# Conferences in Wǔhàn (武汉市) & Běijīng (北京市), China

In the summer of 2019 I was able to spend four weeks in China. One week during The 37th Annual International Symposium on Lattice Field Theory (just "Lattice 2019" by the people in the field) in Wǔhàn (武汉市) and three weeks during a summer school "Frontiers in Lattice QCD" in Běijīng (北京市).

You can find all pictures in the Google Photos album. I have a bunch of images in this articles, but I took too many to show them all here. This article contains 19,029 words and 111 images. Have fun!

The following map shows the cities that I've visited in China to give you a rough impression.

This document is very long, so here is an overview over the contents:

## Language

I do not speak any Mandarin, therefore there was a huge language barrier. There are languages like Spanish that I do not speak either, but at least it uses Latin letters. This means that I can just type in the letters into dictionary or translation software and get some of the meaning. Chinese uses complex symbols. Once one knows the pronunciation and Pīnyīn transcription into Latin characters one can enter it on a computer. Pīnyīn is not unique, there are multiple words that have the same transcription but differ in accents, like with "wuhan":

But to make it even worse, even with accents it is not unique either:

In this article I therefore write the Pīnyīn with accents and include the actual Chinese symbols in parentheses. This way people illiterate in Mandarin will be able to get a hunch on the pronunciation and literates will be able to read the real thing.

One important thing that one should supposedly learn before the trip are the genders for the restrooms: The male ones are marked with nán (男), the female ones with nǚ (女). It turned out that most use the standard pictographs and or English writing. Only in one restaurant they only had Chinese symbols.

In order to deal with the language issues there I have downloaded the complete simplified Chinese and English languages for Google Translate. This way I can perform full text translation both ways offline. On Android I have also enabled the Pīnyīn input, this way Chinese can enter text on my phone. Also I have installed the Pleco dictionary app, from which the above screenshots were taken.

When I was sitting in the plane from DUS to PEK, an elderly Chinese woman had the seat next to me. She did not speak any English, which always works as a fallback in academia. While there was still cellular network available we had a very interesting way of communicating. It turned out that she does not know the Pīnyīn input system. On her phone she draws the symbols and then uses auto completion to select the symbol that she wants. She would type something in WeChat on her phone. I took a picture of that, let it be processed on Google's servers and got an automatic translation to English.

I would write my answer in English on my phone and have it translated into Chinese for her to read. After takeoff the optical character recognition did not work any more, so we did not have this way for her to enter Chinese characters on my phone to translate. The Pleco app has the ability to swipe letters. But later on during the flight I found out that the Google keyboard for Chinese also has the swipe ability. This way it works even for people who do not know Pīnyīn.

There are a surprising large number of people in Běijīng who learn German and were looking for a language partner. From what I learned they have English in pre-school rather early on and also classes in German are offered.

During my time there I picked up a few things and started to recognize the subway stops and could somewhat pronounce them.

## Passport & visa

My last travel outside of the Schengen area was quite some time ago, so my passport had expired. Getting a new one is not hard, but it takes quite a bit of time. Getting an appointment with the city administration usually takes about a month, the passport would then take another month to be delivered. Then I would have to apply for a visa. Fortunately I managed to get an appointment with the city within a week, and they have an express option for the passport, so this was done within two weeks. Obtaining the passport in time turned out to be no problem.

The visa application was a little more involved. It could only be done 50 days before the departure. The institute took my application and sent it to the consulate in Frankfurt am Main. The application form is quite lengthy and I had to provide a bunch of information. They wanted to know which regions I have traveled to in the past year as well as the names and occupations of all my close relatives.

Another thing that was new to me were the invitation letters. In order to get a visa, you need an invitation letter from the local university or company. These invitations have to be provided for the visa application. I have heard that Russia has a similar system, but China is the first country that I traveled to that has this system.

After filling in all these forms I handed my passport to the secretary who kindly had organized everything else. A few weeks later I got my passport with visa back.

## Flight to Wǔhàn

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.

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 dus001@airchina.com[ 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.

## Money

Most countries seem to be much more progressive in terms of cashless payments than Germany. China seems to be heavy on mobile payment, having AliPay and WeChat Pay. Apparently you need a Chinese bank account to use either of the system. This means that I was not be able to use them while I was there for mere four weeks.

One possibility seemed to give money to a local and then have them gift it to me within one of the payment apps. This way I might be able to pay with the app without needing a Chinese bank account. I have tried this with a Chinese colleague. He has sent me a red letter with a little bit of money as a test. Before I could open it, I needed to verify my identity though:

According to the regulations of the People's Bank of China, you must first complete real-name authentication in order to use WeChat Pay for Red Packets, Transfer, payments, etc.

It seems that this is just basic law against money laundering and other nefarious intents. The only available options to verify my identity are either a China mainland ID card or a Chinese bank card (I presume debit card), both of which I do not have. So although I really wanted to try it, WeChat payments are out of me.

With my credit card I was at least able to buy some water bottles at the airport. They are 500 ml each and only cost 5.00 CNY each. At the then current rate this was 0.64 EUR, which I consider a steal for airport water bottles.

Also the card allowed me to draw money from an ATM there. I ended paying pay cash in most places as credit card acceptance is low. This is what their money looks like:

There is a 1 CNY coin but also a 1 CNY bill. This is somewhat like the 5 DM coin and the rare 5 DM bill that existed before 2002.

At one of the restaurants they even had a WeChat Pay code for each table. So you could just scan the code at your table and have paid. During exit you would just show the payment confirmation and it would be done.

Tipping is not a custom in China. There people get paid for their job and find it insulting to be gifted money. It suggests that they are not getting paid enough. I really like this culture, it makes paying at a restaurant easier and one does not feel obligated to compensate the low wages like one is especially in the USA.

## Food

Being a vegetarian with some food allergies makes traveling a bit more involved. I have heard that Chinese cuisine uses a lot of peanuts, therefore I wondered how people cope with that.

### Preparation before the trip

I found a couple of sources that cover the topic:

They pretty much all say that one needs some sort of sheet stating the allergies. In most articles they warn about peanut oil. As the allergic reaction is triggered by the proteins, the oil should be generally safe. The post on Reddit especially states that.

Being a vegetarian is not unheard of in China, but it seems to be rather unusual. The Buddhists eat vegan, therefore one could go into the Buddhists restaurants and have that covered.

A colleague kindly wrote me a note in Chinese stating all my allergies and foods that I do not like to eat. I have tried this in a Chinese restaurant here in Bonn and it worked just fine.

