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Exponential Economist Meets Finite Physicist (2012)

dothemath.ucsd.edu

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Re: Exponential Economist Meets Finite Physicist (2012)

#121

Post by mnl »

cinquemb wrote: post #110
mnl wrote: post #108

Earlier quoted context omitted.

You're mixing up laws with models. Conservation of momentum is a physical law, that is, we're not making that up, we always see it. The Navier-Stokes equation is a continuum mechanics model of fluids with interesting mathematics, but it's not fundamental, it relies on conservation of momentum and additional reasonable assumptions about the fluid, in the same way that for instance the van der Waals equation is reasona…

The law I was referring to in this case was Stefan–Boltzmann law (heavily reliant upon assumptions on a given black body that break down under certain circumstances, that people like to hand wave away because they haven't had to deal with the complexities of said circumstances before), which may as well as be a model as far as I'm concerned.

No, it isn't, it's what you get after integrating to all frequencies the Planck distribution for the radiation of a black body in thermodynamic equilibrium, which if you can get a sufficiently black one, you can check out it matches perfectly. I mean perfectly, that's what remote sensing satellites start with for determining surface temperature, after convenient linearization and modeling emissivity. That's what we see in the CMB, again perfectly. It's like this, I'm sorry.

(Look at the CMB spectrum —and refs therein—: https://commons.m.wikimedia.org/wiki/File:Cmbr.svg)

Re: Exponential Economist Meets Finite Physicist (2012)

#122

Post by paraschopra »

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.

The point isn't whether we can do that or not, but should we do it or not.

In all these visions of techno-utopia, poor suffer the most while the rich exploit the resources, and then expand that exploitation to more areas in hopes of making a profit.

Why do you feel we will not do the same to Mars what has happened to the Earth? It's possible that once we go to Mars we will exploit _both_ Earth and Mars.

Re: Exponential Economist Meets Finite Physicist (2012)

#123

Post by sdenton4 »

drdeca wrote: post #77
lutorm wrote: post #42

Earlier quoted context omitted.

Yeah, as far as I understand, there's nothing preventing you and me just trading the same money back and forth at ever increasing speed, creating economic "growth" without physical limits.

There are physical limits on how fast you can do that. Bremermann's limit, (or some extension of it?), says that the minimum amount of time needed for a system with average energy E to change to an orthogonal state, is inversely proportional to E (specifically, pi * h_bar, all divided by 2E ). So, assuming that “I have the money” and “you have the money” are orthogonal (collections of) states, then there is a maximum…

Of course, we've seen a similar type of fiction already in the history of economics.

"This piece of paper represents a chunk of gold!"

"No, it doesn't."

Re: Exponential Economist Meets Finite Physicist (2012)

#124

Post by BlueTemplar »

bshipp wrote: post #47
Terr_ wrote: post #40

Earlier quoted context omitted.

I think it's more about self-unfulfilling prophecies. I mean, a happy ending for Ebeneezer Scrooge doesn't necessarily mean that the Ghost Of Christmas Yet To Come was a liar.

Malthusian advocates tend to view the economy as static. One of the most recent surges in that line of thinking was the worlds impending doom at the hands of Peak Oil. Every single trendline in the early 2000's showed us running into a supply wall with no possibly salvation. And here we are, not even 20 years later, and America could potentially become a net exporter of oil. economics is hard because supply and deman…

Dynamic systems researchers "tend to view the economy as static" ?!

King Hubbert was laughed at when he predicted in 1956 that USA oil production would peak in a decade or so. It did.

http://www.hubbertpeak.com/hubbert/1956/1956.pdf

In 1998 Campbell & Laherrère predicted "The End of Cheap Oil" before 2010, due to the peak of conventional oil.

http://www.oilcrisis.com/campbell/endofcheapoil.pdf

The International Energy Agency called them "pessimists" :

http://petrole.blog.lemonde.fr/files/2011/04/weo1998.1302253...

In 1998-1999 the price of an oil barrel fell from $30 to $20.

In 2008 it reached $160.

These days it fluctuates between $40 and $70.

https://www.macrotrends.net/1369/crude-oil-price-history-cha...

In 2010 the same IEA said that conventional oil production had peaked in 2006.

https://www.iea.org/publications/freepublications/publicatio...

And while the USA is fairly close to be a [net exporter of liquid hydrocarbons](https://www.forbes.com/sites/rrapier/2018/12/09/no-the-u-s-i...) (not crude oil), the future of tight oil doesn't look good - Laherrere seems to forecast peak tight oil for 2018 :

https://aspofrance.files.wordpress.com/2018/03/lahall19march...

(it takes a while to collect the data...)

