so, many of us read XKCD and may recall this gem,
http://xkcd.com/605/
but how does it apply to economics and fusion power? well a Physics professor at UC san diego is carrying out some of the extrapolations assumed in ubiquitous economic theory and taking them at face value and thinking about the consequences. These are valid starting points, I feel.
http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-energy/ mostly text, full math work up.
http://fora.tv/2011/10/26/Growth_Has_an_Expiration_Date 20 minute little guest lecture that covers germane points, glosses on math
with our own working fusion reactors and an arbitrarily large source of boron and hydrogen in the worlds oceans, we have are given some more choices regarding energy. I would like to emphasize the usage of the word choice. Anybody feel like talking? Anybody feel like melting down the Earth?

wolfram - 30 November 2011 10:56 PM

Anybody feel like talking? Anybody feel like melting down the Earth?

... say what?

Those types of graphics for power use hide a basic fact: the actual per-capita use of energy is badly skewed in favor of a relatively few groups compared to the bulk of the population. The rest of the people are simply doing their best to catch up to a still-advancing energy elite… and they will continue to do so. Energy inequality is no different in its effects than any other form of wealth inequality. It exists but it’s not something to be praised or worshipped.

Add to that the fact that the various “limits to growth” groups tend to overlook something: that population growth tends to decline as median prosperity rises.

And add one more factor: once each person has sufficient power to modify their individual environs and/or modify themselves to suit their desires no more power will be needed.

.. and the issue resolves itself

The question then becomes at what energy level can a future population expect to live comfortably with a given energy reserve.
 
A more reasonable future is one with a population of 14 billion people on Earth (double the current population, offworld populations wouldn’t count, of course) and each person of that future Earth having access at will to energy reserves of up to 1 megawatt of power for use 24/7/365 for a thousand years.

The measurement of energy reserves on that scale (1 MW/millennium per capita for double the current population) is one “Zap” ... and last time the subject was brought up hereabouts the questions were along the lines of how just many megazaps of boron-11 were actually accessible on Earth…

As for heating in the relatively near-term, it’s not an issue. Adoption of fusion will actually reduce both direct heating effects and climate-change heating effects even while increasing energy availability for all.

And, as opposed to the nasty trick carbon fuel use played on us, by the time we actually start using enough energy to directly heat the planet we might have to paint the roofs white… or not, if we’re in the middle of another glaciation…

the human body operates at 100 watts, in the pretty heavily industrialized countries there’s about a 1000 watts per person, an order of magnitude more. a megawatt is another 3 orders of magnitude, it’s like the average person has 10000 people’s worth of mechanical slaves. I wonder if anybodies done that analysis, position in a hierarchy or something based on available wattage. Anyway, non sequitur.

You seem pretty confident that deviating/abandoning from every bodies favorite economic models will be a walk in the park.

wolfram - 03 December 2011 04:06 PM

the human body operates at 100 watts, in the pretty heavily industrialized countries there’s about a 1000 watts per person, an order of magnitude more. a megawatt is another 3 orders of magnitude, it’s like the average person has 10000 people’s worth of mechanical slaves

... but the human brain/body combination is actually pretty efficient at using that energy to accomplish a very wide range of tasks… but as for our gadgets at this time? Not so much. They tend to be either very efficient at a very limited set of tasks or not so efficient at a wider range of tasks. Thus more gadgets and/or more power per gadget are needed to accomplish a given set of tasks.

So while a megawatt per capita would be a giant leap forward in comparison to current available reserves it seems that at this time it would be nowhere near the equivalent of 10,000 people supporting one person. But that will change over time with advances in technology.

... BTW…. doesn’t “slave” in that usage imply sapience? Probably not a good idea to tick off the AIs…

wolfram - 03 December 2011 04:06 PM

I wonder if anyone has done that analysis, position in a hierarchy or something based on available wattage.

I’m sure Cordwainer Smith would have had no problem at all adding the concept to the list.

wolfram - 03 December 2011 04:06 PM

Anyway, non sequitur.

No sequin left unturned.

wolfram - 03 December 2011 04:06 PM

You seem pretty confident that deviating/abandoning from every bodies favorite economic models will be a walk in the park.

The timing would indicate no need for that.

The current state of play is that the <1% spend good money just to perpetuate the myth that anyone can rise to the elites with luck and pluck… while simultaneously utilizing utterly corrupt governments to maintain their position at the top.

