kengr

I came across a reference to a Tesla valve today. Far from the first time. But this time it clicked with a old memory.

Back in the late 60s, my mom bought a tabletop fountain. I got curious and took it apart to look at the pump (I put everything back together just fine). It was rather odd. a donut shaped magnet with some wire coils and a copper tube thru it.

The only moving part was a steel tube that fitted inside the pipe and had oddly shaped plastic pieces on its ends. When AC power was applied, the tube moved up and down in the pipe at 60 Hz.

At the time, I couldn't figured out how it pumped the water. Now, I realized that the tube was a Tesla valve. Ingenious design as there was nothing to break during any reasonable service life.

Police raid Stonewall Inn, 01:20 am EDT, June 28, 1969

Never forget

It all started a few weeks back when a friend gave me a couple of "surplus" laptops They were part of a bunch that had been retired by a company he does tech support for.

Anyway, one had a virgin (re)install of Win 10 on it, and I played around a bit. It was designed to hook up to a docking station which had some nice extra. And they were cheap on e-bay. So I bought one. And when it arrived, I hooked it up to the monitors and keyboard/mouse on the kitchen table I use as a workbench.

This meant fayanora and I could resume our long lapsed weekly TV nights. We are way behand (watching shows from 2021 now) but we are making a dent in the backlog. Good thing because space was getting aa bit tight on the server.

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Specifically, computer utilities. I've been doing some long needed cleanup on my ridiculously large collection of images and the like.

This mostly consists of two things. First, checking to see if the source sites (various tuimblr accounts at the moment) are still up, and if there is any content I don't have.

The utility I used to use for that quit working some years back. and no updates or word from the author. Since I needed to do something about this, I finally got around for looking for a replacement. Found one. WF Download. Works even better than the old one did. There is the small issue that it uses a different (and arguably better) naming scheme for the downloaded files.

Which brings us to the *second* issue. Checking for duplicate files in the downloads. Now, way back in the 80s there was a program named Unique Filer. It had the concept of "base folder" and "compare folder". So it could compare all the files in the base (and its subfolders if you wished) against all the files in the compare (again, including subfolders if you wished).

Now it presented a list of the matching files. and you could wade thru them one by one. *or* you could tell it to nuke all the file in the compare folder that matched files in the base folder. Zip done.

It quit working with Windows 7. Maybe because it was very old or maybe because it was a 16 bit program (originally written for Windows 3) and I'm running the 64 bit version of Win 7. In any case no longer workee.

What I use now is Duplicate File Finder, It lets you compare files in a folder or folders and present a list of dupes. Each and every one of which has to be individually deleted...
[delete][enter][down][down] (repeat ad naseum)

*why* has the concept of "base" and "compare" folders been lost?

This was sparked by watching a remastered copy of and old BBS civil defense videos. Basically about what to do before and after a nuclear attack.

It got me thinking about the stuff I read back in the 70s and 80s about building fallout shelters, and other "how to survive getting nuked" stuff.

So I considered survivors of an attack, and what they might maintain in the generations after (assuming moderate collapse of civilization here).

Now, deliberately built fallout shelters are useful for other things as well. Storm shelters, "panic room" type refuges, etc. And the food and water stockpiles are a good idea for pretty much any sort of disaster. So, those could survive thru generations.

Other things, like improvised air filtering and air circulation are a bit harder to maintain, but far from impossible. and they are again useful for other situations (bad or long lasting dust storms, or persistent smoke from wildfires for example.

It's even possible to build radiation detectors with some pretty low tec. And radios are harder, but given some knowledge & resources, they could persist for a long time. Crystal sets are very simple, and you can use chips or transistors from "dead" electronics as the crystal. Transmitters are harder, but still a lot more doable than you might think.

So you could have a "primitive" looking society with lots of hidden and fairly sturdy shelters, bigger stockpiles than you might expect and some unexpected emergency communications. Won't that set the cat among the canaries for "more advanced" raiders.

This also reminded me of a bit that used to come up on the Traveller SFRPG mailing list.

Sure, the planet is primitive, but it does have a spaceport (even if it's just a cleared hunk of land and somebody with a radio).

If it gets many visitors, odds are somebody will have put up some sort of satellite network. In Traveller, you can literally toss some cheap stock satellites out an airlock and they'll self position and organize into a network.

This means comms. Even if only for the convenience of off-worlders visiting and prospecting. Not that much harder to have the satellites do weather monitoring and the like.

Receivers are common, and cheap (think android cell phone). So natives *will* manage to get them. Maybe at first, just so they can get weather info and contact other villages in an emergency.

Some bright boy (either an off-worlder or perhaps an "enlightened" native in government) will bring in receivers for "school by satellite) like India and other places have. This too will help.

But even at this point to your typical off-worlder, the place will look the same on the surface.

*Under* the surface, things are different.

Picture Bwana and his friends who've hired a "native guide for a safari. Or to help them explore for minerals.

They'll be impressed by how well the guide knows the country and what keen eye for the weather he has. He'll be snickering to himself when he checks the weather photos and GPS, as well as aerial shots of the terrain ahead. No need to worry the off worlders with details they don't need to know.

:ikewise imported weapons (in small numbers at first) and imported vehicles. In some ways like the third world here, in other ways different because the tech level was higher when things started getting introduced.

This sort of thing can make for fun stories or fun gaming sessions.

New head-canon:

In The Wandering Inn, at one point the innkeeper has a sore throat (from doing hours of singing) and a cold (from being out in the rain).A mage cures her of the sore throat, but apologizes for not being able to do anything about the cold because she doesn't have a high enough spell.

She explains that the cold is the most common illness, and people have been using magic to cure it from centuries. Now the low level spells won't cure it anymore.

Read a few stories recently where authors *really* should have done some research.

In a SF series, the author has colonies on planets around Type O, B, and A stars.

Sorry, won't happen. Type O and B stars aren't on the mainsequence long enough for planets to *form* much less become habitable. Not sure about Type A stars but it'd need to be looked up.

These things aren't just "color" for the stoiries, they are physical details that need to be checked.

Then there's the fantasy series I've been reading. Medieval setting, with dragons and some magic.

They've got a captured dragon (magically bound so it can't *easily* get free. This was not exactly planned. But they've got it in a courtyard, and have a chainmail "net" over the courtyard. Aside from the fact that I don't think a 100 foot or more span of chaimail could support its own weight, there's the fact that it'd take months, if not a year or more, to *make* the chaimail. That's all hand labor.

There are also mentions of gunpowder but no evidence of it being used for anything.

Finally, they are drinking water with meals. Now some of this is likely because it's a YA book. But historically, and *practically* they'd be more likely to be drinking wine (perhaps watered, but still wine) or small beer.

This is because of water putity issues.

Details do matter.

Had a story idea involving kid's games.

I know that some forms of tag have a safe zone thing. If you can get to the tree, rock or whatever you are safe from getting tagged.

I have vague recollections of something similar in some games of hide & seek.

What I'm wondering does anyone recall any other games that incorporate a similar rule/concept.

Heard an ad on YouTube the other day. Went something like this:

Sale! Today only! Buy now for realy low discounts!

Methinks the copy writerwas aa mite confused about what "low discounts" actually means, or he was being unintentionally truthful.