Gimont

Hello! I just saw your post about the conference. I know it's very niche, but I'd love to hear / read more about your sangaku presentation. I actually went back to Konnō Hachiman-gū this afternoon, hoping to see more examples, but no such luck. (I cannot decipher them, of course, but I taught English at a faculty of engineering, and my students could. Sometimes. )

I'll put together something about the shrine, but どうぞお先に。Nudge nudge hint hint.

Hi, thanks for the message!

The presentation was in two main parts: first the historical context of the Edo period and function of sangaku in developing mathematics during that time, and second a closer look at Kashihara Miminashi Yamaguchi-jinja's example with a modern solution. I can't read the sangaku in full, but I have been able to pick out the parts with numbers and compare some of their results with the formulas.

I can probably put together a mini-series at some point. Which parts would you want to hear more about? (That's a general question btw: anyone can reply and add the conversation of course.)

Three castles above Éguisheim

The village of Husseren-les-Châteaux is a peculiar one: at 1.2 km², it is the smallest commune in Southern Alsace, totally surrounded by Éguisheim. Beyond the vineyards, in the hills above the village and on the border with Éguisheim, are three castles, separated by... nothing.

Unlike other places where several castles can be found, such as Andlau or Ribeauvillé, this was only one unit, with the Dagsbourg and Weckmund being extensions of the original Wahlenbourg in the middle. Each section had its own dungeon.

I visited with my sister on a very overcast day two years ago, with low cloud descending on the hills. It made for some moody shots. We weren't alone up there - which was probably helpful! Also we used a car, and the car park isn't far, so it wasn't a creepy hike up or down.

As for the castle itself, it was destroyed during the Six Deniers War in 1466. The Habsburgs intended to conquer Mulhouse, and used the flimsy pretext of a miller being owed six deniers to start the invasion. But Mulhouse found allies in neighbouring Swiss cantons (before the Swiss Confederation was a thing) and won, taking out the fortress of Éguisheim along the way... as well as the miller whose complaint gave the Habsburgs the excuse they were waiting for.

The first race car I supported: the McLaren MP4/13-Mercedes

Aidan Millward, a YouTuber who talks a lot about racing history and current affairs, recently went to an exhibit at Silverstone and came face to face with the first Formula 1 car he supported, Damon Hill's 1996 championship-winning Williams FW18-Renault. Which reminded me: I've met my first F1 hero too.

The Formula 1 season I remember paying attention to more or less in full was 1998, and the driver I supported - as you usually start in sport by supporting someone before growing more neutral when they leave - was Mika Häkkinen. Like Hill two years earlier, Häkkinen was in a car designed by Adrian Newey, who had changed teams in 1997, and he won the championship with it. The McLaren MP4/13 has a wonderful shape, and the black, silver and white with red accents is an unmistakable turn-of-the-millennium livery.

This car can be found at the Mercedes-Benz Museum in Stuttgart, courtesy of McLaren's engine partner of the time. On the racing floor of this very complete museum, well worth the visit, the MP4/13 is in fine company: Mercedes's other F1 champions from the 1950s with Fangio and since 2008 with Hamilton, Sauber Group C sportscars, the CLK-GTR, DTM touring cars, race trucks (yes that's a thing), and many more...

This monument needs no introduction. I just want to show the names of French scientists and engineers that adorn the base of the Tour Eiffel's first floor - just visible at the bottom of the above picture. Similarly to the German names on Strasbourg's Palais Universitaire, if you've studied science at length at any point, you'll know some of these: Cauchy, Navier, Lavoisier, Ampère...

The best timepiece in the world (IMO): Strasbourg Cathedral's Astronomical Clock

I could go on about this thing for ages. There's so much history, so many symbols to spot, and so much information on display... This is going to be a long one.

I guess I'll start with the artistic aspect on which I have the least to say because it's the least up my alley. There's loads of mythology and Christian symbolism going on on this 18-metre tall monument, and these are the main draw for the general public, because they move around.

Like cuckoo clocks in neighbouring Schwarzwald, this astronomical clock has automatons. Every quarter hour, the lower level of the photo above sees a change of "age": a child, a young man, an adult and an old man take turns to be in the presence of Death, whose bells toll on the hour. At high noon, the upper level also moves, with the 12 disciples passing before Christ, and the rooster at the very top crows.

Moving on to what really makes me tick: the amount of information on this clock is incredible. The time, obviously, but actually two times are on display on the clock at the bottom of the picture above: solar time and official time. Given Strasbourg's position in the time zone, there is a 30-minute discrepancy between the two. Then there's all the astronomical stuff, like the phase of the Moon (just visible at the top), the position of the planets relative to the Sun (middle of the picture), a celestial globe at the base (pictures below, on the right)...

The main feature behind the celestial globe is another clock displaying solar time, with the position of the Sun and Moon (with phases) relative to the Earth, sunrise and sunset times, surrounded by a yearly calendar dial. These have remarkable features, such as the Moon hand that extends and retracts, making eclipses noticeable, and the calendar has a small dial that automatically turns to place the date of Easter at the start of each year. This sounds easy, but look up the definition of Easter and note that this clock is mechanical, no electronic calculating power involved! Either side of the base, the "Ecclesiastic Computer" and the "Solar and Lunar Equations" modules work the gears behind these features.

The accuracy of this clock and its ambition for durability are truly remarkable. Relative to modern atomic time, it would only need adjusting by 1 second every 160 years, and it correctly manages leap years (which is not as simple as "every 4 years"). It just needs winding up once a week.

