HN Theater @HNTheaterMonth

The bacteria are mentioned in Albert Bartlett's famous lecture here: https://www.youtube.com/watch?v=F-QA2rkpBSY

It's clickbait titled and split into 8 parts, for who knows what reasons, but that quote is the tl;dr version of it. Exponential growth is unintuitive, and chasing endless growth is not going to work out well for us.

Even if the bacteria find another entire jar of open space - as much space as has ever been known, as much space as they have used in their entire history - a fully terraformed Mars hanging out in the back yard previously unseen - it only lasts a single doubling-time.

⬐ elbasti

Found a 3 minute version: https://www.youtube.com/watch?v=73xdpoQFLQk

If you run in a straight line, toward a cliff, you can hope that when you get there, a bridge will have been built. And it may work quite often. It has for us in the past (although we are kin to forget the cost we paid for it).

But it's not a bad answer to suggest to slow down to give time for the bridge to be built, or just change course. You can also assume some of us will not die in the fall even if the bridge is not there, and part of the group will survive. But it's not bad to suggest we could choose another way.

The thing is, even if the universe is not a closed system, our Earth system can be approximated as such, once we consider social/logistical/scientific bottlenecks, education, time available, speed of consumption and reaction, inertia, and our desire to avoid a genocide.

I keep posting this video (in 8 parts):

http://www.youtube.com/watch?v=F-QA2rkpBSY&feature=list_othe...

Because I wish more people would watch it.

It's a very good mathematical and political explanation of why we can't continue just thinking "growth". It addresses the usual rebukes such as "we are not in a finite system", "this is not a zero sum game", "innovation/adaptation will save us" or "we can make it sustainable/reasonable".

I particularly like the part where Albert Allen Bartlett explains how our growth affects democracy, comfort, health, and peace, not just resource consumption.

⬐ icebraining

For people who prefer to read, here's a transcript: https://www.albartlett.org/presentations/arithmetic_populati...

⬐ marcus_holmes

thank you. I wish every presenter, no matter how good, realised that some people prefer reading to watching video.

⬐ marcus_holmes

this is exactly the ecological mindset I was talking about.

To use the example he uses: Boulder, Colorado, if it grows at 5% per year, will start running out of livable space near the town centre. As it expands, property prices will increase and adapt to the rising demand, and growth will slow as the once-attractive city becomes less affordable and less attractive. The councillor who wants 5% growth now (because at this point in time, 5% is fine) might be perfectly aware that 5% growth can't be continued for 70 years. That wasn't the question he was asked - having a single idealised growth rate for all time is ridiculous. The growth rate will need to adapt to circumstances.

The part about coal consumption is also simplistic and naive, because it doesn't take price into account. If coal becomes scarce, the price rises, and demand drops. You can cheerfully say "coal will last 1000 years" (if you wanted to, but why you'd want to is another question), because coal consumption is not going to continue at a steady pace until suddenly there's no more coal. As the coal stocks dwindle, the price will go up and less critical uses of coal will stop, and demand will decrease, until eventually 1000 years from now, the last piece of coal is in a museum and way too expensive to burn.

The "peak oil" thing that he talks about is the perfect example. Everyone (for good reasons) thought we'd hit peak oil in 2008. Then the oil price rose enough to make fracking viable, so natural gas took over providing energy for a bunch of things that we'd been using oil for (and they also found more oil fields), and suddenly there's enough oil and western civilisation continues as normal. The whole thing was a huge false alarm and the Hibbert curve is expanded yet again.

anyway, interesting talk, thanks for sharing :)

⬐ ripsawridge

Bartlett is the most amazing presenter nobody ever heard about. I like his talks/papers very much.

⬐ ratel

The analogy of the cliff seems nice, until you give it some thought. a) We are not actually running. What does stop and think about it actually mean? If there is a cliff and if we can stop or change direction. why not on the edge of the cliff, why way before that? b) Nobody is excepting a bridge to miraculously appear, but we might be thinking about how to cross that cliff when we get there and prepare. Humans are actually quite good at that. Will it costs us more than we were expecting when we could not yet see that 'cliff' yet. Definitely, but we were not born with foresight and have a limited time-frame of reference even if we can predict with some certainty. The later is why we are not investing everything for the time our sun will turn off its light. Call it the human condition.

As for your insistence that 'growth' cannot be sustained. I suspect you mean population growth, although nobody is actually "thinking" as in wishing for that. I for one cannot have a meaningful conversation on that. People who really belief that is our biggest problem are no longer here to have that conversation with and all others tend to mean: There are too many _other_ people. That discussion has been taking place under many different guises, none of them remotely interesting.

⬐ mistermann

> a) We are not actually running. What does stop and think about it actually mean?

To me, "running" refers approximately to "going about business on our current trajectory; the status quo". "Stop and think" means just that: stop and think, but think deeply. Thinking shallowly is effortless, thinking deeply is a different story (perhaps especially for those of higher intelligence, whose shallow thinking can often be equivalent to the layman's deep thinking).

For any given problem, is the situation more complex than it appears on the surface? Have I overlooked anything? Are there non-obvious second order effects that are invisible when thinking about the situation in isolation, but manifest themselves in the real world of integrated systems? Are there any examples in history where shallow thinking got humanity into trouble? For this, the speaker gives the example of the Aswan Dam, on the Nile river; many other things could be added to that list, such as war.

> If there is a cliff and if we can stop or change direction. why not on the edge of the cliff, why way before that?

Momentum, and lack of support from an often selfish, non-unified, and shallow thinking public (see how quickly China can execute on disruptive projects vs the glacial speed in democracies that require consensus).

> b) Nobody is excepting a bridge to miraculously appear, but we might be thinking about how to cross that cliff when we get there and prepare. Humans are actually quite good at that.

Good, but not perfect, especially when the problem is not purely technical, but involves (even in part) relationships with other humans (see: seemingly minor actions that lead to major interpersonal, tribal (political polarism, culture wars), or international conflicts).

I like this part from the 8th segment of the playlist (emphasis and [additions] mine):

> ...now except for the petroleum graphs the things I tell you are not predictions of the future, I'm only reporting facts and the results of some very simple arithmetic, but I do this with confidence that these facts, this arithmetic, and more importantly our level of understanding of them will play a major role in shaping our future. Now don't take what I've said blindly or uncritically because of the rhetoric or for any other reason. Please, you check the facts, please check my arithmetic, if you find errors please let me know. But if you don't find errors then, I hope you'll take this very very seriously.

> You are important people, you can think, and if there was ever a time when the human race needs people who will think, it's right now. It's our responsibility as citizens in a democracy to think, and so to be successful with this experiment of human life on earth we have to understand the laws of nature as we encounter them in the study of science and mathematics [and psychology and sociology]. We have to remember the message of this cartoon: thinking is very upsetting it tells us things we'd rather not know. We should remember the words of Galileo, he said I do not feel obliged to believe that the same God who has endowed us with sense reason and intellect has intended us to forgo their use. We should remember the words of Aldous Huxley, he observed that facts do not cease to exist because they're ignored. And we should remember HL Mencken social philosophy, he believed that it was in the nature of the human species to reject what is true but unpleasant [or unpleasant, in some psychologically counter-intuitive situations], and to embrace what is obviously false but comforting, and we should remember Eric Sevareide's, law he was a newscaster who made the transition from radio to television back in the 1950s he observed that the chief source of problems is solutions. Now let's just look at an example the Nile River for

⬐ sametmax

Watch the video, your points are addressed.

That's not the problem. They have the right to. We encourage it. But there are too many humans.

This is just a hisper example, but pollution, food quality, democraty, education and the health system suffer from the same problem.

It's going to get worse and all we do is finding temporary solutions, not adressing the elephant in the room: promoting growth forever is not sustainable.

I really lile this conf:

https://m.youtube.com/watch?list=SP6A1FD147A45EF50D&playnext...

Because it addresses the problem mathematically, and answers the usual rebukes about innovation, moderation and other "sustainable growth".

⬐ melling

I’m sure we can handle more people on this planet if we don’t all eat meat daily, we don’t need to drive cars, and don’t get on airplanes to travel 200-500 miles.

How much wasted space do we have in cities because we build around cars?

https://www.fastcompany.com/90202222/heres-how-much-space-u-...

⬐ sametmax

Watch the video. This is addressed as well.

There are many variables to this: the time we get to react, the effect on democracy, the innovation fallacy, our perspective on resources availability, etc.

⬐ throwaway50003

We are a reaaally far cry from exhausting all our resources. Overpopulation is a concern but all trends point at a curb of growth in the 2050's. The problem isn't that we collectively consume too much, it's that some consume waaaaay too much and others fight for crumbs and get told off when they dare yearn for more.

Guilt-tripping middle-class and poor people into accepting lower standards of living is dangerous imo, because silly contributions you may make are dwarfed by corporate contributions. Studies show that people who do token actions such as eating less meat are less likely to take part in actions that matter e.g. dismantling Exxon and putting its top execs behind bars).

⬐ NotPaidToPost

Forecast is a 60% increase of the world population by the end of the century...

The future of climate change and the environment is hopeless because of that as we already don't do anything now.

I don't know who's childishly downvoting any comment that points this out. I can only suggest that they wake up and smell the coffee.

⬐ sametmax

This is addressed in the video I linked as well. Watch it, your point is logical but doesn't take in consideration several variables.

⬐ newswriter99

That's my point. From my perspective, the headline isn't: "There are too many humans" Instead it's: "It was better when only us privileged humans got to do this thing"

⬐ toomuchtodo

There is nothing wrong with that inconvenient truth. Finite systems don’t care about political correctness.

Perhaps a better headline would’ve been, “Not everyone can join the middle class”.