In order to make it easier during the beginning I just took some "safe" foods from Germany. I ended up buying dry bread and crackers, as well as some dried fruits. Additionally I took some black bread which will stay good for around three weeks.

### Restaurants

On the first day a colleague and I went for lunch. We did not look for restaurants beforehand, we just tried our luck and went up the street. In Germany (or also Spain for him) we know how restaurants look like. But there we had a hard time figuring out what the business behind a particular storefront actually is. We managed to find something that looked like a restaurant and just went for it. Having had no idea what different styles of food there are, we needed to just start somewhere. The owner family seemed exhilarated by our sight. Supposedly there are very few non-Chinese people in the city of Wǔhàn. They seemed excited to have us as their guests.

I pulled out my allergy note and they started reading. First with a curious interest, then with a little chuckle and after half a minute they were scrambling to find out what food they could serve us. It took a while, but they eventually came up with four dishes that were vegetarian and free of nuts. Most Chinese restaurants have a picture menu, so they just showed us pictures and we either nodded or told them via translation app that it was okay.

These things were tasty and the consistency of the white dough was rather peculiar, so I guess that it has been rice dough. I did not bother them to give the names again, so I cannot tell you what this actually was.

They also served us green tea in a seemingly traditional tea kettle. There was a wooden frame with a tea boiling device on it. They put a lot of tea into it and demonstrated how this works. One pours water into the top, lets it steep just five seconds and then opens a valve to pour it into a little bowl. From there one would put it into little shot glasses and have the tea. Instead of creating a whole kettle of tea in one go, one would just refill the hot water and get fresh tea. We often let it steep too long, so we got rather bitter tea. After many rounds of tea we finally managed to get mild tea out of this procedure. Unfortunately I forgot to snap a picture of that.

They also gave us western cutlery, but we tried with the chopsticks. My colleague is much more experienced with them, but at the beginning of my month in China I did not expect mastery from myself. Towards the end of the trip locals actually complimented on my confidence with the chopsticks. I use them differently then they do, but apparently they differ in their usages as well and nobody judged what I did. Similar to other students I eventually grew overly confident into abilities and got less and less careful with obvious results.

Instead of ceramic plates they just gave us plastic plates wrapped in plastic. This felt like such a waste of plastic. In a different restaurant I got a ceramic plate but still wrapped in plastic.

The north and south of China are apparently divided into rice and noodles. In Wǔhàn it is common to have a noodle soup for breakfast, and my hotel also offered this.

My favorite breakfast item were the steamed buns, though. This particular kind is filled with a red bean paste. They all look different, so you had some chance to tell what you have there. In general I am very vary with dumplings or other breaded things as they usually have meat inside.

Most conference lunches were in the restaurant of the hotel. On the excursion day we instead got a lunch package. For me they had a vegetarian one, which contained tofu, vegetables and mushrooms.

Thursday night we had the banquet at a fancy restaurant. As they have inquired about dietary requirements beforehand there were a couple of vegetarian tables and one special allergy table. At that table they just served vegan food without any nuts. There was way too much food for all of us, but it was a very amazing experience. And during the meal they have even brought out different dishes to fill in the gaps.

I have also tried the Chinese restaurant at my hotel in Wǔhàn. There four waitresses gathered around my table to study my allergy card and tried to figure out what they could bring me. They had offered the dish with beef and potatoes and I did not want to take it. Yet I still got it together with the cabbage and rice. In the end it was 95 CNY, which I still find acceptable by German standards.

One evening I was still feeling a bit hungry. Having tried the Chinese restaurant at the hotel already I wanted to try the Western restaurant. There they wanted 108 CNY for a buffet. These never make sense for me, especially when I just wanted to get a snack. So I went outside and looked for food places. There are plenty of street food stands and lots of small kitchens. One looked somewhat trustworthy and as they offered various rice dishes I hoped that they could give me something. I showed my allergy and vegetarianism card, but the clerk eventually shook her head. So I went further on the street and found a western fast food place. It is not one of the common chains, just a store offering the same food. I got some fries, paid 7 CNY and was happy for the night.

The following is the super hot "mapu tofu" which has a style of spice that will numb your mouth. A very strange experience. I did not experience that as it was way too hot for me to even try more than a tip of the chopsticks.

In some restaurants one gets a paper menu and a pencil and just ticks the dishes that one wants to get. The paper is then handed to the waitress. This way nothing gets lost.

In the restaurants one gets served warm water for free. Apparently the Chinese like to drink their water warm, perhaps an resemblance of tea or maybe just for sanitary reasons.

On my eleventh day in China I longed for some western food and ended up going to Pizza Hut. It was rather interesting as in the same shop they serve a lot of barbecue and seafood, as well as escargot (snails). I just had a bland pizza and was happy for the day. One of the locals helped me find a place where one can get Bǐsà (比萨), the transcription of pizza into Chinese. The staff there had me wait for a while because all tables were occupied. I got a receipt with a waiting number and was eventually called when a table got free. An English speaking young man was so helpful to translate. The ordering was a bit cumbersome due to the language barrier again, but with Google Translate I managed to get a pizza. Curiously there was a serving of tomato ketchup on the side with it.

After the excursion to Jǐngshān Park we just went to a random restaurant and ordered some stuff there. The most weird one was the bean curd. It looks like it should have some structure, but actually it is as soft as warm butter. Yet it is not sticky like butter. So whenever you tried to take a bit from it, you would just scramble it into little pieces.

### University canteen

In Běijīng we were given value cards for the canteens on the campus, they gave us roughly 40 CNY per day, we got 840 CNY in total. These were a bunch of 100 CNY cards that have slits in them to mark a certain number. These are briefly inserted at the POS terminal. At the first place that we have tried they have a bunch of little dishes that you just put on your tray. Since I already had spent a week in Wǔhàn I had enough faith in my knowledge of the cuisine there that I did not show my allergy note to anyone and just picked some of the dishes.

The above was my first meal at a Běijīng Dàxué canteen, I have paid just around 10 CNY. The others have taken a couple more dishes and ended up paying around 15 CNY. Even with dinner the 40 CNY are just plenty of money for food each day.

The most peculiar dish that I have seen were bird heads. I would not even know how to eat them, but the local people sure know that. There is the saying that the Chinese will eat everything with wings (except airplanes) and everything with four legs (except tables). That dish made me think of that joke again. Another strange dish is duck bladder with tofu, which I have also skipped.

