I've noticed, particularly on reddit but also elsewhere on the english-speaking internet, that thorium nuclear (MSR/LFTR) power is being hyped. And I can't help but feel suspicious. It seems too good to be true. "burns our nuclear waste", "infinite fuel", "Absolutely safe", "Proliferation is not an issue". Stuff like that. Not gonna provide much evidence for those claims existing here, but I'll say that you can usually find them in any big thread involving energy sources and there's a few TED talks too. Coal, conventional nuclear, renewables, any of those is apparently strictly inferior and we're complete morons for not switching already. Coal apparently causes more damage through radiation than nuclear, nuclear is dirty and renewables need something... anything.. to keep them company in case we can't get enough wind/sun. (Also, batteries and hydroelectric storage don't exist.)

German wikipedia has this to say about thorium hype: "Der MSR/LFTR als Teil einer Thoriumnutzung erhält etwa seit dem Jahr 2010 insbesondere im angelsächsischen Raum starke Unterstützung verschiedener Organisationen, während Nuklear- und Energieexperten eher zurückhaltend sind. Einige dieser Befürworter halten den LFTR sogar für die Lösung fast aller Energieprobleme.[2][3][4][5] Kritiker sprechen aus unterschiedlicher Motivation heraus vom MSR- oder Thorium-Hype[6] oder sogar von Astroturfing[7]." - https://de.wikipedia.org/wiki/Fl%C3%BCssigsalzreaktor - paraphrased: MSR/LFTR received strong support in english-speaking areas by various orgs, while nuclear- and energy experts are mostly silent. Some supporters regard LFTR as solution to all energy problems. For various reasons, critics call thorium hyped or even astroturfed. [citations are mostly english, for the curious]

Meanwhile, there's major problems regarding practicality, we can't estimate just how secure it is (keep in mind modern reactor concepts are all "theoretically safe" as long as you keep the human out of the loop and maintain the facility properly.) Proliferation risks of thorium fueled reactors are immense due to U233 (232-contamination doesn't make the weapon less dangerous when used, just more dangerous to handle.). Also, no serious evidence for the capability to burn nuclear waste. And decommissioning a thorium plant seems, as of now, to be just as much of a shit job as a conventional nuclear plant - if not worse.

My main question with this is: How do you view thorium power / did you notice the same trends as I did? I'm just trying to form a conclusion between the hype and a maybe cynical pessimism.

I’m trying to organize a series of statements which reflect the primary pressures pushing civilization towards collapse. Ideally, I could be as concise as possible and provide additional resources for understanding and sources in defense of each. Any feedback would be helpful, as I would like to incorporate them into a general guide for better understanding collapse.

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We are overwhelmingly dependent on finite resources.

Fossil fuels account for 87% of the world’s total energy consumption. 1 2 3

Economic pressures will manifest well before reserves are actually depleted as more energy is required to extract the same amount of resources over time (or as the steepness of the EROEI cliff intensifies). 1 2

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We are transitioning to renewables very slowly.

Renewables have had an average growth rate of 5.4% over the past decade. 1 2 3 4

Renewables are not taking off any faster than coal or oil once did and there is no technical or financial reason to believe they will rise any quicker, in part because energy demand is soaring globally, making it hard for natural gas, much less renewables, to just keep up. 1

Total world energy consumption increased 15% from 2009 to 2016. New renewables powered less than 30% of the growth in demand during that period. 1

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Transitioning to renewables too quickly would disrupt the global economy.

A rush to build an new global infrastructure based on renewables would require an enormous amount resources and produce massive amounts of pollution. 1 2

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Current renewables are ineffective replacements for fossil fuels.

Energy can only be substituted by other energy. Conventional economic thinking on most depletable resources considers substitution possibilities as essentially infinite. But not all joules perform equally. There is a large difference between potential and kinetic energy. Energy properties such as: intermittence, variability, energy density, power density, spatial distribution, energy return on energy invested, scalability, transportability, etc. make energy substitution a complex prospect. The ability of a technology to provide ‘joules’ is different than its ability to contribute to ‘work’ for society. All joules do not contribute equally to human economies. 1 2 3

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Best-case energy transition scenarios will still result in severe climate change.

