perestroika

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[–] [email protected] 15 points 1 week ago

Why the water isn’t killing the fire?

Could be anything from sodium to calcium carbide to fluorine. :) Sodium makes hydrogen with water, carbide makes acetylene with water, and flouride just oxidizes water by grabbing hydrogen away from oxygen.

If the character's plan is to try fascism next, I think they're into fairly agressive substances. :P

[–] [email protected] 10 points 2 weeks ago* (last edited 2 weeks ago)

While the article takes no solid position about the benefits and harms of alleviating global warming with solar geoengineering, it does correctly point out that discussion and governance of the subject is lacking.

Some hypothetical examples:

Case A:

  • a coastal country experiences increased storm surges, a large percentage of its population stands at risk, it perceives climate change as an existential risk
  • this country decides to engage in solar geoengieering to cool the planet, however its neigbours on higher ground don't perceive a risk from warming, instead they fear that wind patterns could change and deprive them of rainfall
  • they accuse each other of violating each other's rights, start a trade dispute and eventually make war

Case B:

  • lots of people are convinced that efforts to control climate change by reducing carbon output have failed
  • they decide to go for solar geoengineering, but the predicted impact on food production is -10%
  • this affects the poorest of people most adversely, but there is no compensation mechanism
  • cooling the planet succeeds, but results in outbreaks of famine

Case C:

  • lots of people are convinced that efforts to reduce emissions have failed
  • solar geoengineering allows to cool the planet to pre-industrial levels
  • does incentive to reduce emissions disappear now?
  • if the cooling effect is terminated, extremely fast warming may now happen

Myself, I perceive this as a last resort. If reasonable measures don't save the day, this is one of the less reasonable measures that could buy time. I would like people to research this, so that capability would exist. But I would not be easily convinced of the necessity of taking action, as long as alternatives remain.

[–] [email protected] 18 points 2 weeks ago* (last edited 2 weeks ago) (1 children)

So it's mainly asthma that people develop due to exposure to nitrogen oxide - and treating all the patients puts a considerable burden on society.

Unrelatedly, as a side note, I got curious about Portuguese cooking - for some reason the graphs show that cooking food in Portugal requires a three times higher percentage (30% as opposed to 10%) of overall energy consumption, implying either lower energy use for everything else, or higher energy use for cooking.

I wonder if there's some secret sauce that is only made in Portugal and which is extremely energy-intensive? Or just a case of broken statistics...

[–] [email protected] 1 points 3 weeks ago* (last edited 3 weeks ago)

I mean sure, if you’re at such extreme latitudes that you have months of total darkness, then solar will have a problem there. Maybe small modular reactors make sense for those niche applications.

Currently, solar still makes economic sense, but from April to October. Lots of it was built rather fast, now the adoption is slowing since the grid can't accept it everywhere.

Consequently, summer is when oil shale miners rest and prepare for the next season.

Since the goal is to get rid of mining oil shale, big plans exist to install a lot of wind power. Sadly, this has gone embarrassingly slow, and it cannot cover winter consumption, and there is not enough storage.

As a result, some companies and building out storage, but only enough to last a few hours.

...and in the next country southwards, there is a huge gas reservoir that could accept methane, enough to last the whole winter, but nobody has a good enough handle on methanation to renewably produce a considerable quantity and store it there. :o

With regard to reactors, it seems likely that getting one would take 10 years and the local country here doesn't even have legislation built out for nuclear power. They're drafting it. Starting from zero is quite slow.

[–] [email protected] 1 points 3 weeks ago* (last edited 3 weeks ago) (2 children)

That's a pretty big gap to cover with spamming more panels. I would venture to guess: this approach would work up to latitude 45 or so.

https://www.engineeringtoolbox.com/surface-solar-radiation-d_1213.html

Where I live, in midwinter, the day is 6 hours long. Over here, wind turns more heads than solar. But yes, solar is riduculously quick to install.

[–] [email protected] 4 points 3 weeks ago* (last edited 3 weeks ago) (6 children)

Since 2021, nearly 4 full years, the world has closed less than 1% of active coal power plants.

Closing will come later, when alternatives are widely available. What renewable energy does currently - at least here - is forcing those plants temporarily out of the market, especially during summer months and windy weather. The plants will exist and stay ready in case of need for well over a decade, maybe even two - but they will start up ever more rarely.

Technically, the deal is: we don't have seasonal energy storage. Short term storage is being built - enough to stabilize the grid for a cold windless hour, then a day, then a week... that's about as far as one can go with batteries and pumped hydro.

To really get the goods one has to add seasonal storage or on-demand nuclear generation. The bad news is that technologies for seasonal storage aren't fully mature yet, while nuclear is expensive and slow to build. There's electrolysis and methanation, there's iron reduction, there are flow batteries of various sorts, there's seasonal thermal storage already (a quarter step in the right direction)...

...but getting the mixture right takes time. Instead of looking at the number of closed plants, one should look at the sum of emissions. To remain hopeful, the sum should stop growing very soon.

