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I’ve just read the wiki page on Magnetorquer but I couldn’t find what I was looking for: ballpark numbers.

What kind of current are you driving those coils with (amps or dozens of amps?). What order of magnitude is the resulting force (a few newtons?)

I’ll gladly read the paper but knowing myself I won’t remember why exactly when a few weeks passed.


This is the reason I cringe every time I hear or read statements like “we went to the moon”, “we’ve split the atom”, “we developed antibiotics”, …

No, we didn’t. A few who are not like us did.


Not really, no. The point of the "we" is too highlight the incredible collective effort which was required from all these massive endeavors. It goes all the way from the steel cool astronaut to the great machinists which had to build the parts.

I think it's one of the greatest benefits of ever working on a massive industrial project. You quickly realize how incredibly complex these things are and how utterly powerless a person alone is.


Add to this all of us who pay taxes to subsidize the effort.


And basically everybody working to make such an advanced society possible.


ok you have reduced my cringe.


  dementia, weight loss, unsteadiness, jerking movements and facial twitches
This actually describes my benzodiazepine withdrawal symptoms. The only thing missing is the suicide-inducing tinnitus.


Tinnitus is terrible. There are days I'd rather be deaf, but I know a few people that are deaf and realize that that is just my idiot side looking for a quick solution to the problem ignoring the downsides (and I love music). It is so frustrating.


I’ve occasionally found them, but only when their color contrasts with the background during walks. Can they be found year round? Do they have a preference for logs?


I’m going to go against the standard advice of this book or that course.

Pick up (broken) equipment and start disassembling it to figure out how they turn A into B [1]. Go down the rabbit hole of hunting down the service manual of the thing or one of its siblings. Look at how the pcbs follow the same pattern in competing design. Look at how all the yamaha, sony, medion, … amplifier/tuners are made in the same way and learn from it. Notice that one that is costlier and has those few quircks in its design. Notice how different variations of a theme achieve the same result, but died out because the tech doesn’t scale or simply proved to be suboptimal. Try to repair your broken equipment by understanding the path that the signals and power lines follow.

Rinse and repeat a few years and you’ll get a grasp on what the innards of an unknown electronic thing looks like without opening it. Then open it and be amazed that there was a different, cheaper, simpler way to turn A into B.

All along the way you’ll experience that most educational resources aren’t actually that good at explaining, or that they follow a different school of mathematical notation, or that they’re really good at explaining this detail but the rest is missing.

Design your own pcbs. Remember that - like software - hardware design is iterative. Remember that - unlike software - hardware iterations cost money.

Hope this helps.

[1] the ways to turn A into B are rather limited and it relies heavily on electromagnetism and conservation of energy.


I think you can take a bit more directed approach too.

You can build a micro-controller with a circuit that controls a stepper motor. Let the motor do something simple/fun. Connect the fun doohikie to give feedback to the microcontroller — e.g. using some kind of an encoder chip that converts motor's rotation amount to numbers that will tell the microcontroller how much to move, initialize the doohikie's start state.

But you can understand a lot more if you don't use the HBridge chip for the motor. Build the bridge circuit yourself. Build your own power supply for the microcontroller too(if you want to).

You can pick a path to go down on and focus on specific parts:

1. For the h bridge there is lots to learn. Designing the operational amp for D2A conversion as well as amplification/signal modeling — which you will need for the motor for current limiting in the h bridge per motor spec for the doohickie you want to power — That will teach you quite a bit about analog electronics and design. What kind of currents you need to protect and how e.g. using opto electronics. Limiting noise from power supply and parasitic noise so that your circuit does not misfire. You will likely need a set up of an oscilloscope, soldering irons and breadboards to prototype. Learn some basics from a book about design then go back to the circuit and build.

2. If you build your own PCB for this. It is a multi month project. You can learn a out CAD and chip layout. But I think you can do this in parts for example you can design the initial PCB only for the digital components and then connect it to a breadboard where you can prototype the H bridge you want.

3. If you choose to learn digital design and embedded system programming then maybe you can build the tougher analog parts for motor control using store-bought components and chips and focus mostly on the programming the microcontroller. That is a totally legitimate part too. You could use an old MCS-51 microcontroller and learn about data and program memory addressing and interrupt handling from scratch.


Thanks for submitting this. I’m currently working on the schematic of a VNA and having a ref design is a big help.


How does this work on a practical level? Do you scrape the soil to a depth of a foot and submit it to electrolysis or is the soil washed and the sludge then processed? How many grams of halogens does this recover per square acre of contaminated site? Does this sterilise the site?


Yeah, this makes no sense.

