Nord Streams

You know about the Nord Stream 1 and 2 pipelines: we can safely conclude they were sabotaged. Commander Salamander discusses it, and in the comments one finds that many people blame the US--not surprisingly, given Biden's -- shall we say ill-considered? -- remarks.

Trying to figure out why is a bit harder.

Russia already had them shut down, so what could they gain by breaking them? They could get credibility as a "we can do more than just this without going nuclear" as someone suggested at that link above, or demonstrate a bit of Stenka Razin-esque resolve (I won't let any benefits or joys distract me from the fight!)--but only if it is known that they did it.

I don't quite see how the US benefits, though there are factions here or in Germany eager to make permanent dents in hydrocarbon use--it's really scary if they've run amok. The pipelines aren't that deep; non-state actors could have done it. But I don't think Biden's handlers would let him actually damage the pipelines.

Ukraine, to try to damage Russian interests long-term--but these things can be fixed, and on the time-scale of the war would be if Russia cared to.

I'm missing something here. Maybe the internal factions have more freedom of action than I suspect.

UPDATE: The pipes involved are fascinating.

UPDATE2: I was out of town for a bit when this came up. An unmaintained gas pipeline with dropping pressure on one side can be a time bomb--and tinkering with it carelessly can trigger problems. So, maybe we can't safely conclude sabotage.

Re-reading

I mostly read things I've not read before, but now and then I re-read something for fun. The last four books I re-read for fun were Treasure Island, Descent into Hell, The Man Who Knew Too Much, and A Canticle for Leibowitz. I wonder if that reveals anything profound about my character. Does your list?

Curious results

I asked Amazon for "domra instrument". Of the first 19 entries, one was a decal of a domra player. OK. I was also offered a blue kazoo, a bongo drum set, a harmonica, a jaw harp, an Otamatone, a "wave bead ocean drum", a portable analog synthesizer, six kalimbas and five steel tongue drums. The next page includes more of the same, a Tibetan singing bowl, a percussion box (the wooden one you sit on), and some sheet music for a domra--which is at least within shouting distance. Asking for "alto domra" gets me sheet music, recordings, and blood pressure meters.

It's hard to believe the algorithms are that wild. They can't be blocking Russian-related vendors, can they?

Nope; asking for a balalaika returns an offer for a violin kit, followed by several for balalaika prima (and that blue kazoo again, and a ukelele). I guess the domra is just not weird enough for quick recognition, so it isn't so popular. Or that sponsored offers are shoved in anyplace they might be remotely relevant. But I still don't understand the blood pressure meters. Maybe they figure you'll need them after the interminable search for what you want.

UPDATE: "domra folk musical instrument" finds one, mixed in with with the kalimba and flute and wave bead ocean drum.

Tiny bonds

How do they bond those tiny wires in a computer? No soldering tip I have is small enough. Heated air is used to solder pre-soldered components to robot-registered spots on the board. (Have you seen what a resistor looks like? -- a tiny box with metal ends.) But that's not the whole story; there are sometimes little wires involved too--often where you can't see them, like inside the epoxy.

Themosonic bonding: a little bit of heat, a little bit of pressure, and a little bit of vibration--none are enough by themselves but together they suffice to bond tiny wires together. And the heat is kept low enough to keep from damaging anything else.

Oh, and epoxy is nice for keeping light off of sensitive chips.

Do a fifth of Americans agree with QAnon?

QAnon's been in the air for a few years now. One of the members of our Braver Angels group has a friend who's a true believer. I'd had only the vaguest idea of what they actually believe (assuming they all believe the same things), but since they seem to have some staying power, I decided to spend a little time trying to figure them out. I generally assume that for anything anti-establishment, Wikipedia takes the worst case and expands on it--I don't think this was an exception.

One article seemed pretty scary--One in Five Americans Agree with the Core Tenets of QAnon. That's a survey I had to see.

Figure 1 explains it. There are 3 "core tenets", and they lump "Completely Agree" together with "Mostly Agree" to get their numbers. Oddly enough, "Don't know" was never more than 3%.

