up with.

To me, nuclear war is the more likely scenario to set us back centuries. Humans are erratic and stupid under duress and it's not like we don't have a lot of WMDs out there in gov't hands that may be forced to act because the families on the street want their MTV and fast-food back.

[Starglider]

Please provide an inertial confinement fusion design that produces better than 1:1 thrust to weight, or failing that even a rough study that shows that this is possible.

Hydrogen-boron, MC fusion and a couple of other concepts are considered to give far better thrust in low gear, as it were. It depends a lot on the technology and how far it can be reduced in mass for starters, which is way off in the future given fusion for power production is a dream right now.

Quit throwing 'concepts' around and quote an actual design study that shows that inertial confinement fusion can be used for earth launch applications. I specifically did not mention MC fusion because unlike IC fusion that should actually work, given fairly generous extrapolations of current technology aimed at fusion power. It's still going to take a huge amount of additional effort on top of the effort needed to get ground-based fusion power stations working.

Synonym for 'I was throwing out cool-sounding buzzwords without bothering to check whether they're actually plausible'.

Which is rich coming from someone proposing Orion based ships when the planet is facing a crisis that might make such a thing fantasy for centuries.

What is this 'might make' crap. That's not even a convincing attempt at a rebuttal. Orion ships are feasible to build right now using existing engineering expertise and nuclear warheads. We could do it in less time than it took to develop all the Apollo tech from scratch. It almost certainly won't happen, because the political will will not be there. Of course the window of opportunity to build them might close for a while. But right now, it is technically possible and it is the only very heavy lift option we (by which I mean 'the US government') could realistically deploy in the near future. Regardless, that is irrelevant to you proposing literally impossible (i.e. VASIMIR) solutions because you didn't check your facts.

Just as well that I did then, because I certainly don't see how impossible pure fusion via an AM component is to replace the fission trigger.

Which I specifically mentioned in my earlier post, but nice attempt at a dodge. AM-initiated fusion is getting serious study, but doing an initiation with even vaguely practical amounts is an unsolved problem. For outer space applications, the main problem is that antimatter production is horribly uneconomical - given indefinite amounts of energy it's doable, but you'd have to build a lot of reactors/solar cells and particle accelerators (research such as wakefield acceleration may bring down the costs from extortionate to merely extreme). But for earth-launch applications antimatter is hobbled by the containment problem - right now there is no known light, compact way of containing antihydrogen at any kind of useful density. Even if you solve that, you'd have to make sure the thing (and presumably its power source) is 100% reliable under launch accelerations and vibrations, as enough antimatter to initiate a few thousand fusion bombs is going to blow a big hole in the vehicle (possibly vaporise it, depending on exactly how efficient the process is) if it fails. No sane engineer would want to use something that vulnerable to exploding under shock, control failure or power failure in a launch vehicle.

I mean fusion drives in general and the idea of such drives using AM as a more compact source should MC or IC prove inadequate is not fantastical anymore than what you propose.

I hope you're not proposing to use a pure antimatter drive to lift off from an inhabited planet. That really would be silly.

Afterall, we've not even entered the energy crisis and we're now debating the relative merits of giant expansion programmes into space. Does not that seem a tad beside the point to you?

'I was wrong but instead of admitting it I'll question the validity of the debate'. If you weren't ok with the topic drift you could've just stayed out of the space arguments.

I was unaware AM initiated fusion was magical. My mistake.

More weasel dodges. VASIMR type drives don't work for lift-off, period. You made the mistake of proposing a specific solution without checking your facts, just admit it. There's no currently plausible way for laser or particle beam inertial confinement fusion to work for lift-off. AFAIK there's no currently plausible way to initiate a fusion device without either a fission trigger or an undetermined (but large enough to be quite dangerous) amount of antimatter, which we can't produce in useful quantities, won't be able to any time soon, and have no sufficiently robust way to store.

I wouldn't worry about grey goo. For anything to work at that size, bacteria, which have evolved over billions of years anyway, will likely deal with them in no time flat. No single bacterial species has ever converted the planet to a mass of itself and nor will any human nanomachine. The nanowankers out there simply don't understand that the vast majority of what they propose already exists and has done so for far longer and doing far better than any dream they came up with.

