Entries this day: headed-home language-exchange-with-akiko lesson-in-akihabara worked-at-scc

headed home

23:35 Thursday 11 July 2019 JST

I'm on a local train in Shinjuku which will leave in less than a minute from now. I could have taken an express train which would get to our station faster, but would not have afforded me a seat to write.

23:59 Thursday 11 July 2019 JST

Just woke up in Kyodo. Soshigaya-Okura now. Super tired. Too tired to write kanji.

00:02 Friday 12 July 2019 JST

Express train. I am changing.

00:11 Friday 12 July 2019 JST

Yay I got a seat on the express train in 向ヶ丘遊園 station.

Next stop is 新百合ヶ丘.

language exchange with akiko

23:05 Thursday 11 July 2019 JST

Akiko and I went to her train line's side of Akihabara, and ate at the Indian restaurant on the 9th floor of the BIC Camera building. Bottomless cheese nan seems like a good deal until I eat the second one!

We talked about her upcoming trip overseas and pets and other stuff I am too tired to remember, much less write. Oh, we also talked about commas and when to use them. Tough question!

Her Japanese teacher told her to add 、 when she wanted to say ね. That's as good as most rules I've heard for commas in English.

These are notes she wrote in the last three lessons.

lesson in akihabara

19:51 Thursday 11 July 2019 JST

Today there were only 1.5 students in my Akihabara class. This number is down from our high of like 8 last year when I had to stop checking homework during the lesson because there ended up being no time for class. I guess there would be time with just 2 students' worth of homework.

Anyway, the lesson kinda devolved into a China vs Japan debate. I should have nipped it, but I was too tired and I kinda thought the students would sort it out.

worked at scc

16:58 Thursday 11 July 2019 JST

Interesting to talk about the Meisner effect and flux pinning at SCC today. I have always assumed I understand the meaning based on the English presentation, but I felt a bit unsure when I was breaking it down in detail for Yasu as he was practicing his explanation of the same.

My understanding: when a superconductor is below its critical temperature it pushes (almost) all magnetic flux out of itself. This is the Meisner effect, apparently named after a scientist named Meisner.

Impurities in the superconductor mean some lines of magnetic flux pierce the superconductor and the superconductor "remembers" the strength and direction of those lines and pins itself to them. This is called flux pinning, apparently not named after a scientist.

What is this "memory"? I guess while the material is not a superconductor, magnetic flux pierces it like any other non-ferrous material. As it becomes superconducting as it passes below its critical temperature the flux already passing through it are... what exactly?

(( I wonder if electrical resistance in normal conductors is what causes the magnetic fields??? hmmm ))