Sparks a poppin

I read an interesting article that charged raindrops' charge is sufficient to, with time, blast through many protective coatings, including Teflon.

The question Ni, Berger, Butt, and their colleagues asked was what this charge does to the surface that the drop lands on next. To find out, the team released 35-microliter water drops, about the size of a large raindrop, containing a pinch of salt to mimic rainwater, onto a surface tilted at 50 degrees. The drops slid about four centimeters, picked up a charge, rolled off the edge, and then fell five millimeters onto a copper plate coated with a 60-nanometer film of Teflon, which is one of the most chemically resistant coatings on the market today.

That, btw, is the part that might not model real raindrops accurately--I'll address that in a moment.

The tilted surfaces were mostly chosen to mimic raindrops in the real world. One was a leaf from a Tradescantia spathacea plant growing in one of the researchers’ offices. Another was a PVC foam board from a hardware store. The third one was a sheet of transparent polystyrene sold as window glazing. Only the fourth one, the fluorinated coating on quartz, was more of a lab creation than something people usually see everywhere around them. The charges the drops picked up ranged from 0.2 nanocoulombs off the leaf to two nanocoulombs off the fluorinated quartz. A nanocoulomb in something the size of a raindrop works out to be a few thousand volts.

And yes, electrostatic effects (at raindrop speeds that's a good approximation) distort the raindrop into something pointy that creates a high voltage difference in the fraction of a second before impact, up to the kilovolt scale, which will cause a tiny dielectric breakdown. The researchers find damage to the surface.

The polymer coating is changed by the zap, and the underlying surface begins corroding.

The researchers identified the corrosion products on copper by Raman spectroscopy and X-ray diffraction. They found cuprous oxide and basic cupric chloride, the pale green compound familiar from weathered copper roofs. Elemental mapping of the damaged zones showed oxygen and chlorine flooding in and fluorine and carbon from the Teflon flooding out—exactly what should happen when a coating has been disrupted.

Another study looking at rain on solar cells finds a voltage spike as the drop rolls off.

It seems like a plausible real effect, and suggests that protective coatings (like paint) need to include other factors besides chemistry.

OTOH, the first other study I found (1953) found that raindrops had a little less charge. A nanocoulomb is about 3 esu.

The average measured free charge brought down by positively charged rain was 0.022 esu (.007 nanocoulomb) per drop, and by negatively charged rain was 0.031 esu (.01 nanocoulomb) per drop. The ratio of the negative free charge to the positive free charge brought down by rain was 1.2, while the ratio of the number of negative drops to the number of positive drops was 0.88.

That's quite a bit less charge on the natural raindrops that aren't sliding off a roof or something. Under a tree, the raindrops can pick up an order of magnitude more charge than an unimpeded drop, but still an order of magnitude less than sliding off flourinated quartz. So, under a tree, raindrops could hit a few hundred volts. Unimpeded drops, maybe a few dozen.

Some other studies of raindrops are comparable. This has obviously been a matter of some study--trying to understand what is the relationship of rain and lightning, for example.

And therefore, of course, one can find other, contrary estimates: "At the rain-forming level" 50 esu/gram times .03 gram (.3 for a heavy storm drop) is 1.7 esu (.6 nanocoulomb) (6 for a heavy storm's drop). And another that didn't find much difference in charge with raindrop size. And different proportions of positive and negative depending on the rain type (pre-monsoon, monsoon I, monsoon II).

And "The results show that the magnitude of the electric charges range between 1 and 50 pC (.001 and .05 nanocoulomb) and more than 90% of the charges are mainly carried by raindrops >1 mm, even though most of the raindrops are smaller than 1 mm."

Interesting. My guess from a quick-and-dirty literature review is that the effect in real life is smaller than the lab effect. Nature is always finding ways to erode what you build.

Transitive

My wife ran across Cill Chais the other day. It sounded familiar. I gather that Lynn DeShazo modified the tune a bit, adding a chorus, to create the song Ancient Words. Michael W Smith covered it, and often gets credit for it.

Fine enough song, but one line is fingernails on the blackboard (*): "We have come with open hearts; Oh let the ancient words impart."

It wouldn't be that hard to fix, keeping the rhyme: "Give us what ancient words...", "Changed by what ancient words...", "We need what ancient words...", etc.

The next time the song comes up at the men's group I'll plead for a modification.

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(*) for those old enough to remember chalkboards. That video does not reproduce the sensation; not sure why.

Computer visualization

I have not seen much 3-D math visualization; I'm not sure why. Modern computer packages should make it quite easy to do, and I gather the 3-D goggles have become much cheaper. Even 2-D, when you are able to rotate and zoom on the image, can put on your desktop things that used to require craftsmen to build. This is part of a collection of math geometry models at U of Illinois.