You're plumbing new levels of ignorance now. Do you even know the difference between 'wet nanotech' and 'dry nanotech'? Do you comprehend the difference between diffusive transport and channeled transport? Have you read any recent papers on the uses of inorganic nanoparticles, or advances in lab-on-chip microfluidics, or the capabilities of sillicon-based nanomachinery? Do you have any comprehension of how much centralised processing can optimise performance over simple dispersed chemical feedback mechanisms? No, you do not, you are grabbing at uselessly simplistic analogies that experts in the field have long since analysed and discarded.

[Sikon]

In order to build anything like the baseload from nuclear needed, you're going to expend far more energy than would be used in making the same number over a more leisurely time-frame.

The energy involved in building the nuclear plants is vastly less than their energy payback.

A rule of thumb is that one can indirectly tell an upper limit on energy requirements from economic cost. Anything using an astronomical amount of energy costs a lot of money to buy that energy. Likewise, anything costing relatively very little to construct doesn't involve an enormous amount of energy in its construction, because that is part of the basic requirements for it to be so inexpensive.

In the case of my preceding post's illustration of nuclear replacement of 100% of U.S. fossil fuel electricity generation in 20 years for about $23 billion/year, 5% as much as the Department of Defense budget alone, one automatically knows that the energy cost of building the reactors isn't astronomical, or else the expense of the energy used would make their cost be more than so relatively small.

More specifically, one could get into details as illustrated in the large web page here, which illustrates that a typical 1000 MWe nuclear power plant involves around 4.1 petajoules (thermal / thermal-equivalent) to build and decommission. In contrast, at about a 90% typical capacity factor, it produces around 280 petajoules of electricity per decade. Nuclear power has a particularly good energy payback ratio.

Look at the production of cars via large industrial production lines. They use several times more energy to produce a whole car in a day, than would be needed to make the same vehicle in, say, several days or weeks even.

That's a very doubtful claim, probably indirectly from some publication promoting primitive, politically correct local cottage industries, instead of the big, ugly, noisy centralized factories that really work for efficient industrial production.

Mass production like producing cars quickly on an assembly line is done because it is efficient, allowing a huge number of completed items to be produced relative to the size, cost, and labor expenses of the factory. That's what allowed Ford to outcompete some more primitive, less efficient manufacturers early in the last century. Here's a brief illustration:

The production of long-runs of standardized goods for a mass market was introduced into the United States at the beginning of the 20th Century. The first industrialist to make full use of this system was Henry Ford and as a result it became known as Fordism. This has been described as "the mass production of standardized goods, using dedicated machines and moving assembly lines, employing unskilled and semi-skilled labour in fragmented jobs, with tight labour discipline, in large factories."

Initially it took 14 hours to assemble a Model T car. By improving his mass production methods, Ford reduced this to 1 hour 33 minutes. This lowered the overall cost of each car and enabled Ford to undercut the price of other cars on the market. Between 1908 and 1916 the selling price of the Model T fell from $1,000 to $360 [in those dollars, much different from today's dollars that far back]. Following to the success of Ford's low-price cars, other companies began introducing mass production methods to produce cheaper goods.

From here.

In fact, the ultimate ideal for nuclear power plant economics would be standardization and relative mass-production to get costs down further than would otherwise be the case, to get economy of scale. Instead of each plant having to be separately engineered, use one exceptionally good design over and over again. That's even part of the difference between the inexpensiveness of cars versus space launch vehicles (rockets) today. Spend $100 million engineering a rocket of which 10 are produced, and the engineering cost per rocket is $10 million. Spend $100 million engineering a car of which 1 million are produced, and the engineering cost per car is $100. (There are a lot more differences, of course, but it is one factor).

Indeed, even the Maine Yankee performance assumed in my cost estimates isn't the ultimate economics conceivable. Maine Yankee was $1.14 billion converted to today's dollars for a 920 MWe plant as mentioned in my last post, about $1240/kilowatt. Yet, as mentioned within a quote here, Commonwealth Edison completed its Dresden nuclear power plants for $146/kW in 1970/71 dollars, which is a mere $740/kW in today's dollars. If things were ever done nearly ideally, standardization and mass-production allowing nuclear power plants costing around half as much as Maine Yankee per kilowatt might become a significant possibility. I just intentionally avoided supposing such since it deviates from what people expect to be obtainable and could be seen as more doubtful.

And here's part of one nuclear engineer's suggestions:

How To Build 6,000 Nuclear Plants by 2050

We asked nuclear engineer James Muckerheide how many nuclear plants would be needed to bring the world's population up to a decent standard of living, and how to do it. Here are his answers.