[–] [email protected] 8 points 1 month ago* (last edited 1 month ago)

Also relevant: "Always shoot the messenger first." :)

If news unsettles a person, and there's a cognitive dissonance upon processing their world model ("everything OK with climate") and sensory input ("another big freaking hurricane") then if the person isn't a model of rational thought and already has a fad for conspiracies...

...one might find it easier to add another conspiracy theory to one's collection, as opposed to harder steps like refreshing one's model of how the world functions. :o

[–] [email protected] 2 points 1 month ago* (last edited 1 month ago)

Seems like a useful monitoring and accountability tool. :) Especially if its quantity estimates can be made accurate.

[–] [email protected] 3 points 1 month ago* (last edited 1 month ago) (1 children)

I think the study analyzed the footprint of the person, not the vehicle:

In this new study, the research team investigated whether consumers who purchase and drive such vehicles have a smaller carbon footprint than other consumers

The merits of electric vehicles are irrelevant to their study - and their study is irrelevant to the merits of electric vehicles.

So maybe they're not lying (or maybe they are, if they made a direct claim about the power mix of the Finnish grid), but they're definitely far from barking under the correct tree. They're barking in a different forest, not of transport economy, but of wealth and consumption. :)

[–] [email protected] -1 points 1 month ago* (last edited 1 month ago)

The proliferation of a new technology typically doesn't start from poor people.

It starts from fanatics first. I built my first EV. It was crap, I cut it apart and sold the metal (environmental footprint: awful). Then I built my second EV. It drove around 10 000 km, but had to be retired due to metal fatigue (enviromental footprint: neutral at best, lesson learned: big).

I bought my third EV on a crashed vehicle auction. New front axle, stretching the frame back to correct dimensions... I drive it every day, but it's a crap car that I'd not recommend to my worst enemy. :) Environmental footprint: positive, I can produce fuel for myself from April to October. But if the same vehicle would be used by someone who doesn't produce (or buy) renewable power, the footprint would be less positive.

Anticipating the demise of my factory-made electric microcar, I am however building another EV. Again the footprint is negative, but I need information about how to easily manufacture one, and obtaining information has a cost in resources. :(

Meanwhile, of course, truly rich folks buy fancy and electronics-laden self-driving EVs which some then proceed to crash or mishandle due to lack of clue. People are like that and it will stick out in statistics.

IMHO: if they hadn't bought an EV, they'd have bought another kind of status symbol and would have used it even more wastefully. What matters more is what the average person can and will do. And how do we influence the auto makers to produce less resource-intensive vehicles?

[–] [email protected] 8 points 1 month ago* (last edited 1 month ago)

I have a solar panel that died. A piece or plywood flung by a storm went right through it, leaving a 30 cm "wound".

Well, to be honest, it's alive, just weaker - the panel remains suitable for pumping water on the field during muddy season. I wouldn't take a good panel to such a bad place, but this panel, I have no worries about.

As for what happens when they really, really die - they get disassembled. The aluminum frame gets taken off and goes into metal recycling. Junction boxes go to where plastic goes - not a nice place. The glass and doped silicon go into a crushing mill, after which they get separated. The glass is easy to recycle, but the doped silicon is difficult to refine again to such a purity, so it likely won't become a solar panel. But it's a very small fraction of the panel's mass.

[–] [email protected] 3 points 1 month ago* (last edited 1 month ago)

On individual scale, precisely that - a split type AC with one half indoors (or in a water tank) and the other half in an outdoor environement (air, water or ground).

If you're extracting heat from the environment, the machine lets the working fluid evaporate into the outdoor heat exchanger and compresses it back into the indoor heat exchanger. If you're cooling your premises - reverse that.

However, on a city scale, it's like "you've got a lot of sewage at 30 C" -> "your heat pump is a large building" -> "your sewage outflow is now at 10 C, but your underground heat reservoir gets charged to 140 C (stays liquid because of water column pressure), and you spend much less energy pumping the heat than you would spend heating the water directly".

 

Some Chinese researchers have found a new catalyst for electrochemically reducing CO2. Multiple such catalysts are known, but so far, only copper favours reaction products with a carbon chain of at least 2 carbons (e.g. ethanol).

The new catalyst requires a specific arrangement of tin atoms on tin disulphate substrate, seems to work in a solution of potassium hydrogen carbonate (read: low temperature) and is 80% specific to producing ethanol - a very practical chemical feedstock and fuel.

The new catalyst seems stable enough (97% activity after 100 hours). Reaction rates that I can interpret into "good" or "bad" aren't found - it could be slow to work. The original is paywalled, a more detailed article can be found at:

Carbon-Carbon Coupling on a Metal Non-metal Catalytic Pair

Overall, it's nice to see some research into breaking down CO2 for energy storage, but there is nothing practical (industrial) on that front yet, only lab work.

 

To my knowledge, this is the second time a sample is returned from an asteroid to Earth - only preceded by Hayabusa-2 fetching a sample from asteroid Ryugu. The capsule has been found and the sample stabilized with nitrogen. Fetching the sample required 7 years, studying it will require a bit of time too.

