perestroika

joined 1 year ago
[–] perestroika@slrpnk.net 3 points 1 day ago* (last edited 1 day ago)

Looking at the beatiful show, I cannot avoid thinking: "each of them a potential weapon".

So in fair weather, when communication is smooth and all navigation systems are working, it's entirely feasible to coordinate a swarm of 10 000. Wow. :)

Soon enough, they will be coordinating each other in the presence of electronic warfare, and swarms of 100+ fly already, so 1000 is the next step. Anyone doing air defense is probably designing energy weapons (lasers, masers, etc) at a pace approaching madness, besides making ever-cheaper drones.

As for the environmental footprint - if each drone withstands 10 performances, they will probably save resources. :)

[–] perestroika@slrpnk.net 3 points 1 week ago* (last edited 1 week 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".

[–] perestroika@slrpnk.net 8 points 1 week ago* (last edited 1 week ago)

I have had many encounters with cops, and I decide about the extent of cooperating with them on a case-by-case basis.

  • landlord is illegally evicting my mother's neighbour --> I call cops and they prove how useless they are at prevention, but the matter goes to court and the landlord gets convicted later, and it was my only time to testify in court
  • cops accuse me of ignoring their lawful order --> sorry, I was listening to music, didn't hear nothing, no comment, no comment, I admit nothing (nothing came of it)
  • cops intrude into the squat yard without knowing it's a squat --> "the ~~droids~~ drunken people you look for are elsewhere" --> the cops go elsewhere
  • cops raid the squat --> refuse to provide documents until threatened, require cops to provide their own ID, contest every statement and discuss the matter publicly in media
  • cops try to steal equipment during a demonstration --> pull the equipment back and yell to them a description of what it is (I assume they thought I was planting a bomb instead of packing up)
  • cops want to interview me about illegal demonstrations --> I politely tell them to fuck off, then call back and volunteer for the interview to convey the opinion of other anarchists :D
  • a new squat is being established --> establish a security perimeter that is watched with attention and never let cops close
  • an attempted squat gets burglarized and set on fire -> inform the fire brigade that a bottle of propane could be present (fortunately it was stolen), the fire brigade had better things to do than involve cops
  • a new squat gets burglarized --> pepper spray the burglar and take their tools, without involving cops
  • a new squat gets burglarized, episode N --> threaten the burglars and take their tools, without involving cops
  • cops try to fall into a hole in ground during a stupid training excercise --> tell the cops not to go there, as they might fall in (leave untold: it would be a major embarrasment for squatters to rescue them)
  • the squat is suddenly in the security perimeter of a NATO summit --> find some military lurking in the yard and invite them into the squat so they could be reasonably certain we don't have anything that shoots down planes :P (runway was about 250 m away)
  • a drunken person tries to SWAT me at a street party --> fully explain the situation to the SWAT team and later participate in amateur theatre with cops to get the drunken person safely removed from the police station :o
  • one drunken neighbour hits their spouse and when I forbid, hits me --> seeing that the neigbour has already paid for his deed since pepper was 100% effective and he'll feel extremely bad for many hours, I did not file a complaint to cops, although they were called and showed up
  • after two geniuses tried to steal my car, but fled after a warning shot --> I did not involve cops
  • after some person attacked his partner and hit her on street --> I pepper sprayed him, and since he took out a knife and attempted to come at me (I evaded, no harm occurred to me), I did call cops and make a complaint, as did the woman he had hit
  • cops call me about one neigbour's car --> I don't remember anything (I did actually remember, but wasn't in a mood for helping them repress a neighbour)
  • my car gets burglarized --> I ask the cops for info, they have none, I don't involve them beyond that

...etc.

[–] perestroika@slrpnk.net 4 points 2 weeks ago

P.S. I have once used DC to power a pump "directly". I use quotation marks because the pump (a water pump) was a brushless DC motor with an integrated controller. I used it on a field for removing water after a spring flood. Its controller accepted 24..48 V input, and it was powered from a 40 V solar panel brought on a wheelbarrow. :)

[–] perestroika@slrpnk.net 6 points 2 weeks ago* (last edited 2 weeks ago) (1 children)

instead of powering the heat pump from the wall, the heat pump can be connected directly to a PV

I have no experience with this exact combination. I know that "batteryless" inverters exist, but most of them are on-grid inverters. In that scenario, all that matters is monitoring your production: if you don't want grid energy, you only run your system when your PV produces enough.

Another type of batteryless inverters are "pump inverters". Farmers seem to like them for pumping water from wells into water towers. A pump inverter can be configured to run at 50 Hz (or 60 Hz for North Americans) and 230..240 V (or 110 V for North Americans) alright, but it is not designed to power electronic devices, but dumb agricultural motors. There is considerable risk involved with powering a heat pump from a pump inverter, unless you find an exceptionally simple and dumb heat pump with very limited or resilient steering electronics.

