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Exponential Economist Meets Finite Physicist (2012)

dothemath.ucsd.edu

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Re: Exponential Economist Meets Finite Physicist (2012)

#51

Post by azernik »

jbotz wrote: post #16
evdev wrote: post #11

Am I missing something, or hasn't energy per capita in the developed world already stopped growing? As well as population growth in rich societies?

Energy consumption has not stopped growing in rich societies... so long as the economy grows, energy consumption grows. The relationship isn't perfectly linear only because the available metrics are imperfect, but if you have any data that outright contradicts this rather reasonable assupmtion, please show us.

Money (and hence economic size) is an arbitrary measure of "value" that does not necessarily correlate with energy consumption.

Re: Exponential Economist Meets Finite Physicist (2012)

#52

Post by acchow »

Absolutely there are thermodynamic limits to energy "use" on the planet.

But isn't it obvious that we will expand into space stations and then eventually onto other planets?

> But if energy became arbitrarily cheap, someone could buy all of it, and suddenly the activities that comprise the economy would grind to a halt.

This segment contained a number of logical leaps that I can't agree with. It is possible for energy cost to fall arbitrarily low without reaching zero. And you can imagine an arbitrarily low price that would skyrocket quickly if someone actually tried to buy all the energy.

> So once our fixed annual energy costs 1% of GDP, the 99% remaining will find itself stuck. If it tries to grow, energy prices must grow in proportion and we have monetary inflation, but no real growth.

I'm not able to follow the claim here. Can anyone shed some light?

Re: Exponential Economist Meets Finite Physicist (2012)

#53

Post by Mirioron »

jammygit wrote: post #33
TaylorAlexander wrote: post #21

Earlier quoted context omitted.

Mars does look a lot closer in 2019 than it did in 2012. Back then it seemed like no real plan existed, except for one little company not a lot of folks believed in. Now we’ve got billionaires in a space race and suddenly it seems obvious that we’ll colonize space to some degree even in the next 100 years, likely with some aggressive growth. We’ve only recently come off the gloomy decades after Apollo where space exp…

The biotech to terraform (or live under domes sustainably) is a longer ways off though. All the attempts to create biodomes I’ve read about have either failed or cheated on a large scale. Unless we have an Asimov-esque robot driven “colonization”, but does that fully count?

You mean caves instead of domes, right? You need protection against radiation and rock provides a lot more of that.

Re: Exponential Economist Meets Finite Physicist (2012)

#54

Post by Mirioron »

jbay808 wrote: post #9
seiferteric wrote: post #5

Only complaint is the discussion about super computers consuming vast amounts of power. I do think there is still room for many more doublings in efficiency for computers, it will likely require a switch to a completely new technology though. Also a bit more wild speculation... He does not account for the idea of space based manufacturing (he just mentions living in space). It's at least conceivable we could one day…

"I do think there is still room for many more doublings in efficiency for computers" I don't think our finite physicist is arguing that exponential growth can't happen temporarily, just that eventually we hit the boundaries of our petri dish. It's a challenge to economic models that sometimes deny in principle that the petri dish even has boundaries.

If the universe is infinite then that does imply that eventually the petri dish will be too.

Re: Exponential Economist Meets Finite Physicist (2012)

#55

Post by dosy »

scythe wrote: post #14

Tom Murphy's website occasionally comes up in futurist circles. His general point that unbounded exponential growth is impossible is obviously correct, but I find his condescending attitude tiresome and he often exaggerates the apparent validity of his pessimism through questionable arguments. For example, he first insists that the conversation about energy consumption be confined to Earth and ignore space exploratio…

It does seem like physicist enjoys spreading the pessimism of that position in a condescending way, which makes me think the allegedly "faithful" write up of the dinner conversation, was in fact compensating for one where the physicist felt they had been beaten, and was so annoyed by that they have re-written the conversation in this more favorable way where it appears they win the argument.

Besides, I think that pessimism (what the physicist probably thinks is realism) rests on one key point, that the price of energy will have a non-zero floor. If you remove that, everything is possible, even assuming steady that energy use, and requiring continued economic growth.

I think the avoidance / supposed maintenance of the "energy price floor" point was too weak. The assumption was that it will still be a purchasable resource ("someone could buy all of it" and hold everyone else hostage), but what if energy becomes unlike that? What if energy in the future is unlimited and no one can buy all of it because everyone can access it? And the only constraint Earth imposes is that no one uses too much so we don't boil off the atmosphere or whatever.

I think that's likely. Zero point energy, free energy from the vacuum. Some whistle-blowers say our secret space program already drives its ships with this kind of power.