One day I just tried a new dish and I still do not really know what it was. The best guess has been thinly sliced potatoes. Unfortunately it was too spicy for me, which one might have guessed by the chili on it.

They also offer buns at the price of 0.20 CNY, so that is like 0.03 EUR. There are versions filled with meat available, these cost twice as much. I have tried the plain ones and they are really bland.

On the third day of lectures in Běijīng I have tried a different place to have lunch. One of the local students has been so kind to take me to lunch with him and invited me. He took my note and picked out a meal for me, which is an amazingly helpful thing to do. He picked out thinly sliced potatoes with vegetables and rice as well as egg sting in tomato sauce. It was not too spicy and really delicious. After having had four meals in the one canteen I really longed for something different. In general the egg sting is a really popular way of serving egg in China and likely also other Asian countries.

At the end of the summer school we all had a lot of lunch money left. As it was non-refundable and we found a campus restaurant in the last week, we had a bunch of fancy dinners during the last week. But even when we had a table with 10 people there would only be a bill of around 500 CNY and each of us had several hundred CNY to spare. And even after having a bunch of lunches and dinners there, I still had a bunch of cards. We tried giving them away, but surprisingly a lot of people turned them down. It actually took quite a few tries to give the cards away.

### Snacks

Although the articles suggested that most meals in China would contain nuts, this is not the case. I have only encountered very select main courses with nuts. There are many snacks with nuts, though. These here are the snacks that were offered at the hotel in Běijīng, all nuts.

I wanted to get a particular sweet that a Chinese colleague had brought to Bonn once. So I have showed the picture I had taken back then around and local people told me what this was (Qīng tuán, 青团) and where to get it. So I went to the store they told me and show them with the translator that I wanted that particular one. For some reason they did not have it and they just showed me something else that had bean paste in it. It turned out to be made from flaky pastry instead of rice dough.

Interestingly they use tweezers to handle the cash money. This seems like a sensible alternative to wearing rubber gloves. But on the other hand a bakery store near my home does not use rubber gloves and instead have printouts from a study that showed that there are not that many germs on money after all and that wearing rubber gloves does not really improve things.

Later on the Chinese student told me that the stuff that I had in mind is only available in April, so I could not get it now and would have to try some of the other stuff that one can get.

There are many candy stores to be found in the city, most have a bunch of stuff where you can just fill up a basket and pay by weight:

### Supermarkets

In a shopping center in Běijīng we have found a Carrefour supermarket, which was just huge. And there was just another one below it, I guess they have even more stuff there. There are so many different things that I was instantly overwhelmed. In the snack aisles one can find tons of preserved meat products as well as another aisle with nuts and related products.

They had a few aisles with imported goods. The Crunchy Valley bars I have some feeling for. In Bonn they cost 2.00 EUR per box, in Dublin they were already 3.00 EUR per box. And in Běijīng they are 29.90 CNY, which is pretty much the price from Dublin.

## Internet access

A lot of internet services that are used in the Western world are blocked in the mainland of China. This means that everyday things like everything Google, WhatsApp or Telegram are not be accessible. There are lots of suggestions of using a VPN to get around the blocking. Besides being illegal one is also up against a firewall which uses deep package inspection and artificial intelligence. Colleagues already told me that they experienced the physics institute VPN to get blocked within a couple of minutes. I decided to not bother with any of this and just make sure that I have the data that I need offline. Colleagues have tried using VPN with different outcomes.

There is a website where you can check domains for their accessibility from within China. This way I could already see that my website and my email server seem to be fine.

Google Drive is blocked, so I have to put the files onto my phone and tablet without the cloud. Using the SSHelper app I just started an SSH server on my Android devices and copied all my papers onto it. I have also downloaded some YouTube videos with the youtube-dl program and put them on my tablet to watch in the plane.

I have noticed that the whole of Wikipedia is blocked as well. This made it a bit cumbersome as I regular use it. Also Google search is blocked, so I have been using Bing. This also has the ability to show pages from its cache, this way one can still access Wikipedia pages. I wonder whether this is intentionally allowed or just a little gap in the filtering.

The connection speed to servers outside of China is really bad. Sometimes it just does not work at all, sometimes I can get 1 MB/s. This Comic sums it up pretty well.

After a while of being there I still got WhatsApp messages and could reply to them. Sending pictures did not work, but text messages came through somewhat reliably. WhatsApp Web was not accessible at all. For Telegram I received the notifications but could not see any messages in the app. This is something that I do not understand. Telegram tries rather hard to evade the filtering in various countries, WhatsApp seems to abide by the local laws, it should not work for me, yet it did.

### Cell phone

My cell phone provider charges heavily outside of the EU, therefore I planned to obtain a local SIM card. My phone supports dual SIM, so this seemed like a perfect fit. One can of course buy them there, but one can also just order them online from Germany. They have to be activated when in China with a simple phone call, so that should be easy to do already at the airport.

According to this site there are three cellular providers: China Mobile, China Unicom and China Telecom. Only the middle one has a network that works with European phones (non CDMA), therefore I ordered such a SIM card via beachSIM with 1 GB of LTE data within 30 days for 19.90 EUR. The time starts at first usage, just like the 30 days of the visa start at entry. Also a perfect fit.

Locally you can apparently get 30 GB for just 10 EUR, there is a China Unicom store right on the Běijīng Dàxué campus, this would also be a slightly cheaper option. The concrete offer from China Unicom is 5 CNY basic fee per month and then 1 CNY per 100 MB. That is much cheaper than the SIM card that I bought.

As lots of services that are widely adopted in the western world are blocked in China, like WhatsApp and Google, I already installed WeChat while I was in Germany. Without access to the Google Play Store I could not have installed it in China.

Android displays a "no internet connection" sign while I was there, both with WIFI and cellular networks. They seem to check whether they can reach some Google service, and as the phone cannot, it determines the internet as broken. It somewhat makes sense!

One could get a SIM from Hong Kong, their internet is not filtered. If you have such a SIM card and go to the mainland of China, you will still have unfiltered internet. They are bit more expensive but a real sensible alternative to fiddling with VPNs.

### Public WLAN

At the airport of Běijīng I saw that they have a public wireless network. One has to have an account in order to use it, though. The only option that seemed sensible for me is the WeChat login. It just did not work. After I was through the security again I saw a little machine that creates an account for you. You just have to let it scan your passport. I am not entirely sure what I have signed up for with that, but I was then able to use the internet. Well, with the restrictions.

Conference hotel WLAN is really slow and had connection drop issues. Some of these issues might be caused by the transfer to outside of China, but still it was not really fun to use.

