Future Civilizations and Energy Production

[ClydeH]

Okay, because I posted a link in the thread below this one to the place of where another science discussion was taking place, instead of removing the link, the guy with a full message inbox also closed the thread.

Pardon me, but I still would enjoy to have the discussion on debunking this guy.

So let me reitterate some things.

Someone is saying that the Soviet physicist Kardashev is a complete moron for his rating system of future civilizations, the type 1, 2 & 3 system you may have heard of. They claim such a thing is complete science fiction. They say that in the future, civilizations will not use more and more energy, but less and less.

I said, take a look at GDP and how it scales over time, as this is related to energy production. It is obvious by looking at GDP that our civilization consumes and produces more and more energy over time.

They said I am stupid because GDP has nothing to do with energy production, even though Dr. Michio Kaku suggests in his book, Parallel Worlds, that a civilization's energy production is tied to GDP.

They said, in the future, we should use the power of an AA battery, not the power of a star.

So, to debunk this, wouldn't we only need to look at the second law of thermodynamics and entropy to note that a civilization scales in energy output over time?

I thought it was conventional wisdom that a civilization would inevitably consume and produce an ever increasing scale of energy over time, instead of less, someday. Meaning that eventually, it would not be "science fiction" to believe that those people would eventually harness energy on the planetary level, and then on the solar level.

To top it off, the person claims that Kardashev was just some fool seeking to publish a paper. I find it hard to believe that some foolish idea would gain international scientific acceptance, but hey that's just me.

What are your thoughts on this?

Again, my thoughts are that an "AA battery" theory of future energy usage is preposterous, because only so much physical work can be performed from a certain amount of power in a battery, and due to energy conservation, you could never have process efficiency increase to the point where incredibly small amounts of energy are needed and used to do large amounts of work. That would violate energy conservation and hint at free energy being given off in such a system.

 

[Ryan_m_b]

Personally I disagree with the notion that the Kardashev scale is a linear means of judging technological development. It could be that a Type I civilisation can be more productive than a Type II thanks to the efficiency of their technology.

Energy efficiency is a very important topic regarding a civilisations energy usage. I can't find a link right now but at the recent EU Future Emerging Technologies conference they showcased some amazing designs for technology that recovers wasted energy from every day items. Examples included using the accelerometers in smartphones to charge them as the owner walks, plates that can be fitted to the underside of car engines to reclaim energy through the vibrations etc. Things like this combined with other technologies designed to improve efficiency (double glazed windows for example) mean that a future civilisation may be able to do with 1GW what we do with 10.

In spite of this the AA battery suggestion is ridiculous, to show that is wrong simply use hypothetically perfect machines and see how far an AA battery will get you. For example;

Assume we had a machine that perfectly transformed energy into momentum within a set radius, assume that we fitted this machine in a vehicle that had a perfectly frictionless skin (so that we can ignore wind resistance). And now let's make this perfect vehicle mass 200kg. Now using the tables found http://www.allaboutbatteries.com/Energy-tables.html we see that a lithium ion AA battery holds ~11Kj. To make our perfect vehicle hover would take ~10j per kg per second to counteract gravity, it masses 200kg so to hover we need 2Kj per second or 2KW so our AA battery will only last 5.5 seconds.

I know this example is silly but if you can think of other hypothetical scenarios employing perfect (i.e. 100% efficiency with no loss) machines such as perfect mass/energy converters you can easily show him how little energy an AA battery can give. Use examples like this to show that there are fundamental limits on how much work can be done with a set amount of energy. Increasingly efficient technology can bring us closer to this hypothetical maximum but going beyond that would violate the first law of thermodynamics.

 

[ClydeH]

Thanks for your input, Ryan.

Yes while the Kardashev scale may not represent the integration of vastly improved efficiencies into its formula, what it does predict is that future civilizations will simply make more and more energy. While the civilizations may improve efficiency of processes in everyday life, wouldn't it be almost certain that they would eventually have to reach for the stars? I mean, the options are, remain on Earth and eventually become part of a red giant sun, or move the entire race off the planet. Huge amounts of energy would be needed to accomplish distant goals of survival. I know I am getting far ahead of myself here, but I really don't see how an economy, and not to mention population can forever increase without energy output scaling greater as well.