They then spend about an equal amount perpetuating the myth that any attempt to rein them in and hold them accountable to the society that created and supports them is actually an attempt by “moochers” and “leechers” to “seize their hard-earned wealth…”

All that aneutronic fusion would do would be to enable the first myth to come closer to reality than they’ll like while removing any grounds at all tor the second myth.

Given the elite modus operandi I’m sure they will try to justify seizing control of the practically limitless power that aneutronic fusion represents… if for no other reason than just to see if they can… but they’ll be trying to do that at the exact same time that the global population is realizing that the elites casually condemned billions of them to an early death just to maintain their (literal) grip om power.

They live in a love-hate relationship with the idea of mass revolt but they need not be torn down… unless their fear and lust for validation through force causes them to insist on it.

zapkitty - 03 December 2011 10:02 PM

... but the human brain/body combination is actually pretty efficient at using that energy to accomplish a very wide range of tasks… but as for our gadgets at this time? Not so much. They tend to be either very efficient at a very limited set of tasks or not so efficient at a wider range of tasks. Thus more gadgets and/or more power per gadget are needed to accomplish a given set of tasks.

So while a megawatt per capita would be a giant leap forward in comparison to current available reserves it seems that at this time it would be nowhere near the equivalent of 10,000 people supporting one person. But that will change over time with advances in technology.

... BTW…. doesn’t “slave” in that usage imply sapience? Probably not a good idea to tick off the AIs…

I will admit that 1 megawatt of computers given our current algorithms and programming hutzpah is not going to be able to compete with 10000 humans in terms of, say, dirty limerick writing. But how does a megawatt of backhoe compare to 10000 humans in terms of ditch digging? Looking at wikipedia has a 1950’s back hoe clocking in at 50e3 watts(68 hp), or 500 people’s worth of energy. It’s listed as having a 14 thousand pound operating weight. I don’t know what that term means, but i’ll treat it as what it can lift.

14e3/5e2=140/5=28 pounds per person. Hrmmm, my back pack gets that heavy from time to time. I guess that the advantage of mechanization is you don’t have to pay health insurance.

I think the point about earth overheating is the one in that article that has the shortest timescale and therefore the most pertinent. As zapkitty points out, population stabilisation should help to stabilise energy consumption. But what if sufficiently abundant energy caused heat to be produced on earth faster than it could radiate off, shifting the overall temperature in and of itself? It’s not enough to say that greenhouse-gas-related climate change is mitigated; you can still overheat. We would need some way of either, on a massive scale, converting heat back into another form of energy, or some way of increasing the rate of heat transfer away from earth.

Warwick - 14 December 2011 09:16 AM

... But what if sufficiently abundant energy caused heat to be produced on earth faster than it could radiate off, shifting the overall temperature in and of itself? It’s not enough to say that greenhouse-gas-related climate change is mitigated…

But you are actually speaking of two different things and they have two different solutions. The Earth is actually a big spherical radiator that easily handles thermal inputs in the 122 petawatt range. This is closely balanced by solar input… more or less… and the planet stays habitable for us.

But with GHGs we’ve essentially been painting that radiator black and we have created a feedback loop that has the temperature skyrocketing. But we are not generating that heat ourselves… the Sun is. We need to stop painting and let the black paint flake off. The Earth will gradually cool on its own… if we’re not too late…

But here’s the important part: the Earth will still be a radiator with a frickin’ huge capacity and the heat generated by FF units will still be radiated to space either directly or indirectly.

Dropping the use of all carbon fuels means that even with increased total human energy usage via FF the temperature will be dropping back towards the normal Earth energy budget. That means both ice ages and hot spells. Both of which are eminently survivable by humans even without fusion power.

As for heating the planet via FF… if it’s ever going to be an issue it will take a very long time for human energy usage to build up to that level. When you’re talking enough FF units to affect the heat balance of the planet you’re talking of a entirely different level of human existence. It can only be guesswork at this point

But I’m silly, so… without the “black paint” effect feeding back on itself it should be easy to make needed modifications in time to avoid problems. One such might be installing radiators at large FF complexes as auxiliary cooling units for use at night… radiating much of the nightly heat output directly to space. And also by then we should be able to generate and dismiss clouds on command…

... and if nothing else we can always paint the roofs white*

*One of the suggestions for dealing with global warming was painting the roofs white… that was analyzed and found to be both insufficient and inappropriate to the problem of climate change… but should be fine for FF direct heating issues in that future time.

zapkitty - 14 December 2011 11:46 AM

Warwick - 14 December 2011 09:16 AM

... But what if sufficiently abundant energy caused heat to be produced on earth faster than it could radiate off, shifting the overall temperature in and of itself? It’s not enough to say that greenhouse-gas-related climate change is mitigated…

But you are actually speaking of two different things and they have two different solutions. The Earth is actually a big spherical radiator that easily handles thermal inputs in the 122 petawatt range. This is closely balanced by solar input… more or less… and the planet stays habitable for us.

The article extrapolates to 10^17 W in 400 years, 10^18 W in 500 years.

Against that you have that heat radiation is a nonlinear increasing function of temperature.

I guess if you could localise the energy use, you could indeed put up towers into the atmosphere to conduct the heat upwards, but I’m not sure if that would work.

Warwick - 14 December 2011 12:07 PM

The article extrapolates to 10^17 W in 400 years, 10^18 W in 500 years.

Yes, any arbitrarily large number can be too big to deal with

I was speaking of a hypothetical point where FF use grew enough to have an appreciable input on global temperatures…  a concept which is pure SF at this time but solutions still seem quite possible.

The article speaks of something far beyond that and gets there through extrapolations I myself find unlikely. I can play the game and handwave something clever but that’s all it would be… Perhaps the borg of that era will use the oceans as part of a vast liquid droplet radiator system with gigantic water cannons shooting streams of seawater into the exosphere and catching the droplets as they fall…

zapkitty - 14 December 2011 01:54 PM

Warwick - 14 December 2011 12:07 PM

The article extrapolates to 10^17 W in 400 years, 10^18 W in 500 years.

Yes, any arbitrarily large number can be too big to deal with

I was speaking of a hypothetical point where FF use grew enough to have an appreciable input on global temperatures…  a concept which is pure SF at this time but solutions still seem quite possible.

The article speaks of something far beyond that and gets there through extrapolations I myself find unlikely. I can play the game and handwave something clever but that’s all it would be… Perhaps the borg of that era will use the oceans as part of a vast liquid droplet radiator system with gigantic water cannons shooting streams of seawater into the exosphere and catching the droplets as they fall…

According to you, an appreciable impact would be 10^17 to 10^18 W. Are there reasons why FF could not produce this? So why is it pure SF?
Projecting 400 years into the future is too far for reliable predictions, but then, so is 400 days to some extent. And he makes quite conservative assumptions, it could be 250-300 years before you’d see some problems.
Do your water cannons take less energy to power than the increase in radiation they achieve?
I think probably radiation is a red herring and you’d instead need some kind of clever way to recycle some proportion of the heat being created back into other forms of energy.

Warwick - 14 December 2011 02:32 PM

According to you, an appreciable impact would be 10^17 to 10^18 W.

Well, what I gave was a numberless figure… “sufficient FF usage to start causing problems”... because I’m a lazy kind of guy

And I usually try to qualify the “zap” as a measurement of energy reserves and not as an indicator of actual power usage.

I’d not run the numbers on this before so I just tossed out rough ideas. I’ve got some numbers now and they are interesting…

Warwick - 14 December 2011 02:32 PM

Are there reasons why FF could not produce this?

None that I’m aware of.

Warwick - 14 December 2011 02:32 PM

So why is it pure SF?

The purpose of the article was to provide a proof that energy use expansion, and by corollary economic expansion can not continue indefinitely because of physical limits.

Which is true.

But It’s one thing to extrapolate a trend as a thought exercise aimed at the supporters of the <1% and another thing to continue to do so in disregard to other potentially limiting factors such as declining population increases with increasing prosperity, thermal load carrying limits and planetary engineering options. Which the author acknowledges.

So, yeah, straight line is SF

Warwick - 14 December 2011 02:32 PM

Projecting 400 years into the future is too far for reliable predictions, but then, so is 400 days to some extent. And he makes quite conservative assumptions, it could be 250-300 years before you’d see some problems.

But in an future where FF works his predictions run into and are mooted by limits defined by other scenarios. I’ll get to those numbers in my next reply.

Warwick - 14 December 2011 02:32 PM

Do your water cannons take less energy to power than the increase in radiation they achieve?