[...]
[...]

So, nuclear power plant construction should be transformed from the mode of plant-by-plant construction of ad hoc projects, into a manufacturing-based strategy. France is a prototype [with French electrical generation being mostly nuclear now, instead of the usual coal domination]. In 1973-1974 a national decision was made to build nuclear plants in convoy series, to make decisions on designs and to install those designs multiple times, with evolutionary enhancements in size, costs, and safety for future plants. Many plants are put on line in a manufacturing planning mode, not constrained by plant-by-plant decision-making and plant construction mode only as individual project profits can be reasonably assured.

This allows the advantage of mass production, with programmatic commitments to make the vessels and major components to support a plant assembly approach. Individual plants would be installed to meet the electric power market needs. This is especially true of the modular gas reactors.
[...]

From here.

********

As said before, I don't expect much nuclear power conversion until after the public has extreme motivation from peak oil effects, due to that unfortunately being what it may take to override the anti-nuclear bias which has developed by now. But the technical potential of nuclear power outside of those socipolitical factors is awesome. And that's what will probably be realized eventually, e.g. after an initial focus unfortunately likely more on other energy like coal.

********

[...]

In some ways, the biggest picture for the long-term future is whether mankind expands into space or not. If mankind ends up with a stagnant or declining civilization with too little drive for progress, too little industrial capability, too much like non-sapient animals, then mankind would die out sooner or later like 99.9% of past species have died out from various causes over past millions of years.

On the other hand, the ability to apply technology and industry is what may make humanity's fate different. If mankind expands into space, mankind will presumably eventually send out colonization starships. Such would occur well before reaching the level of utilizing a large portion of the 400 trillion terawatts of space solar power available and the about trillion trillion tons of usable material available in the solar system. For example, those energy and matter resources available in this solar system correspond to literally trillions of times those used by the civilization of today (which is like a thin film on the surface of a planet, not like disassembling asteroids, moons, etc.), and they are many orders of magnitude more than enough for humanity to start propagating from star system to star system, spreading out beyond the the ability of the vast majority of potential disasters to ever ruin, natural or artificial, not in this billion years. Indeed, in that regard, the one good aspect of FTL being probably impossible is that the isolation of different colonized star systems tends to make it unlikely for all to experience the same disaster in event of trouble.

[The Duchess of Zeon]

On the other hand, the ability to apply technology and industry is what may make humanity's fate different. If mankind expands into space, mankind will presumably eventually send out colonization starships. Such would occur well before reaching the level of utilizing a large portion of the 400 trillion terawatts of space solar power available and the about trillion trillion tons of usable material available in the solar system. For example, those energy and matter resources available in this solar system correspond to literally trillions of times those used by the civilization of today (which is like a thin film on the surface of a planet, not like disassembling asteroids, moons, etc.), and they are many orders of magnitude more than enough for humanity to start propagating from star system to star system, spreading out beyond the the ability of the vast majority of potential disasters to ever ruin, natural or artificial, not in this billion years. Indeed, in that regard, the one good aspect of FTL being probably impossible is that the isolation of different colonized star systems tends to make it unlikely for all to experience the same disaster in event of trouble.

Even if we can cheat/twist our way around the light barrier there's absolutely no guarantee that speeds will anything remotely approach typical sci-fi speeds. Like that one bunch of stuff about Heim theory from the 2005 article by those Austrian guys, allowing for FTL travel, still suggests that an absolute limit would still exist at around 50c, IIRC. That is impressive but still means that, say, a roundtrip to a star 100 lightyears away would take 4 years.

[Sikon]

Regarding using antimatter in propulsion:

With antiproton-catalyzed microfission/fusion (ACMF) mentioned by me before in another thread, it seems worthwhile to cover how it is plausible.

The discussion here is not to suggest ACMF being used for earth launch, as there are more suitable methods. A long discussion of the best methods for people and cargo will be for another post, probably another thread.

But it is worth explaining how antiproton-catalyzed microfission/fusion can work despite antimatter requirements, not for earth launch but potentially for interplanetary travel (or, in far different form than the ICAN II spacecraft, interstellar travel).

Antimatter tends to be poor practicality if one is getting even a hundredth of the total energy from it. However, the counterintuitive aspect of ACMF is that it can require less than a billionth as much antimatter energy as the nuclear energy it substantially helps release.

