Saturday, April 29, 2023

I'll pass

A penny-farthing (somewhat modernized) on back roads and back trails. I'd not be comfortable walking that last one.

People race them too.

Maritime oddity

Today's Maritime traffic has a very odd feature: from about Ecuador to French Polynesia is a purple column of what is mostly classified as "Pleasure Craft" (without a name). One suggestion I heard was "Maybe a race?"

UPDATE: Douglas2 found the answer, in the comments below. Thanks!

Friday, April 28, 2023

"Don't just do something, stand there!"

Please!

So you have a theoretical amelioration for putative global warming. Great. Are you sure there are no side effects? Warming is potentially good for some areas; did you ask them about your plan?

Thursday, April 27, 2023

The Provincial Letters

I'd read Pensees, but not The Provincial Letters. It seems some things don't change much. A sample:
"Do not flatter yourself with that," said the father; "there are still such things as mortal sins- there is sloth, for example."

"Nay, then, father dear!" I exclaimed, "after that, farewell to all 'the joys of life!'"

"Stay," said the monk, "when you have heard Escobar's definition of that vice, you will perhaps change your tone: 'Sloth,' he observes, 'lies in grieving that spiritual things are spiritual, as if one should lament that the sacraments are the sources of grace; which would be a mortal sin.'"

"O my dear sir!" cried I, "I don't think that anybody ever took it into his head to be slothful in that way."

"And accordingly," he replied, "Escobar afterwards remarks: 'I must confess that it is very rarely that a person falls into the sin of sloth.' You see now how important it is to define things properly?"

History

AVI has some musings on history and what is possible and what isn't.

My wife was listening to a youtube series on Gettysburg places and museums, and the obvious question came to mind--When they reconstruct a site, what time do they reconstruct it to? Day 1? Day 2? When the house was a home, or when it was a sniper roost, or when it was a field hospital?

Or perhaps reconstruct it as it was when the new owners brought home their twins, or when the daughter of the house accepted the proposal, or when the materfamilias died--maybe thousands of significant events in only a century and a half.

Sunday, April 23, 2023

Church Fathers and the Babylon Bee

From Tertullian, via Pascal:
If the reader has met with passages which have excited his risibility, he must ascribe this to the subjects themselves. There are many things which deserve to be held up in this way to ridicule and mockery, lest, by a serious refutation, we should attach a weight to them which they do not deserve. Nothing is more due to vanity than laughter; and it is the Truth properly that has a right to laugh, because she is cheerful, and to make sport of her enemies, because she is sure of the victory. Care must be taken, indeed, that the raillery is not too low, and unworthy of the truth; but, keeping this in view, when ridicule may be employed with effect, it is a duty to avail ourselves of it.

To treat them seriously would be to sanction them.

From the same letter: "according to St. Augustine, "charity may sometimes oblige us to ridicule the errors of men, that they may be induced to laugh at them in their turn, and renounce them"

But.. "the same charity may also, at other times, bind us to repel them with indignation"

Yes. I'm afraid so.

Friday, April 21, 2023

Constantinople

I had no idea so many old images of Constantinople existed. Or that a serpent column (a bronze column topped with snakes) made as a votive for Apollo would wind up moved to Constantinople and used as a Christian monument. (Good grief! Amazon wants 104.5 for that book!)

The author's research appears on another site as well, which includes a section on the additional fathers: writings of the Church Fathers that aren't in the usual collections. You can spend a lot of time exploring...

Thursday, April 20, 2023

An Oversight

When I was young I was "the cat who walks by himself, and all places are alike to me." Or at least that was my bent; in practice I did like sleeping in a bed, and liked other things I took for granted.

But somehow or other I overlooked one of the more obvious characteristics of cats: napping.

I am trying to correct the oversight.