Efficiency losses are small anyway, but mostly happen during battery storage or when voltage needs to rise or drop considerably (e.g. a transition of 700 -> 24 V or 24 -> 240 V would cause a small efficiency loss).

I’ve heard that a PV can directly power a compressor

This seems unlikely as the compressor would have to be a brushed DC motor. That kind of motors don't last long, they wear out their brushes. Long-lasting motors are brushless, and those generally cannot be run on DC power. For example, a "brushless DC" motor is essentially a three-phased AC motor, just its controller (full of smartness and MOSFET transistors) accepts DC input.

If you have a good technical overview of your heat pump system, maybe you can locate a point where regulated DC can be fed into the system, but that would be hacking. Alternatively, maybe a niche market already exists for DC-powered heat pumps, e.g. for caravans, trucks or ships? But on niche markets, prices typically aren't good for you. :(

[–] perestroika@slrpnk.net 4 points 4 weeks ago (1 children)

Relays: my use for truck relays is switching on heaters in my thermal storage water tank. Not big ones, though - I use relays rated for 24V and 40A of current. Since they are old, I have applied a safety margin and only let 25 A flow through them, so each of them handles 24 x 25 = 600 W.

As for using DC appliances: benefits do exist. If a household has a low voltage DC battery bank (some do, some don't) then dropping the battery voltage a few times to power car parts comes with a smaller efficiency loss. In my household, DC appliances are used for lighting, communications, computing, cooling food, pumping water and soldering electronics. The rest goes via AC. I think a car air conditioner could cool some small storage room decently. With big living rooms, it would have difficulty since it's a small device.

[–] perestroika@slrpnk.net 2 points 4 weeks ago* (last edited 4 weeks ago)

it would (as far as i understand with high school chemistry) be strictly more efficient to electrolyse rust directly

I'm not a chemist either, but I do know a bit of chemistry.

Typically, you need a solution of NaOH (sodium hydroxide) to directly reduce iron oxide in an electrolysis cell. If your iron oxide contains impurities, those may react with NaOH and ruin the fun. Also, if you have exposure to CO2, your NaOH will gradually degrade, producing NaHCO3 and losing potency.

My impression: wet electrolysis is great for making high purity iron, but it would be hard to make it work for energy storage.

[–] perestroika@slrpnk.net 8 points 4 weeks ago* (last edited 4 weeks ago) (5 children)

Relays can be used for anything, and a car contains a fair number.

You can make a pulse jet engine from a muffler parts, but a solarpunk society would probably not do that. :)

Copper brake pipe and cooling radiators can be used as heat exchangers for other stuff.

Air conditioner parts can be reverse-used for Stirling engines or to pump heat in other contexts.

 

This is not just a "happy birthday" post for Linux, but also a reminder that despite it becoming big and professional, the freedom to tinker with Linux remains accessible.

I had to use this freedom recently when I discovered that V4L video pipelines could buffer up to 32 frames both on the encoder and decoder (unacceptable, we demand minimum latency!) so it was again time to recompile the kernel. :)

My previous time to recompile parts of Linux had been a week ago. Some hacker had discovered a way of tricking their WiFi card beyond the legally permitted power - with what I understand as thermal compensation settings. Wanting to taste the sweet extra milliwatts, I noticed that nobody was packaging that driver as a binary, so the only way to get it was to patch and recompile its kernel module.

Finally of course, thanks to Linux we have countless open-source drivers and if you want to venture onto the path that Linus Torvalds took - of building an operating system - congratulations, you have less obstacles in your way. :) Some people have taken this path with the Circle project and you can compile your homebrew and bare-metal kernel for a Raspberry Pi with reasonable effort, and it can even draw on the screen, write to serial ports and flip GPIO lines without reverse-engineering anyone's trade secrets. :)

[–] perestroika@slrpnk.net 6 points 1 month ago* (last edited 1 month ago) (2 children)

Yep, indeed, I'm already discovering differences too. :) A good document for techies to read seems to be here.

https://reticulum.network/manual/understanding.html

I also think I see a problem on the horizon: announce traffic volume. According to this description, it seems that Reticulum tries to forward all announces to every transport node (router). In a small network, that's OK. In a big network, this can become a challenge (disclaimer: I've participated in building I2P, but ages ago, but I still remember some stuff well enough to predict where a problem might pop up). Maintenance of the routing table / network database / is among the biggest challenges when things get intercontinental.

