Stephen Hawking: Off Earth by 2110?

[Temujin]

Well, he's at it again.

Stephen Hawking: Off Earth by 2110?

Alan Boyle writes: We may have just 100 to 200 years to figure out how to get off this rock and give our species a cosmic insurance policy, physicist Stephen Hawking says in a fresh interview with BigThink. Hawking has said this sort of thing several times before - but every time he mentions the time frame, it adds an extra bit of urgency to the warning.

This time, Hawking's views are given a stark spin: "Abandon Earth - or Face Extinction." But Hawking isn't really suggesting we should just give up on our planet. It's just that right now we have all our eggs in one planetary basket. Here's the key passage:

• "If we are the only intelligent beings in the galaxy, we should make sure we survive and continue. But we are entering an increasingly dangerous period of our history. Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill. But our genetic code still carries the selfish and aggressive instincts that were of survival advantage in the past. It will be difficult enough to avoid disaster in the next hundred years, let alone the next thousand or million. Our only chance of long-term survival is not to remain inward-looking on planet Earth, but to spread out into space. We have made remarkable progress in the last hundred years, but if we want to continue beyond the next hundred years, our future is in space. That is why I'm in favor of manned, or should I say, 'personed' spaceflight."

Hawking said that "if we can avoid disaster for the next two centuries, our species should be safe as we spread into space."

The threats that Hawking is worried about break down into two categories: First, there are the doomsdays we could bring down upon ourselves - such as biological or nuclear attacks, or human-caused climate change that has such sudden effects that we can't adjust. The other category would be catastrophes that we don't cause: for example, a direct hit by a huge space rock or a supernova blast; or a bizarre, or a supernova blast world-changing eruption of super-volcanoes; or the emergence of a novel pathogen that our species can't fight.

The first category encompasses issues that we can do something about, and Hawking of course favors taking whatever action is necessary to save the environment and human society. The second category, however, takes in plausible extinction scenarios that humans couldn't do much about. Either category of catastrophe would require the human species to have an off-planet Plan B.

I've said for years that extinction avoidance is one of the five E's that explain why we have to spend our time and effort on space science and exploration. And I'm not by any means the first person to figure that out:

• "The earth is the cradle of humankind, but one cannot live in the cradle forever" - Russian rocket pioneer Konstantin Tsiolkovsky, 1895
  
  "Earth is too small a basket for mankind to keep all its eggs in." - science-fiction writer Robert Heinlein
  
  "Since, in the long run, every planetary civilization will be endangered by impacts from space, every surviving civilization is obliged to become spacefaring - not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive." - astronomer-author Carl Sagan, 1994
  
  "The dinosaurs became extinct because they didn't have a space program. And if we become extinct because we don't have a space program, it'll serve us right!" - science-fiction writer Larry Niven, as quoted by Arthur C. Clarke in 2001

Mars would offer the best nearby second home for humanity and our allied species - and on that score, Hawking's view has been echoed by SpaceX founder Elon Musk, who says his ultimate aim is to make Homo sapiens a multiplanet species. In the longer term, our distant descendants will have to leave Earth entirely before the sun goes all red-giant on us. Humans would have to move outward to the solar system's rim - or perhaps eventually to other star systems, on a voyage that would most likely take many generations.

How can humans do that? Hawking doesn't put forward any detailed answers, but in recent months he has outlined three way-out ideas for time travel, including wormholes, black-hole encounters and super-fast acceleration. In the "Star Trek: First Contact" time line, humans came up with warp drive - and were visited by friendly Vulcans - in the year 2063. Will humans get that lucky in real life? Maybe there's an astronomically remote chance. But Hawking has another warning about that: We'd better be careful about the aliens we come across.

So what do you think? Considering all the trouble that NASA has been having with human spaceflight lately, how much do you think we can get done by 2110? Will it make a difference for our species' survival? Weigh in with your thoughts in the comment space below.

He's certainly spot on. What I find most intriguing though is some of the commentary below from the anti-intellectual, selfish, short term thinking, have absolutely no understanding of science, head up their ass brigade.