⬐ sametmax

That would make it subject to outcry because it could be understood as "you are not allowed", while the problem is that "there are too many of us for this lifestyle"

⬐ coldtea

>There is nothing wrong with that inconvenient truth. Finite systems don’t care about political correctness.

Some care is needed though, because neither the poor butchering the rich classes with machetes during a revolt care about political correctness either...

>Perhaps a better headline would’ve been, “Not everyone can join the middle class”.

How about, "less tourism, whether upper or middle class"?

I'd like to see wannabe tourists earn the right to travel, as opposed to it being the default or just what money buy you. Maybe a cultural exam based on the destination? Make people work for it. Of course that's not in the interest of huge tourism industries, domestic or abroad.

People that travel just to drink cheep beer or expensive champagne in another country, could always just stay at home and drink there.

⬐ sametmax

> How about, "less tourism, whether upper or middle class"?

That won't work on the long run. Watch the video, it is addressed.

I'm amazed it's such a sensitive topic. Some people are litterally angry in the comments out people suggesting degrowth.

Since we have math lovers here, I'll post a fantastic math oriented conf on the topic:

http://www.youtube.com/watch?v=F-QA2rkpBSY&feature=list_othe...

It reminds me of this lecture from Albert Bartlett: https://www.youtube.com/watch?v=F-QA2rkpBSY&feature=list_oth...

Eventually, any kind of growth is limited in a closed system, so it makes sense that it will be the dawn of capitalism, provided we don't escape in space before.

But I'm surprised, almost disapointed, that we need to reach this extreem. I was expecting injustice, greed, health issues and the ponzi scheme aspect of our economic system to be the kicker. It never happened.

Still, it's a finite resource and we consume it more and more. Obligatory link: https://m.youtube.com/watch?feature=list_other&list=SP6A1FD1...

⬐ gepi79

IMO Thorium reactors are too late. In some decades, there will be enough solar power, wind power and fusion power anyway.

But there is enough Uranium and Thorium for many centuries, even millennia.

The most important problem to solve is climate change; besides aging as the most important reason for misery and death today.

https://www.youtube.com/watch?v=W6HyNk5Duvk

⬐ opportune

This is probably true, but they should still be researched in case they become useful in other settings, e.g. Mars, or even places on Earth with poor renewable energy potential

A big problem with Mars is that getting fuel there is expensive, they sometimes have large dust storms, and their atmosphere is very thin. Solar power would work fine there 90+% of the time, but outside of fission, there doesn't seem to be any good technology for powering a human habitat over long periods. A rich thorium deposit on Mars could go a long way in creating a self-sustainable habitat. Some thorium reactor designs are notable for their high inherent safety, which is probably a big concern for any human habitat on Mars for morale reasons (think about how much a fatal nuclear disaster on a Martian colony would scare people about space exploration)

⬐ gepi79

I agree.

But going to Mars in the next decades is a useless horrific suicide mission that only serves to make a few people famous.

IMO persons will colonize moons, planets and space ships once their biological body is replaced by a machine body. In a biological sense, the human race will die on Earth.

⬐ opportune

I agree that focusing on Mars soon is useless, but in the near-term Thorium could be useful for non-windy locations near the poles.

⬐ AngryData

I think people are underestimating the amount of energy production required for sustainability. We use fossil fuels in many other applications besides turning into combustion fuels and if we want to start scrubbing CO2 so we don't turn into Venus that is even more energy. Take fertilizer production for example, we already know it is an energy intensive proccess, a large portion of global energy supply is used on making fertilizer, but it goes farther than that. The base reagents we turn into solid or liquid synthetic fertilizer is more fossil fuels which doesn't get accounted for as energy production, yet it is containing a ton of energy still. We could draw what we need for the fertilizer from the atmosphere and water, but it will increase our energy expenditures for production an entire order of magnitude higher, if not more. Who is counting the carbon pollution from that fertilizer after it comes out of my ass or rots on the ground? The same goes with other processes and materials. Plastics is a big one, nobody counts the amount of 'energy' stored within plastic as a material, plastic doesn't easily degrade, but it does degrade and release its decomposition products into the earth and atmosphere, and at increasing rates if we take the reports of plastic-consuming bacteria evolving and gaining numbers seriously.

⬐ gepi79

I do not know about the effects of plastic decomposition on the climate.

But the replacement of animal products by vegan food is the only sane choice for medical, ethical, economic and ecological reasons.

http://www.cowspiracy.com/

http://www.whatthehealthfilm.com/

https://www.youtube.com/channel/UCGJq0eQZoFSwgcqgxIE9MHw/vid...

https://www.youtube.com/channel/UCJRjK20fHylJyf-HiBtqI2w/vid...

A great case has been made about this by Albert Bartlett.

You can see his very well made conference on youtube: https://www.youtube.com/watch?v=F-QA2rkpBSY&feature=list_oth...

It's one of the reasons I'm very excited about vasalgel:

https://www.parsemus.org/projects/vasalgel/

This procedure has been tested for 10 years in India under the name of RISUG and has been quite successful up to now.

I really hope we can demonstrate it's efficient and safe in the US, as:

- the procedure it incredibly simple: a simple injection

- it's semi-permanent: up to 10 years with one injection

- it's supposedly reversible : back to fertility in 3 month after an injection of another product

- it's not hormone based. In fact it does not appear to affect the body outside of the injection area.

- it's on the male size. Now given than less males want children than females and that there are still many males having children despite not wanting them, I'm curious on the effect perfect male control can have. Not only on the population growth, but also on the quality of fatherhood. I just hope it won't make STD more common because people will avoid condoms.

Reversibility has been an issue to prove on rabbits for now. So the suspense is killing me :)

I like that, Albert Bartlett, in this excellent video:

https://www.youtube.com/watch?v=F-QA2rkpBSY&feature=list_oth...

says something like:

Well, you have 2 columns. On the left one the nice ways to solve the problem. On the right one the nasty ways. The good news is that nature will always find a way to solve the problem. The bad new is that if we don't use the solutions from the left, nature will use the ones from the right.

⬐ stouset

This video is amazing and should be mandatory reading before one is allowed to offer their opinion on anything remotely related to exponential growth.

This "growth rate" measured in percent has always concerned me. It looks to be unsustainable. Interesting video: https://www.youtube.com/watch?v=F-QA2rkpBSY

No, and in most cases where it has it, it shouldn't... https://www.youtube.com/watch?v=F-QA2rkpBSY

1. The impulse to say 10 cents was there, but solving the equation led to the right answer.

2. Got this right in a few moments by thinking about it (no math).

3. Instantly knew the answer thanks to having watched "the most important video you'll ever see": https://www.youtube.com/watch?v=F-QA2rkpBSY

I would suggest this too https://www.youtube.com/watch?v=F-QA2rkpBSY

⬐ ehsanu1

While there are many who people do not understand exponential growth, such as that video's target audience, I'm pretty sure that none of them are population projectionists.

⬐ rasz_pl

Its not that they dont understand, they dont even think about it. Even Hans Rosling from the clip above spends whole 3 seconds on the subject of energy needed to support 20 Billion people living at the same comfortable level as top billion people today in developed countries.

I seem to remember some funny back of envelope calculations that put energy needs of earth in 100 years (assuming current growth) at _full output_ of our sun.

>some fairly massive blocks that were allocated but unused

Watch this clip to understand why fractional solutions wont save us : https://www.youtube.com/watch?v=F-QA2rkpBSY

Warning, its "Perhaps the most boring video you'll ever see, and definitely the most important."

Your remark about finite resources made think about this video about the exponential funtion:http://m.youtube.com/watch?v=F-QA2rkpBSY&desktop_uri=%2Fwatc...

Excellent. Reminds me of the lecture describing that "the greatest shortcoming of the human race is our inability to understand the exponential function"

http://youtu.be/F-QA2rkpBSY

⬐ wes-k

Thanks for sharing this! Albert Bartlett does a wonderful job explaining the consequences of sustained growth rates.

I find overpopulation to be one of the greatest concerns that we are not adequately dealing with. Albert's bacteria in a bottle analogy made me think of Elon Musk's attempt to bring human life to other planets.. will we not just be expanding our time of growth? Maybe we should start choosing a way to reach a population growth rate of 0% and see what countless problems are resolved.

⬐ Ygg2

If you think overpopulation is a real problem, then you have no knowledge of statistics[1], which makes me doubt everything else you said. We'll probably have problem with underpopulation, not overpopulation.

[1]http://xkcd.com/605/

⬐ foxylad

I didn't understand why everyone was wittering on about sustainability until I read "Collapse" by Jarod Diamond. It illustrates how dangerous it is to ignore sustainability, and how rare it is in human societies.

It seems to me that we have a choice:

1. Figure out how to cut our population growth to 0%, and then educate everyone on the planet as why they should do this instead of breeding to the max. Our kids will be happier than us.

2. Breed to the max until everyone on earth (and maybe Mars) is only just hanging on by their fingernails, probably living extremely unpleasant lives of violent competition and constant starvation. Our kids will be less happy than us.

Sadly I think option 1 is unlikely due to the tragedy of the commons.

You are not alone: www.youtube.com/watch?v=F-QA2rkpBSY

on this topic - this is a video worth watching http://www.youtube.com/watch?v=F-QA2rkpBSY

There's an interesting lecture from Albert Bartlett [] on the same subject, but he uses the value of 70 to calculate the years to double. [] http://www.youtube.com/watch?v=F-QA2rkpBSY

It's worth bringing up The Most Important Video You'll Ever Watch [1], which the lecturer characterizes as humanity's biggest problem is our inability to understand the exponential function. Watch all 8 parts.