A bunch of cafes offer public WLAN, this is not really unusual. I was surprised by finding public networks in parks, though.

### Classes of filtering

Before I had just assumed that there would be just two classes of internet in China, one being filtered and one being without any filtering at all. It turns out that it is much more fine grained. I think that there are four classes.

1. There are people with SIM cards from the USA with a roaming plan, they seem to have completely unrestricted internet in mainland China.
2. The next level you have is the Hong Kong style internet which I also happen to get via eduroam at the university. There you can access Google Search via google.hk and also use things like Google Photos from my Android phone. A lot of services are usable, but Facebook for instance is blocked. Sending images via WhatsApp works just fine. If I had gotten a Hong Kong SIM card I would have likely also gotten this level of access over the cellular network.
3. The hotel WLAN connection does not allow things like the German TV network ZDF, it also seem to block sending images on WhatsApp, at least most of the time. I found that some messaging apps also work via the hotel WLAN, but this somehow depends on the day.
4. The most restrictive is my China mainland cellular. There I cannot access said messaging apps. WhatsApp and Tinder work most of the time, though messages sometimes get stuck for half an hour before they are send out.

## Wǔhàn

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!

### Hotel

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 Trip.com 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 Trip.com.

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.

### Conference

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.

### Metro

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.

### Traffic

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.

### Excursion

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.

## Domestic travel to Běijīng

After the first week I had to do a transfer from Wǔhàn to Běijīng. These are around 1050 km linear distance apart:

If you started in Bonn and went 1050 km linear distance, you would already be in Spain. This should give a first impression on the size of China.

There are two sensible options to travel this distance: plane and train. Booking a plane with a German website would have cost me around 300 EUR. The airports in both cities are a bit further out, so this is not really the most comfortable option. The Chinese railway system supposedly is very good according to a colleague, so I checked their booking website and saw that the connection is available for 78 USD in second class on a G-class train. This is the fastest type going between 250 to 400 km/h.

The trip would take 4:20 hours. They supposedly have separate tracks for the fast trains, so this should run very smoothly. The train only stops two times on that route, see this map:

If you would take the same distances in Europe, the train would only stop in Berlin, Köln, Basel and Milano.

We have booked the train via the website and payed in USD currency. The tickets would have to be picked up at any train station in mainland China, similar to the process of Deutsche Bahn.

At the Wǔhàn Main Station we have picked up our tickets. As always there have been multiple queues and the ones that we have picked was the slowest one. There was one person wanting to purchase a ticket, and somehow it took five minutes for him to figure out which ticket to buy. Once it was our turn we just presented them with booking numbers and passports and got our paper tickets.

The departure is on the third floor, we had to go up two levels. There was a security check, though not as thorough as at an airport. I did not have to empty my pockets before going through the security scanner. They wanted to check me with the handheld metal detector, but that was no way as thorough as they had checked me in Běijīng on my transfer there. We proceeded to our gate, it really felt like an airport. Before we even got to the security check we had to present our passport and ticket again. From behind the security one could get a first glance on the trains.

According to the instructions from the booking process we have planned to be at the station 90 minutes before the departure. We were lucky and did not have any waiting time except when picking up the tickets, so we just spend a lot of time sitting near the gate. Eventually we got to go down to the train platform. On the ground there are printed labels indicating the train car numbers.

All this was much more organized than the ICE trains in Germany. There the train just stops roughly at a particular position. One of the posters there tells you which car is located in which section, but that only works roughly. Sometimes the order of the train cars is reversed. This just does not happen with Chinese high speed rail. Also inside the train all seats face forward, which is nice for people who have a hard time riding backwards. German trains are build in a symmetrical way such that the cars do not have an orientation. This means that half of the seats are oriented backwards, though.

During the first part of the trip the train was going around 300 km/h, which you can only get between Siegburg and Frankfurt am Main in Germany. During the excursion the guide told us that there had been an accident and therefore the trains were operating at only 70 % of their maximum speed at the moment. I am not sure whether the 400 km/h that are advertised are before or after that reduction, though.

The tickets were checked again inside the train. One nice thing about having all reserved-seats was that the crew knew where one would sit. I have seen a sleeping passenger being woken up just before his exit station. This is a very nice service. In general there are extremely many people working in various places. A German train might have a few conductors on it. In China you have many conductors, several cleaning people and a couple of policemen on the train. Also at the security posts there usually are people just standing there without an apparent task at hand. This feels a bit strange, but apparently it is just a cultural thing to have more people around. Also in the metro in Běijīng I saw people just standing next to the escalators and presumably making sure that people use them correctly.

On the over four hours of train ride I eventually got hungry. I went to the board restaurant where the two waitresses enthusiastically read my allergy card and told me with gestures that this was a really good idea. They eventually gave me a plastic box which had a plastic wrapped pack of ramen noodles, some wrapped pack with powder and vegetables and a plastic fork in it. Then they poured some hot water over it and told me to wait two minutes before starting to eat. It did cost 25 CNY. At some store you could probably get it much cheaper. Eating the entangled noodles with the plastic fork proved difficult as they always slipped off and fell back into the container.

We arrived at the west railway station, Běijīng Xī (北京西), just on time. The Chinese high speed rail is separated from the regular trains and therefore there are no delays. Normal trains supposedly have regular delays, though. At the exit we had to present our train ticket yet again to leave the station. From there we made it to the subway. With the whole Open Street Map for Běijīng on my phone I was quickly able to figure out that we would need to take the line 9 to Guójiātúshūguǎn (国家图书馆) and do a transfer to line 4. That one would then take us to Běijīng Dàxué Dōngmén (北京大学东门), the east gate of the Běijīng university. Just as in Wǔhàn the subway system is easily accessible and transfers are just exiting the train and going to the opposite platform. We arrived on Sunday late afternoon and the subways were packed, much more than in Wǔhàn.

One can compare this train trip to one which I did after my journey to China. I wanted to go from Bonn to Dortmund. I had booked an IC train which was supposed to take around 1:30 hours. When I arrived at the station in Bonn I checked with the DB Navigator app whether something had changed. And it said that the train was cancelled completely. So I looked up alternatives and found the combination of a RB to Köln Messe Deutz and from there an ICE to Dortmund. The RB would be leaving a minute after I checked, so I ran and managed to get into it.

That RB then needed to do an extended stop in Köln South station because of some electronics hiccups at Köln West. After being like 15 minutes late compared to the original schedule of that train we finally started off again only to stop midway before Köln West. It took longer and longer and I eventually managed to board the ICE train. There in the car that I was in the air conditioning was broken. With 38 degrees Celsius on the outside this was a sauna outright.