[LionElJonson]

I'm planning on starting a private aerospace company, and this is one of the ideological reasons for doing so (manifest destiny and a personal love of the idea of space megastructures being a few others).

[Stuart]

I agree with Hawking; I think his analysis is absolutely correct with one exception. It's already too late. We've missed our chance. Had we gone full-bore for space exploration from the 1960s onwards, then we had a chance but that never happened. Now even with a full-bore effort, that missed fifty years will be critical. I think this is probably the explanation behind the Drake Equations Dilemma. There is a very fine window between the technology developing to take a species into space and safety and bringing about their own extinction. That window is so fine that the overwhelming majority of intelligent species miss their chance and slide gracefully or not-so-gracefully into extinction.

[LionElJonson]

I agree with Hawking; I think his analysis is absolutely correct with one exception. It's already too late. We've missed our chance. Had we gone full-bore for space exploration from the 1960s onwards, then we had a chance but that never happened. Now even with a full-bore effort, that missed fifty years will be critical. I think this is probably the explanation behind the Drake Equations Dilemma. There is a very fine window between the technology developing to take a species into space and safety and bringing about their own extinction. That window is so fine that the overwhelming majority of intelligent species miss their chance and slide gracefully or not-so-gracefully into extinction.

That's real optimistic. "We've already missed our chance, so we might as well give up!" Fuck that. The stars belong to humanity, and I intend to give them to them.

[MKSheppard]

I dunno. We were never going to go into space in a SERIOUS way, not with chemically fuelled rockets.

It seems that the best NASA budget can afford is about 6-8 launches of superheavy rockets a year.

If Saturn V had been continued to be produced, that's still only 720-960 tonnes a year into LEO; or 270-360 tonnes to Lunar Orbit.

From 1975 to 2010 is 35 years; or 25,200-33,600 tons to LEO.

That's fairly optimistic and assumes a steady launch rate, with no multi-year pauses like what happened after Challenger and Columbia.

Payloadwise, missions are expensive.

The Mars Mission as envisioned by Boeing in 1968 with NERVA would be about 1,230-1,300 tonnes; and establishing lunar bases would consume a lot of tonnage.

The only way human exploration of the solar system can become feasible is through two ways:

1.) Someone puts the money down to fund a Sea Dragon -- at 450 tonnes to orbit; even a slow launch schedule of four a year puts 1,800 tons into orbit.

2.) Someone puts the money down to fund an advanced airbreathing aircraft that releases a rocket at 5,000+ MPH at 167,000 to 250,000 feet. Since you can now reuse the biggest part of the launch complex, costs drop dramatically.

I don't see either happening any time soon.

The best we can hope for is that the US Military funds an EELV replacement in the 2040 time frame that uses the two stage advanced airbreathing concept that I outlined above in #2. By then the technology should be mature enough that it can be buried in the black budget.

[Temujin]

I agree with Hawking; I think his analysis is absolutely correct with one exception. It's already too late. We've missed our chance. Had we gone full-bore for space exploration from the 1960s onwards, then we had a chance but that never happened. Now even with a full-bore effort, that missed fifty years will be critical. I think this is probably the explanation behind the Drake Equations Dilemma. There is a very fine window between the technology developing to take a species into space and safety and bringing about their own extinction. That window is so fine that the overwhelming majority of intelligent species miss their chance and slide gracefully or not-so-gracefully into extinction.

That's real optimistic. "We've already missed our chance, so we might as well give up!" Fuck that. The stars belong to humanity, and I intend to give them to them.

Sadly Stuart is probably right. And what makes it worse is how much more time (and resources) we'll piss away before we actually get serious about getting into space again. Though that doesn't mean we shouldn't try.

I also have to agree about his comment regarding the Drake Equation. People always assumed it would just be something like nuclear war, going out with a bang; but between resource depletion and environmental ruin, it's probably just as likely to go out with a whimper.

