12 ms·
Our greatest shortcoming is our inability to understand the exponential function
- jackowayed 16y agoThe 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.
- redorb 16y agogive 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?
- kalid 16y agoJust for fun, I made a quick calc for you: http://tinyurl.com/3xl32bx 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 16y agoWow, instacalc is pretty awesome.
- jackowayed 16y agoThe 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 16y agoUsing 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 16y agoThat's roughly 38 square meters per person. For the most dense city, that's plenty of space.
- robryan 16y agoAt 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.
- jackowayed 16y agoI'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.
- ihodes 16y agoThe 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.
- jackowayed 16y agoIt'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.
- jwegan 16y agoDefinitely 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.
- tibbon 16y agoI'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 16y agoThe 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&dataset=MD 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&dataset=MD 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/ 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 16y agoIf 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).
- prodigal_erik 16y agoI'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 16y agoBut 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]).
- KingOfB 16y agoI 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!
- skybrian 16y agoYes, 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.
- ars 16y agoThat'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.
- ModelCitizen 16y agoA 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.
- wendroid 16y agoYeah, JS is pretty good, he's going to win some stuff http://www.motogp.com/en/riders/profiles/julian+simon http://www.motogp.com/en/riders/profiles/julian+simon
- wendroid 16y agohumourless dolts
- skybrian 16y agoActually, he doesn't think much of Julian Simon and says why.
- deleted 16y ago[deleted]
- ModelCitizen 16y agoWhich 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 16y agoEhrlich 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-bomb-scenario-3-1970.html 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.
- KingOfB 16y agoAnyone 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 http://www.theoildrum.com/story/2005/12/18/1387/0641
- henrikschroder 16y agoFrom another comment: http://www.gapminder.org/videos/what-stops-population-growth/ http://www.gapminder.org/videos/what-stops-population-growth... You can play with the data here: http://www.gapminder.org/world/#$majorMode=chart$is;shi=t;ly=2003;lb=f;il=t;fs=11;al=30;stl=t;st=t;nsl=t;se=t$wst;tts=C$ts;sp=6;ti=1950$zpv;v=0$inc_x;mmid=XCOORDS;iid=phAwcNAVuyj0TAlJeCEzcGQ;by=ind$inc_y;mmid=YCOORDS;iid=phAwcNAVuyj2tPLxKvvnNPA;by=ind$inc_s;uniValue=8.21;iid=phAwcNAVuyj0XOoBL_n5tAQ;by=ind$inc_c;uniValue=255;gid=CATID0;by=grp$map_x;scale=lin;dataMin=0.7454;dataMax=8.6$map_y;scale=lin;dataMin=22;dataMax=84$map_s;sma=49;smi=2.65$cd;bd=0$inds=;example=59 http://www.gapminder.org/world/#$majorMode=chart$is;shi=t;ly...
- pmiller2 16y agoPeople 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 16y agohttp://commons.wikimedia.org/wiki/File:Star-sizes.jpg http://commons.wikimedia.org/wiki/File:Star-sizes.jpg - Scale of celestial objects.
- raimondious 16y agoIf our perception is scaled logarithmically, wouldn't that give us an intuitive sense for exponentials?
- aresant 16y agoPart 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.
- iamwil 16y agoI 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.
- mhartl 16y agoBefore 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 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 http://en.wikipedia.org/wiki/Logistic_function
- abrahamsen 16y agoTo the point: What seems like exponential growth often turn out to be better described as S-curves.
- seabee 16y agoThe 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.
- wazoox 16y agoHuh. 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.
- dagw 16y agoI 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.
- chrischen2 16y agoWell one benefit of increasing population is that we increase the chances of geniuses being born, and increase the diversity of the population.
- jluxenberg 16y agoNeat 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 16y agoIt'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 16y agoIt 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 16y agoYes, but why use it, when you can do a logarithm?
- sesqu 16y agoFew 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 16y agoYes. I was more on the line of suggesting taking out your calculator, if you want to know when your investment doubles.
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- netcan 16y agoA 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. .
- Tycho 16y agoI'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?
- indrax 16y agoI 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.
- madair 16y agoIn 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.