But the ICE was also accumulating delays because they waited in Köln to get everyone from other delayed trains onboard. This likely is a good thing because I managed to get it as well and potentially others from other delayed trains. But then between the cities of the Ruhrgebiet the train was going really slow and accumulated even more delays. In the end I managed to sip up my buffer of 20 minutes and got there 45 minutes late, so over on hour later for a trip that was supposed to take 1:30 hours in the beginning.

I really like the train as a concept, but Germany is just screwing it.

## Běijīng

Běijīng (北京) literally means northern (北) capital (京). The name "Peking" is the official name in English and German and corresponds to the same city. I just prefer to use the Chinese name. There is also the city of Nánjīng (南京), the southern capital. Depending on how you count there are 23 million people living in Běijīng, which is completely beyond my comprehension. Compared to Wǔhàn that is just a factor 2 adding to the factor 50 Wǔhàn has to Bonn.

To really get an idea about Běijīng, compare these maps with the same scaling comparing it to Bonn. You can see that the metro area of Běijīng easily fills both Bonn and Köln and all the space in between.

### Hotel

For the summer school in Běijīng I got a room booked at the Zhongguan Xinyuan Global Village PKU together with another student attending the school. This is the guest house of the university.

The organizers have paired me up with a Master student from Frankfurt, so it was very easy to communicate and get along while we shared the room. I wondered whether pairing up with Chinese students would have made more sense to learn more of the culture. But as there were plenty of discussion opportunities pairing the students roughly according to culture seemed to make more sense after all.

Our hotel room was significantly smaller than the one that I had in Wǔhàn for myself. We still managed, but it would have been nicer to have some more space for week two to four instead of having all that unused space in the first week.

The toilet was a very US-American style: You have to press the flushing handle for quite some time until slowly a vortex emerges. I really do not get these toilets that are filled with large amounts of water. At least we did not have a standing toilet which seem to be common in public locations in China.

One day I have tried the gym of the hotel, one just pays 10 CNY and can use all the equipment and badminton and squash courts that are there. It is below ground and fully air conditioned. While I was running on the treadmill it just hit me how ridiculous this actually is: There are many parks there where one could be running. But during the day it is so hot that it would be extremely taxing. Also with the pollution the exercise will be like smoking a full pack of cigarettes. So there I was running on an artificial running track, breathing air conditioned air and seeing artificial light ...

I have also tried running on the PKU campus. There are much less cars there and a surprising amount of parks.

After that I just continued my laps, there were few other people there and I only had to share my lane with one other person. There were a few people learning to swim there. When I was finished I went to the lifeguard's table and picked up my sheet of paper. It then had some additional markings on it, as well as a red stamp. I presume that this means that I have passed.

If I had a one inch photograph of me I could also have gotten a proper plastic card that would be valid for the next three years. I really wonder why they have this measure in place. It seems to be local to Beijing as the name suggests. Perhaps they had a bunch of tragic accidents and therefore now required people to show that they can swim before letting them into pools. And "deep water" there just meant two meters, so it is not really deep, you cannot stand, though.

During the breakfasts I never really noticed music. One day one of the group pointed out that they are playing the same playlist every single day and that he is going to snap if he is going to hear that particular song one more time. Then I started listening to the music and recognized the song. The days after I could not overhear the music and noticed that the same song came up every single day. They seem to have some short playlist that is just looped endlessly. I guess since most of the people there do not understand the English lyrics they do not mind as much as I would do.

In both hotels the room service would change my towels every single day. They have an explicit dirt towels basked under the sink, yet they still change all the ones every single day. I really would like to keep my towel for a week at least. It feels like such a waste of resources. Also they have taken out the shower mat every single time, so I had to put it back into the shower every single morning. I guess it is nice, but it really feels like a waste of resources for no real benefit.

### Summer school

The summer school was held at the physics department of the Běijīng Dàxué (北京大学). The building itself does not seem particularly fancy compared to all the other buildings.

We had a first lecture on Monday morning, then a photo session. In Wǔhàn there already was a group photo with all the 300 conference participants. They had set up a set of bleachers which they did not deemed too safe. They told us to not lean against the back rail. Although I thought that this would be totally unsafe and an exception, the bleachers they put up in Běijīng were rather unnerving. There was the attempt of a guardrail, some hollow poles without an end cap. There was rope taut between them, but well below my center of gravity. If I had lost my balance just for a bit, I had either impaled myself on the hollow pole, been tipped over and fell head first to the ground or suffered some other horrible injury. Luckily nobody got hurt in the process of taking the picture.

The physics building is not part of the campus, it is just slightly off to the east. We crossed the large street and entered the actual campus. Our badges have a special sticker on them which grants us access to the campus. There are guards at every entrance actually looking at them. This was a strange sensation as I have never seen a university campus that was access restricted.

The campus is very nice, on the first day after lunch we have walked to an artificial lake which gave a really great sight.

### Weather

When we arrived in Běijīng and left the air conditioned train the 37 °C with high humidity hit us. It took less than a minute for me to feel horrible. The subway was air conditioned again, the walk from the subway station was in the heat again. The buildings are all air conditioned, which only made the transition worse. This aspect really felt like being in the USA where I have experienced extreme differences in temperature due to air conditioning as well.

I am not very good with direct sunlight, so I wore my likely ridiculous looking hiking hat. After everyone made their snarky comment I enjoyed the shade. Locals just carried umbrellas which seem to be the better choice.

Most days we had an UV index of 7, and everything beyond 3 means that I need to wear sunscreen. Others had similar issues, but apparently just going for lunch and back was fine for most people.

At the lecture hall they had a large stack of water bottles for us students. They were usually all taken by the end of each day.

The amount of water bottles that have been drunk during the summer school is really mind boggling. Take around 76 people there, 15 days of summer school and each drinking perhaps six bottles a day. Then you are at a staggering number of 6840 bottles. They have been collected and apparently they go into recycling. But even if that plastic is recycled, it still takes a huge amount of energy to process all that material and make new bottles from it. I am really happy that I can just drink the tap water at home and not produce plastic waste. The hotel has a sign next to the sink that explicitly states that it is no drinking water. so it seems to make sense to drink bottled water there.

The lecture hall was also air conditioned with the large appliances that blew cold air into the middle of the room from the two back corners. This made a bunch of seats having a constant draft, which is exactly what I do not want. I already caught a cold during the last days in Wǔhàn and it got worst in the first days of Běijīng. I was reminded of the worst cold that I ever had, which I got in the USA during the summer.

