perestroika

Interesting idea. :) What kind of a mattress do they use for leveling roads?

The current plow has many problems:

• it is imprecise, unless the pulling chain is short
• regardless of the chain length, it "wags its tail" when encountering resistance (this can be a plus if the car isn't powereful, though)
• it is shallow and weighs less than conventional road plows (can be a plus because I need to carry it without pulling muscles or joints)
• it has the simplest geometry, a triangle

Generally, a snow plow does level the road also - but only a little because the ground is frozen and everything is slippery, and the mechanism (with a spring if fancy) is holding it just above ground. When I look at my plow after working, the steel of the downward edge shines - it has worked hard against the ground.

My take:

• there is no universal time, there is your time and an external observer's time
• if you fly straight at a planet, you crash into it in a finite your-time, for an observer behind you, the light of your crash will be delayed by a tiny amount due to the planet's gravity
• if you fly straight at a highly massive neutron star, you crash into it in a finite your-time, just a bit quicker for youself due to its great mass, and the light of your crash will be delayed a bit harder, but will escape and show that you crashed
• if you fly straight at a black hole, you crash into it in a finite your-time, just much quicker due to the high mass of the hole, and the light of your crash will be delayed indefinitely, and will not show that you disappeared

A small error correction:

Conventional solar PV installations are installed on a rooftop or in a field. They convert the low voltage direct current (DC) power produced by solar panels into high voltage alternate (AC) power for use by main appliances and rely on the power grid during the night and in bad weather.

Actually, typical on-grid systems have a quite high PV voltage, because there's a lot of typically 40 V panels in series - far greater than the grid voltage. For example, solar arrays might send 900 V to the inverter, which produces 400 V for the grid. This is to save on copper (wiring diameter). With a higher voltage, more power can be pushed through the same conductor.

For a beginner, this is something to avoid - voltages above 48 V can easily become lethal to humans. To avoid wasting money on copper, instead of raising the voltage it's possible to keep the wiring short - and ultimately, copper isn't super expensive. :)

To the chapter "How to build supporting structures?" I would add a new genre: a fence. A vertical solar panel between rectangular wooden poles (either rammed into ground or screwed into ground with metal tips) can be attached firmly with screws. Adjascent panels can share the same attachment post, so to install N panels, you only need N+1 posts. The toughest part is measuring them well, since at the point where the fence wants to go crooked, one has to interrupt it with an extra post.

It stays cool in summer (better convection), snow-free in winter (snow falls off) and is better protected against hail. I have found that compared to other structures, a solar fence gets up in the smallest amount of time, for the smallest amount of money.

Interesting solution, thank you for introducing. :)

But how much are "lifestyle consumption emissions" compared to total emissions? I have never seen the term before, so I cannot put it in context.

What I imagine:

• if a poor person heats 30 square meters, and a rich person heats 3000 square meters, that is a lifestyle-related emission, and will differ considerably
• if a poor person drives a car, but a rich person drives a luxury car, emissions will differ, but not considerably (the poor person's car is old, while the rich person's car has engine volume like a truck), but if the poor person has no car, emissions will differ considerably
• however, if the rich person takes a plane ride every week, and the poor person twice per year or once per decade, that will differ considerably
• both persons will need to eat, but if the rich person eats fancy food, maybe the transport, packaging and other factors add up to make a considerable difference? or maybe not...

...etc. A breakdown of how would be nice to see.

This is an interesting approach to the question, because it contrapositions not the ordinary "voting vs. activism", but a different pair of actions, namely "campaigning vs. activism".

A few words about voting

Voting is cheap, accessible and doesn't require much of your time either - IMHO you should always vote, but assume it accomplishes very little. I won't blame a person if they don't vote - but if a population consistently does not vote, I will say that "they had it coming". The way to anarchy likely doesn't go crashing through populism and authoritarianism, so people should bother to prevent these. Everyone can stop voting at the point when parliaments get sortitioned (drawn with a lottery).

A few words about campaigning

If you campaign for a political power that doesn't represent you well, that's putting in more effort - for a not exactly increasing return. I have assisted a socialist politician in their campaign. During the course of this work, I learned a few things that were useful, but the guy lost laughably. In my country, votes "lost" by an individual candidate still contribute to a party's success, but in your country, things may differ, so take note of what the rules are. :)

A few words about activism

Activism can get you goods directly. Both voting and campaigning are low-return activity, but if you can figure out a way to make some part of society work better without a general referendum - go for it! :)

I think they have mis-interpreted the "good marriages take work" sentence. The foremost work seems to be - adopting a compatible method of solving problems.

Many people go into marriage blinded by love, seeing only the bright sides of their partner, and ignoring potential problems. When the short-term love (in my language, there are two words for love, one means "falling in love" and the other means "love") wears off and the person sobers, they have either a marriage or even a family with the other person...

...and their problem-solving and communication strategies may not be compatible. This can lead to suffering and fortunately there is divorce - but if one doesn't want to walk that way, then indeed - work awaits.

Adultery on the other hand, is a product of resignation - the marriage isn't working well, one is not bothered enough to divorce it, but enteres into affairs and falls in love with other people.

Now, instead of one unhappy relationship, there is an unhappy and an unsustainable relationship. In the first one, people have lost attraction or don't get along. In the second one, people cannot find time and struggle to make commitments. Maybe the second relationship has potential to be a better one than the first, maybe not.