[–] perestroika@slrpnk.net 4 points 1 month ago* (last edited 1 month ago) (4 children)

Interesting project, thank you for introducing. :)

I haven't tested anything, but only checked their specs (sadly I didn't find out how they manage without a distributed hashtable).

Reticulum does not use source addresses. No packets transmitted include information about the address, place, machine or person they originated from.

Sounds like mix networks like I2P and (to a lesser degree, since its role is proxying out to the Internet) like TOR. Mix networks send traffic using the Internet, so the bottom protocol layers (TCP and UDP) use IP addresses. Higher protocol layers (end to end messages) use cryptographic identifiers.

There is no central control over the address space in Reticulum. Anyone can allocate as many addresses as they need, when they need them.

Sounds like TOR and I2P, but people's convenience (easily resolving a name to an address) has created centralized resources on these nets, and will likely create similar resources on any network. An important matter is whether the central name resolver can retroactively revoke a name (in I2P for example, a name that has been already distributed is irrevocable, but you can refuse to distribute it to new nodes).

Reticulum ensures end-to-end connectivity. Newly generated addresses become globally reachable in a matter of seconds to a few minutes.

The same as aforementioned mix networks, but neither of them claims operability at 5 bits per second. Generally, a megabit connection is advised to meaninfully run a mix network, because you're not expected to freeload, but help mix traffic for others (this is how the anonymity arises).

Addresses are self-sovereign and portable. Once an address has been created, it can be moved physically to another place in the network, and continue to be reachable.

True for TOR and I2P. The address is a public key. You can move the machine with the private key anywhere, it will build a tunnel to accept incoming traffic at some other node.

All communication is secured with strong, modern encryption by default.

As it should.

All encryption keys are ephemeral, and communication offers forward secrecy by default.

In mix networks, the keys used as endpoint addresses are not ephemeral, but permanent. I'm not sure if I should take this statement at face value. If Alice wants to speak to Bob tomorrow, some identifier of Bob must not be ephemeral.

It is not possible to establish unencrypted links in Reticulum networks.

Same for mix networks.

It is not possible to send unencrypted packets to any destinations in the network.

Same.

Destinations receiving unencrypted packets will drop them as invalid.

Same.

P.S.

I also checked their interface list and it looks reasonable. Dropping an idea too: an interface for WiFi cards in monitor/inject mode might help some people. If the tool gets popular, I'm sure someone will build it. :)

[–] perestroika@slrpnk.net 6 points 2 months ago* (last edited 2 months ago)

Well, today they are actually in production, while 5 years ago they were in laboratories.

[–] perestroika@slrpnk.net 4 points 2 months ago* (last edited 2 months ago)

As an anarchist who would welcome other anarchists - sadly, I doubt if that's a reliable recipe to stop climate change.

Limiting (hopefully stopping) climate change can be done under almost any political system... except perhaps dictatorial petro-states. However, it takes years of work to tranform the economy. Transport, heating, food production - many things must change. Perhaps the simplest individual choices are:

  • going vegetarian (vegan if one knows enough to do the trick)
  • avoidance of using fossil fueled personal vehicles
  • improving home energy efficiency (especially in terms of heating)
  • avoidance of air travel
  • avoidance of heavy goods delivered from distant lands

The rest - creating infrastructure to produce energy cleanly and store sufficient quantities - are typically societal choices.

As for corals - I would start by preserving their biodiversity, sampling the genes of all coral and coral-related species and growing many of them in human-made habitats. If we're about to cause their extinction, it's our obligation to provide them life support until the environment has been fixed.

Also, I would consider genetically engineering corals to tolerate higher temperatures. Since I understand that this is their critical weakness, providing a solution could save ecosystems. If a solution is feasible, that is.

Corals reproduce sexually so a useful gene obtained from who knows where would spread among them (but slowly - because typical colonies grow bigger asexually). Also, I would keep in mind that this could have side effects.

As for tempeature - it will be rising for some time before things can be stopped. Short of geoengineering, nothing to be done but reduce emissions, adapt, and help others adapt. The predictable outcome - it will get worse for a long while before it starts getting any better.

 

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.

 

People at MIT made a capacitor of cement and carbon black (not to be confused with soot). It worked and they are planning to test bigger samples. The construction of such capacitors is easy and they can be structural elements in architecture.

 

Summary: water + copper particles + room-temperature liquid metal (consisting of indium and gallium) = highly conductive gel with interesting properties.

Drying it slowly to evaporate the water allows simply getting conductive traces. Drying it fast allows printing objects that transform their shape when heated.

Commentary from me: indium and gallium are expensive metals. This is promising stuff, but not promising enough to go replicating at once. For most use cases, cables, soldering and PCBs are still the better option.

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