It sounds like it could be used to decontaminate a waste stream, but how do you select out the offending materials from a site?? What magic breaks halogenated bonds while leaving others (which are easier to break) alone? And how does the solvent work?? Remember, teflon only became practical when they found a solvent for it--and it's the solvent that's the real problem. Teflon is non-reactive enough for the body to pretty much ignore, the solvent (which of course isn't 100% removed from the final product) has one reactive spot and is a problem. They've tried to hide behind a game of musical chairs, using "different" solvents, but the dangerous part of the molecule is unchanged as that's what's needed to do it's job. A longer or shorter inert tail makes it "different" from a legal standpoint, not meaningfully different from a toxicity standpoint.

Why am I thinking scam?


DMSO is a pretty common solvent. It's still nasty stuff, but easy to clean from a sample.

Take a bunch of contaminated soil, wash with DMSO, filter out soil, wash again, take all of that and electrolyze it.

Take the soil, dilute with lots of water and boil in a chamber with a fractionating column / distillation setup to reclaim the last of the DMSO.

I'd be surprised if this was in any way economical, but it's the cheapest way to permanently get rid of DDT, and the production of benzene and other hydrocarbons is a nice side benefit to reclaim some of the cost.


> It's still nasty stuff

I've only ever personally used DMSO in chemistry labs, but Wikipedia [0] makes it look pretty safe: it claims that it has a higher LD50 than ethanol and that it's been FDA approved for human usage, so I wouldn't call it nasty. Now, I wouldn't really want to drink it because the side effects and taste sound pretty unpleasant, but it appears that it would be safe to do so.

[0]: https://en.wikipedia.org/wiki/Dimethyl_sulfoxide#Toxicity


DMSO readily absorbs through your skin, meaning it is a great carrier for pretty much anything else that you don't want in you.

At the scale of "washing tons of soil to remove DDT" it'd be quite unfortunate if something went wrong and tons of DDT tainted DMSO got dumped into the wild.


Yeah, for anything that will dissolve in DMSO, but DMSO doesn't dissolve teflon. It can't grab the halogenated bonds.


>Why am I thinking scam?

It seems scam adjacent because a high proportion of other stuff written in the same tone by the same types of people is a scam. The researchers don't write these puff pieces generally and the people that do spend the rest of their day writing "not technically a lie" type inflated corporate newspeak puffery that are basically "we're actually doing the customer a factor by charging more for less" tier lies.

It's also not unlikely that the experts involved provided a list of possible use cases and "making benzene from 3rd world dirt" was way down it and they had no idea the writer would lead with it.


Today we scrape however many meters deep of soil and haul off to a landfill. I assume you'd scrape it up, run it through something to pull out everything bigger than a pebble. Wash the pebbles, the rinse water goes with the soil through the cleaning process.

Certainly what comes out of the machine will not be living.


I guess it'd be a good time to add some bacteria and life back into the soil that in a controlled manner.


The real practical and immediate help would be ground water contamination. How many bad chemicals now permeate the water supplies around farming communities. Can this be used to treat the drinking water supply?


The soil is mixed with water to create a slurry which is then passed through filtration units which are sensitive to particular chemicals. Now the soil is fine but your filtration media is highly contaminated.


It could be used to decontaminate open water bodies as well as ground water. We have ways of producing electricity cheaply enough these days and so using that electricity to perform electrolysis makes sense - - even if it needs to be done only during times of the day where there is good sunlight.


Way more than a foot, but that's the general idea.

There's a soil remediation project near my workplace (former railway depot). They've dug up several meters deep by now.


I think itd be meant for the facility that uses the halogenated compounds in the first place, integrated into their process.


  a process that can be used *on site* to render environmental toxins such as DDT and lindane harmless and convert them into valuable chemicals – a breakthrough for the *remediation of contaminated sites*


This plant gave up photosynthesis, shrank its genome, and learned to clone itself—and somehow survived for 100 million years.


Same experience here. The more commonly known the stuff it regurgitates is, the fewer errors. But if you venture into RF electronics or embedded land, beware of it turning into a master of bs.

Which makes sense for something that isn’t AI but LLM.


I opened the article expecting to read about its use in plant breeding: colchicine is renowned there for inducing polyploidy. Never knew it has a history in medicine.

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


Never heard of it, please tell me more about using it in plant breeding!


Humans have two copies of each chromosome. Plants in nature can have many more, and some can be induced to duplicate their chromosomes which sometimes gives them larger seeds and resilience to environmental conditions. Similar to hybrid crops but somehow containing the full genomes of both parents. Bread wheat is hexapoloid (containing sub-genomes from three varieties of wheat) and quinoa is tetraploid (containing two different species). There have been projects for ~100 years to make polyploid rice with heavier grain-weight, but they haven't been able to reproduce.


Super interesting, thanks!


Same here. I have a bottle in my freezer for that purpose.


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