I have come to the conclusion that there simply are too many of us. We can probably sustain our current levels for a century, maybe two, but at some point scarce resources (and their subsequent cost) will have a devastating effect.

Basically, we need to correct our population before nature does.

As much as people point to space being our future, I simply (sadly) do not agree. While there might be plentiful resources in the asteroid belt (and on other bodies) nothing compares to how cheaply we can pull things out of the ground here on Earth. Our society is predicated on cheap, plentiful resources such that it can't survive them being several (or even one?) order of magnitude more expensive.

As far as interstellar space goes, even if we solve the reaction mass problem and have perfect (100% efficient) conversion of matter to energy, it will still be prohibitive to go to even the nearest stars.

Perhaps the simplest explanation of the Fermi Paradox is that potential growth for a starfaring civilization is geometric (being a sphere ultimately limited by the speed of light) while growth rates are exponential. And exponential will ultimately "win".

[1]: http://www.youtube.com/watch?v=F-QA2rkpBSY

⬐ snowwrestler

The world population growth rate is not exponential; in fact it has been declining for decades. It seems increasingly possible that the human population will stabilize or even decline in this century.

⬐ im3w1l

The strongest selection pressure in the western world is for people to spend every waking hour making babies. It sounds very likely that population growth will pick up its pace this century unless it is actively prevented.

⬐ tsotha

And yet all indications are that's not what happens. The most likely scenario is by mid century the world population will be in decline and continue to do so at an accelerated pace until at least 2100.

Medicine has given us control over our fertility, and the way modern societies are structured children are a financial liability.

⬐ Dove

The strongest selection pressure in the western world is for people to spend every waking hour making babies.

True as that may be, people are not acting the way that would lead you to expect.

World population appears to be on a logistic curve --

http://en.wikipedia.org/wiki/Logistic_function

http://en.wikipedia.org/wiki/File:World-Population-1800-2100...

-- and birth rates for a lot of the world are close to or below replacement.

http://en.wikipedia.org/wiki/Fertility_rate

The selection pressure is real, but it is not the only force in play. Economic pressure is acting too, and it is against raising children; they are expensive to raise to adulthood, and you cannot derive any material benefit from them. It seems to me that, in this case, the economics have much greater force than the genetics. Whatever disposition toward childbearing you inherit from your parents, whether genetic or ideological, is a small thing compared to whether circumstances make providing for them practical.

In general, when dealing with a complex system, it is not enough to know that a single force is acting on it. You need to understand all the forces, and how strong they are and how they behave. All too often, this is the case with selection pressure arguments -- supposing that the force in question is the only one in play, without any regard for whether it has the power to do the job expected of it.

I find that the best course of action is usually to look at the actual data, and see how the system really is behaving, apart from theory. Nontrivial systems very rarely meet naive expectations.

⬐ InclinedPlane

Psssst. Want to know a secret?

More humans doesn't equal less resources, it equals more resources. The Earth isn't "running out" of anything, the idea of a carrying capacity for a technological species is ridiculous.

⬐ wazoox

You're exemplar of this video subject: exponential growth can't go on forever, and you obviously didn't understand that. That's quite sad. Another article for reference:

http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-e...

⬐ InclinedPlane

I have a degree in Mathematics, TYVM.

Human population isn't growing exponentially, only pseudo-exponentially.

⬐ wazoox

Resource consumption is growing exponentially. That is the real problem.

⬐ csomar

Sorry, I'm not an expert in that kind of stuff. But since resources don't get out of Earth, then the total loss of resources is 0.

Resource consumption is growing exponentially

Hmm, really? My computer is thinner, so is my TV (and probably my future car), I don't purchase paper any more (or almost don't purchase/use it) and I consume more digital products than physical ones. Yet, even if I purchase double of what I have the next year, I can't keep in that pace for too long.

⬐ wazoox

> But since resources don't get out of Earth, then the total loss of resources is 0.

Soil washed down to the ocean is lost to agriculture, if not lost to the planet itself, for instance. I'm quite sure that the planet will be OK whatever we do; the human race, however, may disappear quite easily.

> Hmm, really? My computer is thinner, so is my TV

Yes, and to build a new computer uses infinitely more than not building it in the first place. Your old computer isn't magically transformed back into a new one, or ore.

Every transformation needs energy. As long as energy is so cheap as it can be considered free and so largely available as it can be considered like infinite, everything's fine.

Just to remind you that a "service economy" relies on large, general availability of masses of almost free energy and resources. However, energy may soon turn more expensive and rarer.

We've been in peak oil for the past few years, and the production will began to drop any time now, probably within 3 to 5 years. There are no credible alternative to cheap fossil fuels, unfortunately, for most of their uses (transport, plastics, chemicals, fertilizers...).

So far, the way the world economy is currently organized cannot survive a massive change in energy availability. Particularly with the current accent put on economic growth. By definition, economic growth must stop at some point, by lack of resources, then go down. In the near future, economic recession will be the normal state of matters. How will we manage it? Without sinking into chaos? I really have no idea.

⬐ Game_Ender

Energy is the only resource that matters. With enough energy and technology we can recycle and transform whatever current raw physical materials we have available, no matter how inefficient it is.

With the population leveling off, I think the amount of physical materials needed at any one time will stop growing exponentially. Consumption will rates will still be increasing, but we can recycle the raw materials to keep the absolute amount needed within physical limits.

⬐ zmj

> Perhaps the simplest explanation of the Fermi Paradox is that potential growth for a starfaring civilization is geometric (being a sphere ultimately limited by the speed of light) while growth rates are exponential. And exponential will ultimately "win".

I read a paper within the last few months that used simulated expansion into a galaxy to debunk that idea. The fallacy is that growth is continuous and ceases simultaneously across a civilization. The (simulated) reality is that only a tiny percentage of frontier colonies need to survive to prevent extinction and eventually resume growth.

I wish I could find the paper. Anyone know the one I'm talking about?

⬐ huherto

Is it an exponential function or a simoid?

⬐ radu_floricica

Don't remember if the video addresses this (saw it years ago), but aren't most exponentials just part of the ever-present logistic curve? ( http://en.wikipedia.org/wiki/Logistic_function )

⬐ astrofinch

That video is a joke for anyone who has more than a superficial understanding of math. Just because a process has fit an exponential curve does not mean exponential growth is going to continue forever. Past growth patterns are fairly weak evidence of future growth patterns. ("Housing prices always go up!")

That's not to say we shouldn't fear a process that is inherently exponential in nature, like the reproduction of bacteria or a nuclear reaction going supercritical. But if the process only appears from the outside to have been growing exponentially, that's only a weak indicator that it will start behaving in an insane fashion.

In any case, it seems that as nations become more developed people stop having kids:

http://www.overcomingbias.com/2010/11/fertility-the-big-prob...

⬐ pbhjpbhj

The demographic transition might slow population growth, but for how long? http://www.nature.com/nature/journal/v460/n7256/abs/nature08... suggests that populations passing through the DT eventually recover and begin to grow again.

There's not a clear causality either.

⬐ astrofinch

It says their fertility rate goes up; there is no mention made of it surpassing the replacement rate.

⬐ pbhjpbhj

Suggests.

From the full paper:

>"* Morespecifically,ourfindingsreduce,if notyetcompletelyreject,fearsofpopulationdeclinethathavebeenincorporated inmanynationalpopulationforecastsforhighlyadvancedcountries.Nevertheless,weexpectcountrieslaggingbehindintermsofdevelopmenttocontinuetheir fertilitydecline,consistentlywithcurrentscientificknowledge.Moreover,some countriesatintermediatedevelopmentlevelsarelikelytofaceadeclineinpopulationsizebecausethesecountriesdonotyet—andmaynotintheforeseeable future—benefitfromthereversalofthedevelopment–fertilityrelationshipthathas occurredatadvancedHDIlevels*"

http://ccpr.ucla.edu:8080/CCPRWebsite/events/ccpr-previous-s...

⬐ wazoox

> Just because a process has fit an exponential curve does not mean exponential growth is going to continue forever.

Did you watch the video? This is precisely what it's talking about. Though the economy and energy usage have grown up exponentially for the past two centuries, we cannot hope that it will go on forever. Population growth isn't a concern per se, resource overconsumption and the impossibility of future economic growth are.

⬐ crististm

Resource consumption is directly related to population. So if the latter is not a concern then neither the first.

As Tyler Cowen points out in "The Great Stagnation", maybe these first 20 doublings or so were the low hanging fruit.

Kurzweil keeps saying that people underestimate exponential processes (its also the topic of "The most important video on math" [1]), but I think it cuts both ways. It is by no means clear that the next 20 doublings will proceed at the same rate as the last 20.

People might just say, "Siri via the cloud is good enough for me, I don't need Siri running directly on my phone".

[1] http://www.youtube.com/watch?v=F-QA2rkpBSY

Not sure if you've seen this series: http://www.youtube.com/watch?v=F-QA2rkpBSY (despite looking/sounding boring at the start, stick with it; it's really captivating and interesting), but it is amazing just how much 'small' growth (even 2-3% p/a) can cause things to double in much less time than you'd imagine.

Or if you haven't got the time to watch the whole thing (is close to an hour all in all), this touches on a couple of the topics the video covers: http://www.worldpopulationbalance.org/exponential-growth-tut... (naturally doubling every minute is on a much faster scale to the Human population!)

Reading things like this always brings me back to the Fermi Paradox [1]. There are lots of stars in our galaxy. Our observation of many nearby planetary systems and our understanding of the chemistry of life suggests life should be relatively common but we've seen no evidence of it.

While life (on Earth) is at times incredibly resilient it's also really fragile. A supernova such as this must essentially sterilize space for light years around it and it bathes its neighbourhood in gamma radiation. Did this kill off some nascent civilization? Supernovas seem to be relatively rare (compared to the number of stars) but think: over billions of years what are the odds that such a thing--or something equally as deadly such as an asteroid or comet impact--won't happen?