[HMS Conqueror]

I have minimal interest in preserving the human race in and of itself. I obviously would rather people not die, but spending hundreds of billions to save just a handful of people in a life that is not really worth living such that they can't ever rebuild human civilisation anyway seems like an ill-advised and inequitable use of resources. I also disagree that humanity is likely to implode any time soon.

It will happen eventually, but not until it is cheap enough to do properly at an acceptable cost. That's a few centuries away.

[GrandMasterTerwynn]

I agree with Hawking; I think his analysis is absolutely correct with one exception. It's already too late. We've missed our chance. Had we gone full-bore for space exploration from the 1960s onwards, then we had a chance but that never happened. Now even with a full-bore effort, that missed fifty years will be critical. I think this is probably the explanation behind the Drake Equations Dilemma. There is a very fine window between the technology developing to take a species into space and safety and bringing about their own extinction. That window is so fine that the overwhelming majority of intelligent species miss their chance and slide gracefully or not-so-gracefully into extinction.

That's real optimistic. "We've already missed our chance, so we might as well give up!" Fuck that. The stars belong to humanity, and I intend to give them to them.

Do you have anything meaningful to contribute to this thread? Like, an actual plan? With numbers? (and by numbers, I mean costs.) And an explanation of why people would choose to go along with your plan? I mean, as it is, it's like listening to a three year old child tell his mother that he plans to be a football player astronaut when he grows up.

Stuart's assertion deserves far more consideration than your "football player astronaut" blathering.

From a certain point of view, his assertion is almost certainly correct. The best time to have had a sustained space push was the 1960s and 1970s, since we were already dispatching human beings to the Moon and back. More forward-thinking government and more risk- and cost-tolerant people could have sustained the momentum of the early Apollo landings, and parlayed them into greater successes. Only politicians are, by their fundamental nature, short-sighted; and the U.S. was coming off the expensive, and ultimately fruitless, adventure in Vietnam.

And that was back when we had a lot of room left to expand, and economic potential left to tap. Fast forward to today: The United States has either shuttered or outsourced much of its manufacturing capacity. The American people have gotten used to their McMansions, their McDonalds, their McDebt, and their 2.28 cars per household. The US has become the self-appointed police of the world, with military commitments that have only ballooned since the end of the Cold War. You could end our engagements in Afghanistan and Iraq tomorrow, and it won't benefit the space program. There's too much debt to be repaid, and too many at-home costs to manage.

So who's left? The Russians? To imagine that they'd be capable of sustaining a renewed space exploration effort, when they can't even prevent their own countryside from burning down . . . utter hilarity. Europe? The European nations suffer many of the same systemic issues that the US does. China? India? They have huge populations of people who have been primed to expect and demand more Western lifestyles . . . you know, a lifestyle based on massive consumption financed by money they haven't earned yet. Their economic growth is explosive, but it's only just keeping up with growing domestic demand. The same goes for any potential dark horses.

And this is at a time when the world will very shortly have to deal with that other thing they should've been dealing with back in the '60s and '70s . . . i.e. changing over the fossil-fuel based energy economy for one based on nuclear, solar, and other sources. It is shortly before the time where all that CO2 we've been pumping into the atmosphere really comes back to bite us in the ass. All of that will force the economic paradigm from "grow, grow, grow!" to "make do with what you've got." Trying to provide a lifestyle better than "abject poverty" for the nine billion people who will be on the planet in 2100 under those sorts of economic constraints is going to leave very little for space interests.

Let's face it, for the ramp-up period, space is a luxury. A very expensive luxury. Yes, it eventually pays off and becomes a utility, rather than a luxury. Yet, even when we could afford the luxury of the Moon and beyond, we chose to settle for a second-story apartment with a view. Now, in order to get our eggs out of the Earth basket, we have to first reinvent the 1960s on a budget that'd have a 1960s rocket scientist resigning in disgust and taking up something more lucrative and rewarding, like hog farming.