5%+11% at least mostly agreed that the "government, media, and financial worlds in the U.S. are controlled by a group of Satan-worshipping pedophiles who run a global child sex-trafficking operation." That seems pretty far out there--but look at the format of the responses. Completely agree, mostly agree, mostly disagree, completely disagree. There's no option for disaggregating the bundle of claims. One could believe that the elite include some fraction of pedophiles (what was Epstein up to?), and that the elite cover for each other (what's new?).(*) How do you slot that belief into the questionaire's framework? "somewhat=mostly?" I don't quite get where the "Satan-worshipping" is supposed to come from--some aspects and actions of our elite seem satanic but I, with Screwtape, don't think they need to believe in the devil to accomplish them.

6%+16% at least mostly agreed that "There is a storm coming soon that will sweep away the elites in power and restore the rightful leaders." This seems remarkably optimistic. I'm not quite sure who the "rightful leaders" are--nominally we pick them, though I don't know who voted for the "White House" that keeps walking back Biden's pronouncements. In any event, that the current elites will eventually be swept away is something history tells us--nothing lasts--it's the "soon" that is debateable. "If it can't go on forever, it won't"--but once again, there's no option for disaggregating claims.

5%+13% at least mostly agreed with "Because things have gotten so far off track, true American patriots may have to resort to violence to save our country." I seem to remember that this was an article of faith for the left back in the late sixties and into the seventies. Given the avalanche of panic-mode news stories we're buried in, I'm a bit surprised the numbers aren't higher.

Bottom line--I'm not persuaded that QAnon as such has as much traction in population as PRRI wants me to think. If their questionaire had allowed disaggregation of claims, or weighting of how certain their predictions are, I'd find it more useful.

---

(*) We always have a few pedophiles among us, including the elite. It wouldn't be terribly surprising that the incidence would be higher among the elite--there are always plenty of groupies, but a) one could get jaded and b) I suspect a lot of the groupies want something that their target may not be disposed to allow, such as political input, notoriety, etc. Some simalacrum of innocence might be attractive.

Si vis pacem

I read Commander Salamander for news about the Navy (if anybody knows something similar for Army or AirForce, I'm all ears). He has an all-too-regular post on diversity, about the things we spend time and money on instead of defense. I'm curious what our adversaries' frank opinions are. I can guess, but the real thing is likely more colorful.

Probably the best we can hope for is a Zhuge Liang bluff, with the city doors open and the general playing music on top of the wall, but I'm afraid the world has already seen these commanders at "work" and knows better.

Bateman

Althouse referenced an article on "feminist science". Charity demands that I ignore the "feminist science" aspect of the article, but the claim that Bateman's principle had been disproved was interesting. "Hogamus Higamus, Men are Polygamous. Higamus Hogamus, Women Monogamous" is the executive summary of the principle. Careful studies have both supported and deprecated the claim--wikipedia has summaries.

There's been some objection to that formulation for a long time--I don't think you can attribute it to the sex of a modern researcher. An old tradition (possibly thanks to the glorification of monk-hood) held that women were the dangerous sexual aggressors. (Dangerous to one's morals, as opposed to physically dangerous, of course.)

The reversal in attitude is interesting. I don't think it demands explanation, partly because I'm not confident in how universal those claims about antiquity are, but it seems reasonable that if the pool of available men becomes small thanks to high death or imprisonment rates, competition among women should increase. I wonder how Augustine would have interpreted twerking. "We've always seen African women gather in villages and wiggle their butts in loincloths, especially during rites of passage to signify that they are fertile"

I see that Razib Khan is addressing a related issue, but it's behind a paywall.

Predatory conferences?

Are there Predatory science conferences?

Yes. For about a dozen years I've gotten email invitations to speak at physics conferences where the topic had nothing to do with my field--sometimes it seemed to be more about chemistry. I couldn't be bothered to learn about them--if they didn't know what I did well enough to target me better, there was something wrong with their pitch.

Predatory journals aren't new either--I remember a student (who went on to better things, fortunately) who, needing a publication in his record, wrote up the meaning of the terms in the Bethe-Bloch formula and submitted it to a journal that took anything. Although, to be fair, I don't know if he had to pay for publication. Somebody does, one way or another.

