If you haven't read it, I'd highly recommend the book, "The Alchemy of Air" about the invention of Haber-Bosch.. It was unbelievable what they went through to fix nitrogen, they literally invented new fields of study in materials science and chemistry. The perils of a Jewish inventor creating a new method for making explosives under the Third Reich is a side story in the book but another fascinating historical anecdote.

And also Zyklon which would become Zyklon B when the warning eye irritant was removed to make it a better weapon for murdering people. There was a RadioLab[1] episode that talked about how it was eventually used on some of his own relatives.

[1] http://www.radiolab.org/story/180132-how-do-you-solve-proble...

> under the Third Reich

I think you mean under the Kaiser, not the Third Reich.

Hitler was made Chancellor on January 30th, 1933. Fritz Haber died on January 29, 1934 in Switzerland. Carl Bosch was not Jewish.

Here is a quick intro to Fritz Haber: https://www.youtube.com/watch?v=tdEE5uvFhOM

I do indeed. Thanks for the correction.

HN is becoming the single source responsible for most of my total book spending... Anyway, just purchased it. Thanks for the recommendation!

The earth could probably support 100+ billion people at reasonable comfort levels with slightly better technology as long as we give up the idea of life outside of zoo's.

That said, past experience has demonstrated the Human population can easily grow at 5% per year. At that rate it's doubling every 15 years. Trying to double the universes food supply every 15 years is just not possible indefinitely.

PS: 2^n is crazy. It takes less time than you might think before the mass of humanity is growing faster than a sphere expanding at the speed of light could support.

Uh, the current growth rate is around 1% per year, and it's decreasing as countries enter the first world. That's a doubling every 70 years. See https://en.wikipedia.org/wiki/Population_growth

We've got a lot of efficiency left in terms of agriculture as well, so there isn't much reason to think reaching the carrying capacity of the planet is a particularly pressing issue. The amount of food that we already grow that we don't eat roughly 1/3 already, and the vast majority of land doesn't contribute to agriculture.

I don't disagree with what your saying.

The counter argument goes something like this. Let's double every 1,000 years for the next 1,000,000 years that sounds easy.

Let's see that's only 7billion * 2^1,000 or err ~7 * 10 ^ 310 people. Hmm, there are only ~10^83 atoms in the observable universe. I guess they must be really tiny people.

So, yea it's not a problem in right now and probably not for a long time yet. But, as soon as you start doubling something has to give.

population doesn't keep doubling over and over again. It follows a logistic curve (https://en.wikipedia.org/wiki/Logistic_function ). Human population probably reached the midpoint of the curve around 1980 (http://www.growth-dynamics.com/articles/Kurzweil_files/image... ) and is expected to become fairly level between 9 and 13 billion (http://esa.un.org/unpd/wpp/Graphs/ select Population -> Total Population -> WORLD)

Yes, it follows a logistic curve because it hits carrying capacity. The top of that curve is not a pleasant place.

The top of the curve can be unpleasant. It doesn't have to be.

The worst is when population goes past carrying capacity and then crashes. That's when you get mass die-offs.

Population can settle down at carrying capacity simply through reduced birth rates matching up with death rates. That's the situation we see in much of the western world, with better availability of birth control etc.

The top of the curve is unstable. A new plant virus destroys a major crop and suddenly billions starve.

Every part of the curve faces that sort of instability. The number of crops actually growing isn't particularly higher than the number needed to sustain the population, and we can't just spin up enough food for billions of people even if we do have plenty of land to do it on.

With humanity, "carrying capacity" is unlikely to be food-limited.

The large number of overweight Americans is a huge pool of excess food and takes a lot of extra daily calories to maintain. As is the large number of livestock being produced and all that corn ethanol etc.

The top of the curve removes that as we can't pay for the inefficiency's of livestock or the extra daily calories to be overweight and feed 50+ billion people.

"carrying capacity" is set by a lot more factors than just food.

Human population is expected to level off at 10-13 billion based on factors relating to social organization, not the 50+ billion that could theoretically be fed.

Replace food with water, land, etc and you get the same instabilitys. Social factors at the limits can easily lead to war, revolution, and or the breakdown of society.

sure, but you don't need to be at the limit to have that sort of instability. It becomes a bit more pronounced when there's less leeway, but it's not different in kind, only a little bit in magnitude.

In this case, population isn't close to carrying capacity, but is following that curve anyways.

Several advanced economies like Japan have already hit the top of the curve. No starvation needed.