[GrandMasterTerwynn]

I have minimal interest in preserving the human race in and of itself. I obviously would rather people not die, but spending hundreds of billions to save just a handful of people in a life that is not really worth living such that they can't ever rebuild human civilisation anyway seems like an ill-advised and inequitable use of resources. I also disagree that humanity is likely to implode any time soon.

It will happen eventually, but not until it is cheap enough to do properly at an acceptable cost. That's a few centuries away.

Humans in space requires huge, dedicated, up-front costs. Just chipping away at the problem over the course of "a few centuries" will result in the ability to launch a really tiny Earth-observation satellite for really cheap. It won't get humans out of LEO, and into orbital habitats, since the two problems are orders of magnitude apart.

Of course humanity won't implode any time soon. We could keep shambling along like this for, at least, another century. Yet, we're living on borrowed time as it is. We've taken a few hundred million years of solar power input and burnt it all in the course of a couple of centuries. We've gotten used to getting better than 5:1 returns on our energy investment, when sustainable energy resources and consumption would yield much closer to 1:1. We've gotten used to agricultural yields produced by the ecological equivalent of strip-mining with nukes. If humanity is constrained to just Earth, the planet can comfortably sustain, perhaps, two or three billion people. Which means in a couple of centuries, some six or seven billion people will eventually have to bugger off. The process of deciding who gets to live could well make every other war in modern human history seem like a quaint Ren-Faire re-enactment in comparison.

Which is why this attitude of "eh, whatever, we'll get to it in a few centuries" is just breathtakingly stupid.

[HMS Conqueror]

I have minimal interest in preserving the human race in and of itself. I obviously would rather people not die, but spending hundreds of billions to save just a handful of people in a life that is not really worth living such that they can't ever rebuild human civilisation anyway seems like an ill-advised and inequitable use of resources. I also disagree that humanity is likely to implode any time soon.

It will happen eventually, but not until it is cheap enough to do properly at an acceptable cost. That's a few centuries away.

Humans in space requires huge, dedicated, up-front costs. Just chipping away at the problem over the course of "a few centuries" will result in the ability to launch a really tiny Earth-observation satellite for really cheap. It won't get humans out of LEO, and into orbital habitats, since the two problems are orders of magnitude apart.

Then it should never be done. However, since economic growth seems to be exponential I would not be so intimidated by orders of magnitude.

Of course humanity won't implode any time soon. We could keep shambling along like this for, at least, another century.

If by shambling on you mean reaching the pinnacle of material prosperity, scientific knowledge and population size - all still increasing - then I see no problem for humanity's survival.

Yet, we're living on borrowed time as it is. We've taken a few hundred million years of solar power input and burnt it all in the course of a couple of centuries. We've gotten used to getting better than 5:1 returns on our energy investment, when sustainable energy resources and consumption would yield much closer to 1:1. We've gotten used to agricultural yields produced by the ecological equivalent of strip-mining with nukes. If humanity is constrained to just Earth, the planet can comfortably sustain, perhaps, two or three billion people. Which means in a couple of centuries, some six or seven billion people will eventually have to bugger off. The process of deciding who gets to live could well make every other war in modern human history seem like a quaint Ren-Faire re-enactment in comparison.

Which is why this attitude of "eh, whatever, we'll get to it in a few centuries" is just breathtakingly stupid.

lol, there is no conceivable shortage of energy on earth for millions of years. The only issue is the cost of generation, which economic growth takes care of over time. The reason we use the cheap-and-nasty methods first is that we have less money and technological capability in the present (whenever that may be) than in the future.

[Guardsman Bass]

We've gotten used to getting better than 5:1 returns on our energy investment, when sustainable energy resources and consumption would yield much closer to 1:1.

Energy is the least of several bad problems. Even aside from remaining reserves of oil and coal (neither of which are about to run out anytime soon, not when there are still rather large reserves to hit), there's natural gas (which we have plenty of, particularly in the US), nuclear (mostly political limitations), solar, hydroelectric, tide power, wind - the list goes on.