"Speak no evil" rabbit chasing

The "See no evil, Hear no evil, Speak no evil" Three Monkeys (or perhaps four: "Do no evil") may distantly relate to the Analects of Confucius: "Look not at what is contrary to propriety; listen not to what is contrary to propriety; speak not what is contrary to propriety; make no movement which is contrary to propriety". At any rate a philosophy which used this 3-fold admonition may have come from China to Japan in the 8'th century, and the maxim became part of the folk religion of Koshin. The saying in Japanese is "see not, hear not, speak not", in which the negation part "zaru" is a pun on the word for monkey. Who could resist?

The tie-in of Koshin with the monkeys has to do with the Three Corpses (or Worms), malevolent creatures that live inside humans. Every 57'th day in a 60-day cycle, while the human sleeps, the creatures ascend to heaven and report on their host's deeds, taking special delight in reporting the misdeeds in hopes of punishment for the poor human. (your own personal accusers)

At first it was only the elite (the ones who first adapted the faith) who tried to stay awake all that day and night to keep the 3 from reporting, but apparently the notion of having a regular all-night party became popular. That there is a relationship between the monkeys not seeing or reporting on evil and the hope that the evil spirits will do the same seems clear enough, but the details aren't.

Things not good to say

I'd looked up one Godspell song, so youtube offered me "Turn back, O man." The lyrics sounded a little off, but my ear for lyrics has always trended mondegreenish, so I looked it up. It turns out to be a hymn from 1916, though with decidedly different music and choreography. And the "off" bit is in the original: "Yet thou ... Still will not hear thine inner God proclaim".

When I hear "inner god" or "god within" I don't think of "indwelling Holy Spirit" but either Hinduism or the semi-gnostic do-it-yourself denial of "organized religion" that's been so popular in our culture. As far as I can tell, that's what most other people think of too, so as AVI points out, that's what the phrase means now--unless you preface it with an explanation.

So if we want to use the old hymn and keep the intended sense (at least I hope the intent was orthodox), we should probably revise it, because the words, though strictly accurate, are no longer good to say.

I wrote before that: A husband may say of his wife: "She is mine." That is true enough, but it is much safer to say "I am hers." Likewise "Mother of God" is a true title for Mary, but a dangerous one to try to use. And a Christian, given God's Holy Spirit, with a changed and increasingly sanctified life, may truthfully stand to pray "God, I thank thee that I am not like other men"--but I wouldn't recommend it.

I've recommended Charles Williams' works before--but I probably should do that with care, since he frequently uses occult environments, and I know of at least one person who became interested in tarot after reading Williams. (The underlying themes of his novels are Christian, but an on-ramp can become an off-ramp.) I'm not sure I ought to say "Read him" to all and sundry.

The slogan "Blue Lives Matter" seems banal enough, but that's not the way it's taken--I'd use the phrase with caution. It isn't always a good thing to say.

By the same token, "Black Lives Matter" isn't always a good thing to say either, without some explanation. Does it refer to the banal plain meaning, or the political slogan that stands for a lot of claims--some true and some lies, or does it refer to the corrupt organization whose main interest, if their children's education material is any guide, is unusual sexual claims?

But

Am I God to tell you what you shouldn't say? Quite a few Catholics will assure me that honoring Mary in no way diminishes from their worship of God--and I know that's true for some friends.

Will people die because you pulled an Andrew May?

Are you God to tell me there are kinds of knowledge too dangerous to be learned?

Granted, I think we can agree that if you discovered how to make a 25kT nuke from a speakerphone and a box of Oreos we should suppress that information. But I decline to believe that closing your eyes and pretending will have much effect on already active realities. (Grim is more hopeful than I about that writer.)

Yes, I self-censor. I tried to teach the kids to too. But I object to you trying to do it for me. I won't do it to you.

Painless tattoo

Microneedles are made of ink in a soluble matrix, and bundled into a pattern that is pressed onto the skin for a few minutes until the matrix dissolves.

Prausnitz’s lab has been researching microneedles for vaccine delivery for years and realized they could be equally applicable to tattoos. With support from the Alliance for Contraception in Cats and Dogs, Prausnitz’s team started working on tattoos to identify spayed and neutered pets, but then realized the technology could be effective for people, too.

Bundling of the microneedles onto a patch sounds a bit complicated. Anything customizable would probably require a fancy machine to manipulate the needle stock (limited color palette?) to embed them in the patch. Doable, and if there were economies of scale it might be saleable. I assume you'd have to build up a market first, with standardized images and messages.

