Conference in Wǔhàn (武汉市)

The 37th Annual International Symposium on Lattice Field Theory (just "Lattice 2019" by the people in the field) in Wǔhàn (武汉市)

Going to Wǔhàn and back from Běijīng will obviously be done with a plane. I have just booked some flight which did not have a long layover and no unnecessary stops in Zürich or Amsterdam. My flight left at 13:05 hours from Düsseldorf airport. On the way I bumped into some computer science students that I just happened to first meet two days before the flight. They were also on their way to a conference, but in the USA. One just had a little backpack for the whole week. In contrast, I had my large suitcase full of stuff.


I took an earlier train than I strictly needed but having an hour to spare in case the train has some issues is always better than having to pay like 150 EUR for a taxi to race to the airport. There was plenty of time to kill in Düsseldorf. The check-in took a while. The long queue consisted mostly of Asians, I only saw two other Westerners there. For some reason they only had two booths opened up, so the queue just crawled along.

Right in front of the security screening there was a young Chinese woman who seemed a bit lost. She wanted to purchase a one liter zipper bag for her liquids but did not have the necessary 1 EUR coin. Luckily I keep all my cables in exactly these zipper bags to keep them from tangling, so I just gave one of them to her. She seemed overly happy about this. These are the really nice situations where one can make a seemingly large difference with just a little gesture.

As the flights from DUS to PEK and PEK to DUS are going to be 10 hours, there will be several meals on it. According to the German Air China website you can get various special meals served during the flight. They however give you a Chinese phone number. Besides having to pay 3.00 EUR/minute to call there, I doubt that this makes so much sense as my flight was booked from Germany and I start in Düsseldorf.

So I wrote on email to Air China in Germany, I had found on some other website. Half an hour later I got a reply telling me that I had reached the office in Berlin but I should rather contact the one in Düsseldorf. They gave me as an email address. I have tried this next but got an error email saying that this does not exist. Their email addresses are clearly IATA airport codes, so I just wrote to and specifically asked for a confirmation. That was on the 2019-05-15. Then on 2019-05-28 I had the impression that this email just got lost and called the airline at DUS (list of airlines in DUS). The clerk told me that for this flight I had already booked the vegan menu. So everything was fine, they just did not tell me about it.

On 2019-06-05 I got an email from Düsseldorf saying that they could not provide me with a meal and that they are sorry. Incidentally this came from the previously defunct `[ address. Having the hunch that they could just not get a meal that was guaranteed free of any traces of nuts, I told them that traces would be just fine. Still they could not provide such a meal and sent me :download:`their list of special meals (PDF) \<airchina_special_meals.pdf>]{.title-ref}. And although there are various dietary requirements covered, nut allergy is combined with gluten allergy. But there is no vegetarian option there.

The evening before departure I cooked a meal without any sauces, in the hope that I would get this through the security screening. At DUS they of course noticed it and searched my backpack. The nice security woman told me that this is borderline and that she will make an exception and let me keep it. So even having something which is dry might not get through the screening as stuff like bell peppers can lose a bit of water into the zipper bag that I was keeping it in.

Flight to Běijīng

During the flight the food order did not matter much anyway. We had turbulence the hours after takeoff until the meal, and I was not feeling like having lunch anyway. There was some announcement on the speakers which I did not fully got due to myself wearing headphones. It was something about the meals and that they were sorry to not provide for everyone. I guess some of the ordered special meals could not be sourced for the flight.

A couple hours later the air was calm again and I ate my food. Depending on the time zone it was either a dinner or a midnight meal.

During boarding and exiting the plane they played a nice Chinese sounding music. This is much better than the jingle and slogan that Ryan Air plays when you happen to be stuck on one of their planes.

They have dimmed the light in the cabin early on, and I already set the time zones on my devices to UTC+0800, so the red coloring on my screens (Redshift on Linux, stock night light on Android) would match my destination time zone. The jet lag was annoying nonetheless.

Each seat was fitted with a screen to watch entertaining stuff on. The last long distance flight I had was in 2011 when I went to the USA again. There the screens would always show just one program and one could just pick an audio title that one wanted to listen to. Either German or English voices for the screen or some radio program. Every now and then the screens would show the journey of the plane on a map with some basic information like ground speed and altitude.