Finally, the history. The monumental clock was built in the 16th century, and used the calendar dial above, now an exhibit in Strasbourg's city history museum. It slowly degraded until the mid-19th century, when Jean-Baptiste Schwilgué restored the base and upgraded the mechanisms. The "dartboard" on the old dial contained information like the date of Easter, whether it is a leap year, which day of the week the 1st January is... - all of which had to be calculated by hand before the dial was installed! - and was replaced by the Ecclesiastic Computer, which freed up the centre space for the big 24-hour clock, complete with Solar and Lunar Equations.

As you may have gathered, I am a massive fan of this clock. Of course, nowadays, all the imagery and information would easily fit into a smart watch, but a smart watch isn't 18 metres tall and powered by gravity and gears!

C'est avec grand plaisir que je présenterai le mardi 16 avril à la Maison Universitaire France-Japon de Strasbourg une conférence sur la géométrie pendant la période d'Edo, avec en support le sangaku de Kashihara. Entre grande Histoire et petits calculs. Lien vers les détails 4月16日(火)、ストラスブール市の日仏大学会館に江戸時代の算額についてコンファレンスをします。楽しみにしています！ Looking forward to giving a conference on Edo-period geometry on 16 April at Strasbourg's French-Japanese Institute. Expect a few posts about Kashihara around then. Has it really been 6 years?...

As the maths problems take a break, maybe we can have a brief pub quiz. So...

Q. What's that building on the 10-yen coin?

A. The Phoenix Hall at Byôdô-in, Uji.

Initially built as a villa by a member of the Minamoto clan just before the year 1000, the land was sold not long after to members of a rival clan, the Fujiwaras, who turned it into a Buddhist temple named Byôdô-in in 1052. The most striking feature of the temple is the Amida Hall, which with time gained the name Phoenix Hall due to its overall appearance: the two outer corridors are the wings, and a corridor extending behind is the tail.

At the same time, tea production was picking up in Uji, and by the 14th century, Uji tea had become well renowned. I need to go back there someday, my first visit was just an afternoon flick after completing the climb of Mt Inari in the morning. I thought of going back there in the summer of 2023, but couldn't quite make time for it.

Japan's rail speed record holder: 300X

Sticking with the Tôkaidô Shinkansen and the SCMaglev & Railway Park, this is the (highly abridged) story of the fastest conventional train in Japan.

Following privatisation and sectorisation in the 1980s, and seeing France and Germany take the lead in the high-speed train department, the three JR companies that had Shinkansen lines set about catching up to offer 300 km/h services where they could. The aerodynamics and sheer weight of the venerable 0 Series and its derivatives weren't going to cut it, so each company designed a prototype train to test new technologies.

JR Tôkai's solution was 300X, officially Shinkansen Class 955 - numbers starting with 9 are trains not open to the public, either prototypes or work trains like Class 923 "Doctor Yellow". Launched two years after JR West's WIN350 and JR East's STAR21, it featured two radically different end cars. The more elegant one, in my opinion, is on display at JR Tôkai's museum in Nagoya, while the other is preserved at JR Group's research centre in Maibara. The intermediate cars have all been scrapped.

The three prototypes took turns to hold the national rail speed record, and, 300X being the last, it took the record last, and holds it to this day. We mentioned the fact that the Tôkaidô Shinkansen still had too many relatively tight turns, but the Maibara to Kyôto stretch is the best part, and that's where this train hit 443 km/h in 1996. This video may, or may not, be that run, but it still looks very fast - note the unusually large, "flying saucer" pantograph cowlings.

Unless JR East decide to go completely bonkers with their ALFA-X prototype, it's unlikely that the record is going to be beaten any time soon. It's not in the spirit of these trains, they are pure test beds and run quite extensively with the aim of increasing service speeds. Records also require special preparation of the tracks, which is why the French TGVs made their 1990 and 2007 record runs before the opening of a brand new line.

But JR Tôkai have gone much faster with their Maglev programme, which holds the world speed record for passenger trains outright with 603 km/h. Behind 300X at the museum is a predecessor of that record holder, MLX01, the first Maglev train to clock over 500 km/h. Again, this is not (just) showboating, the lengthy test programme's main aim is to prove that consistent service at very high speed with this technology is feasible, so that the Maglev Chûô Shinkansen can achieve this when it opens (if Yamanashi-ken can agree on a route).

Running around Koblenz station the other evening, I couldn't resist the cute message on this local train. Instead of a deadpan "depot" or "not taking passengers", this train is "going to bed"!

Now that @fredomotophoto is back from Alsace and Germany, I can do a piece on Black Forest clocks without spoiling his trip! The area has a lot of clock-making history, and to this day, typical tourist shops like the one above - TriBär, a play on the town of Triberg and the word Bär which... you can guess, a.k.a the House of 1000 Clocks - are full of cuckoo clocks ticking and going off all the time. It probably gets quite weird working in one of those places...

Triberg is host to the most extreme cuckoo clocks. The world's smallest are housed in the Schwarzwaldmuseum in the town centre. Wall camera on the right for scale.

Further up into the hills, on the edge of Schonach, is the opposite: this is world's first largest cuckoo clock, referenced in this previous post. As it was closed on the day I visited, I don't know much about the history of this clock, but it's housed in a building the size of a small house (gate on the right for scale)... and it isn't the biggest one any more.

The current biggest one is on the other side of Triberg, and located at the base of a big climb on the Schwarzwald Railway Adventure Trail. Gate on the right for scale. The whole building doesn't count as the clock itself (that would be too easy), only the mechanism does, and it is 4.5 m wide, with an 8 m pendulum. It took 5 years to build and its cost is estimated in the millions of euros, so you know what you're in for if you want to beat it. For a small fee, it is possible to visit the interior, but I was a bit pressed for time as I didn't want to miss the next train at the next viewpoint. I just took a break in the shop and caught the 5 o'clock cuckoo before moving on.

Bonus clock from the museum: