
Galactic-Scale Energy - derrida
http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-energy/
======
chime
The author didn't mention it but there is a scale for measuring the level of
technological advancement called
<http://en.wikipedia.org/wiki/Kardashev_scale> that takes the energy
consumption of the civilization into account. According to the linked article,
we will be Type III in 2500 years.

~~~
nknight
I think the real implication is that we would have to _be_ a Type III to
survive at that point.

I suspect this is a practical impossibility. Certainly the speed of light
presents significant challenges.

~~~
arethuza
If we did produce a Type III civilisation I don't think it would be based on
anything remotely like a collection of biological humans. Probably more like
the god like entity playing with humanity in Missile Gap by Charlie Stross:

[http://www.antipope.org/charlie/blog-
static/2007/04/missile_...](http://www.antipope.org/charlie/blog-
static/2007/04/missile_gap.html)

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microarchitect
The population of the US in 1650 was 50k. Now it's 309 million. No surprise
that energy consumption increased by a factor of about 10^5.

Also, the increase in world population isn't going to go on forever. Birth
rates are decreasing in most countries - including third world countries. In
fact, the population of many states in India is increasing not because of
birth rates but due to increasing life expectancy. I can't find a cite now,
but I remember an article which expects world population to stabilize at
something less than 10B. If even that number seems worrying, remember that
vast swaths of land in Central Asia, Siberia, Canada, Alaska, Australia and
Antartica are virtually uninhabited: we don't even need to go the moon or Mars
or something to find space for humans.

We do need to get our act together but our real problems are effective policy-
making and governance. Not finding endless sources of energy.

~~~
sampsonjs
"remember that vast swaths of land in Central Asia, Siberia, Canada, Alaska,
Australia and Antartica are virtually uninhabited: we don't even need to go
the moon or Mars or something to find space for humans." Uninhabited for a
very good reason, with the exception of Canada and Asia, maybe. Seriously,
Antartica?

~~~
nknight
Better to shove people into well-built structures in Antarctica and use more
temperate land for food and energy generation than fill up every inch of what
is traditionally considered "habitable" space and promptly starve.

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espeed
The earth will run out of space before that happens. "If the current
[population growth rate] of 1.3% per year could continue, the world population
would grow to a density of one person per square meter on the dry land surface
of the earth in just 780 years, and the mass of people would equal the mass of
the earth in just 2400 years"
([http://www.albartlett.org/presentations/arithmetic_populatio...](http://www.albartlett.org/presentations/arithmetic_population_energy_transcript_english.html),
[http://www.youtube.com/watch?v=9znsuCphHUU&list=PL63DAFC...](http://www.youtube.com/watch?v=9znsuCphHUU&list=PL63DAFCD223C29352)).

~~~
ckuehne
Or maybe not: <http://www.overcomingbias.com/2011/07/a-galaxy-on-earth.html>.
Who knows.

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iuguy
A couple of years ago I went to a Joint European Torus (JET) reactor tour, the
largest magnetic confinement plasma physics experiment in the world and the
closest (current working) thing to a working fusion reactor.

The temperature inside the plasma on these things reaches 10s of millions of
degrees Kelvin, but on the beryllium plated walls it's fairly cool (it'd have
to be otherwise the tiles would be destroyed). They also had a smaller
spherical tokamak called MAST that was quite interesting. We got to go into
certain areas that are normally closed off (as they're normally shut down).

If you want to see what a fusion reactor looks like, there's some pictures I
took from the trip are here:
[http://www.flickr.com/photos/z3r0kl3w/sets/72157623979315835...](http://www.flickr.com/photos/z3r0kl3w/sets/72157623979315835/)
\- I hope you enjoy them as much as I did.

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erikstarck
Imagine this article being written 2000 years ago. The energy demands of today
would seem equally "impossible".

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bemmu
If we start thinking in the scale of thousands of years, I could very well
imagine using this much energy, if we get some nice automated self-sustaining
expansion going.

Robots that build solar panels (and more robots) from raw materials they
gather, powered by energy they themselves are helping to create. It would be
like sending a virus out, no need for any intervention once you get the
process going.

They would go out and convert everything into whatever we need. In 2500 years
they could even reach other stars.

------
ordinary
It's that time again: "The greatest shortcoming in the human race is our
inability to understand the exponential function" -Albert Bartlett

------
j1o1h1n
The timeline starts at 1650, the height of the Renaissance, and projects
forwards 2500 years. It would be more interesting to start at 500 B.C. While
the author is making the point that 2% growth is silly, he is missing that
there (if past history is to be gone by) will probably be a Big Reset followed
by 1000 years of darkness, as before.

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hartror
I fun thought experiment but before anyone does a nude run down main street
screaming "we are all doomed" think about this. Our energy use is driven not
only by technology requirements, but also population growth, which is likely
to be far more limited in the future due constraints of land and food.

~~~
tomjen3
Don't forget that richer humans tend to get fewer kids too (this is only
natural as the better life you get, the less improvement to your standard of
living a child is until it dibs to negative when you move of the farm and into
the city).

~~~
Egregore
Actually rich men in developed countries have more kids
(<http://www.healthlibrary.com/news1672.htm> )than poor men in the same
countries.

~~~
hartror
Over all a richer society has fewer kids, at least in the west anyway.

------
dredmorbius
If you haven't previously seen Dr. Barrett's "Arithmetic, Population, and
Energy", I strongly recommend it: <http://www.youtube.com/watch?v=F-QA2rkpBSY>

It doesn't address quite the same scale, but is very sobering.

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sseefried
Similar to something I wrote a few years back:

[http://seanseefried.com/blog/files/a81e39350086cbd6d78c9a2b1...](http://seanseefried.com/blog/files/a81e39350086cbd6d78c9a2b1a7bc5fd-6.html)

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ars
I would love to see a graph of energy usage per capita.

~~~
ars
Assuming I didn't mess up: <http://imgur.com/To9LA>

Interestingly the energy per capita did not change starting at around 1970.
Wonder if it's related to <http://en.wikipedia.org/wiki/1970s_energy_crisis>

I also wonder what happened between 1740 and 1875.

~~~
LogicX
And the other side of the equation: 1973:
<https://secure.wikimedia.org/wikipedia/en/wiki/Roe_vs_wade>

See Also: Crime charts.

~~~
gjm11
You think the legality of abortion in the USA made a big difference to
worldwide energy consumption per capita? Why?

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ck2
Sometimes I wonder if there was a device for nearly endless, nearly free
energy (that was safe) if we'd have fewer wars or more wars (because war would
be cheaper from the material side).

~~~
w1ntermute
If we had a Dyson sphere, people would no doubt be fighting over control of
it. One example of the preliminary stages of this is the fighting that takes
place over the orbital elevator systems in Mobile Suit Gundam 00.

~~~
joshu
What.

~~~
bjelkeman-again
I think he is referring to the anime series:
<http://en.wikipedia.org/wiki/Mobile_Suit_Gundam_00>

~~~
w1ntermute
Yeah, the orbital elevators are multipurpose (i.e., to provide a more
convenient launching point for spacecraft), but one of their primary goals is
to provide electricity. And thus they are closely guarded by the 3 main power
blocs (the Union, AEU, and Jinkakuren). Without energy, they are nothing, as
can be seen from the countries that aren't a part of one of them and thus live
in great poverty.

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Devilboy
I hope we do