Two problems come to mind.

How stable is the delivery system? I assume that some of the microneedles will fall out with handling. Folding the patch would probably make an empty line, sort of like an electronic billboard with a glitch. That would need manual repair--the tattoo artist would still need to be there.

This lends itself to nasty pranks. Your buddy is drunk? Slap one on, and by the time he notices it's too late. Plant one on a beach chair; when the suntan is done there's a new tattoo on her leg, or mostly so.

Even painless, I think I'll pass. I kind of like my skin.

all for the best

In checking a sidenote to a study on Jeremiah, I looked up It's All for the Best. I concluded that the song had too much flippancy to be useful, though the solo of Herod/Judas singing "Some men are born to live at ease, doing what they please, richer than the bees are in honey Never growing old, never feeling cold, pulling pots of gold from thin air" and ending with "Someone's got to be oppressed" is perfect--beautifully cold.

They end singing "it's all for the best" on top of one of the twin towers.

In some sense that's true (following Romans 8:28), but it is hard to know how 9/11 worked for good, even for those who love God. Somehow.

Math for scientists?

In Quillette, Thornett says most STEM majors should skip calculus and learn statistics. I was in physics, which of course needs calculus and differential equations for the models the field uses--and more than just those. But most week-to-week research work didn't use anything beefier than trig--there were months where all I was doing was programming, or hardware work. On the other hand, there were (much shorter) spells when derivations were all I did.

More statistics would have been useful, especially if better targeted to hypothesis rejection, etc. Simple statistics should be taught as soon as possible, starting before high school. How to Lie with Statistics is good.

But I don't think calculus is intrinsically all that hard. There are only two main concepts to learn--what's a derivative, and what's an integral. The rest is just algebra--and the clever changes of variables and whatnot that nobody actually uses in the field. We look them up, or if we need numerical answers, use programs designed to do integrations in stable ways. (Just trying to translate your textbook equations into computer code is fraught with pitfalls thanks to the finite resolution of numbers in a computer.)

I think we can do calculus better if we divide it. One short course would be calculus basics (differentiation and integration), another would be calculus methods (how to play the fancy games), and then you go on to advanced calculus (with the fancy rigor). The first is the one you require of non-math majors.

True, a field geologist may not use much of it, but what happens when he wants to model crustal pressures? Even having just a passing knowledge of rates of change beats just accepting a black box result. I wrote earlier of different levels in math: arithmetic, understanding the abstractions when explained, able to use the abstractions yourself, and able to do research. I think a minimum for most scientists would be "understanding the abstractions when explained." The field geologist needs to know enough to know the tools to use, and have an approximate notion of what sort of results the computer program should give him and why. But how much more depends on what he'll be doing.

There's a story that Terry Pratchett was addressing some physicists, and explaining that he'd wanted to become one, but had problems with calculus and wound up a writer instead--and met with laughter, as people explained that they rarely used anything more than algebra. They were wrong and Pratchett right. If he wanted to understand the field, he needed to know the language. And in the event he probably contributed more as a writer than he ever would have as a physicist.

From "Physicists continue to laugh", translated by Lorraine Kapitanoff:

Group Questioned	Total	Knew	Don't Know	Answer
Writer-Realists	11	7	4	They argue until hoarse in smoke filled rooms. It is not known why they set up unintelligible dangerous experiments using huge apparatus.
Writer-Visionaries	58	58	0	They work on enormous electronic machines called electronic brains. They work primarily in the cosmos.
First year college students	65	65	0	They speculate a lot. They make discoveries no less than once a month.
Graduate students	30	10	20	They solder circuits. They ask the older ones to find the leak. They write articles.
Young scientific staff members, experimenters	19	19	0	They run to the equipment department. They scrub rotary vacuum pumps. They flap their ears at seminars.
Young scientific staff member, theoreticians	19	19	0	They converse in corridors helping to make great discoveries. They write formulae, mostly incorrect.
Older scientific Staff members	7	6	1	They attend meetings. They help younger scientific staff members to find the leak.
Members of the personnel department	5	5	0	Experimenters must arrive at 8.25 so that at 8.30 they can sit silently next to apparatus which is running. Theoreticians do not work at all.
Members of the guard force	6	6	0	They walk back and forth. They present passes upside down.
Representatives of the Ministry of Finance	18	18	0	They spend money to no purpose

Looking for ideas

The teaching garden in the park has had good crops of beans, and the early tomatoes were fine, and most of the flowers (the ones that weren't accidentally weeded) did well. The kids liked those, especially the flowers. (The rest of the tomatoes find it too cool to ripen, and the peppers are slow.) Carrots don't grow very big, but the kids recognize those. (One had been sure that carrots came from the store.)