Space in incomprehensibly vast. The energy required to travel to even the nearest star systems seems... prohibitive.

I'm inclined to think that there are also simply too many of us on this planet, a problem that we'll either correct or will be corrected for us as resources start to run out in the next century or two [2].

[1]: http://en.wikipedia.org/wiki/Fermi_paradox

[2]: http://www.youtube.com/watch?v=F-QA2rkpBSY

Yes, an aging population might be worrisome on the surface, but I find overpopulation more worrying. Therefore, I am happy that people in really populated countries are having less babies overall!

http://www.youtube.com/watch?v=hM1x4RljmnE

Longer (but more boring) version: http://www.youtube.com/watch?v=F-QA2rkpBSY&feature=relat...

If you haven't previously seen Dr. Barrett's "Arithmetic, Population, and Energy", I strongly recommend it: http://www.youtube.com/watch?v=F-QA2rkpBSY

It doesn't address quite the same scale, but is very sobering.

Arithmetic, Population and Energy: http://www.youtube.com/watch?v=F-QA2rkpBSY

⬐ danparsonson

Ah, the power of the exponential function - well worth a watch

Like in these videos? http://www.youtube.com/watch?v=F-QA2rkpBSY

Your discomfiture is well placed:

  http://www.youtube.com/watch?v=F-QA2rkpBSY

The world is mostly logistic curves, but the ponzi needs us to all believe in exponential curves.

⬐ encoderer

TY for the link. Another example of a great lecturer being able to make up for a dry subject matter.

⬐ swombat

Just a clarification for those (like me) who didn't get it:

A logistic curve is basically an S-shaped curve, also known as a sigmoid.

Looks interesting. You should submit it on its own. In fact combined with The prof. Bartlett videos (http://www.youtube.com/watch?v=F-QA2rkpBSY) it makes quite a good usage of arithmetic to counter McCarthy point of view.

I have read through these pages. Undoubtedly many of the things he states, particularly with respect to how long nuclear energy could supply us, are correct but only under the assumption that we don't continue to increase our usage of energy. It's hard to see how that assumption holds in a world that is continually growing its economies. Exponential functions grow very fast. (See http://www.youtube.com/watch?v=F-QA2rkpBSY)

You may then counter that a decoupling of economic growth from its material and energy underpinnings is possible. This has yet to be effectively proven. We have only seen partial decoupling so far. For more information on this see the writings of Tim Jackson in his book Prosperity without Growth.

I also urge you to download this spreadsheet (from the BP website) showing the growth in usage of fossil fuels (http://tinyurl.com/2yhx7d). We may find alternatives to these but if we do, we will have to bring the alternatives online at roughly the same level to supply our societies with the energy they now require to function. This is no easy feat. It's good know, quantitatively, just what's required.

I would urge you to watch this video on how these kind of claims can be made : http://www.youtube.com/watch?v=F-QA2rkpBSY

My thoughts:

1. IMHO learning a second language will largely be no longer necessary because English will increasingly be the lingua franca. That being said, on the fly translation will clearly continue to get better.

2. 150 year life expectancy? This one I don't buy. Medicine here has to be differentiated in two areas: curing and preventing the causes of "premature" death (eg disease) that stop us reaching a "natural" age when we die. That lone won't get us to 150 years. We're probably not far off that limit now. To get to 150 we need to extend the age to which humans can live, which is getting into some fairly serious genetics. I can see such technology coming about but IMHO will be the province of the wealthy for some time and will probably take longer than expected (again IMHO).

3. I disagree with this. Despite all the efforts to stop poverty, even in developed nations, there is a segment of the population who remain poor. It might be controversial but a certain segment (IMHO) are poor and remain poor because they make poor choices.

Also, the definition of "poor" constantly changes. Poverty in the developing world is lack of access to basic health care, food and clean drinking water. In the developed world, poverty seems to mean your iPhone is two generations old.

And yes I realize there is true poverty in the developed world. There are people who are homeless but the scope of "poverty" in such discussions extends way beyond those when we're discussing social policy.

4. Possible. Food production will need to change.

5. Agreed. I think future generations will look back on this age of manually driven cars as being somewhat barbaric, especially considering the number of people who die on the roads.

6. I also agree that the world's will become increasingly urbanized and you will see "mega-cities" as a result. There are efficiency advantages in concentrating populations in such cities.

7. I was just having a conversation with a colleague at work on Friday about flying cars. My position was (and is) that personal flying vehicles won't happen before driverless cars. Humans won't simply be able to reliably fly such vehicles. Also, the energy costs I believe will possibly scupper such plans so we need to find a far cheaper source of energy for this to happen, especially considering we've probably passed peak oil production.

8. This too is dependent on finding a new, cheaper energy source. Without that space travel will (IMHO) still be too expensive.

9. I think this will be partially true but human labour is extraordinarily cheap and will be incredibly hard to completely displace. It's the same reason we still have humans doing incredibly menial work even when such work could be done by robots, that are comparatively much more expensive.

10. Probably true.

Predicting the future is hard. 1900 to 2000 had a massive amount of change, unparalleled in human history. Think about it: we went from the birth of the automobile to handheld computers, putting a man on the Moon, the global Internet and cheap, almost ubiquitous air travel. How much of that could've been predicted?

What's more, how much of that is on the back of cheap non-renewable energy that is ultimately unsustainable? Not just energy, but other resources like metals. The rate at which the world population is growing and using resources is unsustainable so something has to change: whether it be new energy sources are found or the population problem corrects itself.

I seriously urge you to watch:

http://www.youtube.com/watch?v=F-QA2rkpBSY

if you haven't already.

If you think of sci-fi as a predictor of the future (which it has been in many ways), we've vastly exceeded predictions in some fields (eg computers) and vastly underperformed in others (eg space travel). I heard Jerry Pournelle talking abot this with the predictions from the Mote in God's Eye. The handheld computers exist now, being smartphones, less than 40 years after the book was published. But in space travel terms, we're, if anything, behind what we were in the 20th century.

To me the predictable aspects of the future are:

1. Urbanization;

2. Ubiquity of computing and networking;

3. Genetic engineering.

Other things depend on the big question mark that is cheap and abundant energy. We may not find anything, in which case the future will be bleak. If we find something however the world will change beyond recognition.

⬐ manifold

I agree that a 150 year life expectancy is very unlikely in the next 20 years, but the possibility of people who are alive in 2030 reaching 150 seems plausible. I think that's the argument de Grey was making, and their source article had confused the two issues.

⬐ bergie

It will be interesting to see if urbanization of the third world will have positive impact on the environment. Better efficiency and less human intrusion on natural habitats

⬐ acangiano

I believe most of these points will become reality, but some of them by 2120 not by 2020.

⬐ Mz

2. 150 year life expectancy? This one I don't buy. (etc and stuff about "only the wealthy"...)

I don't know. I have a condition with a life expectancy of 36 or 37 and I'm 45. I nearly died at age 35 1/2, then was finally diagnosed shortly thereafter and have spent the last almost ten years reversing the damage. I'm currently healthier than I have ever been. I'm not wealthy and never have been.

I think the information is already available to do amazing things in that regard. Most people just don't believe it and don't pursue it.

⬐ Symmetry

2. Why do you think that only the wealthy will have access to these treatments? Its quite likely that some number of people won't have access, but most new medical technologies are available to most people because the largest cost of any new medical technology is its development. For some disease that everyone suffers from I wouldn't expect the treatment to end up costing more than, say, your typical run of chemotherapy. Something expensive, but that should be covered by most health insurance.

3. He gave an objective definition of "poor" he was using in his prediction, and while I agree that completely eliminating poverty might be impossible getting it down to 1 in 50 seems doable.

EDIT: Edited for clarity.

⬐ derleth

> Why do you think that only the wealthy will have access to these treatments?

To begin with, the companies providing them will have to reach break-even and, in a field like biotech with huge up-front costs, that means making a lot of money from the first clients. Rich people have a lot of money.

> Something expensive, but that should be covered by most health insurance.

Then we're talking about different things. How often does health insurance pay for treatments that are still somewhat unproven in the real world?

> He gave an objective definition of "poor" he was using in his prediction

Right, and everyone seems to ignore the fact that, as measured on an objective scale, how a culture defines 'poverty' creeps up that absolute wealth scale as the culture's wealth grows. For example, at one time kings and rich industrialists could die of appendicitis; now, only the most desperately poor are so deprived of healthcare that having an inflamed appendix is a death sentence.

⬐ J3L2404

>The greatest shortcoming of them human race is our inability to understand the exponential function.

Nice demonstration of rates of growth.

⬐ RiderOfGiraffes

You might be interested in the lengthy discussion from a previous submission of this item:

http://news.ycombinator.com/item?id=1382456

To temper this pessimism with some sobering reality, on another HN thread today I was pointed to this:

http://www.youtube.com/watch?v=F-QA2rkpBSY

Well worth watching.

Somehow, some time the population is going down. Way down.

http://www.youtube.com/watch?v=F-QA2rkpBSY really demonstrates the elegance of bolo ties.

Great rule, should be the very first thing taught in high school when you get to exponents.

Dr. Albert Bartlet of University of Colorado has an excellent lecture on its implications for population growth, environmental degradation, and other big picture problems:

http://www.youtube.com/watch?v=F-QA2rkpBSY

http://www.youtube.com/watch?v=F-QA2rkpBSY

⬐ mhartl

Before people freak out about exponential growth, please consider John McCarthy's Slogan. (Yes, that John McCarthy; Lisp isn't the only thing he's done.)

  He who refuses to do arithmetic is doomed to talk nonsense.

http://www-formal.stanford.edu/jmc/progress/index.html

Based on reactions to this video (among other things), I'd add Hartl's Counterpoint:

  Just because you're willing to do arithmetic doesn't 
  mean you're not talking nonsense.

In case you're wondering why you shouldn't freak out, I offer you this: http://en.wikipedia.org/wiki/Logistic_function

⬐ gursikh

Dr. Albert A. Bartlett is fully cognizant of that point. He says in part 8 of that video:

  "Except for the petroleum graphs, the things I tell you are
  not predictions of the future. I am only reporting facts and
  the results of some very simple arithmetic." (1:22)

He acknowledges the potential fallibility of his estimations. He goes on to say:

  "Please you check the facts. Please check my arithmetic. if
  you find errors, please let me know. But if you don't find
  errors, I hope you take this very very seriously."

⬐ seabee

The video also makes the point that people are ignorant of the exponential function's effect, believing that constant growth is possible, when it clearly is not.

The Dr. also mentions that 0% growth is inevitable, so that is covered - but I had no idea it was called the logistic function, thanks.

⬐ rsheridan6

In the context of population growth, the logistic function means that something has made it stop. He dealt with this is the second video - he says we'll get zero population growth one way or another, because exponential growth forever is impossible.

Around minute 7 of the second video (did you actually watch it?) he points out that many of the checks on population growth are generally considered bad things - war, famine, disease (the alternative being birth control). This is hardly a reason not to freak out.

⬐ mhartl

did you actually watch it?

Yes.

many of the checks on population growth are generally considered bad things - war, famine, disease

The countries with the lowest population growth (e.g., Germany, Italy, Bulgaria, Japan) are among those with the least war, famine, and disease. Something else is going on.

⬐ presidentender

Do you notice that the countries with the lowest population growth were severely battered in wars during the last century?

⬐ mhartl

Italian birthrates aren't low because of Il Duce. Once people reach a certain level of wealth, they voluntarily stop having lots of kids.

⬐ BoppreH

There were many other reasons listed, including low immigration, small families, contraception/abortion, abstinence and pollution.

This checks do apply do the countries you cited, but the list is still far from comprehensive. They are far better than war, famine and disease, but still regarded as bad things, which is the point.

⬐ mhartl

The dominant source of low birthrates in rich countries is people choosing to have smaller families.

⬐ abrahamsen

To the point: What seems like exponential growth often turn out to be better described as S-curves.

⬐ fburnaby

The reason that the curve levels out for biological populations is that the rates at which members start starving to death or killing each-other increases to cancel out the birth-rate. That does seem to be of some concern.

⬐ wazoox

Huh. This guy is simply making the very basic point that politicians, economists and bankers selling us "growth" as a solution to unemployment, debt, etc are plainly lying. Growth (population, GDP, energy availability, etc) will stop at some point. An economy that relies entirely on growth to merely function is doomed to fail spectacularly at some point in time.

⬐ fgf

nuclear power could deliver far more energy per year than is used yearly now for thousands of years. Innovation makes energy more useful. When the potential for growth these two cause is exhausted there's scifi stuff; solar power from satellites around the sun; fusion; etc.

⬐ seabee

Right, but it's still finite to some degree, and selling people on growth which we cannot guarantee is possible is just plain irresponsible IMO.

⬐ anamax

> Right, but it's still finite to some degree, and selling people on growth which we cannot guarantee is possible is just plain irresponsible IMO.

Do you plan as if disk drives won't get more capacity? That ram and cpus won't get cheaper?

It's only irresponsible if you promise growth that won't happen. It's irresponsible to ignore growth that will or can happen.

⬐ LiveTheDream

Is it still lying if you don't know that you are wrong?

⬐ dagw

I agree that population growth cannot go on forever (although I consider doubling the current number quite likely). However I see no reason why energy availability can't keep growing for many many centuries to come. We aren't tapping the full potential of nuclear fission, to say nothing about fusion. Things like solar energy in all its variations is also a source we basically aren't using at all. Give us 50-100 years an we'll no doubt come up with some new source of energy we haven't even considered yet.

⬐ wazoox

> However I see no reason why energy availability can't keep growing for many many centuries to come. We aren't tapping the full potential of nuclear fission, to say nothing about fusion.

Nuclear fission is currently on decline. We aren't even building enough power plants to maintain its output, nor are we likely to do so in the next 20 to 30 years. Industrial nuclear fusion is decades away, probably a century.

From the 18th century onwards, we went from tapping ever better energy sources (denser, lighter): animal power, coal, oil. There aren't any better energy source than oil available now, or in the foreseeable future. At some point, we'll have to do with /less/.

⬐ pjscott

> Nuclear fission is currently on decline. We aren't even building enough power plants to maintain its output, nor are we likely to do so in the next 20 to 30 years.

Define "we". Take a look at China's nuclear power program sometime; they've brought the cost of their CPR1000 plants down to where they're cheaper to build than coal plants of the same size, and they're well on their way to do the same for the more modern AP1000 reactor design. They've got a bunch of new nuclear plants under construction, with more on the way as they pick up momentum. We're talking about 10-15 large reactors coming on line every year, with the production rate increasing as they ramp up.

Also, they've got their first commercial-scale pebble-bed reactors being built right now. If I remember correctly, they're also looking at incorporating thorium into the fuel mix.

Also, they're working on 40% and 70% more powerful versions of the AP1000 that will not add much to the cost. Nuclear power in China is going to be seriously cheap.

Also, they're working on fast breeder reactors, which use uranium much more efficiently. They're building two BN-800 reactors, working together with Russia, since Russia has been profitably operating fast breeder reactors in the BN series for decades.

If you're only looking at the US and Europe, then sure, the Nuclear Renaissance is looking a little feeble. But the US and Europe are not the whole world.

⬐ Daniel_Newby

"At some point, we'll have to do with /less/."

This part of the long business cycle always produces a lot of arguments for austerity. So far they have always turned out to be spectacularly wrong.

"Nuclear fission is currently on decline."

Nuclear power, both fission and fusion, is currently in a renaissance and we appear to be laying the groundwork for the next stage of advances: gas- and metal-cooled reactors, superconductors, mechanical compression systems, reliable mode-locked lasers, dielectric wall and wake field particle accelerators, electronics that can do real-time gigahertz feedback, etc.

When the next long expansion gets into full swing, I predict that the nuclear logjam will break loose.

"There aren't any better energy source than oil available now, or in the foreseeable future."

There's a lot of solar power in space. A lot. And literal mountains of metal, richer than the best terrestrial ores and pre-smelted too. At some point technology will tip the profit margin positive on exploiting it.

⬐ wazoox

> So far they have always turned out to be spectacularly wrong.

So far, there weren't 7 billions humans neither.

> Nuclear power, both fission and fusion, is currently in a renaissance

Absolutely not. This is GE and AREVA PR, but doesn't reflect the truth. We aren't building enough nuclear plants now to compensate for the future closing of the old ones. The numbers aren't even ramping up fast enough. As time goes by, there will be less and less active nuclear plants.

Fusion research is blooming, but it didn't make much progress, particularly compared to the huge effort (see ITER).

> There's a lot of solar power in space. A lot. And literal mountains of metal, richer than the best terrestrial ores and pre-smelted too. At some point technology will tip the profit margin positive on exploiting it.

This is science-fiction. I'm pretty close to say this is complete BS. "Space ore" simply can't happen unless you find the way to harvest the power from some magic ponies yet to discover.

⬐ Daniel_Newby

"We aren't building enough nuclear plants now to compensate for the future closing of the old ones."

Which is an intentional choice, arising from a combination of ennui, defeatism, and witch hunting. Those political movements seem to have run their course.

"Fusion research is blooming, but it didn't make much progress, particularly compared to the huge effort (see ITER)."

Most of the tokamak megaprojects were done to give academics a safe way to demonstrate activity. ITER is the plasma physics version of string theory. In my opinion, the real progress has come from small quiet projects involving vacuum physics and power electronics.

"'Space ore' simply can't happen unless you find the way to harvest the power from some magic ponies yet to discover."

It's metal, not ore. If you can lay your hands on asteroidal metal, you can turn it into useful articles with a blacksmith's forge. Fancy alloys and precious metals are more effort, but often easier than dealing with crappy terrestrial ores.

The magic pony is to cancel the failed Shuttle, yet another stagnant megaproject. And avoid replacing it with other doomed megaprojects. The barrier to space activity is heavy lift capability to get there at all. Once you can get above the atmosphere cheaply enough, the solar system is your oyster. (It's like Fed Ex. The capital investment to build Fed Ex is ludicrous, but once somebody has the balls to do it, entire industries rise up from nowhere to exploit it.)

⬐ wazoox

> The barrier to space activity is heavy lift capability to get there at all.

Pipe dreaming. The barrier to space is the _tremendous_ amount of energy required to get anything to low-earth orbit, let alone getting raw material going back from Jupiter's vicinity. Even with 1000 times better technology (which won't arrive soon), your asteroid iron still will be costlier than platinum.

Science-fiction is mostly fiction, you know.

⬐ Daniel_Newby

Nope. The energy cost is trivial. The cost of joules for a vacation to Europa is within upper middle class aspirations. It only costs so much because our lifters are hideously inefficient.

The reason rockets are so inefficient is that we don't know how to keep cracks from spreading through our structural materials, so we have to derate their strength by huge factors to get reliability. Nano- and micro-composite materials look like they will be able to vastly improve this situation (and indeed already are in the latest jetliners), and the rocket equation gives big big cost savings for weight savings. High strength materials are also good for rotovators and other semi-passive lifters.