What's interesting is that, based on these projections about hitting critical energy output, we won't need this ZPE for another 250 - 600 years. So maybe that's why, if it does exist, it is not going to be released until then. Kind of sad that 40 years ago or so, some bureaucrat planner may have robbed the human race of free energy for the next few centuries because of the projections of an economist and a physicist, not these two, but some other pair tasked with considering the economic and physical implications of then soon-to-be back-engineered alien technology.

Re: Exponential Economist Meets Finite Physicist (2012)

#57

Post by BurningFrog »

Chathamization wrote: post #24

> per-capita energy use has surged dramatically over time Per capita energy use seems to be declining in advanced economies[1]. > But if energy became arbitrarily cheap, someone could buy all of it, and suddenly the activities that comprise the economy would grind to a halt...There will be a floor to how low energy prices can go as a fraction of GDP. That seems to be a bizarre understanding of how the economy works.…

> That seems to be a bizarre understanding of how the economy works.

Right. Things only become arbitrary cheap because there is a practically infinite supply of them.

Re: Exponential Economist Meets Finite Physicist (2012)

#58

Post by ajnin »

TaylorAlexander wrote: post #21
pmalynin wrote: post #10

I think the dismissal of space colonization over a period of 400 years is...unreasonable. We could move all production to Mars for example and only consume the shipped resources. Sure that’s one doubling right there, but we could continue this process.

Mars does look a lot closer in 2019 than it did in 2012. Back then it seemed like no real plan existed, except for one little company not a lot of folks believed in. Now we’ve got billionaires in a space race and suddenly it seems obvious that we’ll colonize space to some degree even in the next 100 years, likely with some aggressive growth. We’ve only recently come off the gloomy decades after Apollo where space exp…

Sure it seems closer now than before, but reaching Mars is still very very far, it's nothing like going down the road to the chemist, for example let's say that we want to pursue the current population growth but on Mars, that's an estimated 82 million new people per year (130 million if you count only births), using the Starship SpaceX is currently developing that would take 820000 launches per year or 2250 per day.

But those ships are not like planes, you can't reuse them multiple times a day, the trip to Mars takes something like 6 months, and that's a launch window that opens only once every 2 years, the rest of the time it takes longer and more propellant, so your ships would make the round trip in 1 or 2 years, so you'd need to build 820k to 1.6 million ships only to be able to shuttle the population to Mars and stay constant on Earth.

That would be a serious industrial investment. A quick search says that there are around 24000 planes in service in the world, and over the course of history, 150000 planes have been built, including all military and commercial aircraft. So we'd need to build a production with many many times more capacity that all the airplane builder that exist today.

Then there is the energy cost of those ships, Earth gravity well is actually pretty deep and chemical propulsion only just is able to escape it. That many launches is going to need a lot of energy, a rocket can hold up to 500 tons of fuel, multiplied by several thousands of launches per day, and you reach a non-negligible percentage of the current daily worldwide energy expenditure.

The idea of being able to mine asteroids or outsource production in a meaningful way on another planet is similarly unrealistic, escaping gravity is not easy. Of course the technology will improve, but not by the several orders of magnitude that would be needed. When we colonize space, it is likely that it will be more like seeds, with only relatively minimal exchanges when the scale reaches a whole planet.

Re: Exponential Economist Meets Finite Physicist (2012)

#59

Post by dosy »

acchow wrote: post #52

Absolutely there are thermodynamic limits to energy "use" on the planet. But isn't it obvious that we will expand into space stations and then eventually onto other planets? > But if energy became arbitrarily cheap, someone could buy all of it, and suddenly the activities that comprise the economy would grind to a halt. This segment contained a number of logical leaps that I can't agree with. It is possible for energ…

I think it's a condensed version of saying:

If we have finite energy at a fixed price (of say 1% of GDP in total cost), then either the rest of the GDP (which is not energy) does not grow, and so the demand for that energy (and so its price) remains the same, or it tries to grow (and cannot "is stuck") because growth will increase demand for the energy and therefore drive up prices, but since it is energy and fundamental to everything, all prices will go up, so we will have inflation, but inflation is not growth.

Re: Exponential Economist Meets Finite Physicist (2012)

#60

Post by Glyptodon »

Water seems more interesting than energy as a bound. If energy gets as cheap as breathable air is now due to some sort of long running series of changes and improvements cornering the market would be like trying to bag the whole atmosphere and then charge people for it. The cheapest things are the most impossible to corner. Not that I have any idea whether some sort of ability to do more with less can bound energy use below some arbitrary output threshold.
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