Tell us an interesting random fact you stumbled across (Part 1)

This is how folks here have often questioned unknown initialisms–its sort of a polite joke. In this case only the “Social Democrat” comment was a joke. The “Straight Dope” was a best effort guess.

Is “SD” widely known or something? Its not known by me. I did ask politely. Its not some game or affectation to wonder what people mean when they are not clear. I resent your implication.

Step daughter probably. Regardless it makes no difference as to the actual content of the post.

For the record I didn’t take this as confrontational or rude.

SD is “stepdaughter”; I thought the abbreviation was more generally known.

Just learned that there are more giant redwoods in Great Britain (~ 500,000) than in California (~80,000). It seems the Victorians really liked them and planted a lot of them. Now they are starting to outgrow every other tree in Britain, but they are still juveniles and not yet self-seeding:

Then I wondered: where else could there be sequoyas? So I found this map for Spain (article in Spanish, with images):
https://www.arbolesconhistoria.com/2021/09/23/mapa-secuoyas-de-espana/
They write there are at least 150 redwoods in Spain and probably many more small ones. And this site claims

there is a whole forest of redwoods in Cantabria, more than 800 trees.

Talking about Victoria - there are at least 2 plantations in Victoria, Australia. Both were established in the 1930s to investigate suitability for timber production. They are now popular picnic spots, and are very interesting places to visit, being totally different to the local native environments.

  1. SD is far from common for whatever it seems to be.
  2. Humor is standard here.
  3. Um, I think I’ll leave this one out, lest …

If the joke were something inappropriate like Sperm Doner or something I’d see the mod’s point, but otherwise not worth a second look.

My New Zealander friend was telling me that her Dad claimed that if he bought his compass with him to visit her here in the UK his compass would still point south. She was dubious but he packed his compass on a visit and they looked and it indeed pointed south. I guessed this was because magnets have poles and compasses magnetised to point towards south will always point towards that pole.

Anyway, I looked for a cite for this and instead the claim is that the compass becomes unusable because the weighted side is pulled down and stops the compass from being able to spin. But the article does only refer the northern hemisphere compasses in the southern hemisphere and goes on to say that compasses in the south are weighted differently. I’m trying to get my head round where compasses actually point to… there are tons of articles about taking a compass into the southern hemisphere and I cannot find a thing about taking one the other way. Anyway there an interesting fact in here somewhere even if I’m not yet sure exactly what that fact is. Perhaps my friend expressed it in the wrong way, does anyone know?

https://www.reference.com/science-technology/compasses-work-southern-hemisphere-32e4bec40efd6471

Compasses point North/South. The “point north” is looking at the end (usually painted) indicated as the end to look at. Let’s say Dad’s compass has the south end indicated because he’s in the southern hemisphere. Why would that be any different in the northern hemisphere?

Because…

A compass designed for the southern hemisphere is weighted differently…

So apparently there is a difference. No idea what though.

Maybe because as you get closer to the magnetic poles north or south, the compass wants to point downward towards the pole rather than horizontal to the Earth’s surface?

I get that, but my question is if a compass “points south” why would that change anywhere else on the planet?

I found a cite that hopefully answers your question.

The SPS Observer.

Well of course the south end of the needle is weighted, it has to be heavier so it always points down toward the south pole. :wink: /s

Interesting. I knew about the dip angle, that the direction of the Earth’s magnetic field is not perfectly horizontal, especially as you get closer to the poles, but I didn’t know that compasses are designed taking that into consideration. I thought the effect was small enough that it could be ignored.

There are also compasses called “dip compasses”, that are deliberately mounted in such a way as to tell the angle of the local magnetic field (after you’ve determined the direction of the horizontal component). And compasses designed to give both components at once.

TIL: Bob Odenkirk has a son Nate who’s forging a name for himself in his own right as a humorist. Here he also forged an exchange of letters between Shel Siverstein and Dr. Seuss

TIDL (today I didn’t learn) if there had been a real exchange between Silverstein and Geisel, which is what I was originally looking for. (Or Odgen Nash, or Gelett Burgess).

Basil Rathbone only won two movie sword fights in his career. Pity the villains!

Chinese scientists generate energy from a “drinking bird” toy:

Led by South China University of Technology’s Prof. Hao Wu, a team of scientists recently took one of these toys and added two disc-shaped triboelectric nanogenerator modules to either side of it. These devices harness the triboelectric effect, in which certain materials become electrically-charged when they’re rubbed against one another – it’s what’s responsible for the static charge that occurs when you’re combing your hair.

The whole rig is thus known as the drinking-bird triboelectric hydrovoltaic generator, or DB-THG.

In lab tests conducted at a room temperature of 24 ºC (75 ºF) and a relative humidity of 20% ± 5%, it was able to operate for 50 hours using just 100 mL (3.4 oz) of water. It also achieved a voltage output of up to 100 volts, which was sufficient to power devices such as calculators, temperature sensors, and 20 linked LCD screens.

I, for one, welcome our new DB-THG overlords.

Do we know how many real sword fights he won?