But while onions and radishes grew very nicely the kids had less than no interest in them, and they don't believe that anything but iceberg is real lettuce. Squash looks weird. They'll take home bags of greens sometimes. The adults haven't been coming by much.

As you can see raspberries or apple trees are out of the question in the small containers, and for teaching purposes I think we want annuals anyway. A few weeks after the kids do the planting we have to have a little lesson on the how and why of thinning.

Any suggestions for kid-friendly zone-5 crops?

Before you get the wrong impression, my wife does the lion's share of the gardening and teaching over there; I'm an occasional auxilliary to do heavy lifting and try to show kids how to wash carrots.

Bertrand's Paradox

Simple question: Given a circle, what's the average length of a chord of the circle? OK, maybe that's too messy; try something simpler: What's the probability that a chord will be longer than the side of an inscribed equilateral triangle (radius * √ 3)?

Depending on what method you use to define the chord, you get 3 different answers, all of which look perfectly reasonable. The first is the most obvious--fix one point at one corner of that inscribed triangle, and then just pick other points on the circle to draw the chords to.

If you draw the picture, it seems instantly obvious that you should get 1/3 of the chords being longer than the specified value. But if you look closely, you might notice that for the same small angular range, the density of chords for points close to the original point is higher than for those chords reaching to the opposite side of the circle--is this the kind of uniformity of distribution we want? It would seem to give too many short chords, for a lower probability of long ones.

Other approaches give 1/4 and 1/2 for the probability. Therein lies the paradox--which of the 3 values is it? The video (3blue1brown) doesn't need much more than high school geometry; give it a whirl.

Bottom line--sometimes you have to be very very careful to define what you are trying to measure.

Icons

One of the problems with being the icon of a nation is that you get blamed for what the nation does. It isn't surprising to see things like ""Most of our grandparents were oppressed,” Mugo tweeted hours after the queen’s death Thursday. “I cannot mourn.”" She even gets blamed for not apologizing for slavery--which the UK particpated in but was instrumental in uniquely helping end almost a century before Elizabeth was born.

Kaiser Wilhelm got a lot of blame, but he wasn't just a symbol--he helped push the Great War.

That doesn't excuse the over-the-top nastiness the infamous CMU prof poured out, of course.

Puppies under the table

The passages about the Syrophoenician woman always seem odd. Jesus had already demonstrated care for gentiles, going out of His way to heal a demoniac. So why the strange remark?

The best I can do is try to visualize the scene and figure out what other people would have been thinking, and then guess--and since my guesses aren't consistent I'll leave them out and you can make your own.

Jesus left the majority Jewish region and is in the neighborhood of Tyre--reason unspecified, but there are probably a lot more pagans than Jews here. He enters a house--presumably a fellow Jew's, presumably welcomed, and with at least some of the 12. The passage doesn't say if they were preparing to recline at the table to eat, though that would have had to happen sooner or later. At banquets the Greeks and richer Romans reclined with the men eating first; I gather there's not a lot of evidence of Jewish practice here--and family meals were different. Greeks used chairs or stools around a table for family meals, low tables for banquets.

So who is present, and what's going on? This isn't a Jewish area, so I'm not sure they had the custom of open door banquets where non-guests can stand around and marvel at the feast and the wonderful guests the host has found. The door is open, though, for temperature control, if nothing else. If the host is introducing his family the children will be present, otherwise probably not.

You'd get dogs only at the family table--I leave to you to imagine what dogs would do at one of the low banquet tables. (Jesus' word for dog is a word for pet or puppy, not the street dogs of universal disrepute.)

