20 Hacker News comments link this video. Each one links back to its thread.
stousetAug 2025Strongly recommends
From Tom Murphy's excellent Do the Math blog[1]. Only 70% of the incident sunlight enters the Earth’s energy budget—the rest immediately bounces off of clouds and atmosphere and land without being absorbed. Also, being land creatures, we might consider confining our solar panels to land, occupying 28% of the total globe. Finally, we note that solar photovoltaics and solar thermal plants tend to operate around 15% efficiency. Let’s assume 20% for this calculation. The net effect is about 7,000 TW, about 600 times our current use. Lots of headroom, yes? When would we run into this limit at a 2.3% growth rate? Recall that we expand by a factor of ten every hundred years, so in 200 years, we operate at 100 times the current level, and we reach 7,000 TW in 275 years. 275 years may seem long on a single human timescale, but it really is not that long for a civilization. And think about the world we have just created: every square meter of land is covered in photovoltaic panels! Where do we grow food? Seriously, if you haven't read his take on things yet, at least the first few posts are a must-read. It's on par with the Arithmetic, Population, and Energy lecture at UC Boulder by Al Bartlett (popularly titled "The Most Important Video You'll Ever See", which is less hyperbole than you might think; the lecture is riveting)[2]. To very TL;DR things: solar and tidal energy (and their derivatives like wind) are essentially the only sources of energy we can rely on as our energy requirem
in “The Sunlight Budget of Earth” · View on HN
jodrellblankJun 2019Strongly recommends
The bacteria are mentioned in Albert Bartlett's famous lecture here: ▶ this video 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.
in “The poisons released by melting Arctic ice” · View on HN
tristanperryOct 2011Strongly recommends
Not sure if you've seen this series: ▶ this video (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: [link] (naturally doubling every minute is on a much faster scale to the Human population!)
in “You are the nth person alive on earth” · View on HN
dredmorbiusAug 2011Strongly recommends
If you haven't previously seen Dr. Barrett's "Arithmetic, Population, and Energy", I strongly recommend it: ▶ this video It doesn't address quite the same scale, but is very sobering.
in “Galactic-Scale Energy” · View on HN
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porkradishFeb 2016Recommends
This "growth rate" measured in percent has always concerned me. It looks to be unsustainable. Interesting video: ▶ this video
in “This is the most depressing chart in the world” · View on HN
rasz_plApr 2014Recommends
>some fairly massive blocks that were allocated but unused Watch this clip to understand why fractional solutions wont save us : ▶ this video Warning, its "Perhaps the most boring video you'll ever see, and definitely the most important."
in “ARIN down to 1.00 /8 – Akamai got 104.64.0.0/10 yesterday” · View on HN
merkatMar 2012Recommends
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. [ ] ▶ this video
in “The Rule of 72” · View on HN
wazooxFeb 2011Recommends
Looks interesting. You should submit it on its own. In fact combined with The prof. Bartlett videos ( ▶ this video ) it makes quite a good usage of arithmetic to counter McCarthy point of view.
in “Lisp inventor John McCarthy on human progress and its sustainability” · View on HN
SkyMarshalOct 2010Recommends
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: ▶ this video
in “How Fake Money Saved Brazil” · View on HN
cletusOct 2010Recommends
To temper this pessimism with some sobering reality, on another HN thread today I was pointed to this: ▶ this video Well worth watching. Somehow, some time the population is going down. Way down.
in “The middle class is over. It's not coming back.” · View on HN
dflockApr 2010Recommends
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: [link] The Greatest Shortcoming of the Human Race is our inability to understand the exponential function: ▶ this video I'm not being alarmist - so
in “Peak Everything?” · View on HN
itistoday2Jul 2015Cites it
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": ▶ this video
in “Why slow thinking wins” · View on HN
grannyg00seDec 2012Cites it
Excellent. Reminds me of the lecture describing that "the greatest shortcoming of the human race is our inability to understand the exponential function" ▶ this video
in “The Most Dangerous Equation [pdf]” · View on HN
bfrsDec 2011Cites it
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] ▶ this video
in “A Googleplex for $1000 by 2040?” · View on HN
EGregAug 2011Cites it
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! [link] Longer (but more boring) version: ▶ this video
in “Women are rejecting marriage in Asia. The social implications are serious.” · View on HN
carsongrossMay 2011Cites it
Your discomfiture is well placed: ▶ this video The world is mostly logistic curves, but the ponzi needs us to all believe in exponential curves.
in “Why Not All Earnings Are Equal; Microsoft Has the Wal-Mart Disease” · View on HN
sseefriedFeb 2011Cites it
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 ▶ this video ) 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 ( [link] ). 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.
in “Lisp inventor John McCarthy on human progress and its sustainability” · View on HN
cletusJan 2011Cites it
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. Po
in “Predictions for the World in 2030” · View on HN