I've always found the use of EROEI misleading when used in arguments like this. If we're converting energy from a form that's plentiful but not as useful, to a form that is more useful, then it doesn't really matter if we lose energy in the process as long as we have the former. It's like with the hypothetical "hydrogen economy", where we'd effectively be taking a net loss in terms of energy by using electricity to crack hydrogen.

If humanity is constrained to just Earth, the planet can comfortably sustain, perhaps, two or three billion people. Which means in a couple of centuries, some six or seven billion people will eventually have to bugger off. The process of deciding who gets to live could well make every other war in modern human history seem like a quaint Ren-Faire re-enactment in comparison.

That type of population decline may very well happen even without the mass death and conflict. Birth rates, across the globe, have been on a decline for decades, with the Developing World (nevermind the rich countries) expected to fall below the replacement level before the end of the 21st century. After that, it's just a matter of waiting for the top-heavy elderly segment to die off (short of someone discovering an immortality drug, or stumbling on the Singularity). *

Where are you getting this "two or three billion" figure?

* By the way, this type of drop-off in population pressure is probably a bad thing for space colonization. If the human population becomes relatively static and at least somewhat comfortable on Earth, you're going to have a hard-time convincing large numbers of people to move off-world without some type of massive project to draw them in (like terraforming Mars).

Which is why this attitude of "eh, whatever, we'll get to it in a few centuries" is just breathtakingly stupid.

I agree that it's stupid, although I'm not as pessimistic as Stuart over the threat of biological warfare (I've read the Alibek book too). Over a time period of centuries, we're basically gambling with the survival of our civilization, in the hopes that one of those Near Earth Asteroids won't fall on us. It has happened before, including possibly at the end of the last Ice Age.

Then it should never be done. However, since economic growth seems to be exponential I would not be so intimidated by orders of magnitude.

That's a rather extreme position to take. Much of the major infrastructure built in the US and Europe was done with government aid and direction, with those same government supporting the initial investment either directly or indirectly (in the US, for example, we supported the railroads' expansion with land grants).

Not that I think space colonization will be profitable, at least not until there's an actual population of colonists off-world.

[open_sketchbook]

Where the hell do we put these people? Space colonies? I can't see that working out in the long term, stuff breaks down too fast. If Earth got taken out, the space colonies would be on borrowed time. The Moon? Same problem as the space colonies. Mars? We can't keep our own environment stable, how the hell are we supposed to terraform Mars? What happens on Mars when Earth does collaspe? Generational ship elsewhere? There is nowhere to go.

We're fucked. Big deal. We've always been fucked, we've just advanced the timeframe.

The broad universe is hostile to life. Within a few hundred million years everything on the planet will die out anyway as the output of the sun changes. Our fleshy forms and biological species is doomed, DOOMED I say! If we want to survive, our best bet is to survive in name only; to give AIs an image of us and let them do all the spreading out and exploring and such. They can handle the timeframe and live where we cannot. That's the best I got.

[GrandMasterTerwynn]

I have minimal interest in preserving the human race in and of itself. I obviously would rather people not die, but spending hundreds of billions to save just a handful of people in a life that is not really worth living such that they can't ever rebuild human civilisation anyway seems like an ill-advised and inequitable use of resources. I also disagree that humanity is likely to implode any time soon.

It will happen eventually, but not until it is cheap enough to do properly at an acceptable cost. That's a few centuries away.

Humans in space requires huge, dedicated, up-front costs. Just chipping away at the problem over the course of "a few centuries" will result in the ability to launch a really tiny Earth-observation satellite for really cheap. It won't get humans out of LEO, and into orbital habitats, since the two problems are orders of magnitude apart.

Then it should never be done. However, since economic growth seems to be exponential I would not be so intimidated by orders of magnitude.

Apparently, you live in a world where all problems can be solved with enough spending and wishful thinking. I used to live there too. And then I turned twelve. Economic growth is only exponential if you still have resources to spend to sustain that growth. You can only flog the planet for so many resources before the cost of extracting that next unit of resources becomes more than you can readily afford.