Even if every renewable energy technology advanced as quickly as imagined and they were all applied globally, atmospheric CO2 levels wouldn’t just remain above 350 ppm; they would continue to rise exponentially due to continued fossil fuel use. So our best-case scenario, which was based on our most optimistic forecasts for renewable energy, would still result in severe climate change, with all its dire consequences: shifting climatic zones, freshwater shortages, eroding coasts, and ocean acidification, among others. Our reckoning showed that reversing the trend would require both radical technological advances in cheap zero-carbon energy, as well as a method of extracting CO2 from the atmosphere and sequestering the carbon. 1

The speed and scale of transitions and of technological change required to limit warming to 1.5°C has been observed in the past within specific sectors and technologies {4.2.2.1}. But the geographical and economic scales at which the required rates of change in the energy, land, urban, infrastructure and industrial systems would need to take place, are larger and have no documented historic precedent. 1

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Global economic growth peaked forty years ago.

Global economic growth peaked forty years ago and is projected to settle at 3.7% in 2018. 1 2 3

The increased price of energy, agricultural stress, energy demand, and declining EROEI suggest the energy-surplus economy already peaked in the early 20th century. 1 2

The size of the global economy is still projected to double within the next 25 years. 1

Our institutions and financial systems are based on expectations of continued GDP growth perpetually into the future. Current OECD (2015) forecasts are for more than a tripling of the physical size of the world economy by 2050. No serious government or institution entity forecasts the end of growth this century (at least not publicly). 1

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Global energy demand is increasing.

Global energy demand has increased 0.5-2% per year from 2011-2017, despite increases in efficiency. 1 2 3

Technological change can raise the efficiency of resource use, but also tends to raise both per capita resource consumption and the scale of resource extraction, so that, absent policy effects, the increases in consumption often compensate for the increased efficiency of resource use. 1 2 3 4

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World population is increasing.

World population is growing at a rate of around 1.09% per year (2018, down from 1.12% in 2017 and 1.14% in 2016. The current average population increase is estimated at 83 million people per year. The annual growth rate reached its peak in the late 1960s, when it was at around 2%. The rate of increase has nearly halved since then, and will continue to decline in the coming years. 1 2

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Our supplies of food and water are diminishing.

Global crop yields are expected to fall by 10% on average over the next 30 years as a result of land degradation and climate change. 1

An estimated 38% of the world’s cropland has been degraded or reduced water and nutrient availability. 1 2

Two-thirds of the world (4.0 billion people) lives under conditions of severe water scarcity at least one month per year. 1

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Climate change is rapidly destabilizing our environment.

An overwhelming majority of climate scientists agree humans are the primary cause of climate change. 1

A comparison of past IPCC predictions against 22 years of weather data and the latest climate science find the IPCC has consistently underplayed the intensity of climate change in each of its four major reports released since 1990. 1

15,000 scientists, the most to ever cosign and formally support a published journal article, recently called on humankind to curtail environmental destruction and cautioned that “a great change in our stewardship of the Earth and the life on it is required, if vast human misery is to be avoided.” 1

Emissions are still rising globally and far from enabling us to stay under two degrees of global average warming. 1 2

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Climate feedback loops could exponentially accelerate climate change.

In addition to increased atmospheric concentrations of greenhouse gases, many disrupted systems can trigger various positive or negative feedbacks within the larger system. 1 2 3 4 5

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Biodiversity is falling rapidly.

The current species extinction rate is 1,000 to 10,000 times greater than the natural background rate. 1 2

World wildlife populations have declined by an average 58% in the past four decades. 1

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The marginal utility of societal complexity is declining.

Civilization solves problems via increased societal complexity (e.g. specialization, political organization, technology, economic relationships). However, each increase in complexity has a declining marginal utility to overall society, until it eventually becomes negative. At such a point, complexity would decrease and a process of collapse or decline would begin, since it becomes more useful to decrease societal complexity than it would be to increase it. 1 2 3

Intro

Hello everyone,

@wanda-seldon has been giving us an introduction to quantum physics. For now, she will be given a short break to prepare new stuff. In the meantime I will be covering some classical mechanics, more specifically thermodynamics. In part 1, we need to work our way through some of the more dry concepts, so we can understand and appreciate the horrifying implications of the fun parts. So I promise, this will be the most verbose one.

Some of you may have briefly seen a version of this posted, that was due to me misunderstanding the schedule with @wanda-seldon. If you saw that one, I will mention I rewrote nearly all of it to be more readable.

Now, on today's agenda: The basics of heat, work and energy and how it's all related.