Another big opportunity is to shift some of the propulsion to the ground. It should be straightforward to shine launch lasers up the tail of a standard rocket and reduce its propellant requirement by many percent, which the rocket equation then multiplies into a large cost savings. Exclusively laser launched vehicles are also possible but speculative at this point (they need visible light lasers to get range but those are still too inefficient). Most of the necessary technology exists or can easily be built. All we lack is the optimism to make the investment.

As for getting metal back, the asteroid belt is energetically close despite the distance. A small nuclear reactor and patience will do the job.

⬐ dagw

I totally agree that we aren't building enough nuclear power plants, but that is purely for political reasons. The research is still happening and once there is a change in the political climate we'll be able to ramp up nuclear power over a few decades.

Also if we look back at the past 1000 (or even just 100) years of human history, we've been pretty good at discovering and harvesting 'magic ponies' of all shapes and sizes.

⬐ wazoox

> we'll be able to ramp up nuclear power over a few decades.

Maybe if thorium comes on the radar.

> we've been pretty good at discovering and harvesting 'magic ponies' of all shapes and sizes.

Well, not that much. By the end of the roman republic, most of what made the industrial revolution possible was available, but it didn't happen until 18 centuries later.

⬐ dagw

While Thorium reactors are cool and all, they aren't necessary. It's not like we're about to run out of uranium any time soon. Hell, you can take your basic 1970's uranium reactor, incorporate everything we've learned about nuclear safety over the past 40 years, throw in some generic improvements to basic turbine technology and have a fully functional power plant that will do a splendid job for decades to come.

⬐ wazoox

And still no proper way to manage nuclear waste.

⬐ CamperBob

I know! We can vaporize it and spew it into the air, like the coal industry already does with their radioactive waste!

⬐ pjscott

Here are some options. Forgive my brevity, but I'm tired of people simply asserting that there's no way of managing nuclear waste.

* Throw it away. Deep-sea subduction zones work nicely for this. Tremendously wasteful, though; that "waste" is valuable fuel.

* Recycle the waste to decrease its volume. This isn't a full solution, but it makes the waste cheaper to store for a while.

* Store the waste for a while, and later we can use it in breeder reactors or fusion/fission hybrids. There's so much useful U-238 in that slightly-used fuel. After this, the waste is pretty much dead.

⬐ wazoox

I'm tired of this toon and particularly of the general political atmosphere on HN (technology will solve all problems! yay!).

If it's so easy to get rid of nuclear waste, why didn't we do it yet?

⬐ whughes

So far, technology has solved all problems. What else is there?

⬐ sesqu

GP just said. Because getting rid of it would be stupid - the current approach is building long-term storage.

⬐ infinite8s

Except about 200 years of science and math starting from the end of the Renaissance Period.

⬐ wazoox

The Antikythera mechanism (2 century BC) basically reset what we believed of science, mechanics and mathematical knowledge during antiquity. That, and some other things : Hero's Eolipyle, Nero's emerald monocle, Provence "industrial" mills... They had the ability, they lacked the will.

⬐ whughes

They lacked metallurgy, banking, agricultural technology... The Industrial Revolution was built on hundreds of years of slow progress and access to tons of natural resources. The Aeliopile was a toy that opened doors; it wasn't going to power any steamships.

⬐ infinite8s

There's a strange parallel to the evolution of life on Earth. Took about a billion years before the simplest single-celled organism developed all the basic mechanisms/components, and then a few hundred million years from complex multicelled organisms, and finally a huge explosion in diversity in the last hundred million years. I wonder if evolution and technological progress plotted on the same relative logarithmic scale would overlay each other?

⬐ mbreese

The ancient Greeks even had an initial stream engine, but never put it to practical use, relegating it to parlor/temple game.

http://en.wikipedia.org/wiki/Aeolipile

⬐ wazoox

That's what I mean : they had the ability to go to industrial age, they lacked the will, the impulse.

⬐ joeyo

Also, they had slavery.

⬐ anamax

> Nuclear fission is currently on decline. We aren't even building enough power plants to maintain its output, nor are we likely to do so in the next 20 to 30 years.

That's a choice, one that we could change.

There are no technical or economic obstacles to building nuclear plants for far less money and in far less time that are just as safe (or safer) than what we have now. (France is an existence proof for much of the potential savings.)

There are, however, legal and political obstacles.

⬐ jluxenberg

Neat math trick from the video:

70 / x = number of years of constant growth required for a quantity to double given that it grows at x percent

The example used in the video: if the price of lift tickets goes up by 7% per year, in 10 years, that price will double.

(and actually, the constant 70 is an approximation, the actual constant is ln (2) * 100)

⬐ chaosmachine

It's also a useful way to tell when your investments will double in value. 5% interest: 70/5 = 14 years to double your money.

⬐ Luc

It also works for inflation or other yearly recurring charges. Those small percentages add up quickly - at 3% inflation and 2% charges the value of your investment in today's dollars/euros will halve in 14 years. Yikes!

⬐ eru

Yes, but why use it, when you can do a logarithm?

⬐ sesqu

Few people can do logarithms in their heads - and those that can, usually do it using similar tricks. I realize that "doing math in your head" is well on the decline, but it is pretty essential for speedy approximations, which are what many decisions tend to be based on.

⬐ eru

Yes. I was more on the line of suggesting taking out your calculator, if you want to know when your investment doubles.

⬐ jefffoster

See http://en.wikipedia.org/wiki/Rule_of_72

⬐ jackowayed

I've thought about his point that lowering the death rate makes the problem of population growth worse a lot, especially in the context of Africa and the like.

"Oh they're starving because they get almost no rain, so that land really shouldn't support anywhere near as many people as are there. Let's give them food aid."

10 years elapse, and say they're getting 7% per year growth thanks to food aid keeping them from starving, lack of contraception, etc.

"Oh, there's twice as many of them now, so they're starving despite our current food aid. Double the food aid!"

Repeat until you realize that you can't double the food aid forever.

⬐ Flow

http://www.gapminder.org/videos/what-stops-population-growth...

⬐ JoshCole

In the video explaining exponential growth it talked about how we would need to abandon many things we deem good in order to avoid over population. This video puts things in less grim terms by pointing out that increasing the average life expectancy reduces the number of children per women.

⬐ Flow

Yes, and I think it's very possible that our energy consumption continues to grow, despite the number of people on Earth stabilizes. What do you think?

⬐ JoshCole

Eventually it would have to stop growing, but I don't know if it will cease through foresight or catastrophe.

⬐ ihodes

The trick is realizing that the last 3 words of your third sentence are the most important part of your slightly offensive post. That, and education.

Starving a people until they can eat off of the barren land they inhabit is certainly one way of taking care of the problem. Educating them on the merits of contraceptives, and teaching them how to use their land to greater effect is another.

⬐ mistermann

Africa is not a barren land, much of Africa is perfect for farming. Much of Africa is not "perfect" for farming, but well good enough. However, if you have external nations bringing you food for free, why the hell would you go through the trouble to grow a crop, it's seriously hard work!

And, if you're in the part of Africa where growing crops is not feasible....move?

⬐ iamwil

To add, there are unstable places in parts of Africa with civil wars that displace people into refugee camps where they can't do much farming.

⬐ skybrian

You realize that this isn't about renting a U-haul, right? It's about traveling, on foot or by public transportation, to somewhere where you don't own any land, don't speak the language, and don't know anyone. In other words, to become a refugee. There are plenty of people like that already, but they tend to move to the cities.

⬐ wendroid

I'm not offended by "them food aid."

⬐ jackowayed

It's not as easy as giving them contraceptives. Culture and pragmatism both frequently encourage large families.

For example, farming families have major incentives to have large families so that the kids can help with the farming tasks. So you'll need a China-like child limit or some other way to incentivize them to actually use the contraception you provide.

⬐ ihodes

I didn't say "just give them contraceptives."

That's why education is key as well. People who are well-educated have less children, on average. Look at the US, for example. So educate them, and enable them to become wealthy. Right now, they can't.

⬐ pbhjpbhj

>People who are well-educated have less children

But that doesn't mean that a well educated farmer will have less children. He can be as educated as you like but unless he can increase productivity in some way (access to loans for equipment say, like through Fairtrade) then he still has as much work to do and still needs to provide the labour.

Suppose the education increase yields, unless we're on top of the trading practices then the value falls - everyone's yield has increased, if this means the market saturates he might make less money (perhaps none). If the market hasn't saturated he still needs more labour to gather the increased yield but gets the same income to share amongst the labourers - increasing the pressure to provide cheap labour by expanding his family.

In short the problem is more complex and IMO is not due to lack of education. What you're saying is that a poor agricultural labourer should sacrifice there own ability to earn more in order to stave off over-population - why is it down to them.

I'll go with the converse though. If you ensure that workers get a fair wage (Fairtrade again), one that can pay basic healthcare and education costs and ensure they have healthy food intake and a reasonable dwelling, then there is less pressure to reproduce (but possibly more opportunity to choose to? again it's complex).

⬐ derefr

Then send them yams and pomegranates. ;)

(For those unaware, they both contain progesterone; wild yams were the first plant to be used in synthesis of birth control pills.)

⬐ fleitz

"We" won't need to give "them" food aid forever, population growth levels off as wealth increases. Possibly the best thing that could be done for Africa is to end farm subsidies and argicultural tarrifs in the developed world.

Here is a great link to the farm subsidies recieved in Manhattan, it's odd how one never notices the wealth of family farms surrounding central park. http://wildgreenyonder.wordpress.com/2007/10/

⬐ ericb

Possibly the best thing that could be done for humanity in the next hundred years is to solve the lack of empathy for individuals and groups of people we have not met. I think if you had some friends in Africa that would be affected by your solution, you would feel very differently.