Sure, maybe we'll figure out how to economically extract even less conventional hydrocarbons (like shale oil = kerogen, which you have to "cook" before it can be used), but these will be even more expensive and polluting !

Re: Exponential Economist Meets Finite Physicist (2012)

#125

Post by sadness2 »

> thermodynamic limits impose a cap to energy growth lest we cook ourselves .. I’m talking about radiating the spent energy into space

Huh? This seems to be a critical premise for establishing a crisis, yet it's incoherent and essentially imaginary.

Ok, some ways we use energy have poor thermal efficiency. Light bulbs are the classic example, but look at the improvement from incandescent bulbs to LED's. Most uses of energy just move heat around within the environment, and if anything that would tend towards thermal equilibrium (a sort of microcosmic 'heat death'?), not "cooking".

Re: Exponential Economist Meets Finite Physicist (2012)

#126

Post by baking »

paraschopra wrote: post #122
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.

The point isn't whether we can do that or not, but should we do it or not. In all these visions of techno-utopia, poor suffer the most while the rich exploit the resources, and then expand that exploitation to more areas in hopes of making a profit. Why do you feel we will not do the same to Mars what has happened to the Earth? It's possible that once we go to Mars we will exploit _both_ Earth and Mars.

Kardashev looked at the physics in 1964 and said that civilizations that don't grow fast enough (energy use requiring expansion to other planets) risk planetary catastrophes and would not be expected to survive many thousands of years. Sure Earth could get lucky, but betting on that seems irrational.

Re: Exponential Economist Meets Finite Physicist (2012)

#127

Post by cinquemb »

mnl wrote: post #121
cinquemb wrote: post #110

Earlier quoted context omitted.

The law I was referring to in this case was Stefan–Boltzmann law (heavily reliant upon assumptions on a given black body that break down under certain circumstances, that people like to hand wave away because they haven't had to deal with the complexities of said circumstances before), which may as well as be a model as far as I'm concerned.

No, it isn't, it's what you get after integrating to all frequencies the Planck distribution for the radiation of a black body in thermodynamic equilibrium, which if you can get a sufficiently black one, you can check out it matches perfectly. I mean perfectly, that's what remote sensing satellites start with for determining surface temperature, after convenient linearization and modeling emissivity. That's what we s…

And then take those same sensors and apply that to the said materials I mentioned above, above and it breaks down…

"Oh but we haven't observed it in the cosmos from our cherry picked backtested 'sufficiently black' ones so it doesn't matter"

Rah rah rah, if you want to continue more just, email me cinque [underscore] mcfarlane - blake [ - a - t] brown [- d - o -t] edu

Re: Exponential Economist Meets Finite Physicist (2012)

#128

Post by simonh »

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.…

Energy blackmail certainly was possible, OPEC did it in the 1970s. I don't think it's possible anymore though.

Even for oil the supply is too diverse nowadays, and we're rapidly becoming much less dependent on oil than we were. Even if you could buy a plurality of the gulf oil, what about Russia, shale oil, etc? How do you also dominate coal, solar, wind, nuclear, etc? They are too varied, too geographically and politically diversified.

Re: Exponential Economist Meets Finite Physicist (2012)

#129

Post by BlueTemplar »

sadness2 wrote: post #125

> thermodynamic limits impose a cap to energy growth lest we cook ourselves .. I’m talking about radiating the spent energy into space Huh? This seems to be a critical premise for establishing a crisis, yet it's incoherent and essentially imaginary. Ok, some ways we use energy have poor thermal efficiency. Light bulbs are the classic example, but look at the improvement from incandescent bulbs to LED's. Most uses of…

No, it's basic thermodynamics : https://www.sciencealert.com/scientists-have-developed-a-sol...

Re: Exponential Economist Meets Finite Physicist (2012)

#130

Post by fallingfrog »

cinquemb wrote: post #97
AstralStorm wrote: post #96

Earlier quoted context omitted.

Correct, the are multiple ways to extend each of the limits, even one based on food, however mathematical limits on complexity exist and are really hard to surpass. On the upside, we're really far from them. Smart matter is not quite in our grasp. Once we figured out information-theoretic entropy we got tools to set bottom limits on everything. I'm not entirely sure when, but Kolmogorov was quite some time ago. The m…

Kolmogorov was about 90 years ago. Shannon, similar. Neither of their accomplishments will limit future accomplishments and understanding (except those bound slavishly to such frameworks [as good as they may be today in certain applications]) >Existential risks in fact. (E.g. reliance on a single source of energy without fallback.) Existential risks for oil companies investors or CSP investors?

Now, not to be rude but if you think we are going to break the laws of thermodynamics or other physics then you literally believe in supernatural forces. As in magic.
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