Of course humanity won't implode any time soon. We could keep shambling along like this for, at least, another century.

If by shambling on you mean reaching the pinnacle of material prosperity, scientific knowledge and population size - all still increasing - then I see no problem for humanity's survival.

You are, of course, aware that there's no such thing as a free lunch, right? Where, praytell, are we going to get the resources to provide nine billion people with a First World lifestyle? And yes, we're liable to bump right up against the edge of scientific knowledge in a century or two. That fact should be profoundly worrying, as it suggests that there aren't going to be any magic-tech solutions to get us out of the corner we're painting ourselves into. I suppose the name "Malthus" means nothing to you.

Yet, we're living on borrowed time as it is. We've taken a few hundred million years of solar power input and burnt it all in the course of a couple of centuries. We've gotten used to getting better than 5:1 returns on our energy investment, when sustainable energy resources and consumption would yield much closer to 1:1. We've gotten used to agricultural yields produced by the ecological equivalent of strip-mining with nukes. If humanity is constrained to just Earth, the planet can comfortably sustain, perhaps, two or three billion people. Which means in a couple of centuries, some six or seven billion people will eventually have to bugger off. The process of deciding who gets to live could well make every other war in modern human history seem like a quaint Ren-Faire re-enactment in comparison.

Which is why this attitude of "eh, whatever, we'll get to it in a few centuries" is just breathtakingly stupid.

lol, there is no conceivable shortage of energy on earth for millions of years.

Proof? Mind you, there is the sun, but I've already established that we've blown the equivalent of millions of years of solar energy input in the form of fossil fuels. Allegedly, we can sustain current levels of energy usage through nuclear power for many megayears . . . assuming the widespread adoption of breeder reactors, and the profitable large-scale extraction of uranium from seawater. All of this assumes that we'll spend the few trillion dollars needed to convert our petrochemical energy infrastructure into a nuclear/solar one before we hammer the planet's petrochemical reserves to the point where we're spending huge amounts of money just to keep up with our energy demands.

And don't forget that energy is only one part of the puzzle. You also have to feed all those people, and they have to live somewhere. And they have to do so while dealing with the legacy of climate upset that we'll be leaving them.

The only issue is the cost of generation, which economic growth takes care of over time.

And what is going to fuel this endless economic growth? Fairy dust and unicorn shit?

The reason we use the cheap-and-nasty methods first is that we have less money and technological capability in the present (whenever that may be) than in the future.

Oh yes. We've moved from cheap-and-nasty methods to expensive-and-nastier methods. And that's just to keep up with growth in demand. Yet I don't see any multi-trillion dollar projects on the horizon to convert our petrochemical lifestyle to a nuclear/solar one. Do you?

[Broomstick]

Then it should never be done. However, since economic growth seems to be exponential I would not be so intimidated by orders of magnitude.

It only seems to be exponential because that's our recent experience. There have also been times when the economic engines reversed.

For an instructive example see Easter Island. It's a beautiful example of what happens when overpopulation crashes hard. Just because the 20th Century was all progress (actually, it wasn't until around 1945 in the US, and later than that in the rest of the world) doesn't mean the 21st Century will be.

Of course humanity won't implode any time soon. We could keep shambling along like this for, at least, another century.

If by shambling on you mean reaching the pinnacle of material prosperity, scientific knowledge and population size - all still increasing - then I see no problem for humanity's survival.

You know, Ancient Rome was pretty damn snazzy, too - then the Dark Ages came along. Gee, that really sucked. How about the collapse of the Mayans?

Civilizations can and do fall. Typically, what's left behind never re-achieves to the extent of the Big Golden Age.

