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Civilizational Collapse, Part 4

johncarlosbaez.wordpress.com

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Re: Civilizational Collapse, Part 4

#151

Post by tlb »

enriquto wrote: post #147
EForEndeavour wrote: post #144

Earlier quoted context omitted.

> the sky is blue because air is blue This comes off as a smart-alecky non-answer to anyone not already familiar with what gives things colours in the first place. John Baez's answer captures the core mechanism in two sentences and one diagram, and provides more detail below for the curious: > A clear cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more than they scatter re…

That is not the point. The point is that anything scatters and absorbs the light in a particular way, and we cal this phenomenon the "color" of the object. "Vegetation is green because chlorophyll is green" is deemed a correct answer. The same for the sky and for anything else. Ref: https://www.explainxkcd.com/wiki/index.php/1818:_Rayleigh_Sc...

Substances don't have a single "color". Air, for instance, scatters blue but transmits more red. So if you look at a light source through a lot of air, it's red (such as a sunset) and if you look obliquely to the light source, it's blue.

Re: Civilizational Collapse, Part 4

#152

Post by dredmorbius »

kurthr wrote: post #59
andreitp1 wrote: post #58

Earlier quoted context omitted.

How exactly would they be "wasted"? Seems to me that they would just end up back in nature and deeding other organisms as part of the food chain.

Exactly, what if the animal just dies without being eaten... are 100% of it's nutrients wasted? Or did it lead a full life and return from which ot came?

This is where scavengers and decomposers come in.

It's relatively rare that living organisms die without being part of some further biological change, though that does happen. Fossil fuels are formed through lack of biological decomposition, as are precursor materials: peat bogs, kerogenated biomass, abiotic methane. Deaths in desert, arctic, or alpine conditions may simply dessicate and degrade rather than being eaten.

The entropic channel may pass through biological mechanism, but there's no obligation that it must.

Re: Civilizational Collapse, Part 4

#153

Post by dredmorbius »

chimprich wrote: post #106
whatshisface wrote: post #74

Earlier quoted context omitted.

I'm not an expert on global agriculture, but a lot of the famous Texas cattle ranches can basically only grow grass. If the natural state of the land is brush that only goes up to your ankles you aren't going to feed much other than grazers off it. The efficient solution would be to use the good land to grow food and the rest of the land to feed livestock, and that's what tends to happen (feedlot factory farms fueled…

> the famous Texas cattle ranches can basically only grow grass Why? Anyway, wheat is a grass.

Wheat is the simple-starch-rich seed kernel of a hybridised grass.

Much of Texas lacks water -- generally West Texas, a line extending from roughly Austin. In the US generally, the 100th parallel divides the moister east from the drier west. Topsoils are also far poorer than further east.

There was an experiment conducted some years ago on dryland farming. It ended poorly:

https://en.wikipedia.org/wiki/Dust_Bowl

Timothy Egan's The Worst Hard Time is an excellent telling of this:

https://books.google.com/books?id=np1RwDQfpjsC&pg=PP1#v=onep...

Re: Civilizational Collapse, Part 4

#154

Post by [deleted] »

andreitp1 wrote: post #58
ahelwer wrote: post #53

Earlier quoted context omitted.

When you eat an animal, you are consuming (in this analysis) all nutrients it has consumed over its entire life, of which 90% are wasted vs. just eating those nutrients yourself. It isn't talking about bioavailability or whatever.

How exactly would they be "wasted"? Seems to me that they would just end up back in nature and deeding other organisms as part of the food chain.

[deleted]

Re: Civilizational Collapse, Part 4

#155

Post by JoeDaDude »

ddxxdd wrote: post #12

This feels reminiscent of the current issue of long-term data storage. Flash drives are volatile and can lose your data any minute. Solid State drives are slightly less volatile, and a hard disk has magnetic fields that will last decades, but nothing will keep our gigabytes of data alive and intact for future archaeologists. If the Library of Alexandria can burn, then so can any form of digital storage. On a side not…

As you probably know, the Long Now foundation has wrestled with the problem of extended time period preservation of physical buildings. In the video linked below, they discuss how ancient people attempted to carry knowledge through the generations. Some of my favorites: the stone markers for the high water mark of Tsunamis, and the temple that is physically rebuilt in exact duplicate every 20 years.

https://www.youtube.com/watch?v=nphxoUxSvgY

Re: Civilizational Collapse, Part 4

#156

Post by dredmorbius »

Filligree wrote: post #36
tonyedgecombe wrote: post #16

Earlier quoted context omitted.

A lot of modern resource extraction relies on easily available energy. The days of oil coming out of the ground or being able to dig for coal on the surface have long gone. My guess is you are right, once lost it won't be coming back.

There are alternatives. It won't be as easy or as cheap, no, but windmills and nuclear plants can both be built with WW1-era technology.

WWI-era technology was built on coal, and fueled by oil.

The amount of fuel required to smelt iron and produce high-quality steel (a technique only perfected in the 1860s -- previous high-quality steels such as Damascus and Japanese tamahagane were forged rather than smelted, with the iron and carbon impurities literally hammered out, often by hand. Water- or wind-driven trip-hammers could help with this.