Wednesday, April 19, 2023

Speculating beyond the author's intent

The last line of the Bergmans' song "What are you doing the rest of your life?" runs "All I ever will recall of my life is all of my life with you"(*)

It's not perfectly precise. I do in fact recall some of my life before I met my wife. It's hazy, but lots of things in my past are. But it does feel like the most significant part.

Perhaps our life with the Spirit of Christ will have a similar retrospective. Will the Spirit transform everything, or only what we let Him?


(*) Quite a contrast from the almost cowardly line "I don't want to change your life" from the song "I'd really love to see you tonight."

Friday, April 14, 2023

Ancient steel

AVI sent me a link about an iron chisel (900BC) from Rocha do Vigio (Portugal), which possibly was effectively tempered steel.

The paper has more details about the chisel (they were able to do studies on the haft, but because they are destructive, not on the tip) and their attempts to reproduce the stelae that seem to date from that era also: plus or minus a couple of centuries (some say 1300-800BC, others 1000-600BC). The rocks were of an extremely hard varieties of quartzite and quartz-sandstone. They tried stone chisels, which worked about as well as you'd expect. They tried replica iron chisels made using the processes they knew were in use--some hardened by heating and quenching, and one left unhardened. The unhardened one didn't do much of anything. The hardened ones did, though they had to be resharpened every 5 minutes, and re-hardened after a while too. And:

Specimens in four representative binary alloys with 10, 12, 14 and 16% tin have been cast by Bastian Asmus, ... The unambiguous result on the quartz-sandstone was that none of the bronzes could penetrate the surface

I'll get back to that in a moment. It does sound like the sculptors needed something better than one of the out-of-the-box iron chisels of the area.

The iron chisel they found was in spectacularly good shape--when they did a section of it the bulk of the artifact was uncorroded. They could determine the chemical makeup of different regions of the chisel. It looked rather as though an inhomogenous bloom was hammered into a blob that was made into a chisel. Some sections were high carbon, others not so much. Maybe they paid better attention to the tip, but if the haft makeup is any guide it seems as though they weren't being systematic with the iron makeup.

I suspect that a lot of technological progress now and in the past has come about when men were "just playing around." You can come up with a just-so story or three for discovering what can happen (if the iron happens to be the right makeup) when you quench red-hot iron. And if the overseer is curious about why some rods got tougher and others didn't, he might come up with some rough-and-ready tests for what "good" iron tips should look/taste like. Then everything depends on how secret he wants to be about it. "Gorri made really good iron, but his apprentice's stuff is mediocre."

Usually I put in a phrase like "what jumped out at me was", but several things did this time--mostly to my admiration. I liked that they tried to cut stone with stone; covering all the bases. But they said their bronze chisels "have been cast by". Bronze was hammer worked for maximum hardness, and the result is supposed to be about as hard as unhardened medium steel. One variety of bronze can be hardened to 95 HRb, which is comparable to some low end steels. I wonder if the test was quite fair--if the bronze was merely cast and not hardened.

And, btw, high carbon steel rusts faster than iron does. We're less likely to find steel artifacts, and might draw the wrong conclusions from the absence.

For the curious, Neil Burridge offered one of his bronze swords for destructive testing. It doesn't hold up to modern steel swords, but other experiments say it would have been a match for old iron swords.

Thursday, April 13, 2023

crypto

I've been dubious of cryptocurrency.

Aside from its volatility--which makes bitcoin pricing unpredictable ("Nope, the price is now .00457 bitcoin. Plus the tip.")--it wasn't obvious that the tools for manipulating things were either as bulletproof or as anonymous as advertised. The link doesn't quite describe how the feds rolled up bitcoin networks, or under what circumstances they can trace transfers now, though it says some private companies can do some of the work.

But I wonder what happens if some obscure number theorist (e.g. working for the NSA) discovers a new algorithm that, as an unexpected side effect, makes blockchains easier to maliciously manipulate.