Not to mention our current civilization runs on the Magic Potion known as PETROLEUM - which even the most optimistic admit is a FINITE resource. We're burning through it at a breath-taking rate. The best estimates I've seen for alternative sources would give us, maybe 30% of our current energy output, so cut to 1/3 all your driving, the lights in your house, your household appliance use... and that's the BEST scenario. Once it's gone a lot of the "Green Revolution" in agriculture comes to a screeching halt and we go back to 19th Century crop yields (if we're lucky - in some places the soil fertility is pretty much destroyed, so yields would be even less). People will starve by the tens of millions (if we're lucky, it could be worse). Much of our medical advances in regards to disease are becoming useless because the germs keep evolving. All it takes is one virulent pathogen to get loose and we could lose a LOT of people. Lose enough and both the economy and technology go into reverse.

That's totally leaving aside something like Yellowstone having a major eruption - which couldn't do a damn thing about. It would destroy North American agriculture and economy for several years at best - again, tens of millions starve, weather is fucked up, not only does science and technology stop advancing they might even reverse...

There are actually a LOT of threats to both our civilization and our species.

In fact, for long-term health of both the planet and our species the best "solution" I can see is losing about 75% of the current population (actually, we could happily get by with less than 1 billion) and there's much, much more to go around for everyone be it oil, land, food.... except for the nasty, nasty detail that anything that takes out that many people would be absolute hell on Earth for everyone who goes through it, be it plague, war, famine, or natural disaster. And, depending on the mechanism, it might take a LONG time to rebuild to even 20th Century levels of ability.

So, do us all a favor - study history a little better.

lol, there is no conceivable shortage of energy on earth for millions of years.

You fucking moron - you miss the point. NOTHING gives as high a return on investment as petroleum. NOTHING. At least nothing we currently have. Coal might be a close second, but it's polluting as all hell. Nuclear requires a certain level of high tech to build and maintain. Solar - well, plants really aren't all that efficient, there's just a LOT of them and our artificial solar isn't that much better (if it even matches). Wind - not reliable 24/7. Geothermal - limited to certain locations. Hydrothermal - most of them best locations already built up, and there's an environmental cost to using it. Sure, there will always, in a sense, be available energy but nothing we have is as concentrated, portable, and adaptable as oil and its derivatives.

[Guardsman Bass]

Where the hell do we put these people? Space colonies? I can't see that working out in the long term, stuff breaks down too fast. If Earth got taken out, the space colonies would be on borrowed time. The Moon? Same problem as the space colonies. Mars? We can't keep our own environment stable, how the hell are we supposed to terraform Mars? What happens on Mars when Earth does collaspe? Generational ship elsewhere? There is nowhere to go.

Nobody's talking about trying to jump quickly from the current situation to self-sufficient off-world colonies. There would obviously be a long period in-between, when the colonies are more or less still dependent on Earth for a number of resources (mostly technological components and tools that they can't duplicate). At the same time, it's not impossible to develop that type of self-sufficiency off-world, at least not to the best of our knowledge - you just need the resources and the infrastructure.

You are, of course, aware that there's no such thing as a free lunch, right? Where, praytell, are we going to get the resources to provide nine billion people with a First World lifestyle? And yes, we're liable to bump right up against the edge of scientific knowledge in a century or two. That fact should be profoundly worrying, as it suggests that there aren't going to be any magic-tech solutions to get us out of the corner we're painting ourselves into. I suppose the name "Malthus" means nothing to you.

What makes you think the First World lifestyle will look anything like it does now? We're already trending worldwide towards greater urbanization, and that will only accelerate if there's no effective substitute for the gasoline-driven car.

That doesn't mean it will be a lower standard of living - just one that exists in the way it does because of the high prices of certain type of input (like oil).

All of this assumes that we'll spend the few trillion dollars needed to convert our petrochemical energy infrastructure into a nuclear/solar one before we hammer the planet's petrochemical reserves to the point where we're spending huge amounts of money just to keep up with our energy demands.

A few trillion dollars is a minuscule amount of money over the scale of decades. The size of the world economy was $61.1 trillion in 2008, and that's steadily trending upwards.

And don't forget that energy is only one part of the puzzle. You also have to feed all those people, and they have to live somewhere. And they have to do so while dealing with the legacy of climate upset that we'll be leaving them.