Given the mass of raw wood needed to produce charcoal used in both iron and gunpowder production, the embodied mass of wood represented in an age-of-sail ship of the line (typically 72 cannon, half of which would be engaged in a broadside) rivalled or exceeded the mass of the ship itself.

That's not "the cannon and powder weighed more than the ship", but "the fuelwood consumed in producing these weighed more".

Britain, never particularly lush in forests, had stripped itself bare, and relied on imports from Sweden and the Americas to build and fuel its ships. Coal, particularly coked coal, was a game-changer. Even today, 15% of all coal use is "metalurgical", which is to say, coked coal used in steel production, not merely providing fuel to the fire, but chemically bonding with iron.

And that's just steel.

The concentrations of ores from which other metals are smelted are tremendously reduced from pre-industrial times. Copper (virtually all electric transmission and motors), gold and silver, numerous vital and strategic minerals (look up the "Harbord List", dating to WWI, of strategic minerals, now encompassed in the US Strategic Mineral Reserve and successor programmes), and more.

If we can avoid shutting off the grid entirely, some elecrical substitution may suffice. Aluminium smelting is virtually fully electrically-based, and steel recycling (which doesn't require coal) can and does run in electric arc furnaces.

Vaclav Smil's books on energy, Energy and Civilisation, and materials, Making the Modern World, are very strongly recommended.

Re: Civilizational Collapse, Part 4

#157

Post by dredmorbius »

JoeAltmaier wrote: post #33
tonyedgecombe wrote: post #16

Earlier quoted context omitted.

A lot of modern resource extraction relies on easily available energy. The days of oil coming out of the ground or being able to dig for coal on the surface have long gone. My guess is you are right, once lost it won't be coming back.

There's Methane Hydrates underground too. More of that, than oil. Estimated 6X. So we have 6 more tries at civilization?

Oil came shooting out of the ground, and even now generally flows.

Methane hydrates largely seem to be frozen in tundra and on the seafloor. Even accessing them tends to precipitate release. Liquids are far more fungible than either solids or gasses, and methane hydrates tend to be the latter transforming wantonly to the former with very little in-between. Sort of the worst of all possible worlds.

Also a tremendously worse greenhouse gas, though not quite so long-lived as CO2. Centuries rather than millennia.

Re: Civilizational Collapse, Part 4

#158

Post by dredmorbius »

rnernento wrote: post #21
frankbreetz wrote: post #2

If our current civilization completely collapsed, I would think most of our technology would be gone forever. It is hard to imagine another civilization figuring out how to read a hard drive.

Why? There's sooooooo much electronic equipment in the world right now. Huge datacenters, landfills filled to the brim with electronics. I think it's a stretch to assume that would all just evaporate. You could load the entirety of Wikipedia onto an e-reader and power it with almost no electricity. Data centers are basically bunkers and there is a tremendous amount of replication occurring. If anything I think we're…

The supply chain is long and fragile.

With interruptions in the provisioning of everything from the electricity required to parts for power management, cooling, air handling, networking, memory, disks, CPU, etc., the half-life of such centres would likely be on the order of a few years, even assuming local power.

Talent is probably the biggest factor.

Even absent greater civilisational collapse, a multi-billion-dollar-a-year income company such as Google can barely keep the lights on for a given project for 5-8 years, if that. Many startups fail even faster.

Re: Civilizational Collapse, Part 4

#159

Post by gdubs »

dredmorbius wrote: post #142
gdubs wrote: post #102

Earlier quoted context omitted.

The world’s wealthiest (eg, the American middle class) have the largest carbon footprint, and would make the most immediate impact by eating less meat.

A set of mid-sized though significant quibbles. The United States no longer has the largest total national carbon footprint. That title now goes to China, which has exploded past the US. The total carbon emissions title, since 1970 (roughly half, probably somewhat more, of the total since the Industrial Revolution, given ~30-ish year doubling rates), remains the US, though China are on track to surpass this within a…

I’d say when we’re talking about a dietary choice an individual makes, looking at carbon on a per capita basis is the right way to look at it. Especially given that the US consumer is a very influential one in the world. China is set to put a substantial chunk of global emissions under a carbon tax in the near term, which should prove to be a market force which drives down meat consumption, among other things.

The US agricultural system has global implications — from tooling and process, to subsidies and what poor countries grow. A fundamental change in the American diet would have an enormous ripple effect across the globe.

Re: Civilizational Collapse, Part 4

#160

Post by chimprich »

eitland wrote: post #101
ahelwer wrote: post #69

Earlier quoted context omitted.

Yeah, and the vast amounts of land used to grow those things can be redirected to other things that humans can eat. I have no idea why otherwise smart people get such a brain block on the topic of meat-eating. These "gotcha" points fall apart if you take 10 seconds to think about it.

As someone who grew up on a steep farm where grass, fruits and potatoes where the only options that worked out in practice (most of it is steep, summer is short and unpredictable) I'd say maybe you should reconsider. One easy thought experiment that helped me understand: given how extremely poor our ancestors where and how hard they worked to make ends meet there must have been some advantage to keeping animals. Othe…

> given how extremely poor our ancestors where and how hard they worked to make ends meet there must have been some advantage to keeping animals

Our ancestors generally ate far less meat.

They could also feed smaller animals like poultry on scraps of food, which doesn't really scale to feeding the billions of animals we currently raise for food.

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