Such is illustrated in the details of the ICAN II concept paper here. There are 362 metric tons or 362000 kg of propellant. Each shot involves 0.8 kilograms propellant mass with a 0.003-kg nuclear fuel target. * So there are about 453000 shots involved. The total amount of antimatter needed is 30 nanograms. That amounts to around 6.6E-17 kilograms of antimatter per shot. Antimatter energy needed is ~ 5.96 joules per shot (E = MC^2). Each shot is about 302 GJ. So the ratio of nuclear energy release to antimatter energy is an impressive 51 billion to 1.

In fact, the total energy of the 30 nanograms of antimatter stored, 30 trillionths of a kilogram, is a mere 2.7 MJ. That's as much energy as 0.7 kilograms of TNT, chemical high explosive. It is a hazard, but not necessarily an unacceptable one. In principle, it is even possible to design a ship able to survive a hypothetical loss of containment of that quantity of antimatter without injury to crewmembers (or have an array of multiple storage units so any single one has less antimatter energy stored than an ounce of TNT-equivalent). Such is not like trying to make something capable of withstanding a nuclear bomb. The key is that the quantity of antimatter is so little.

A fairly inaccurate, very rough analogy would be like lighting a match that starts a forest fire burning many orders of magnitude more than the mass of the match. For a detailed explanation of a tiny amount of antimatter working and the source of the preceding figures, see the paper. They talk about using antimatter for ignition, with ignition with a pulse of 10^11 antiprotons, which one may observe to be many times less than a trillionth of a gram (proton mass). There is still an external driver needed to compress the pellet, but the requirements are less than for pure fusion without this technique.

* The technique of using nuclear fuel to blast away many times its mass in surrounding propellant allows higher thrust at the appropriate Isp than would be the case without the inert propellant, although the interplanetary ship doesn't need or involve a very high thrust to weight ratio, rather having a few hundreds of 1g acceleration in this particular design.

***********

On a separate topic:

The factors particularly limiting the performance of nuclear rocket engines like the NERVA design with internal heating of propellant (as opposed to external pulsed propulsion) are primarily material limits of real-world materials (e.g. avoiding melting). If anything, magnetic-confinement (internal) fusion would tend to be harder to make as lightweight because it requires a lot of extra hardware as opposed to running propellant through a hot, solid fission fuel element for excellent heat transfer. MC fusion might be used for ground power generation, if made working and if capital costs were competitive, but it is relatively unlikely to be used for earth-to-space rockets.

[SirNitram]

What is this 'might make' crap. That's not even a convincing attempt at a rebuttal. Orion ships are feasible to build right now using existing engineering expertise and nuclear warheads. We could do it in less time than it took to develop all the Apollo tech from scratch. It almost certainly won't happen, because the political will will not be there. Of course the window of opportunity to build them might close for a while. But right now, it is technically possible and it is the only very heavy lift option we (by which I mean 'the US government') could realistically deploy in the near future. Regardless, that is irrelevant to you proposing literally impossible (i.e. VASIMIR) solutions because you didn't check your facts.

Orion will not work, especially not in any scenario where the oil infrastructure collapses under us first. They're an infrastructure-heavy investment; you must first get uranium to the piles, then make the bombs, then build a spaceship big enough to be worth the investment, then you must actually launch the thing. And then you will have one ship that goes up, and you better have packed a RV and smaller, conventional LV's to re-staff the behemoth.

Frankly, a NTR or NER would be ten times more useful, because among other things, they scale, and aren't infrastructure-heavy. When facing the potential collapse of your infrastructure as the reason to go great-guns into space, you don't want something that will fail to get to second launch because you ran out of gas to finish building the second LV.

[The Duchess of Zeon]

Orion might be particularly useful, however, as a cable-laying ship for a space elevator, sort of like the Great Eastern in laying the transatlantic telegraph. A huge Orion could carrying the whole initial cable set for a space elevator into orbit and could serve as its pre-fitted counterweight. It lowers the first cable to the ground, and all the other cables are dragged up that one and fixed in place, each in turn.

[SirNitram]

Orion might be particularly useful, however, as a cable-laying ship for a space elevator, sort of like the Great Eastern in laying the transatlantic telegraph. A huge Orion could carrying the whole initial cable set for a space elevator into orbit and could serve as its pre-fitted counterweight. It lowers the first cable to the ground, and all the other cables are dragged up that one and fixed in place, each in turn.

Only if we're trying to lay people-carrying elevators on the first go, which is madness incarnate.