The screens in this Air China Airbus A330-300 were touch screens where you could just select a movie that got streamed just for you. Also one could take a look at the map all the time. I did not watch any movies, though I find it interesting from a technology standpoint. They must have a beefy streaming server somewhere and then just a bunch of little ARM powered devices on each seat.

Curiously I could use the flight map and see that we were over Europe and also Russia. The next time I checked the map would not open, instead it just showed:

Application disabled by crew.

I am not sure of the pattern, it seems that this gets disabled when there is turbulence of something. Perhaps it was also some weird glitch that manifests in this way.

Six hours into the flight we got turbulence again, this made it really hard to find some rest.

Transfer in Běijīng

After ten long hours I finally made it to Běijīng. I was not entirely sure where to go, but there are signs in English all over the place. The employees speak just a little bit of English, it seemed that it was not really possible to communicate in English. And that was the airport where English knowledge should be higher than average.

First I had to use a self-service machine which took all ten of my fingerprints. In order to get to domestic transfers one had to pass another stage where the body temperature was automatically measured as one walks past. This detects people with a fever and a potentially contagious disease. I think that this makes a lot of sense to check for since epidemics can easily wreck havoc with this population density in Asia.

After displaying a normal body temperature I needed to fill out a paper form which pretty much redundantly had the information from my passport and the visa, and the place that I would be staying at, which I already mentioned in the visa application. Having this form filled out allowed me to queue up at the immigration booths. There an officer looked at my passport, scanned another four fingerprints and let me go through the gate. At that point I was officially in China!

From there I took a train to another terminal. I had the impression that the train was already full and wanted to take the next one. Some ten people still managed to squeeze into it, I just happily waited three minutes for the next one.

At the other terminal I needed to go through customs, have my bag scanned for whatever and then go through security again. There I needed to show my passport and boarding card. The officer there took a picture of me with a webcam and then stamped my boarding card four times with the same stamp. Two times on the large part, another two times on the small part. All the stamps are red, I like it. It feels like China has a consistent corporate design.

During the whole process nobody was interested in any of me electronic devices. Also none of my food was questioned or commented, I could just take it all with me to Wǔhàn.

At the gates I saw two karaoke booths. Apparently one can just go in there and have a little session of karaoke and get it recorded.

In Düsseldorf I by chance found an electric socket. In Běijīng they had charging points every couple of seats with four sockets in two different types and some USB-A sockets. China seems to use three different sockets, and the airport features two of them. Luckily I brought a universal adapter with me, so I could just use either one of them.

Flight to Wǔhàn

My flight to Wǔhàn was conducted in an Airbus A320-200. Just before taxiing to the runway there was an announcement that the plane was regarded a public space and therefore subject to camera surveillance. This was followed by "thank you for your cooperation" which I would get to hear frequently in the metro as well. It somehow feels strange, just a bit too much authority in that statement. Although I had booked an aisle seat in Düsseldorf I ended up sitting at the window. But that was nice because I got to take a bunch of pictures from the window.

The start was delayed a bit, yet we still made it to Wǔhàn before the scheduled arrival time. Perhaps the time for this flight was made in a way that would allow for large delays without being officially late.

During the flight I got served a really strange cookie. It was warm and looked like some sort of bread. Yet it was labeled with "beef" on the back. I did not dare to try it, sorry.

Taxi drive

At the airport I thought that it would be easier to just take a taxi to the hotel instead of figuring out a potentially complicated subway system. There were guides leading towards the taxi stands. Before I even reached the exit of the terminal some person approached me and tried to pronounce "taxi". I was told by a friend that there are a lot of scam taxis around. Official taxis have the taxi license of the driver visible in the front of the car. I got away from that person because I did not deem him trustworthy.

Right at the terminal door another person approached my and offered his taxi services. Since that was the taxi exit of the terminal I gave him the benefit of doubt. He lead me away from the main taxi stands, I got suspicious. As we got further from the terminal, I asked via the translation app whether he was an official taxi driver. He just tried to brush away my concerns with asserting that he was, but he did not show me anything that even remotely looked official. When we got to the edge of the terminal parking lot he told me to just go over there and wait while he would get the car. That was the point where I just bailed on him.