Although it was really sunny in Běijīng, on some days there were no really sharp shadows on some days. I am still not sure whether it was just a light overcast weather or whether that actually was light scattering from pollution in the air. The levels of PM2.5 and PM5 were usually really high during my time there.

There are some people wearing breathing masks but much fewer than I have expected. Perhaps the amount of pollution is not as bad as it is on the bad days, so that could explain it. Some of the other international students voiced concerns and had the feeling that their airways were being a bit irritated but could also not differentiate between air conditioning and micro particles.

### Traffic

I was very surprised to see that Běijīng has quite a bike infrastructure, at least close to the university. The campus of course is full with bikes. But just outside the campus there is a dedicated bike lane and tons of rental bikes.

The intersection at the East Gate of the university is notoriously crowded. In the morning one can wait up to four minutes (exactly) in order to pass. People do not seem to care much about the traffic lights. A red light is a mere suggestion to cross the street a bit more careful than usual. We started taking the subway tunnels to cross the street as this is much faster and more reliable.

A very interesting feature that I had only seen in some intersections in the Netherlands is a traffic light phase where most pedestrians and cyclists have a green light. This looks rather amazing.

In general I found that navigating the streets wears me out rather quickly because it works so differently from what I am used to. People cut me off all the time, I get honked at (like everyone else) and sometimes people also bump into me. This makes everything more taxing than in a Germany city where I do not have to think about the traffic. The following panoramic image might give an impression how busy this city can be.

There seem to be many competing bike rental companies having their bikes scattered everywhere in the city. I have no idea how many companies there are, but there are at least eight different companies with nine different products. The companies do not have a share for a particular part of the city, its just that there bikes from every company are abundant in the whole city. I have seen people having multiple apps on their phones such that they can just pick up any of the bikes.

#### Metro

The metro system is very nice in Běijīng as well. It is very accessible with everything available in English as well. The awesome thing is that Běijīng has a few ring lines and a few straight lines. This means that you can go virtually anywhere by taking the straight line, going a bit on the ring line and then going on a straight line again. As the transfers are rather painless, this means that you can get to places very efficiently.

In every subway station there is a speaker announcement every minute:

Please stand firm and hold the handrail.

It is announced by a speaker with a Chinese accent in the English, and there was just too long of a pause between "hand" and "rail" which made me flinch every single time I heard the announcement. In the third week I really disliked being at the stations because of this perpetual announcement.

### Laundry

According to a colleague there are no public laundromats to be found, even in Běijīng. This might sound strange, but apparently laundry is done by hand in the sinks at home. I do not have enough clothes for four weeks, and even if I had it would be tough to fit that into a single suitcase with not more than 23 kg weight. Packing a bit of laundry detergent and clothes line allowed me to get by just fine. The alternative would be giving clothes to the dry-cleaning service either in the hotel or in the city, but that feels like overkill for my clothes.

I bought a tube of detergent and a clothesline and brought it with a handful of pins. It turned out to be difficult to have it hang in the hotel in Wǔhàn because the only suitable suspension anchors made it hang right across the bathroom. This has been much better later in Běijīng where I could just deploy it over the bathtub (there was an additional shower that we used). One has to be careful because hand-washed items start dripping after a few minutes.

The hotel already provided a single retractable clothes line, but the capacity was not enough for the two of us. Eventually we got a letter which told us to put it down and just use the one that is supplied. Luckily we were already in the third week and did not need to wash more clothes.

As many other people have this issue the organizers of the summer school have found a laundry shop on campus where you can wash a load for 6 CNY. That is a very affordable price, though it does not include drying and one still has to come up with a way to dry the clothes.

While I was in the USA I had the impression that people were washing clothes excessively, wearing a pair of pants only for two days at a time and then washing them again. In China I have seen people wearing the same t-shirt for four consecutive days, so it seems that the perceived need for washing varies quite a lot between the countries.

### Nightlife

According to a local there is not much nightlife in Běijīng. I do not really understand this for a city of this size. German cities like Hamburg or Köln have vibrant night life, and even Bonn has some. Cafes and restaurants close really early. I have been to a bar which is famous with the locals and they had live music from 22:30 to around 00:30. It seems really odd that on a Saturday night they would not have been going until like 05:00 or so.

### Sightseeing

As I was legally required by the tourist statues of the internet I needed to to some sightseeing. There are so many interesting places to choose from that it is hard to pick.

#### Old Summer Palace

There are two summer palaces north of PKU, the large old one and the slightly smaller newer one. The older one is supposed to be nicer as tourist attraction, so I just went there first. As I have walked through the university campus to get there I saw that it was just graduation season. Just like one knows from US universities there were many graduates in cap and gown walking on the campus, together with their friends and family. People would get together for photographs, everyone just seemed very happy there.

One needs to buy a ticket in order to enter the old summer palace, they charge 10 CNY for admission to the park and another 15 CNY to see the ruins in the north. That ticket can also be bought later right there, so one does not need to get it directly at the south entrance.

The entrance goes through very traditionally looking buildings with a pagoda, which is quite a sight. The number of figures on the corners of the roof give the importance of the building, this way everyone can see it right away.

The park itself seems endless, I have been walking in it for over two hours and did like 8 km and still only covered a small part of the areal.

There are many tourists there, and lots of tourist groups that just trot behind their flag carrying tour guide. I ventured off to the side paths and found that there were virtually no tourists there, a quite pleasant experience. There are many lakes and canals with bridges to cross them. I have taken many pictures, you would need to take a look into the album to see them all.

One of the key exhibits are the ruins in the north. Unfortunately all the explanatory text was in Chinese, so I did not manage to learn anything significant from there. Still I got to look at a lot of interesting things.

The whole atmosphere is amazing and very calm. I spend the better part of an hour just sitting on a bench in the shade near a lake and enjoying the breeze that we had on that day. Also the view with the mountains in the back is quite majestic. This is a nice place to really relax I would say.

Just like around the lake of the PKU campus there are many cicadas that make a really loud soundscape, making it feel really typically Chinese.

#### Tienanmen Square

While roaming around the city center I had already come close to the forbidden city and the Tienanmen Square during the night. It does not have an outrageous light show but subtle lights to it. In the bus that we were taking past the square there were two security guards. One was in the middle of the bus in the luggage area and stood at the open window. He noticed that I was trying to take pictures and traded spaces with me. So I got do stand right next to an open window that was large enough to easily bend my whole upper body out of the vehicle. It was a very strange sensation as something like this would certainly not be legal in Germany.