Look, it's simple. You only need make the very first elevator large enough to carry the parts for the second. Then you lift up the third. And it's cheaper every time. Eventually you're bordering on Earth in 3001.

[Sikon]

Even if we can cheat/twist our way around the light barrier there's absolutely no guarantee that speeds will anything remotely approach typical sci-fi speeds. Like that one bunch of stuff about Heim theory from the 2005 article by those Austrian guys, allowing for FTL travel, still suggests that an absolute limit would still exist at around 50c, IIRC. That is impressive but still means that, say, a roundtrip to a star 100 lightyears away would take 4 years.

I am assuming FTL travel is probably impossible. Heim theory is interesting, but shifting a ship into a hypothetical different dimension with different physical laws (conveniently with crew somehow surviving rather than becoming a bunch of particles or the like) is quite far-out.

For interstellar colonization, such as in the context of the future of mankind, one needs neither round-trips, voyages as far as 100 light-years at a stretch, nor journeys as fast as 4 years. Alpha Centauri is 4 light-years away. Colonize it. Then have the colonists later send out their own ships traveling further, such as to star systems nearby Alpha Centauri. And so on. Or maybe a faster approach becomes workable with more star systems colonized directly from the solar system. Either way, eventually the entire galaxy that is 100,000 light-years in diameter with ~ 0.4 trillion star systems can be colonized in a few million years or less, actually probably within close to the 0.1 million-year STL limit with enough advancement, geologically a brief time.

Although several percent the speed of light would be more than strictly needed, possibilities range up to a home star system with astronomical industrial output from self-replicating factory systems that could afford to send starships much faster.

The possibility of suspended animation is high, such as the recent experiment putting mice into suspended animation, slowing their metabolic rate by 90% (probably similarly reducing the rate of aging, e.g. extending life) in a manner thought likely workable with humans too. For example, a good situation would be if crew onboard a ship could spend 9 out of every 10 days in suspended animation, making the journey subjectively pass 10x as fast as it would otherwise. Other life extension would also be applicable if developed, as is likely.

Like Starglider suggested, it is also quite possible that mankind might not be baseline biological homo sapiens by even the time of the first starships, depending upon which advancements proceed fastest, in which case this could be still easier.

[Ender]

I'm all about discussing future possibilities for space infastructure, but it is offtopic for this thread. Perhaps we can get a split?

In that vein, I see no reason for us to develop nuclear engines of any kind to get massive amounts of material into orbit - the Saturn V design is 40 years old, and it could throw just under 120 tons into orbit, and not once in its 13 launches had a failure. The Saturn V launched day or night, in foul weather or fair, at the appropriate time to reach its destination. It's a sturdy, reliable, proven design, and I'd be shocked to learn that 40 years of advances in science and engineering could not improve upon that (particularily given the comments I've seen about the rocket industry and its engineers vs profits), and even if so we just keep lighting them off. I'm all about getting impressive engines, but they would be a horse before the cart deal - solar power and construction facilities have primacy for me, just as mines and colonies came before the clippers during the age of sail.

I am assuming FTL travel is probably impossible. Heim theory is interesting, but shifting a ship into a hypothetical different dimension with different physical laws (conveniently with crew somehow surviving rather than becoming a bunch of particles or the like) is quite far-out.

I've never understood how that wouldn't violate conservation of energy - you are removing several thousand tons of mass-energy to a different dimension.

[His Divine Shadow]

I'm not nearly as pessimistic as you guys about space, infact if I where it would only be more incentive to start getting stuff out there now while we can. Start building those bloode nuclear rockets Star_glider mentioned. I want to see the beginnings of an orbital industrial complex capable of self maintenance and growth without the need for materials from the ground by 2030 personally.

[The Duchess of Zeon]

I've never understood how that wouldn't violate conservation of energy - you are removing several thousand tons of mass-energy to a different dimension.

As I understand the proposed extensions of Heim theory, those other dimensions are an integral part of our universe, and therefore the energy never actually leaves it.


I'd find it incredible of this is correct, but it would also be marvelously fitting, in its own way.

And a 50.1c absolute speed limit would make things look a lot better for spacefairing civilization than a 1c one, that's for sure.

There's always reason to hope, it's just not practical enough to discuss or plan for--we need to exploit this system before worrying about others, anyway.