Living space isn't a problem, what with the trend towards urbanization worldwide. Food is trickier, but that's partially because we don't quite know yet exactly how climate change is going to affect a number of inputs in modern farming (particularly water supplies) on the scale of decades.

And what is going to fuel this endless economic growth? Fairy dust and unicorn shit?

Productivity increases, which will be particularly important as the unit price of a number of inputs (particularly oil) rises in the next century. That's ultimately limited by technology, but it doesn't really matter if economic growth slows to a crawl once you have a population with a relatively stable size at a reasonably high living standard.

Oh yes. We've moved from cheap-and-nasty methods to expensive-and-nastier methods. And that's just to keep up with growth in demand. Yet I don't see any multi-trillion dollar projects on the horizon to convert our petrochemical lifestyle to a nuclear/solar one. Do you?

The beginnings are there, with what they're calling the "nuclear renaissance."

Chinese nuclear development
Edging Back to Nuclear Power in the US

There are others. You have to start from somewhere - 42 years passed between the B & O railroad in the eastern US (the first common carrier railroad in the US) and the completion of the transcontinental railroad in the US, for example.

[Pelranius]

How long would it take to build a Project Orion space ship? That's a lot of payload we're talking about there.

[eion]

Mars? We can't keep our own environment stable, how the hell are we supposed to terraform Mars? What happens on Mars when Earth does collaspe?

Considering that what Mars requires to be Earthlike is mostly massive amounts of greenhouse gases and/or heat it's a lot easier than you would think, we've been running a prototype program on Earth for several centuries.

I think we still have some time left before the end is inevitable. The biggest issue is in convincing people that NASA isn’t some massive recreational and social welfare program for engineers but is instead a national species security program.

As for how we start, as Shep pointed out, engineers have been creating super heavy lifter designs for decades.

[Pelranius]

Mars? We can't keep our own environment stable, how the hell are we supposed to terraform Mars? What happens on Mars when Earth does collaspe?

Considering that what Mars requires to be Earthlike is mostly massive amounts of greenhouse gases and/or heat it's a lot easier than you would think, we've been running a prototype program on Earth for several centuries.

I think we still have some time left before the end is inevitable. The biggest issue is in convincing people that NASA isn’t some massive recreational and social welfare program for engineers but is instead a national species security program.

As for how we start, as Shep pointed out, engineers have been creating super heavy lifter designs for decades.

In the worst case scenario, we could repeal the Partial Test Ban treaty and let environmentally flexible nations build a boatload of Orions in forsaken places like the Sahara and Tarim.

The questions lie in mass producing an affordable heavy launch program, and seeing which nation will take the lead in championing the technology.

[Simon_Jester]

How long would it take to build a Project Orion space ship? That's a lot of payload we're talking about there.

Orion has so many drawbacks that it might pay a lot better to build gigantic chemical rockets; at least we know those work; there's no risk of sinking billions of dollars into R&D only to discover that it's physically impossible to build the shock absorbers.

[Pelranius]

Maybe I've been taking Dyson and Pournelle's words a little too seriously.

[PaperJack]

This thread has depressed me

I've read somewhere that a giant rail that extends several hundred kilometers might work well for transfering stuff into space

[eion]

Are you talking about a Launch Loop?

I actually find the Space Fountain a far more likely, and frankly cooler concept. It's a space elevator that you can build anywhere and to nearly any height, avoiding both the major problems of the traditional space elevators.

[Dave]

What about Quicklaunch? It's a sea-based hydrogen-powered space gun. Since it floats, you can relatively easily adjust the inclination and elevation of the projectile.

It seemed to be a workable, cheap way to get to space, at least when I watched the video.

[Broomstick]

Just remember that in this context "cheap" is a relative term. It will also cost more to fly than to drive, and always more to go into space than to fly, simply because of energy requirements for each mode of transport.

[Pelranius]

For 'spacegun' type launch systems, would it be possible to them to launch crewed assets into space, or are they only good for unmanned cargos?