Jesus' analogy is of a family occasion, and the gentile woman is included. What does the homeowner think of this? He'd almost certainly think of the wild curs if you mentioned "gentile dogs," not pets; and the assumption that the gentile woman is a loved part of the family would be a bit jarring.

Was the analogy intended for the woman, for the host, for the 12, for all of them? If it is a gentle rebuke to the woman, what is He rebuking? (We aren't always told the details--see Mark 9:18-19--why does He call them perverse and unbelieving?) If for the host, what attitude is He trying to correct? If for the 12, what is He trying to show (sent to the lost sheep of Israel--but we know He didn't limit Himself to them)?

Elizabeth

I've preference for monarchs who stay out of the way, but that may be something imbibed with the rest of our culture. Probably if I'd grown up with kings, I'd have a feel for the king as an icon of the people, and maybe if the king were sovereign even a respect for a king's authority. It's not part of my mental furniture, though. I wonder what it would feel like.

Elizabeth did her duty as a "monarch who stays out of the way." I wonder to whom she confided what she really thought about the ministers and policies. Maybe Philip; maybe nobody. Rest in peace.

At the side of my desk sit some coins and bills left over from Canada. I wonder how long they'll keep making money with her face on it.

And, of course, I wonder about Charles. I'm told he's unpopular; does he have the gravitas to be an icon?

Harassment

Antarctica is a hard place to work. You're cooped up with the same people for months working and sharing close quarters. Different people sometimes answer to different agencies. And some are jerks. A few years back the first flight to the Pole at Austral Spring brought a US marshall to arrest a man. I don't know what means they'd taken to constrain the culprit before the marshall arrived.

It seems the Antarctica program has had problems with sexual harassment. Apparently the bulk of this is at McMurdo, which has twice the population of all the other stations combined, and apparently has much laxer staff vetting. The upper echelons think most of it is alcohol-related, but complainants disagree. Because this is voluntary survey and focus-group based, there aren't numbers of incidents, much less broken out by who and when.

Harassment training modules are designed for workplace issues, and don't fit so well the environment where workplace and living place is the same place with the same people. They need better designs. Coordinating complaints and responses between (e.g.) the Air Force and the NSF seems like a no-brainer, but hard. (important things are always simple; simple things are always hard) Figuring out who causes problems and why (alcohol can breed misunderstandings) might go some way towards cleaning things up.

I've never been there. If I'd gone: I'm an older man and orders of magnitude less likely to be pursued, I'm not into the dating or bar scene so I'd not be hanging out with young ones who were, and I'd not be taking liberties with non-existent subordinates. I don't think I'd have seen any harassment. It'd be like different worlds.

Teacher at home

Milpitas teachers are struggling to afford housing. The school district is asking parents to take them in

The average rent for a one-bedroom apartment in Milpitas is now nearly \$3,000 a month, a 15% spike since last September... That works out to roughly half the annual salary for early-career teachers in the district, who earned around $68,000 last year.

Some districts are looking to create teacher housing on school property--but that's expensive.

Imagine the relationship a family would have with a live-in teacher. What sort of boundaries get set? Of course one model doesn't fit every situation, and I can't imagine everything being successfully firewalled. So how much extra help does Junior get from the teacher? How much extra help does the teacher get from the family?

Some years ago I mused about the possible increase in the number live-in servants. I should revisit that. We'd need some changes in home design.

Some background on Roman slavery

I got side-tracked into looking up Roman slavery: apparently its extent is not well attested and consequently estimates are disputed. I hadn't realized that exposed babies might provide a slave pool--I'd heard of exposed girls being raised to be slave prostitutes, so it makes sense that boys might be raised and sold too. Some might have been bought from captors outside the Roman Empire--the surrounding nations fought each other too. "Adverse moral judgments focus on the supposed greed and general turpitude of slave dealers, who were accused of tricking out their wares to defraud buyers, and likened to pimps"--note that the concern is for the customers rather than the slaves.

His estimate of the free population in the cities and countryside is 6.5-7.5M and 49-52M respectively, while estimates for slave populations are 1.3-1.9M and 3.5-6.5M respectively: 20%±2 slaves in the city vs 10%±3 in the country. They weren't all captives--children born to a slave woman (provided she was a slave throughout the pregnancy) were also slaves.