I am not picking on you here--I think this is a failing in the way we're wired that some part of us (including me) can consider tragedy at that scale as a possible solution.

⬐ effn

Do you seriously believe that subsidies of western farmers is helping people in Africa? What is the "tragedy as a possible solution" you are speaking of?

⬐ ericb

Honestly, my mistake.

I read something that made sense to me which was that OP was objecting to subsidies to African countries--not subsidies for Western farmers. My objection makes no sense in the context of what OP actually said.

⬐ dhimes

Possibly the best thing that could be done for humanity in the next hundred years is to solve the lack of empathy for individuals and groups of people we have not met

I assumed that was one of the roles of religions, but they seem to have a difficult time getting the idea to stick in the majority of their believers.

⬐ bryanh

Though this is logically sound, the core issue remains. Are we to tell them a little starving and death now is good for you in the long run? I think it is extremely interesting to ponder where lines of morality lay on issues like this.

⬐ mistermann

Well, 1 thousand deaths now to achieve self sufficiency, or X deaths later, where x is likely much larger than 1 thousand.

Not to mention, why the fuck in this day and age is the west still responsible for African people eating? We have the technology, the entire country has been geographically analyzed for where maximum food can be produced, etc etc. It is not a geographical problem, it is a political and cultural problem.

It seems fairly obvious they can't sort out this problem, so whats the next move?

We can tell them where to grow food, and where not to. We have given them Billions of dollars in aid. What else can you do?

Of course, this is assuming foreign aid exists to achieve what it says it is trying to achieve....I can think of several groups of people that would like to keep Africa in the stone age for the time being.

However, this doesn't dismiss the responsibilities of the leaders and citizens of Africa. All the technology you need is available on eBay, how about some charismatic man rises up and convinces you to get your shit together?

⬐ crayz

We have the technology, the entire country has been geographically analyzed...

The entire country of Africa?

⬐ henrikschroder

But things are improving.

http://www.gapminder.org

The GNP and life expectancy of Africa is about as good as it was in the western world around 1930, that's not exactly stone-age, and the situation is steadily improving. They'll get there.

⬐ fleitz

The first step to answering that question is to start thinking of Africa as a continent full of individuals rather than through terms like "us" and "them".

Most answers in the affirmative involve a lot of rationalization and dehumanization and in the modern world likely some kind of starvation default swap sold by a financial institution.

We're all individuals sharing this planet. We are not our government(s). (Unless you're a head of state, then maybe)

⬐ pbhjpbhj

So if a vaccine for a deadly disease is not 100% safe then you wouldn't use it at all as actively killing 1% is worse than passively allowing 80% (say) to die?

When making considerations of the well being of whole populations one has to consider the whole population not the individual.

A decision to withhold food aid now might kill 10%, but supplying that food and buoying up the population until the next big crisis is likely to kill far more people and could push us beyond sustainability - there is a point at which renewable resources become to depleted to recover. Sure, one can consider that the Jones family will lose their daughter and so we have to send food but this leads us on and on to overpopulation.

⬐ fleitz

I would provide access to the vaccine and individuals could choose whether they wanted to take it.

It actually doesn't lead us to overpopulation. Once wealth & education increases to a certain point cultures change and people have fewer children. Paul Ehrlich went over this in the 60s and then made the famous wager with Simon over resources. I think this Malthusian argument has been thoroughly debunked.

The best result for the well being of whole populations is generally achieved by each person in that population doing what is best for themselves.

⬐ joeyo

I would provide access to the vaccine and individuals could choose whether they wanted to take it.

That actually is a really bad idea from a public health perspective. Generally you need well in excess of 50% of the population to be vaccinated before it starts to provide protection to non-vaccinated individuals.

See:

http://en.wikipedia.org/wiki/Herd_immunity http://en.wikipedia.org/wiki/Mathematical_modelling_of_infec...

⬐ prodigal_erik

I'm not usually a fan of long talking-head videos but this was absolutely worthwhile. What's most chilling is the story of the bottle and the bacteria, and the realization that somehow finding a whole new planet would only tide us over for a couple more generations, after which we'd need two more....

⬐ zemaj

But it's all considered in a vacuum. Even though the majority of the population don't understand the problem, this is ok. We have an economic system that benefits those who predict impending needs and place themselves in situations to provide for them.

Take a look at the green industry ramping up. In the not too distance future, I think most of us here expect oil replacement to be highly profitable.

I disagree with these doomsday predictions from pure arithmetic. It seems to me that the reverse is true - exponential "problems" provide the core drive for our economy. What drives the entire start-up industry? I'd say it's identifying profitable exponential growth scenarios and providing for them. To me, this explains how primarily capitalist countries tend toward stability, until them become strangled by ever increasing regulation (that's not to say I'm against regulation in general, but I think we need to be as proactive about removing it as we are about adding it [wow, I went off topic there]).

⬐ skybrian

Yes, many people are working on solutions, but I think the point is that for green industry to succeed, growth in energy consumption has to actually stop, and preferably reverse. It's good to be clear about about the goal.

⬐ seabee

To be clear, is this because green energy is (yet) incapable of satisfying our current needs, or purely because our ability to generate green energy is as finite as from oil?

⬐ skybrian

Actually, what I meant to say is that fossil fuel consumption has to stop growing and preferably decline. But there are limits to green energy too. For a British take on this: http://www.withouthotair.com/

⬐ ars

That's not a good goal. And besides not being good, it's also impossible if you are trying to avoid mass catastrophe.

Economic development directly correlates with energy use. To reduce energy use you would either need a massive depression, or for a lot of people to die.

But the news isn't all bad - nuclear power is both green, and sufficiently available to allow us to continue energy growth. So I would make that the goal.

⬐ code_duck

No, to reduce energy use you'd need for people to take conservation seriously and to dramatically improve efficiency. Plenty of energy is wasted on inefficient cars, poor insulation, wasteful industrial processes, and so on.

⬐ skybrian

In the short term, sudden changes in energy consumption are very disruptive. (For example, see gas prices and the auto industry last year.) But a longer-term, gradual shift towards less energy usage need not be.

⬐ oops

Note that he does say in the video that these are not predictions* , and that it's just arithmetic. He goes on to pretty much agree -- in a less specific sense -- with what you've said: "the consequences of the arithmetic will play a major role in shaping our future."

* Except for the petroleum graphs. Video 8/8 1:00-2:00ish.

⬐ KingOfB

I agree to some degree. I feel like this guy thinks he's playing sim-city and setting the population growth rate. Tell me he doesn't remind you of the domestic advisor!

⬐ wazoox

> To me, this explains how primarily capitalist countries tend toward stability

Except that doubling GDP, resource consumption, etc every 20 years hardly can be called "stability".

⬐ barmstrong

Certainly a great video.

But one thing I didn't like about the bacteria in the bottle story was that he conveniently switched to 100% growth for that example. And then made it sound like Boulder was in the same position "it's 11:59 in the Boulder valely" etc.

But still his main point it dead on.

⬐ sesqu

Well, he had just prior spent some time explaining how to convert any growth rate to 100% just by scaling the time axis. So when he says it's 11:59, he means it's 10 years (or whatever) to the end, if one were to assume constant growth.

⬐ samdk

I'm reminded of Isaac Asimov's short story The Last Question (http://www.multivax.com/last_question.html), which deals with very similar issues on an entirely larger scale.

⬐ DaniFong

There is no sustainable growth without sustainable decay. Makes you wonder about those financial systems based on economies with compounded interest -- exponential growth -- which are supposed to be resident on a finite planet.

The population bomb is kinda heading the other direction though. People moved to cities, where kids were a liability instead of an asset, life was exciting, and women had opportunities. Now birth rates in modernized countries are below the replacement rate (which causes exponential decay as impactful as exponential growth), which is largely made up through immigration.

In the limit case, birth rates in modernized countries are close to zero, and the entire population is comprised of newcomers from the places that are above the replacement rate. These countries could places for opportunity, not familyeither be like companies (where people work and live much of their lives but don't replenish themselves), or they could be like retirement homes.

⬐ zitterbewegung

So the real problem is people don't understand the logistic function? http://en.wikipedia.org/wiki/Logistic_function

⬐ jackowayed

The best illustration of the concept, imo, is that with sustained 1.3%/year world population growth, we'll reach a population density of 1 person per square meter of land in only 780 years.

⬐ robryan

At some point though there will be some kind of event to bring this down. Might be a population number or a resource usage spot, very unlikely to the world could remain at peace as certain countries loss large chunks of people to famines ect, people that have nothing to live for wouldn't want to go down without a fight.

⬐ redorb

give me some context; how many meters per a person are we at currently? / Then give me some focus; what will it be at in my life span... 50 years?

⬐ jackowayed

The population will increase by a factor of exp(.013780) = 25336.5

So we should be at roughly 25,336 meters / person currently. (But remember that plenty of that is more-or-less unlivable--Siberia and the like.)

In 50 years, the population will have increased by a factor of exp(.013 50) = 1.91554, so in the next 50 years population will roughly double, so that number will go down to about 13k meters/person.

⬐ rjett

Using data from the 2000 US Census, Manhattan, the United States' most dense city, had 25,836 people per square km or 0.025836 people per square meter.

⬐ stck

That's roughly 38 square meters per person. For the most dense city, that's plenty of space.

⬐ kalid

Just for fun, I made a quick calc for you: http://tinyurl.com/3xl32bx

In 50 years at 1.3% growth we'll basically double our population, and go from about 8000 m^2 per person to 4000 m^2 per person. After 780 years, the growth starts adding up, you can play with the numbers.

⬐ jackowayed

Wow, instacalc is pretty awesome.