This Is My Father's World

Think of us as God's agents in the world, agents with authority to issue decrees backed by God's Amen.

Does that last phrase seem out of place? We're told that everything is sustained by God. No act, good or bad, could exist without His power.

Sometimes, perhaps often, we have no idea of the magnitude of the executive order we've just signed God's name to.

One snowy day I decreed that I would stop in and have some ice cream on the last leg of my walk. And God ratified that – "Ice cream you shall have, and you also shall meet a fascinating woman in the shop." (46 years so far)

Sin is a little more like treachery, since not all our choices are so benign. We'll answer for every word, presumably for every action too. "What is this you have done with My power?" "Do I put AirTags on my brother?" didn't cut any ice the first time around.

16 years ago I wrote about part of this before; about God as the suffering servant.

Roman freedom and slavery

I found this discussion from 4 years ago interesting. I'm not expert enough on Roman culture (despite the silly claim that men think of Rome every day) to evaluate its take on the different classes of relationship and their utility today. (She thinks the classes of libertas, civitas, and familia are still relevant categories, though in different guises.)

Dolly

I never met her, but I gather from others' testimony that she was pretty universally liked and respected.

I have known people like that. They didn't have the fame, but they had the character, and I wish I was more like them.

Worship instruments

Some music in a worship service is meant for meditation, and some for congregational participation.

Never mind the former for now.

I once caught the fringes of an argument about which was the most important instrument. I won't judge whether that was a noble argument to have, but the answer seems pretty obvious, and none of the disputants touched on it.

The most important instrument in congregational worship songs is the hearts of the faithful. You try to encourage the faithful to lift their hearts to the Lord with songs they sing; so the voices of the faithful are the second most important instrument.

Since typically the congregants aren't as well trained as the stage singers, giving them voices to follow is critical to confident singing. Which puts the stage voices in third place.

Fourth – I'm not sure. Something that gives the beat, but doesn't make it hard for the congregation to hear themselves (which excludes almost all the drum kits I've heard) – a piano-like instrument, for example. Or organ – the keyboard types have the advantage of giving the pitch at the same time.

After that come the things that give flavor (guitar, brass) and control (the mixer).

Down at the bottom comes what I started out on – the monitors giving the musicians what they wanted to hear to play in sync.

Vote by mail

We overlook one of the ways in-person voting gives integrity to the results.

We think of ID – is the person handling the ballot who they claim to be, and is this person eligible to vote in the first place.

Can you extend this to mail-in ballots? We've various proposals for managing this, which you may trust or not, depending on your experience with software. The USPS just came out with some guidelines.

But there's another feature to in-person that's almost impossible to extend to the mail-in voting. Independent observers verify that the voters have gone into the booths alone. Nobody looks over the voters' shoulders, and ballots all go into an anonymous box (no box A for our Beneficent Incumbent and box B for the Evil Challenger).

When our youngest daughter voted by mail, the envelope needed a witness, which I was. For the actual "filling out of the ballot" phase, I left the kitchen. Of course. Anybody who knows me knows I wouldn't lean over her shoulder and make suggestions. But there's no way to prove that.

Perhaps a mail-in ballot was in fact filled in by the person who claimed to fill it in, and perhaps that person is a legitimate voter. That doesn't rule out inappropriate influence.

Our town allowed early voting. Mail-in was one way, but another was to show up at City Hall and vote there. That latter seems reasonable enough. It doesn't have the election monitors present, but you can never tell who else is going to show up and ask why two people are involved with one ballot.

Suppose we deprecate vote-by-mail. With exceptions, of course. For most of us, being out of town on election day is a choice. Not all – my parents were posted overseas for years, though with access to the US embassy, which could have coordinated a voting system. And, of course, those in the armed forces don't always know where they will be next week.

So we need to make some provision to cover at minimum as many of our overseas armed forces as are eligible to vote but are posted away from their voting district. I'd think that at bases this wouldn't be hard – finding observers, setting up a temporary dedicated room and a time for voting, having a single place to receive, collect, and mail back ballots… A ship with a long deployment is slightly more complicated – when do you mail things back?

Men in combat are probably out of luck as far as voting goes, though it might be possible sometimes.

But with the understanding that there are some exceptions which we could account for, what do we lose if mail-in-voting is hard? On the plus side, we lose ballot harvesting. On the minus side, some people get posted to a new location for a long time, from well before the candidates have declared to well after the election, and they won't get a chance to vote. In larger cities in the US one might have reciprocal agreements for receiving/sending ballots at the local city hall, but that doesn't help the oil platform guys much.