What if you postulate hollow beanstalks that can hold pressure up to LEO altitude where they become open frameworks on their way to GEO? If that scenario works then you’d just need to prime the pumps

Warwick - 14 December 2011 02:32 PM

I think probably radiation is a red herring and you’d instead need some kind of clever way to recycle some proportion of the heat being created back into other forms of energy.

What I was thinking of was radiators expansive enough to both increase the FF heat dumped directly to space and to alter the global albedo equation. The radiators would alter their surface parameters as needed. One common idea is to turn deserts into farms, so do that… but make them enclosed multi-story plantlab-type farms and turn the roofs into radiators as well.

Any heat you can recover as electricity is good for your electrical needs but will still come back as heat. Albedo alterations will result in petawatt-range increases in cooling (or heating) but in the end will, again. run into limits.

Coruscant, Trantor, Borg Central… call it what you will, it won’t be Earth as we know it.

heat
global insolation watts     1.73E+17
albedo                       0.3
global absorbed watts       1.21E+17
insolation variance +-            0.1% 
variance in watts +-        1.21E+14
anthropogenic waste heat   1.80E+13

4% global absorbed         4.84E+15*
*Note: cf Chaisson, direct anthropogenic heating equal to 4% of absorbed insolation = 3 degree global temp rise… it can serve as a marker anyway…

FF efficiency 0.45
 
electric  
global 2011 watts   2.08E+12

FF scenarios  
heat equivalent       watts electric     watts heat
waste as FF heat     8.10E+12         9.90E+12
variance as FF heat   5.45E+13         6.66E+13
0.1 c rise               7.27E+13         8.88E+13
0.2 c rise               1.45E+14         1.78E+14
0.3 c rise               2.18E+14         2.66E+14

population
pop1 - 2011         7,000,000,000
pop2 - levels out   9,500,000,000
pop3 - 2011 x 2     14,000,000,000
 
watts electric per capita 2011
global per capita 297
gaza per capita 0.02
iceland per capita 3,152
 
FF watts per capita - electric (thermal) 
FF scenario         pop1               pop2               pop3
waste as FF       1,157 (1,414)    853 (1,042)      579 (707)
variance as FF   7,785 (9,515)    5,736 (7,011)    3,893 (4,758)
0.1 c rise           10,380 (12,687)  7,648 (9,348)    5,190 (6,343)
0.2 c rise           20,760 (25,373)  15,297 (18,696)  10,380 (12,687)
0.3 c rise           31,140 (38,060)  22,945 (28,044)  15,570 (19,030)

current fossil fuel cost per day (2008) ~$15,068,493,151
current electric cost per day (2008) between $4,082,192,000 and $5,890,411,000

FF electric cost per day 
current electric as FF     $99,792,000
waste as FF               $388,800,000
variance as FF         $2,615,760,000
0.1 c rise               $3,487,680,000
0.2 c rise               $6,975,360,000
0.3 c rise               $10,463,040,000

edit: goofed the costs section copy’n'paste
edit Jan 09 2012: forgot 2008 estimated elec cost per day

a quick look at the graph given in the article will not lead any sane person to extrapolate growth that way,
especially as you can already see a marked deviation at the top.

so the author is refuting the straw man argument that there will always be growth, but dwelling on it as though
we just don’t get it, and really need convincing.

Isn’t the dominant mind set in industries “how do we perpetuate growth?” Aren’t engineers constantly bemoaning the fact they can’t aim for some project that might take as long as 3 years, because it would reduce next quarters growth report? It’s transparently obvious that something will prevent the growth paradigm from manifesting, but at the present, it doesn’t seem like it will be because the MBA’s decided en masse that it was silly.

wolfram - 03 December 2011 04:06 PM

the human body operates at 100 watts, in the pretty heavily industrialized countries there’s about a 1000 watts per person, an order of magnitude more. a megawatt is another 3 orders of magnitude, it’s like the average person has 10000 people’s worth of mechanical slaves. I wonder if anybodies done that analysis, position in a hierarchy or something based on available wattage.

What are some ways to show this graphically? 

Think of Information Is Beautiful site.

I think the basic flaw in Murphy’s argument is that a society with such an enormous amount of energy available would find it very cheap by comparison to expand into space. If exponential energy growth continues that far, it won’t be on this planet.

(Murphy has another post skeptical of space colonization, but in that one doesn’t assume vastly larger energy resources.)