⬐ pmiller2

People don't understand exponentials very well because human perception is scaled logarithmically. For example, both the apparent magnitude scale for celestial objects and the loudness scale for sounds (measured in decibels) are logarithmic.

⬐ thangalin

http://commons.wikimedia.org/wiki/File:Star-sizes.jpg - Scale of celestial objects.

⬐ raimondious

If our perception is scaled logarithmically, wouldn't that give us an intuitive sense for exponentials?

⬐ aresant

Part of the problem is that the distant future to humans is never any further out than ~70 years - eg our lifespans.

Exponential resource waste, population growth, etc doesn't become a non-survivable event for a few more generations - at that point we may actually start to see realistic change.

⬐ jwegan

Definitely worth watching the entire series, but for those looking to save time: the first video covers the main point and the subsequent videos in the series just reinforce its significance.

⬐ indrax

I think we actually do have a deep implicit understanding of the exponential function, and THAT may be our greatest shortcoming. We don't understand it precisely, and we don't intuitively relate to "4^x".

But we very intuitively get things like "really big changes will come from small things" And we rate highly getting a seemingly small increase in personal ability. This is why videos like this can capture our attention at all. It seems like a basic ability to recognize and reason approximately about exponential growth is required to do agriculture.

I think this is why we like RPG's and katamari damacy, and talking about peak oil.

I think that this mental flag also makes us extremely sensitive of people 'from the wrong tribe' being in our area.

In short, I think that we were surrounded by exponential functions in our ancestral environment, and developed an ability to recognize them and see them as very important, with out really knowing what they are.

⬐ iamwil

I haven't gotten back into the habit of watching lectures in a while, but this was one of the best ones I've watched in a long time. Thought it was super cheesy at first, and didn't think I was going to keep watching, but it kept me rapt the entire time.

⬐ ModelCitizen

A note on the rest of the series: He spends the remaining time outlining some impending Malthusian catastrophe / peak oil scenario. For a counterpoint, check out anything by Julian Simon.

⬐ rsheridan6

Bartlett on Simon: http://www.albartlett.org/articles/art1998jan.html

⬐ wendroid

Yeah, JS is pretty good, he's going to win some stuff

http://www.motogp.com/en/riders/profiles/julian+simon

⬐ wendroid

humourless dolts

⬐ skybrian

Actually, he doesn't think much of Julian Simon and says why.

⬐ None

None

⬐ ModelCitizen

Which is why I offer Simon as a counterpoint.

Simon believed that there is more than simple arithmetic (as Bartlett calls it) when it comes to growth. You have to throw something like technology into the mix, which is difficult to predict.

The Simon-Erlich bet is a good, real-world illustration of their disagreements.

⬐ rsheridan6

Ehrlich was a jackass who made hysterical predictions. In the 70s, he was predicting an imminent Malthusian disaster - like this - http://www.paleofuture.com/blog/2007/7/18/the-population-bom...

That's a long way from Bartlett.

Don't take Ehrlich as a spokesman for anybody who believes in limits to growth.

⬐ madair

In part three he brilliantly draws a distinction between the objective sciences and others and subtly, if I'm understanding correctly, critiques a proponent of uncontrolled population grown by pointing out that the proponents degree from the same university is not a degree in "mathematics, in science, nor in engineering".

Feynman made explicit observations on this topic, quite critical ones, if I remember right.

⬐ KingOfB

Anyone find any good graphs about population growth? I asked wolframalpha and was pretty dissapointed, google found this article which I found interesting. Second graph in particular. Seems at 1000 and 1400 there were some drastic growth rate shifts.

http://www.theoildrum.com/story/2005/12/18/1387/0641

⬐ henrikschroder

From another comment:

http://www.gapminder.org/videos/what-stops-population-growth...

You can play with the data here: http://www.gapminder.org/world/#$majorMode=chart$is;shi=t;ly...

⬐ Tycho

I've always had this idea in my mind that the 'legendary failure rate of IT projects' is best explained in terms of an exponential increase in points of failure (or even just points of activity) when you deal with computer systems. Are there any famous papers that flesh out this idea? Anyone?

⬐ tibbon

I'm curious what the average price of gall bladder surgery is now. In it his students project 25K by 2000, which we are obviously quite a way past. If you're uninsured, this amount sounds about right likely these days.

Great video. I'm on part 2 and I'll finish the rest in the morning.

⬐ Empact

The HealthCare Blue Book tells an interesting story:

* $16,435 for traditional gall bladder removal, somewhat below the estimate http://healthcarebluebook.com/page_Results.aspx?id=75&da...

* $6,934 for the modern minimally invasive equivalent, far below the estimate http://healthcarebluebook.com/page_Results.aspx?id=74&da...

More evidence that projecting trends without considering technical progress is bound to result the sort of overly pessimistic results that Malthus made famous.

For example, Dr. Bartlett's two-column view on population assumes that people will need some certain number of square feet of land. But why wouldn't we build up, ala NYC? Or settle the ocean (http://seasteading.org/)? Or colonize the stars? Or perhaps even transfer our consciousness to some more efficient representation?

Yes, exponential growth presents problems, but exponential progress in technology has the power to solve them. That's where we (and others like us) come in.

⬐ chaosmachine

If you watch the video, you'll see why "find more land" isn't a sustainable solution. Ultimately, population growth just needs to stabilize at 0% to solve the running out of space problem (but not the running out of resources problem, which is where technology is more likely to help).

⬐ chrischen2

Well one benefit of increasing population is that we increase the chances of geniuses being born, and increase the diversity of the population.

⬐ stck

All we now need is a system for harvesting those geniuses. Who knows how many Srinivasa Ramanujans the world has lost.

⬐ JBiserkov

There's an old joke that says:

  The intellect of the planet is a constant, the population is increasing. 

genius != intelligence, but still :)

⬐ netcan

A lot to learn from this video about explaining things:

- Know your stuff. It's obvious he's been over all of this hundreds of times.

- Figure out great analogies and other aids. Part 3: 5:20 he makes an analogy out of multiplying bacteria in a bottle that fill it in an hour to show us at what point of the exponential function you notice your in one. It's got two parts and is very effective. It allows him to say things like "5 minutes before the bottle is full."

- Introduce your aids gradually and keep using them. Make clever decisions about your aids and make sure they accumulate to a powerful toolset. After that analogy which all the time he introduces the analogy above he has:

  - A trick for calculating doubling time 70/annual growth in %
  - A graph
  - A table 
  - An example (Boulder) that he keeps running scenarios on. 
  - The bacteria analogy 
  

By the time he's 20-30 minutes into a lecture, this guy has a very powerful vocabulary built up. He can take something like oil consumption and examine it with you very quickly using these tools. The bacteria in a bottle analogy is a great example of this. Once he's explained it (kind of hard) and practised it once or twice, he can say "What time is it?" and immediately have his audience understand something relatively complex. .

There's only one planet Earth, finite in size - and therefore a finite amount of natural resources exist within it. Once we've split all the uranium and washed all the phosphorus into the ocean, that's it - you can't think up more Zinc, Rubidium or Lithium - once it's gone, it's gone.

I'm sure we could do vastly more recycling, use alternatives for some things, improve efficiency, develop magical new technologies, etc, etc... but almost no-one I've spoken to about this appreciates just how terrifyingly rapidly we're approaching these limits. If we run out of available mine-able Zinc & Copper in 30 years - which is quite possible - what then? Do we have enough time to switch to coping strategies? Will that be a smooth ride? It seems to me that the front of the train has already hit the buffers, but we've still got our foot on the gas pedal, back here in the cab.

Most of the useful mineral resources on Earth are only available in vanishingly tiny quantities elsewhere in the solar system. We currently do almost no recycling of anything, compared to our consumption. The human population is huge, growing in number, affluence and resource usage per capita. We're on course to run out of the minerals required to run our economy & infrastructure within most of our lifetimes.

Nice infographic with some estimated timescales for various resources: http://www.newscientist.com/data/images/archive/2605/2605120...

The Greatest Shortcoming of the Human Race is our inability to understand the exponential function: http://www.youtube.com/watch?v=F-QA2rkpBSY

I'm not being alarmist - sometimes things are actually alarming.

⬐ eru

We are sitting on a huge ball of matter. And with enough energy--which we can get from the sun for another 5 billion years or so--we can recycle almost anything.

Of course coping may not be easy in the first place.

⬐ khafra

The problem is obtaining enough energy per cubic metre-second, so to speak--over the next 5 billion years, the sun will provide the earth with enough power to do just about anything we'd like to do today. But the reason we don't recycle rare earth metals is because it takes a lot of concentrated energy that we'd rather use for other things.

This problem will only become worse as concentrated energy sources are used up, and we move on to more diffuse sources with lower EROEIs, but expect to have the same surplusses we had in the 1990s.

⬐ eru

According to "Sustainable Energy without the Hot Air" Thorium will last a while. A few hundred years should be possible. That should be plenty of time to develop nuclear fusion.

⬐ dflock

Hmmm. Fusion. Even if sustainable ignition is made to work, and a perfectly functioning fusion reactor can be built - it's still completely unknown if it can be used as a useful power station:

http://www.scientificamerican.com/article.cfm?id=fusions-fal...

Anyone interested in fusion power really ought to read that article. The main thrust of the article is: a) even if you build the reactor, how do you capture the energy - which is mostly emitted in the form of neutrons - and b) where are you going to get the tritium from. Currently the answer to both questions is 'don't know'.

⬐ dflock

It's not really the long term future that I find alarming, it's the near-term transitions. It seems like globally we're finally bumping up against a load of fixed environmental, resource and population buffers almost all at once. Bumpy road ahead, possibly.

⬐ eru

The population bomb is already defusing. The environmental and resource limits might create some serious problems.