It is too early to speculate whether interesting discoveries will follow, but Bennu is considered to be an interesting asteroid - likely not a break-up product, but something that represents the original composition of the solar system.

Bennu is also considered a hazardous space object, ranked high on the Palermo scale of impact risk and kinetic yield, so knowing what it's made of can be practically worthwhile.

More information here:

https://en.wikipedia.org/wiki/OSIRIS-REx

 

The inverse vaccine, described in Nature Biomedical Engineering, takes advantage of how the liver naturally marks molecules from broken-down cells with “do not attack” flags to prevent autoimmune reactions to cells that die by natural processes.

PME researchers coupled an antigen — a molecule being attacked by the immune system— with a molecule resembling a fragment of an aged cell that the liver would recognize as friend, rather than foe. The team showed how the vaccine could successfully stop the autoimmune reaction associated with a multiple-sclerosis-like disease.

 

Most people would typically think than smelling a scent (unless it's a powerful poison or medicament) won't change much in a person's health... but apparently, a variation in the scent environment has effect on the human brain, especially if the person is already old and their senses are degrading. It has also been observed that viral infections damaging a person's olfactory nerves result in changes to the brain - with less input, the neural networks involved with scent tend to atrophy. Coinidentally, some neural networks involved with scent recognition are also involved with memory.

Prios studies already support the idea that training one's sense of smell helps older people avoid cognitive deterioration. This study brings highly significant statistical results and adds one bit - wakefulness is not required to benefit. Apparently, the stimulation a person receives from feeling different scents bypasses sleep (or maybe, even improves the quality of sleep).

 

Long story made short: apparently, the previous administration didn't really try (since it was Bolsonaro's, I am not surprised). EU import controls and financial interventions have also helped:

He believes the slowdown is due to a combination of factors: the resumption of embargoes and other protection activities by the government, improved technical analysis that reveal where problems are occurring more quickly and in more detail, greater involvement by banks to deny credit to landowners involved in clearing trees, and also wariness among farmers generated by the European Union’s new laws on deforestation-free trade. It may be no coincidence that deforestation has not fallen as impressively in the cerrado savanna, which is not yet covered by the EU’s controls.

 

Superconductivity is a condition of matter where resistance to electrical current disappears.

The first superconductors needed cooling to near the absolute zero. The next generation worked at temperatures of liquid nitrogen. A room-temperature atmospheric-pressure superconductor is a highly sought after material (e.g. it would expand possibilities to hande plasma for fusion research and make MRI machines easier to build).

A substance named LK-99 has recently caused interest in the research community. Its a copper-enriched lead apatite, typically made by reacting lead sulphate with copper phosphide. It is speculated to be superconductive at room temperature.

It is also thought that interesting properties are not inherent to the substance, but a particular kind of crystal lattice which this subtance obtains - if produced in certain ways.

The name LK-99 refers to Sukbae Lee and Ji-Hoon Kim, and the number refers to 1999, when these Korean researchers first stumbled upon it.

Studies back then were interrupted. They weren't certain of its properties and it was hard to make repeatably. When a researcher named Tong-Shik Choi died in 2017, he requested in his will that research into LK-99 be continued. The resources were found and his request was granted.

Then, other factors intervened, among them COVID. The first article was rejected by Nature because an extraordinary claim requires extraordinary proof. An article in Arxiv (not peer reviewed) at the end of July 2023 drew international attention, however.

Many persons and teams started attempting to replicate the experimental results. The process is still half way through, but considerable progress has been made.

  • Beijing University, school of material science + Beihang university: the experiment was made, but the effect could not be reproduced (they obtained a paramagnetic semiconductor of little interest)

  • Huazhong University, center for crystalline materials and micro/nanodevices: they obtained a diamagnetic crystal with interesting properties (repelled by a ferromagnet regardless of orientation, a property which a superconductor must have, but which is also shared by non-superconductive diamagnets)

  • National Physics Laboratory of India: failed to replicate the effect

  • Professor Sun Yue, South-Eastern University of China: got a weak diamagnetic crystal

  • Iris Alexandra (from Russia, plant physiologist): with an alternative production method, obtained a tiny but strongly diamagnetic crystal

  • Sinéad Griffin (Lawrence Berkley National Laboratory, from the US): published an article, attempting to theoretically explain how superconductivity might arise in the substance, explanatory tweet here

  • Junwen Lai (Shenyang National Material Science Laboratory, China): published an article about the electron structure of the substance, without opinion regarding superconductivity, with the opinion that gold doping would be better than copper doping

So, strong evidence is absent until now - we may have much merriness about nothing. There is a bunch of hypothesis and enough material to fit on a fingertip. :)

Background:

https://en.wikipedia.org/wiki/LK-99

 

I noticed that we have a community for talking about applied science and engineering in the form of c/technology, about climate science in the form of c/climate, but there didn't seem to be a field-neutral place to discuss any sort of science.

To fill the absence and introduce a few articles which caught my interest, I created it. I think I should make this thread stick to the top of the community, so meta-discussion could be easily located here.

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