Back at the terminal I just asked the security guard where official taxis could be found. He pointed towards some largish taxis right at the curb. One of the drivers noticed the opportunity and approached me and asked where I would be going. He did the route calculation on his phone and showed me that it would cost around 300 CNY. From the friend I already knew that it should only cost around 120 CNY, so I declined. After a short phone call I was told where the actual taxi stand was. There was a queue to wait in. Taxis would just come, and I hopped into one. I was relieved to finally see the taxi driver license on the dashboard.

The taxi ride took around 50 minutes on various highways. We have passed a toll booth where one had to pay 15 CNY.

On the ride into the city I already saw endless tall buildings, you will read more about this later in this article. The taxi ride then did cost 113 CNY including the toll, that is the regular price.


The Yangtze river flows right through the city. Also it merges with a smaller river rather close to the conference hotel site. Standing there one could see that the water of the smaller river is rather blueish whereas the Yangtze shows a more brownish color.

There is a bridge which might look a bit familiar if you know one in a particular city in the USA.

There is a small park on the west side of the bridge, people seem to hang out there. I have seen people playing with kite like dragons, having spontaneous dancing sessions with music and instructor or just going for a run.

There are many more bridges across the Yangtze river, one a little further north also carries railway tracks. This picture was taken from a little elevation and one can nicely see how endless the large buildings seem.

We had been taking a walk and found a bit of nature right next and above a highway. It was very nice to walk there and the air was noticeable more pleasant there. In general I did not have the impression that the air in Wǔhàn was polluted, I recall that Stuttgart was much worse. Some people were wearing breathing masks, but I did not really see many of them.

During the evening one can see that a lot of buildings have LED lights on their outsides. They seem to be controlled centrally for a spectacular light show. The conference hotel and adjacent buildings participate, as well as a lot of buildings on the other side of the river. From my hotel I could also see a lot of these lights. In Bonn we have just the DHL Tower which has similar light capabilities. There some residents sued DHL because they could not sleep at night. These days the lights are only activated during a few special occasions per year. In Wǔhàn these lights are turned off at roughly 22:00 hours such that one can easily go to sleep.

On Saturday evening I was fortunate to be shown a part of the city by a local. We went to a mall and had another very nice dinner. At the restaurant we got a little receipt telling us that there were seven people in front of us. I have seen many QR codes in all places but this receipt also had them. Using WeChat one could get a live update on the waiting time. This is a really interesting thing. During the meeting I got to learn a bunch of trivia. For instance that Chinese boyfriends regularly carry their girlfriends handbag, presumably to impress them given the hard competition from the one child politics.

The weather was rather warm and humid, in principle perfect for shirt and shorts. The conference hotel was cooled down below 20 °C I felt, there I wore long pants. My hotel room also did not have significant windows but an air conditioning unit. Every now and then it rained, and it would usually then rain for longer periods of time. Since it was so warm there was no real point in wearing a raincoat. An umbrella really is the thing to have in this city.

Density of buildings

Wǔhàn has around 13 million inhabitants. You can see the density of the buildings best in this picture that I took from the plane.

And these are not just smallish buildings, they perhaps have 50 stories, I did not count. They are building new ones everywhere in the city, it is expanding very rapidly. The slogan of the city is "different every day" and I can certainly see where this comes from!

No matter where you look, there are construction sites everywhere. It would seem that for every couple of buildings there is a construction site for a new building. There must be many people coming from the rural areas to the cities needing accommodation.

Our tour guide on the excursion told us that the more expensive apartments in Wǔhàn cost around 20,000 CNY/m² whereas in the expensive north of Běijīng one must already pay 100,000 CNY/m². If you take a 70 m² flat and the current exchange rate you are looking at 1,000,000 EUR. That is just mind boggling!


The lattice conference is held in the Hilton hotel near the Yangtze River. Their rooms are quite expensive (around 100 EUR per night), so I stayed in the Tieqiao Jianguo Hotel, which still looks amazingly comfortable on the website. I tried booking through my go-to German portal, but they only had rooms for 450 EUR for the whole stay. Via that I managed to get one for 350 EUR for my whole stay, but I had to pay locally, but the exchange rate has not changed much until then. Curiously the organizers of the lattice conference also offered to book the hotel for us and supposedly had a discounted rate. Still booking the hotel with the conference would have been more expensive than via

When I arrived I got a standard magnetic room key. The room itself was very nice!