Previous posts can be found here: https://tildes.net/~science/8al/meta_post_for_a_laypersons_introduction_to_series

Important note

If @wanda-seldon in her posts mention "energy", it's most likely in the context of energy operators, which is a concept in quantum physics. I'm not going to pretend I understand them, so I will not be explaining the difference. We will cover what energy is in classical mechanics. So keep that in mind if you read something from either of us.

Subject

Summarized

What is heat? Using a lot of fancy words we can describe it as follows. Heat is an energy that is transferred between systems by thermal interaction. And what is work? Work is an energy that is applied in a way that performs... work. The combined energy in a system is called internal energy. This type of energy can be transformed or applied to other systems.

These are a lot of new words, so lets break that down a bit.

Systems

A system is just a catch-all term for something that can be defined with a boundary of sorts. Be it mass, volume, shape, container, position, etc. A canister, your tea mug, the steam inside a boiler, your body, a cloud, a room, earth, etc. They are all systems because you can in some way define what is within the boundary, and what is beyond the boundary.

In theory, you could define every single nucleid in the universe as an unique system. But that would be counter-intuitive. In thermodynamics we tend to lump things into a system, and treat it as one thing. As opposed to Quantum stuff that looks at the smallest quantity. Calculating every single water molecule in my coffee would be pure insanity. So we just treat my mug as the boundary, and the tea inside the mug as the system. And just so it's mentioned, systems can contain systems, for instance a tea mug inside a room.

Energy

Energy is some quantifiable property that comes in either the form of heat, work. It can be transferred to other systems, or change between the different energy types. An example of transfer is my coffee cooling down because it's in a cold room. That means heat has been transferred from one system (my mug) to another system (the room). Alternatively you could say my hot coffee mug is warming up the room, or that the room is cooling down my coffee. Thermodynamics is a LOT about perspective. An example of transforming energy types is when we rub our hands together. That way we convert work (rubbing) into heat. It's really not more complicated than that. An interaction in this case is just a system having an effect on a different system. So a thermal interaction means it's an interaction due to heat (like in the mug example).

This brings us to an extremely important point. So important, it's considered "law". The first law of thermodynamics even. Energy cannot be destroyed, it can only change forms.

Your battery charge is never really lost. Neither is the heat of your mug of coffee. It just changed form or went somewhere else. The combined energy of all types that is residing inside a system is called internal energy.

Heat and work

Let's say we have a system, like a room. And all windows and doors are closed, so no energy can leave. In this system, you have a running table fan connected to a power line, getting energy from outside the system. The table fan is making you feel cool. Is the fan cooling down the room, heating up the room, or doing nothing? Think about it for a moment.

http://imgbox.com/CKtQLLOQ

The first thought of many would be to think that this fan would cool the room down, it sure makes you feel cooler! But it's actually heating up the room. As we remember, internal energy is the energy inside a system (room, in this case). The fan is getting energy from outside, and uses this energy to perform work. The fan accelerates the air inside the room, and this accelerated air will evaporate some of your sweat, so you feel cool. But as we remember, energy cannot be destroyed. So we are importing energy into the system, increasing the internal energy. Some of the work from the fan is also directly converted to heat, since the motor of the fan will get hot.

So if we are not getting rid of any of this excess energy, we are increasing the internal energy. And therefore actively increasing the temperature of the room.

http://imgbox.com/SAtqk7YG

To use a more tangible example: Simplified, this phenomena is why green house gases are bad. Lets define earth as a system. Earth gets a lot of energy from the sun. And a lot of this energy will be reflected and sent back to space. Green house gases will reflect back some of this energy trying to leave earth. So instead of having a roughly equal amount of energy enter the system (from the sun, from us doing stuff, etc) that leaves out in space, we have an increasing amount of energy on earth. This, as a consequence, increases temperature.

Implications

Now, what are the maybe not so obvious implications of this?

Waste heat, from supplied energy or inefficient work is a constant headache in engineering. If we cannot remove enough heat, we will actively heat up objects until they are destroyed. Thats why good cooling systems are important in cars, computers, etc.

Whats next?

Now this was not so bad. In the future we will cover phase changes, equilibriums, entropy, the heat death of the universe and briefly touch upon engines. So thats most likely two more parts after this. After that @wanda-seldon will take over again.

I plan on doing one main part per week, but if something is asked that warrants a small topic I might do smaller ones inbetween.

Feedback

Something unclear? Got questions? Got feedback? Or requests of topics to cover? Leave a comment.