But what's known? There's no data from Republican Rome so: "We are reduced to the mere assumption that slave prices in Republican Italy ought to have been relatively low during the massive expansion of the regional slave complex."

The relative prevalence of private sales versus transactions arranged by professional dealers is unknown. In slave markets, slaves were displayed on platforms and could be undressed for closer inspection; new arrivals were marked with chalked feet. Slaves wore placards (tituli) advertising their qualities around their necks (including their origin, state of health, and propensity to run away), or special caps (pillei) in those cases where the seller would not offer guarantees. Extant sales contracts, primarily from Egypt with rare additions from Italy and Dacia, testify to the scrupulous observance of formal legal requirements, and give us a rough idea of the age distribution of traded slaves, dominated by individuals in their teens and twenties.

You'll probably have read already about diffences between Roman slavery and ante-bellum US slavery (and Caribbean slavery, different yet again). This is interesting background detail--and explanation of what's not known.

"Ideally"

I've read several times that having renewable energy sources charge up automobile batteries is the ideal future for automobiles. But if we're talking about "ideal", how about using renewable energy to synthesize octane or nonane? These have a high energy density; we understand the safety issues very well; we have mature technologies for delivery and for engines.

The only thing we don't have is the synthesis technology. But the phrase was "ideal", not "feasible anytime soon."

Even if it was feasible, right now it is so cheap to distill octanes from oil that I can't see anybody trying to synthesize n-octane for anything other than curiosity's sake. And of course there's the "what's the raw material?" question--we'll run low on coal one of these days too. CO2 or plant waste would be "ideal" raw materials.

Different "ideals" send you in different research directions. Batteries or synthesis?

Interferences

The Niagara Gorge rapids show places where the water seems to sweep high over some obstacle, but the signage assures us that the bottom is scoured pretty flat. Reflections off the sides of the river could produce standing waves where the reflections interfere constructively. It reminded me of shock diamonds, except with incompressible fluid and an irregular channel which makes the reflections show up irregularly.

When there's one road

Scores of travelers leaving the country via the Roberts International Airport nearly missed their flight on Tuesday due to the heavy and uncontrolled traffic on the RIA Highway caused by the United Methodist University’s graduation.

The airline was gracious enough to have delayed by an hour to give passengers a chance to board since half of its travelers were stranded in the traffic. The hour delay in Monrovia, however, led to many passengers missing their connecting flights from Accra, Ghana to other destinations.

There's no other good way to get there. Maybe you could get a ferry ride at SNAFU, but probably not on short notice. And I was complaining about Pittsburgh traffic...

UPDATE: The last time I was in Liberia, there was one working stoplight in Monrovia, and stop signs were meaningless unless enforced by a policeman.

Canoe Plants

Polynesians brought along plants on their explorations, so that wherever they might land, they could produce the foods and tools and medicines they would need to survive, and perhaps travel onward from there. The link lists 24 plants taken to Hawaii, many of them serving multiple purposes. One plant might just be used to make rope, and another produce food, medicine, materials for clothing and for building.

Of the 24, 11 were used for food, 1 for an intoxicant, 12 for building materials and tools, 8 for clothing and beauty, 15 for medicine, and 3 had religious use as well.

They varied from tall trees to small garden plants. Some went wild as invasives, and others required careful cultivation and, in Hawaii, are almost gone.

Math brains

"Are All Brains Good At Math"

Elizabeth Landau should have been clearer about what math is. Counting ability seems hardwired but needs a language that is the start for math. To be able to understand something in math when it is explained to you is another capacity. Being able to use the abstractions yourself is yet another, and being able to do research a fourth (and much rarer) thing.

The answer to her headline question is, as you instantly guessed, "No." She should have asked some parents about their children and math. Some take to the first three types quite easily, others get the first and sometimes the second but struggle to use the abstractions. Same environment, same genetics--random variation.

I believe we can do much better with the second type (understanding when it is explained) with better explanations. I'm trying some things myself. Youtube has some excellent teachers and animators (motion works so much better than little arrows on a page!)--much better than I. And as far as I can tell, Barbara Oakley is correct--you need a foundation of memorization. Perhaps one can find ways to make the requirements less frightening (timed tests could be scary), but there's no royal road.