The view however was not quite the best. One could see new huge buildings in the distance and abandoned looking ones right next to the hotel.

The three small windows in the room could not be opened much, but they could also not be closed properly. Street noise got into the room easily but drowned in the noise of the air conditioning.

There was a desk and a chair, and as usual the chair was much too low and the desk too high. I really do not get how people are supposed to work like this in a business hotel room. There are around 15 cm of discrepancy in height, making working with a laptop rather cumbersome.


The conference was held at the Hilton Wǔhàn Riverside, a five star hotel. The plenary talks took place in the grand ballroom.

The screen that you can see actually is a large LED screen consisting of a bunch of panels.

We had plenty of coffee breaks where the hotel has treated us with green tea, coffee, fresh fruits and a lot of tiny pieces of cake.

I had my own talk in the parallel session on Tuesday evening, it was the last slot of the day. It went very smoothly, and as usual I was quicker than anticipated. But I felt that I conveyed everything that I wanted to say, so it cannot be too bad.

Before my talk I have seen people struggling with the presenter hardware. When I gave my talk, I figured out the problem. The buttons for going forward and backwards in the slides as well as the laser pointer were in one row, with a sight bump on the forward button. One would easily mix these up. My personal presenter has the buttons on the left and right, the laser is triggered with a pistol like trigger on the back. These I never confuse.

We had a shuttle bus taking us from the hotel to the conference each morning. The bus left at 08:10 and usually reached the venue at 08:30. I am not sure whether they wanted us to have a bit time before the first talk or whether they thought that car traffic would be unpredictable at that time of day.

The conference was amazing. The biggest drawback was that I spent most of my time in windowless rooms with artificial lighting. Perhaps this is the best preparation for serving on a ship where there are few windows. Also there have been a couple of sound issues that were slightly bothering, most stemmed from people having the microphone to close to their face. Regardless of this I have met a bunch of people out of my field, had interesting discussions during the breaks and met potential future collaborators.


The subway system in Wǔhàn is very nice. There are lots of lines that go through most parts of the city. Most importantly they do not have a central hub where all lines come together, like most German cities have with their main stations. Instead there are crossings of at most two lanes. This means that instead of traveling to the central hub and changing, you instead have to ride to the intersection and then just switch lanes. They are set up such that in most cases you just go to the platform opposite to the one where you just arrived on.

Additionally the frequency with which they come is so high that there is no schedule. There are ones arriving every three minutes in one line, and every six minutes on some other line. With that frequency you really do not need any fixed schedule any more.

There are displays above every single door, and they are super informative. They tell you the current next or current station, all the ones that the current line will visit as well as the possible transfers. Right next to the Chinese characters there are the names of the stations in Pinyin or English. Also the way it progresses is in the way of travel, the display on the opposite door is mirrored. This made it extremely easy to navigate the subway for me.

The tickets are rather cheap for my standards. The ticket machines let you just pick the last line you want to take and then shows all the stations that it has. You tap on the station and it will directly give you the ticket.

The tickets themselves are little NFC enabled coins that you get from the vending machines. There are entry gates that you present with the coin.

On the exit you just put it into the machine and you can exit the station. As a side effect this means that you can only enter the station with a valid ticket.

On all the subway station entries there are security posts. They will check you luggage with an x-ray machine. On the bigger stations there are metal detectors that one has to go through. I never had to empty my pockets, so it is not as strict as one knows it from airports. Also the metal detectors always beep. The guards just waive their wands in front of you, they also beep. Then they just let you pass. This feels like complete security theater and there is no other point than inventing a couple of jobs.

The subways themselves are very modern and clean. A neat touch are the platform doors. This way you can stand arbitrary close to the rails without running danger of falling down. Also one knows beforehand where the train will come to a halt.

At one of the stations I even saw a water fountain, genuine with warm and cold water.

To my amazement there is 4G cellular coverage in the metro as well. In Germany you do not even have proper coverage above the ground, let alone the subway.

The hand rails in the subway cars have their lower edge at around 182 cm. I keep bumping into them, but I'm also easily the tallest person in the subway.