On the second weekend I wanted to go to the Forbidden City and the Tienanmen Square. I took the subway there and needed to walk up to the security screening. By that time I was completely used to all the security screenings everywhere. There are also passport controls there. There were endless amounts of tourists. The curious thing is that these usually come from less cosmopolitan areas unlike Běijīng or Shanghai. Therefore they are not used to the sight of westerners. While I was in the queue one woman just took a picture of me with her cell phone, and she was not shy about it when I noticed. A second took a selfie with me in the background. On the square a young woman asked me to stand next to her friend to take a picture.

The square itself was not really amazing, it is just a big square. The sheer size is impressive, though. And you can see the entrance to the Forbidden City. So I did not spend much time on the square and just progressed to the next thing, following all the other pilgrims.

#### Forbidden City

The number of visitors to the Forbidden City is limited to 80,000 per day. That just seems mind boggling. This means that in four days the whole population of Bonn would have been there. And they do this on more than four days a year. Other people from the Summer School have told me that one would not need to reserve a ticket. Locals have told me that one should reserve a ticket. I took the risk and went there without a reservation. Some others went on the same Saturday and arrived at around 10:00 and just got in. I arrived at 12:00 and it was already booked out. So no Forbidden City for me.

I then just walked around it and found a nice park.

From there one has a magnificent panoramic view over the forbidden city.

If you open the picture, you can see the stream of tourists leaving the city. Other people told me that most of the buildings are closed and that one constantly has to fight against masses of tourists. So perhaps it was not too bad that I missed out on that and got more time and energy to look the Jǐngshān park north of the Forbidden City.

#### Jǐngshān Park

The Jǐngshān Park (景山公园) north of the Forbidden City costs just 3 CNY to enter. They had no English/Arabic prices set up, so I just gave the clerk a 100 CNY bill and got a lot of change back. On the south side of the park there is a hill with a pagoda from which one can see the whole city. As the Forbidden City defines the city center you can really look around and see high rise buildings in every direction. Perhaps take a look at the photo album to see the various panoramic images that I took from there.

Further up north there is a facility that has been used in sacrifice rituals. At least that's what I understood from the bit of English writing that was to be found.

In order to enter that part I did not have to pay anything more, they just wanted to scan my passport.

In front of the main gate there are two lions that both look like this one:

They differ in the item that they have below their claw. The left one has a lion baby below her, the right one has a ball. The baby symbolizes fertility and makes it a female lion. The ball in contrast resembles power and therefore the right lion is a male on.

#### New Summer Palace

On my last day in Běijīng I went to the New Summer Palace. It is located two metro stations to the west of the Old Summer Palace. Other people had already went there at that point and had positive feedback for it.

When you enter, you cross a bridge over a canal where the Suzhou Street is located below. The emperor had the problem that he could not just go shopping like regular people could. So in his palace they created a whole shopping street just for him to play normal person once in a while.

Behind the bridge there is what I would think of a Buddhist temple. The square really looks impressive. There are the usual male and female lions in front of it.

I could not wait to climb all these stairs. Inside the temple there are huge golden Buddha statues, one was not allowed to take pictures there. The sheer number and size of them is impressive! Behind the temple going further uphill there was one of the most amazing views that I had one this trip.

You can see the large lake, the island with the bridge. Also a bunch of people on boats just going for a little cruise on the lake. Right in front of you are a bunch of trees, you can comfortably stand in the shade while you enjoy the view. And in the very back you can see the skyline of Běijīng, which just seems endless. A professor from Seattle (Washington, USA) got a good view from the plane and said that it looks like one would have taken quite a bunch of Seattles and merged them together into one sheer endless city. I still have no comprehension of the size of this city.

On top of that hill you can hear a loud chatter from people, but also it appears rather far away. When I got down to the marina I realized that there are endless tourists there. It is amazing, they arrive in endless buses, are being guided by professional tour guides with microphone and speakers and then get back to the bus.

From the marina I could also see the actual palace. I did not realize that when I was up there, so I did not buy the extra ticket to enter it. But time was running on short on that Friday anyway, so I could only look at part of the whole areal anyway.

In the north eastern sector of the park there was a really nice spot to just chill out. They played some Chinese ambient music and one could watch the fish and birds move around. I spend a little while there, quite relaxing! Also there were virtually no tourists there. It is amazing how they are just confined to the tour routes and not look at anything besides that.

The New Summer Palace has much more to see than the Old Summer Palace. But I found that the latter had a more beautiful scenery. So for relaxing in nature I would prefer the Old Summer Palace.

My return flight to Düsseldorf was scheduled for Saturday at 01:50+0800. Arrival at Düsseldorf would be something like 06:30+0200, so I would get home in the morning and with sleep on the plane the jet lag should not be that bad. At the airport I bought such an U-shaped pillow. A lot of stores outside of the security area carry them. They ranged between around 300 CNY to a cheap feeling one for 120 CNY. I ended up with a mid-range one, it is amazing how many different models there are!

Before I got to the gate the flight was already marked as delayed, they showed 02:30+0800 instead of the scheduled 01:50+0800.

For some reason it is a problem to bring water bottles through the security check. So I always have to toss them and buy new ones afterwards. The easiest way would be to just empty the bottles and refill them at the drinking water fountains. But I did not know that these existed, so I did not bring any containers. In the domestic terminal on the way to Wǔhàn there was a small grocery store that accepted my credit card and sold water. In the international terminal I could not find such a store. There were many stores under construction, so perhaps one of this kind was being rebuilt. I found two vending machines that accept credit cards, so I purchased a bottle of water there. Also I spent my last CNY on water, I was happy to have spent it all.

The challenge started when I wanted to get more water at the gate. There the vending machines only took CNY cash or WeChat Pay. I had neither. So I went back to the center of the terminal to the ones that do accept credit card. In both of them the water was sold out already. So what would you do now? I had the following items:

• Credit card
• Less than 1 CNY in very small coins
• Several 50 EUR bills
• One full 570 ml water bottle

I wanted to get some more water for the flight and did not want to pay a crazy amount of money for it. It turned out to be quite a quest! I first wanted to see whether I could find an ATM. They did not have one within the security area. Then I tried to go to the currency exchange and wanted to trade 5 EUR for CNY, but the smallest bills that they have are the 50 EUR. I saw that another guy bought currency via credit card, but they sell everything except CNY via credit card. I could have traded a whole 50 EUR for CNY but I really wanted to avoid that. Next I tried to go to Starbucks and wanted to buy water there. They only had Evian for 22 CNY per bottle. That's a bit extreme, but still cheaper than the other options that I had. I tried paying with credit card there but it got rejected and their POS system crashed. The clerk declined to sell me anything, so I left without expensive imported French water. I felt that I was running out of cheap options. There are a row of restaurants, but most of them had already closed at 00:30. The Irish pub still had a clerk at the counter, so I asked whether they would sell bottled water. They had the same Evian for say 26 CNY. But they would not take the credit card outright, so another bust.