If our government endorses a cryptocurrency, I'll be certain that they have backdoors to it. Why would they otherwise? Seriously. The value of the dollar is in the monopoly of its production by and the trustworthiness of the US government. Without ways of verifying that monopoly, it loses a good deal of its value.

Wednesday, April 12, 2023

Inside an LED bulb

Their light isn't as nice as that from incandescents, but they are good for science demos (diffraction grating slides are unbreakable, unlike prisms) and they last. Usually. This one was in the same fixture as an incandescent which has lasted for quite a few years.

It isn't easy getting everything in focus at once, but the ugly solder blobs ar attached to a bit of printed circuit board that almost looks like it is delaminating, although poking it with a knife didn't break it. There are spatterings of solder on the board nearby, and that white stuff on the edge of the solder is some kind of powder. Osram brand, made in China. I suspect the soldering job was manual.

Saturday, April 08, 2023

Cautions

To keep seedlings from growing leggy and spindly, it helps to provide them with a gentle breeze. We have acquired some small fans.
  1. This product is not a children's toy, for children under 10 years old, please use under the supervision of a guardian.
  2. Please do not knock this product, otherwise it will cause internal damage.
  3. Please do not occupy this product in a fire to avoid the risk of explosion.
  4. If the product becomes abnormally hot or deformed during using, please stop charging immediately.
  5. Please do not use this product in a twisted environment (such as a bathroom) to avoid short circuit damage.
  6. If abnormal phenomena are found (such as burnt smell or abnormal sound, etc), please cut off the power supply immediately, please do not disassemble or modify it without authorization.
  7. Please do not put the product into the fire to avoid the risk of explosion.
  8. During the operation of the fan, do not insert your fingers and sharp objects into the mesh cover to avoid personal injury or damage to the fan.

It has apparently similar instructions in other languages, and yes, the French version expects the bathroom to be "twisted" as well. I am trying to picture that.

Thursday, April 06, 2023

Thin

Our Bible study wrapped up a study of Jeremiah, and one of our men joked about Accentuate the Positive. We got a good chuckle out of that, though it is good to remember Who ultimately wins here.

Of course it isn't always in us to be positive about a situation, and it isn't always something to strive for anyway--Jesus wept.

And we have hope. Given Who promised, it can be joyful hope. So, at least in theory, we can, paradoxically, mourn in joyful hope.

It makes "Accentuate" sound kind of tinny by comparison.

Speaking of tinny, at Christmas we hear "A thrill of hope--the weary world rejoices, for yonder breaks a new and glorious morn", and, "I'm dreaming of a white Christmas just like the ones I used to know, where the treetops glisten and children listen to hear sleigh bells in the snow." The one acknowledges pain and hope, the other is a curated memory.

Monday, April 03, 2023

rebar

I've seen enough rusty rebar inside spalled concrete to have wondered if there's something better than iron rebar. Concrete is good under compression, but has poor tensile strength--metal is pretty good at the latter, and can help provide residual cohesion and strength even when there's been earthquake damage. interesting article on tradeoffs, read it Most concrete lets air and water in, and the rebar rusts, swells, and bad things happen. I'd figure that differential thermal expansion wouldn't be good either (leading to cracking), but the sources I've perused haven't mentioned that as a significant problem.

Of course the first thing I didn't think of was stainless steel, which holds up to corrosion a lot better, albeit at quite a bit more expense. For the rebar, that is.

I wondered about non-metallic rebar, but didn't have wide enough experience in materials science to guess at good alternatives. How about rebar made from basalt melted and spun into fibers mixed with resin? You can guess at some downsides (no sharp bends, more expensive, transverse strength is low compared to steel), and there's some degradation of tensile strength if it gets hot.

Something new every day...

Saturday, April 01, 2023

Learning

"Sometimes people ask me how I know all the random s-t I know (with varying degrees of politeness and belief in its veracity), and all I got is 'I have ADHD, an internet connection, really good research skills, and zero self-regulatory mechanisms' " @rahaeli on r/adhdmeme