 

[Mech_Engineer]

I think what you're talking about is summed up in this Wikipedia article: http://en.wikipedia.org/wiki/Energy_intensity

It doesn't seem to me that any of the comparisons scale very linearly, but overall I would say it's likely our energy use will increase with time, since as more energy becomes available more uses for it will tend to appear. There's no way we'll go down to the energy use of a AA battery; even in the future the laws of thermodynamics apply, and a thousand-ton ship going 0.5 light speed requires a fantastic amount of energy

 

[Ryan_m_b]

Thanks for your input, Ryan.

Yes while the Kardashev scale may not represent the integration of vastly improved efficiencies into its formula, what it does predict is that future civilizations will simply make more and more energy. While the civilizations may improve efficiency of processes in everyday life, wouldn't it be almost certain that they would eventually have to reach for the stars? I mean, the options are, remain on Earth and eventually become part of a red giant sun, or move the entire race off the planet. Huge amounts of energy would be needed to accomplish distant goals of survival. I know I am getting far ahead of myself here, but I really don't see how an economy, and not to mention population can forever increase without energy output scaling greater as well.

I agree with the point that an increasing population will have to increase energy input (even taking into account increasing efficiency) however I disagree that we will ever have to "reach for the stars". Firstly population growth in first world countries has massively curtailed and in the EU is even shrinking in many countries. IMO this is down to the decreased need to have children (for two reasons: firstly dramatically decreased infant mortality means that an extremely high percentage of children live to be adults and secondly large groups of children are not needed to provide labour) and the increase in education and rights for women.

Whilst it is true that eventually Earth will be destroyed I don't put a lot of weight in predicting how human civilisation will be in billions of years.

 

[Ryan_m_b]

Found a link to a BBC report on the entries for the EU Future Emerging Technologies competition (winner gets €100,000,000 funding per year for ten years!). Whilst it isn't one of the finalists the report shows the waste energy collector technologies I mentioned in my first post.

 

[ClydeH]

Youre right Ryan I can't let my imagination take over here, I must stick to facts that we can currently study.

Is it a mistake attempting to use GDP to make predictions about energy consumption and production? I only thought that when Dr. Kaku made reference to looking at GDP specifically, that it was a telling source of data, because if we take the world as a whole, instead of comparing countries, then we could make inferences about the world's energy production as a whole when its economy grows.

What would you use yourself if you wanted to make an accurate prediction of energy use and/or energy production over time to see how it is changing?

Also another point I was thinking about. Wouldn't an economy ultimately be driven by the amount of energy a civilization can make? For instance if we made massive amounts of energy more easily available, products would become cheaper as processes such as mining would yield greater returns. Think of large machines that could easily extract the mining products from the Earth. These are all essentially limited by energy available currently and horsepower which can be made, in a sense, would you say so?

 

[Ryan_m_b]

I wouldn't say it's a mistake to use GDP as an indicator of energy production/usage, there probably is a positive correlation between the two. GDP is (essentially) a measure of how much money a nation has, nations with more money tend to be more industrialised, more industrialised nations tend to have more infrastructure and more infrastructure needs more energy. However you may be interested to compare these two wiki articles on list of countries by energy consumption per capita and list of countries by GDP. There are anomalies like Qatar being the top of the list on the former and 55th on the later.

As I said earlier though it could be that if you were to compare the energy consumption of the world from 2000 to 2200 you might see a steady rise that plateaus before falling thanks to increasingly efficient technologies and slower growth. GDP may be sky high but energy production could be lower. In other words GDP is a weak indicator of energy consumption, for cursory glances it's OK but we would have to look deeper for a more detailed answer.

I don't think an economy would ever be run by just energy, for a start you can have all the energy you like but there's only a set amount of elements in the world. A big limit of machines isn't energy but efficiency. The house power of an engine for example isn't limited by how many watts it consumes but how well the engine has been built. Don't get me wrong increasing amounts of energy per capita (thanks to increased efficiency/production) would probably drive down some costs, the cost of energy for one. But the cost of goods and services is always going to be down to not just energy but also labour, material availability and market forces.

 

[samu.k]

It all depends on the advacement of different technologies, and how they affect each other. For example currently price of oil among many is a factor, driving us in a direction of low energy consumption. If a new source of energy were to be discovered, that could produce energy with far lower costs than current ones, there might not be need for lowering our energy consumption and technology could progress in a direction not so greatly affected by the need to have low energy usage.

On the other hand, if the current world situation regarding energy keeps continuing as it is, we might see even more drastic development towards low energy consumption. But as the OP allready said, the energy usage can be only cut to a certain point, due to simple physics.