All subway stations have restrooms, and they seem somewhat clean. The only thing that I found strange was missing soap. Most people did not seem to bother as they did not even wash their hands with water.

In the subway you have people watching videos with their phones. So this seems to be the same in all cultures and one needs to bring headphones in trains if one wants to have some calm time.

Once I wanted to take a bus. So to make sure that I have the right one I have entered the destination station into Google Translate and showed this to the bus driver. He told me to get in. Only then I realized that you could pay with NFC ticket, I only had cash. I felt uneasy about this, and showed some cash. He just smilingly waved at me. Later he notified me that we have reached the station that I wanted to go to. Not having paid for the fare makes me feel uneasy, but the friendliness and helpfulness really swept me away.

A very peculiar thing is that the subway is shut down during the night, like between 23:00 and 05:00. This feels very strange for a city this size, but apparently it is not cost-effective at these times and they also do some maintenance during the night. As taking taxis is not so expensive this apparently works well for the people. This is exactly the same in Běijīng, the subway does not ride there at night either.


The traffic in Wǔhàn seems to be chaotic for my taste, people use their horns regularly. During the bus transfers between the two hotels we often had close calls. Apparently I was the only one stressed by these situations.

The crosswalks there do not give you the right of way, they just mark traffic lights. I have always waited for the green light, others seemed to pretty much ignore it. I have the impression that traffic there is chaotic chaos which seems to work out rather well in practice. One crosswalk even had this light gate which scolds at you when you cross it on a red light.

Rental bikes can be found all over the place. People ride them everywhere, including on the car lanes against the direction of traffic. This is a bike rental station right next to a metro exit.

Some streets even have marked bike lanes. Still I felt that it would be a really bad idea to try riding there. Besides not bringing my helmet, I would also likely lack the app that one needs to unlock them.

There are multiple companies competing in the bike sharing market. This is so intense that apparently they have to update their bikes regularly. Close to the river delta we saw a bike graveyard where apparently they have just dumped outdated rental bikes.

Although there are a lot of cars, there are roughly as many scooters. The vast majority of them are electric, so they do not stink like the two stroke ones that you find in Germany. And some people use them intensively for carrying large loads.

The traffic lights on large intersections have a timer on them. They show in either red, yellow or green how long the current state will last. Some pedestrian lights also have them. This way the really impatient will have something to look at.

There are some pedestrian bridges over busy intersections. The following picture has been taken from one of them.

In general you see a lot of cars from brands that one also sees in Germany, various Asian and European brands. You can also see various American cars that are not sold in Europe (Buick, Cadillac), as well as Asian ones that are not sold in Europe (Infinity). Additionally there are of course many Chinese cars that I have not seen anywhere else.

Another interesting detail is that there a lot of cars are in the long wheelbase version, which is only available for the top models from each car manufacturers. In China you can see Audi A4 in the long version or Mercedes C-Class in long versions. Also people seem to have largish gas engine, that Audi A4 L had a 4.0 TFSI engine, which you either cannot get in Germany or people would not buy them and rather take a Diesel instead.


The conference included an excursion on Wednesday afternoon. We have first been bussed to the Hubei Provincial Museum. There for some reason we had to show our passports and had the backpacks put through an x-ray scanner.

The main exhibit of the museum are the contents of a grave chamber dating back to 2400 BC. One of the things that they had found there are some very large bells. These have the interesting characteristic that they can produce two tones. Using these bells and other instruments found from a similar era the archaeologists were able to reconstruct the music of that time.

Another particularly interesting exhibit is a fancy wine vessel. The technique that was needed to create it had apparently been mastered already. In recent time archaeologists tried to reproduce this to find out what steps they needed to construct it. Similar techniques have only been available in France around 1800 AD. It is remarkable how much earlier they had this in China.

After a short visit to the museum we had a very short bus ride to the East Lake. It is one of largest lakes or even the largest lake in China. Unfortunately we did not have so much time to enjoy the scenery. The feeling there was similar to the Central Park in New York City where you have the park with trees and large buildings behind them.

While I was there a woman asked to take a picture with her friend and me. Apparently it is rare to them to see somebody from Europe and they wanted to show their friends.