[Darth Raptor]

Lightspeed isn't even the real speed limit either. While c is the theoretical upper limit for velocity, we'll never be able to really approach it, let alone attain it. The best we can hope for is some hefty percentage of c. As a ship accelerates toward lightspeed, its mass exponentially increases- and so does the energy required to maintain that accelleration. You'd need a way to reduce your ship's mass to literally nothing in order to reach the light barrier (nevermind break it). Either that or a source of infinite energy (and if you can do that, why leave Sol?). If the whole point is to cheat entropy as long as possible, you'd burn less energy sending colony ships at "slow" speeds. I think people are approaching the relativity problems from the wrong end. If you're immortal, what do you care if it takes 100,000 years to reach your destination? Repairing damaged tissue is a lot more feasible than totally wtfpwning physics.

[MKSheppard]

Orion will not work, especially not in any scenario where the oil infrastructure collapses under us first. They're an infrastructure-heavy investment; you must first get uranium to the piles, then make the bombs, then build a spaceship big enough to be worth the investment, then you must actually launch the thing.

*executes Nitram*

Do you actually think that we ship Uranium and other raw materials around the country in 40-foot tractor trailers?

I'm surprised you don't know any better, seeing as you live in WV, a massive coal industry state:



The typical coal train is 100 to 110 cars long-a mile of coal! Each hopper car holds 100 tons of coal

10,000 to 11,000 tons of raw ore transported in one shot.

As for the more exotic components of the nuclear industry once they've been built:


A US Department of Energy stainless steel-covered shipping cask rests on
a railroad car near the undamaged Three Mile Island Unit One at Middleton, PA, in this this 1986 file photo. Radioactive debris was shipped in the central cylinder, with protective buffers on each end, to a temporary site in Idaho

In fact....

Linka

A new railroad line has been selected as the preferred way to ship nuclear waste across Southern Nevada to Yucca Mountain, but Reno still faces the prospect that waste from Northern California and Oregon could be trucked through Reno, officials said Tuesday.

The proposed railroad line, would cross 319 miles of remote country north of Las Vegas, to assure “the safe, secure and timely transport of materials to Yucca Mountain,” the U.S. Department of Energy said in a statement.

[Admiral Valdemar]

Quit throwing 'concepts' around and quote an actual design study that shows that inertial confinement fusion can be used for earth launch applications. I specifically did not mention MC fusion because unlike IC fusion that should actually work, given fairly generous extrapolations of current technology aimed at fusion power. It's still going to take a huge amount of additional effort on top of the effort needed to get ground-based fusion power stations working.

Given the majority of such designs have barely been past theoretical, I don't see how I can supply working concepts for something relying on technology that may not even be viable for decades. It all hinges on fusion technology progressing. For that matter, Orion has never been shown to physically work outside of scale models and even NERVA was never anything more than a concept with a few tests out in the desert that led to nothing.

What is this 'might make' crap. That's not even a convincing attempt at a rebuttal. Orion ships are feasible to build right now using existing engineering expertise and nuclear warheads. We could do it in less time than it took to develop all the Apollo tech from scratch. It almost certainly won't happen, because the political will will not be there. Of course the window of opportunity to build them might close for a while. But right now, it is technically possible and it is the only very heavy lift option we (by which I mean 'the US government') could realistically deploy in the near future. Regardless, that is irrelevant to you proposing literally impossible (i.e. VASIMIR) solutions because you didn't check your facts.

So what, exactly, is the point of this discussion? Your impossible concept is more possible than mine? I don't even know why we got on to this totally OT line of debate since it's about as likely as me predicting oil depletion to the barrel for the next ten years.

Which I specifically mentioned in my earlier post, but nice attempt at a dodge. AM-initiated fusion is getting serious study, but doing an initiation with even vaguely practical amounts is an unsolved problem. For outer space applications, the main problem is that antimatter production is horribly uneconomical - given indefinite amounts of energy it's doable, but you'd have to build a lot of reactors/solar cells and particle accelerators (research such as wakefield acceleration may bring down the costs from extortionate to merely extreme). But for earth-launch applications antimatter is hobbled by the containment problem - right now there is no known light, compact way of containing antihydrogen at any kind of useful density. Even if you solve that, you'd have to make sure the thing (and presumably its power source) is 100% reliable under launch accelerations and vibrations, as enough antimatter to initiate a few thousand fusion bombs is going to blow a big hole in the vehicle (possibly vaporise it, depending on exactly how efficient the process is) if it fails. No sane engineer would want to use something that vulnerable to exploding under shock, control failure or power failure in a launch vehicle.

Yeah, it would be a dodge, except, I mentioned fusion, so it's not. You didn't specify I had to stick to any specific kind of fusion, so thanks for the semantics whoring.

And given the rate of AM production over the years, I don't see how it will be uneconomical by the time we're throwing these overwanked space projects together. I love how you state it's unrealistic when using Orion is about as likely as China invading the US right now. So please, get off the high horse. Your idea of Orion being done anytime this side of a century is just as dubious as fusion breaking even or AM production coming of age.

I hope you're not proposing to use a pure antimatter drive to lift off from an inhabited planet. That really would be silly.

If you read my post you'd actually know I didn't.

A
'I was wrong but instead of admitting it I'll question the validity of the debate'. If you weren't ok with the topic drift you could've just stayed out of the space arguments.

Actually, I'm questioning why your impossible concepts are worth any more time than mine. Mine hinges on fusion breaking even, AM production continuing in yield growth and total political stability along with a functioning economy of sorts. Yours is not much better.

More weasel dodges. VASIMR type drives don't work for lift-off, period. You made the mistake of proposing a specific solution without checking your facts, just admit it. There's no currently plausible way for laser or particle beam inertial confinement fusion to work for lift-off. AFAIK there's no currently plausible way to initiate a fusion device without either a fission trigger or an undetermined (but large enough to be quite dangerous) amount of antimatter, which we can't produce in useful quantities, won't be able to any time soon, and have no sufficiently robust way to store.

So your argument is because we can't do it today, it's stupid? Okay. And yet, Orion being over half a century old and never even being seriously considered is so much more likely, yes? Admit it, there are plenty of unknowns that aren't physically impossible, only technically limited. And if you somehow think the tiny amounts of AM being proposed in fusion concepts is any less dangerous than a fucking ship full of thermonuclear bombs, think again.

You're plumbing new levels of ignorance now. Do you even know the difference between 'wet nanotech' and 'dry nanotech'? Do you comprehend the difference between diffusive transport and channeled transport? Have you read any recent papers on the uses of inorganic nanoparticles, or advances in lab-on-chip microfluidics, or the capabilities of sillicon-based nanomachinery? Do you have any comprehension of how much centralised processing can optimise performance over simple dispersed chemical feedback mechanisms? No, you do not, you are grabbing at uselessly simplistic analogies that experts in the field have long since analysed and discarded.

No, I happen to have a degree in microbiology and have talked with people who work on micro- nanoscale concepts. You're simply showing gross ignorance if you think nanomachines will be anything like grey goo, which is a hilarious sci-fi buzzword you had to throw in there. Good going, sparky.

It's too bad you didn't take five minutes to read Mike's page on the wanking nanoapologists such as yourself make with regards to the technology. It's a slight problem to do with the laws of physics hindering your little idea, sadly. You know, the same thing you are apparently lecturing me on. That you even mentioned universal assemblers (and for the love of Zeus, even stated them as plausible) makes me think you fell for Drexler's almost alarmist and totally unfounded bullshit that many socialists think will bring a world without money where skyscrapers grow and nanites provide for everything. Ain't happening. Microbes, by the way, are not inefficient, much as you may think, you know.

And don't even bother coming out with the GM organism of doom bullshit. Those fears are so overblown as to be Michael Crichton plot worthy (oh wait, he did use them for a book).

PS.

Nice dodge there with the nanoparticles. They're a wee bit different to grey goo you mentioned above. Yes, they can be a problem, but no more so than vast numbers of inorganic chemicals already polluting the world.

Sikon: About the cars thing, I can't find the numbers again right now, but I do know that while efficiency in production numbers is there in mass production lines (obviously), they do have a lot of energy going into them that naturally wouldn't be needed for smaller lines that don't pump out as many cars. The idea is, we don't want to be throwing so much oil at machines that will suck it down faster, so the automotive industry will have to simply curb their output or else switch to alternatives.

[SirNitram]

*executes Nitram*

Do you actually think that we ship Uranium and other raw materials around the country in 40-foot tractor trailers?

No, I don't. I merely understand, unlike you, that there's more to it than what you think. You've got big ass trains, yay. Aren't you special. Except, as you say, I live in a state where trains carrying massive loads are common. Guess what they run on? Diesel or Diesel-Electric, if you're very lucky. Guess what becomes economically unfeasible as the price of petroleum goes sky high, due to this thing called Demand?

Only if you subscribe to the Biodeisel Will Save Us Meme, are you in a position to think this can be done without first uprooting massive sections of track and updating them to work off pure electric. In which case, why not just stop fucking around with ten thousand ton things that will still need conventional LVs and RVs and just build craft using NTRs and NERs?

[Admiral Valdemar]

The US was in the process of a lot of really quite modern electrified railways around WWII which got put on hold and then abandoned as everyone bought fugly large '50s cars and cheap gasoline. Had public transport been given the love it had before suburbia, then the issue of switching to trains wouldn't be on the table. As it stands now, you've got your work cut out if you want to re-invigorate the rail network to replace roads.

[SirNitram]

The US was in the process of a lot of really quite modern electrified railways around WWII which got put on hold and then abandoned as everyone bought fugly large '50s cars and cheap gasoline. Had public transport been given the love it had before suburbia, then the issue of switching to trains wouldn't be on the table. As it stands now, you've got your work cut out if you want to re-invigorate the rail network to replace roads.

Quite. It's back to what was being discussed earlier, as only electric rail will preserve large chunks of the US and the industry it needs. Amusing it took talking about spacecraft that tip the scales at tens of thousands of tons to bring it back up...

[Admiral Valdemar]

Yeah, enough of the space bullshit. Make another thread if anyone wants to continue that.

Back to the topic, I'm interested on finding what the figures would be for a US network that was a modern electrical rail system. I'm sure that, if ever proposed, would be a great incentive to up the nuclear plant numbers proposed to levels that Sikon and others on the web have proposed. Even China isn't going nuclear with any degree of enthusiasm (not least because of uranium trade disputes with Australia who have the bulk of the ore needed) since they can make coal fired plants far quicker for equivalent output.

But then when you don't give a shit about miner deaths, destroying the environment and making your air unbreathable, I guess it does make economic sense.

[MKSheppard]

Guess what they run on? Diesel or Diesel-Electric, if you're very lucky.

Hey moron, virtually every locomotive built today in the United States is Diesel-Electric, has been for the last couple of decades. It's only in really small applications like little tiny switchers, or specialized locomotives that you see geared diesels or diesel-hydraulics.

How braindamaged do you have to be to think deisel won't become unreasonably expensive for hauling around tens of thousands of tons of steel for this Orion project?

It takes roughly 37.5 gallons per mile to move a 12,500 ton train. So if we wanted to move that 12,500 tons some 3,000 miles; we'd require 112,500 gallons of diesel.

By comparison, it costs 6.3 gallons per mile to move a semi-trailer at 55 MPH or so. These semis can only carry 40 tons. So in order to move those 12,500 tons, we'd need 313 semi-trailers; and to move the same 12,500 tons to 3,000 miles, you would need 5,915,700 gallons of diesel.

Trains for the win!

[Admiral Valdemar]

Diesel will need to be phased out. We need to be switching to efficient electrical drive systems for a variety of reason. I'm sure upgrading current diesel-electrics could be done without total overhaul of the designs.

I'm more concerned with the extent of the network, not the locomotives themselves (though an excuse to go for turbine powered maglev would be cool). Whatever, the fact of the matter is the rolling warehouse that Wal*Mart names its truck fleet needs to die. We already saw how great just-in-time delivery is when fuel is at a premium (UK fuel protests).

[aerius]

Sikon: About the cars thing, I can't find the numbers again right now, but I do know that while efficiency in production numbers is there in mass production lines (obviously), they do have a lot of energy going into them that naturally wouldn't be needed for smaller lines that don't pump out as many cars. The idea is, we don't want to be throwing so much oil at machines that will suck it down faster, so the automotive industry will have to simply curb their output or else switch to alternatives.

I think one big change we'll see is that instead of building 25 million cars a year, each with an expected lifespan of 5 years (numbers for example only) and a shitload of non-repairable throwaway parts, we'll end up building say, 5-10 million a year but build them to last a good 20 years or so with a lot fewer throwaway parts. I think we'll see a similar shift in other areas of manufacturing as well, instead of building zillions of disposable piece of shit gadgets, there will be a shift back towards building things to last. Production numbers will drop a lot, costs will go up a lot, but now you won't have to buy a new TV every 2 years due to the old one dying on you. A good example would be Chris King Precision Components, makers of bicycle parts which basically never fail. Buy a Chris King part, and with proper care you can pass it down to your children and maybe even your grandchildren.