A system with integrity will have friction. How much of each are we willing to trade off?

AI writing and drawing

While it's good to have "le mot juste" immediately to hand, I enjoy composing the words myself, even if it takes a little longer to polish. I’d like to be the one other people quote, thank you very kindly.

On the other hand, my drawing skills are at the “Is that an elephant or a race car?” level, and so there’s a strong temptation to (if I could afford it) have AI create the illustrations. I haven't done so – the free versions gave me ugly and irrelevant slop last time I tried them, and I'm disinclined to throw money at it.

Athleticism

I asked for some assistance in learning proper stretching and core exercises. The trainer (about 24) told me most of the kids she saw got little exercise, and too often needed some remedial practices.

She went on to say that I'd obviously had a more athletic childhood.

I don't know if that's just flattery, or if she was serious.

Anybody who knew me as a youngster knows I was far far more likely to be closeted with a book than running anywhere. Perhaps afternoon wandering in a tropical jungle counts double as exercise? You sweat enough...

Anyhow, if she was serious, the kids she sees must really be in bad shape. I see plenty in visibly bad condition, but also plenty who seem just fine... Perhaps I don't see the troglodytes tampletadytes? (tablet dwellers)

Greater power

Which seems more powerful, to dodge Death, never letting it lay a glove on you and mocking it always just beyond its reach, or to let Death do its worst and shake it off three days later? Which has more promise?

Looking for little people

I'm sure there are people traveling to the Northern Cordillera of the Philippines right now (Yunnan would involve more surveillance and New Guinea more wicked insects) to find mushrooms, either to try them themselves or to sell to curious Americans. And quite a number who are finding similar-looking mushrooms and lacing them for sale to those curious Americans.

That particular hallucination is so specific... little humans running around, swimming in your drink, climbing the bookcase ...

We tend to see faces in things, so maybe there's something hardwired in the brain to reconstruct people-images, but these are supposed to be always small, and dynamic. If everyday experience weren't so devoid of traces left behind by little people, it would be fun to imagine these as invisible imps, but it's hard to write a story about characters that don't seem to do anything.

Archaeology of play

Some Sami stone circles were made by children, not priests.

The default explanation for things archeologists don't understand is that "it's religious."

Fortunately the Sami knew about them: "The local representative who accompanied Thomassen even showed him the place where his great-grandfather had made circles like these when he was a child."

I'd like to say "I told you so," and if I could remember when I posted about hard-to-classify artifacts, I would. Kids build too. I know I did. Their artifacts shouldn't last as long, being made of things children can carry, but accidents can preserve things.

Party platform

Running against Farage one finds a range of candidates, including Howling Laud Hope of The Official Monster Raving Loony Party. Count Binface et al are likely going to be ephemeral, so I will preserve the OMRLP's platform for posterity.

I like "Social Media will be taken down one day a week for a 'Remember when we used to talk' Day"

Doing the dishes

Some jobs we have to do over and over and over -- washing clothes, cooking, cleaning up afterwards, mowing the lawn, watering and weeding ... over and over.

It would be nice to have a "one and done" effort, where we didn't have to be so faithfully persistent. (Quite a few home improvement offerings cater to this desire.)

On the other hand, we're not so keen on "one and done" blessings: we like having blessings like our food supplied persistently.

What if..

we had a world without nuclear weapons? Donald Sensing has a picture. Or 12.

Old vulnerabilties surfacing

About 17 years ago I was designing the SCADA (PVSS II) control/monitoring of an alignment check system. It had taken a bit longer than it should for me to translate the programming jargon, but I got the hang of the paradigm after a while.

Word on the street was that this same software was used by the big boys for power generation and distribution, ditto water, etc. And that the security on the installations was laughable--once you got into the network you could monkey at will. It might be hard to cause damage unless you knew the details of the system. But if you coordinated an arson attack with a water outage... Something as naive as "clicking the power off" button could cause temporary problems, but editing the reaction scripts would cause harder-to-find issues.

This was a few years after 9/11, and one would have expected a certain heightened awareness of vulnerabilities. Perhaps there was, and the details were kept quiet while people tried to fix them. Or perhaps there was, and the cans were quietly kicked down the road.

I gather from the news yesterday that some vulnerabilities still exist--not least to denial of service attacks on such service infrastructure.

You can tell a friend had a big life

when you recognize less than a quarter of the faces in the crowded funeral reception line.

Ouch

Back in the early 70's a short book of humorous, sometimes ascerbic, religious poetry came our way. No, I have no memory of who the author was. I only recall a few fragments, one of which was:

Savior, like a shepherd lead us.
In Thy pastures fatly feed us.
We are Thine, do Thou defend us.
In Thy cause do not expend us.