Still, if everyone involved is aware of that - there is such a thing as ethical polyamory, where no cheating occurs because everyone involved knows they're not the only one - nothing is too bad and the marriage and affairs can run in parallel.

IMHO, the bad thing about adultery is not that it occurs - but that it often occurs in secrecy, with cheating. If one has an intimate affair (maybe a marriage) with person A, one should be open with them and tell of an equally intimate affair with person B. It has the benefit of helping people make informed decisions - not everyone wants a partner who is not committed to a relationship with them. Besides, most people want safe sex, and other partners are a reason to re-calculate the measures taken against transmissible disease.

Confused side note - why does the title link point to a BBC story about South Africa? :) Edit: oh, I see.

To answer the question - I don't know.

For comparison: installing an air-to-air heat pump for a tiny house in Estonia:

• heat pump unit (smallest unit, maybe 3 KW heat output for 1 KW electrical input), bought at the deepest discount: 450 €
• physical installation (mounting on a rack on a wall) - DIY, 0 €
• electrical installation (running a cable to the outer unit and back to the inner from there) - DIY, 0 €
• insulated copper heat pump pipes, 3 meters: less than 60 € (don't remember)
• pressing flanges on the pipes with a car brake pipe tool: DIY [note: leave to technicians, this is tricky], 0 €
• sealing and letting the working fluid into pipes - technician's visit, 100 €

I would imagine that an air-to-water unit costs more (the cheapest are probably over 1000 €, unless you use a pool heat pump which can be crappy), that an average German family lives in a far bigger house (so maybe 3 x more wattage, making the machine cost 3000 € instead), and that they need 3 installation technicians for several hours (maybe 1500 €).

Beyond that - profit?

It is sad to hear that they voted this misfortune upon themselves. I hope it passes with a small amount of reversible damage. During a global economic crisis and time of change, I don't think this government can offer something to placate its voters, and they will get disillusioned.

The article has a slight oversight - it is a bit behind the state of the art.

S. Korea develops technique to recycle discarded solar panels into high-performance solar cells

South Korea moves forward with long-expected solar panel recycling scheme

Reclaiming the aluminum has been possible for a long while. Reclaiming the glass has been "not worth the effort". Reclaiming the doped silicon is apparently a reality in South Korea, however.

As for the story itself, wow - very interesting. :)

“My hypothesis is that George Cove stumbled upon a Schottky contact photovoltaic cell, decades before it was described by Walter Schottky. 21 There is the possibility of both photovoltaic (predominantly) and thermoelectric responses from these devices. The plug was an alloy of zinc and antimony – which we now know is a semiconductor. It was alternately capped by German silver (a nickel, copper, and zinc alloy) and copper on opposite ends. This formed an ohmic contact and Schottky contact, respectively. This is a photovoltaic device.”

According to Philip Pesavento, George Cove probably started with “German silver” as the negative material on both ends of the plugs, and an antimony-zinc alloy (ZnSb) as the positive material. These were the best available thermoelectric materials at the time:

“He probably ran out of German silver and substituted copper to finish making up a bunch of plugs since the difference in thermoelectric voltage between using copper and German silver was small. Then, during testing, Cove noted that these plugs (with a German silver cap at one end and a copper cap at the other end) gave a much greater voltage: 100s of mV’s versus the usual 10s of mV for a thermoelectric generator.”

It's actually a bit more complicated. :) They made vessels from copper when they could - copper is a superb heat conductor. But copper gets toxic fast when you cook acidic food. It gets worse if you don't clean your copper vessels. Wikipedia tells:

Copper is reactive with acidic foods which can result in corrosion, the byproducts of which can foment copper toxicity. In certain circumstances, however, unlined copper is recommended and safe, for instance in the preparation of meringue, where copper ions prompt proteins to denature (unfold) and enable stronger protein bonds across the sulfur contained in egg whites. Unlined copper is also used in the making of preserves, jams and jellies.

Despite not having adequate chemistry or medicine, people in old times had a clue - they saw that copper sometimes fouled and turned green, and suspected this was not good, preferring tin-lined copper vessels as the economical alternative to silver-lined copper vessels.

(Needless to say, industries of that time didn't produce stainless steel - maybe some alchemist blacksmith knew enough to make it, but it was not a thing.)

Lining copper pots and pans prevents copper from contact with acidic foods. The most popular lining types are tin, stainless steel, nickel and silver.

...but the chemistry of the time being what it was - shoddy - sometimes tin was contaminated with lead (Pb), sometimes it was deliberately adulterated with lead, and shit happened.

In the middle ages, guilds had a system of proof marks and inspectors to ensure craftsmen wouldn't add too much lead to tin alloys. The Nuremberg standard for example specified 1 part of lead against 10 parts of tin, but in Luzern, Switzerland, a problematic alloy was used.

As for Romans...

However, the use of leaden cookware, though popular, was not the general standard of use. Copper cookware was used far more generally and no indication exists as to how often sapa was added or in what quantity. (Grape syrup)

Unfortunately, yes.

I've had multipe experiences with seeing a flashlight battery which, according to labels, ought to have the capacity of an electric vehicle cell. And of course they don't - on EBay or AliExpress, there's a 100% chance that they're just deceptively labeled. :)

If one needs high current, measuring the current with a known and low resistance (e.g. car headlight bulb) helps.