I went back to the vending machines and saw that somebody was restocking it. He was just refilling cans, though. I pointed to the water and he communicated that there is no more water. Great. The vending machines at the gates have water but I don't have cash. At the other vending machine I saw somebody attempting to buy a can with bills. I somehow communicated that I'd like to have the cash and payed for his can with my credit card. After that I had a 5 CNY bill which was enough to buy a second bottle of water. At that point I had 1140 ml water capacity again. I refilled that shortly before boarding and then just got water on the plane.

During my stay in China I got to know the food. For the return flight I just booked the vegetarian menu and got a meal which was free of allergy issues for me. I could have just gone with that for the first flight. Next time I know.

The departure of the plane was late at night, I was already pretty tired. With the neck pillow I managed to sleep for more than half of the flight and arrived only somewhat tired in Düsseldorf. Immigration was also with the automated machines, I spent most time waiting for my suitcase. After I left the customs area I went to the first bakery store and got two whole grain rolls with a lot of butter and cheese, I felt like at home again.

During my purchase of the train ticket to Bonn main station I noticed a confused Chinese couple. They asked me in English whether I could help them book a train ticket to Köln main station. As I went there myself this was very easy, I just helped them with the ticket machine. They were very thankful and I just told them that I was happy to return the helpfulness that I experienced in Běijīng. The young woman that sat next to me in the train was also a bit lost, she needed to go to Aachen. I also booked her train but as she took a different one I wanted to make sure that she has all the information needed. Using WeChat I showed my QR code, she scanned it and we had exchanged contact information. Then I sent her a screenshot of the DB Navigator app which contained all the times, train names and platform numbers. The couple exclaimed how difficult the German train system is and I concurred. I really liked the metro systems in Wǔhàn and Běijīng, the CRH was also easy to use. And if I as a German can use the Chinese metro easier than the German regional trains, it should trigger some serious questions.

## Miscellanea

• As a Westerner one stands out a lot in general. Wǔhàn is not really a tourist location, most foreigners there are business travelers that presumably stay at the business and conference venues. While I was walking in the streets or taking the metro I would often see people looking at me in interest. We once walked into a little park where everyone outright stared at us. It was a rather peculiar feeling, like a reversed zoo setting.

This on the other hand made it super easy to get into contact with local people. Just showing them something translated on the phone would usually generate an excited and helpful response.

• The jet lag coming to China has been rather tough, it was a six hour shift for me. Going to the east is generally the worse direction to travel. Many other people had a hard time adjusting at first. I got up in Germany at 06:00+0200 and arrived one day later at 13:00+0800. Although I initially wanted to take a nap, I stayed awake and it turned out to be the better choice. I was still tired the first few days at the conference because my body did not want to get up at 01:00+0200, but after a week it was gone completely.

• Hygiene in general seems a bit less developed. In a lot of public restrooms I have found only one soap dispenser, sometimes not even one at all. Often there are no paper towels. Apparently this does not bother people, most do not use soap, a lot to do not even wash their hands at all. In a museum, the subway station and the university I found that they had the standing-up toilets like they have in the Arabic countries. And they did not have a roll of toilet paper in each of the stalls but a central dispenser. So you would need to know in advance how much toilet paper you would need. The toilet in the bullet train also did not have soap. Unfortunately I could not have taken my hand sanitizer on the plane as it is a flammable substance; I would have liked to use it in a couple of such situations. Also used toilet paper goes into a bucket next to the toilet instead of into it. In the hotels they have western style toilets, though.
• In the western world a door lock closes such that you can imagine the bolt sliding above the lock cylinder. In China I have seen various toilet stall door locks which operate the exact opposite way.
• People in Germany use their phones a lot, but in China people seem to be outright addicted to them. In the subway every single person, no matter which age, would have a smartphone. In places with large crowds (like malls) one can find charging stations where one scans the code, retrieves a power bank and eventually returns it.

• Although Asian people are in general described as being very polite, they do not seem to honor personal space as much as British or US-American people do. I have been bumped into frequently. Also queueing must be described as aggressively. If another person fits between you and the next one in the queue, they just presume that you are not queued and just squeeze in between. One really has to stand the ground in order to keep in the line.

• Power outlets generally have various standards. It seems that there are three standards in wide use within China, and outlets cater to this by having all possible ones available.

• There is a large spectrum of cigarette qualities and a lot of people smoke really cheap ones. Occasionally I would walk through a cloud of smoke on the street and it would me much stronger than you would experience a cloud of smoke in Germany. I have not seen people using electronic cigarettes, they do not seem established in China yet.

• In a bunch of places like the hotel restaurant or the ticket machines in the metro I saw Windows XP. That is end-of-life for quite a while now, Windows 7 is also going to be retired rather soon. I am not sure whether people there are more reluctant to upgrade than in Germany, though.
• A bunch of people from my generation wear gold rimmed glasses. These are not the fashion in Germany. If the fashion in China was completely different, I would not really have stumbled across this. The Western influence is so strong that people seem to wear Western clothes, but the glasses regularly stand out for some reason.
• Sometimes people got up during the lectures to go to the restroom, pick up a bottle of water or hand the second microphone to the person in the audience who was going to ask a question. The Chinese students would usually walk in a hunched way, trying to be quick and less distracting. The American and European students would just casually walk. To me the casual walking was much less distracting than the hunched shuffling. I presume that this is perceived exactly the other way around from a Chinese student.
• The people I have met there in my age are mostly only kids from the policies at the time. In Germany most people have siblings, so this feels really different to be among just only kids. I presume that the whole generation just behaves a bit different because their upbringing is different than the ones from kids with siblings.
• Since WhatsApp only worked on my phone but WhatsApp Web was blocked, I eventually got tired of writing that much text on my phone. Also WeChat Web did not work for me, so I needed to use the phone there as well. I have then thought about getting a Bluetooth keyboard to hook up to my phone. There was supposed to be a large electronics district right south of the campus where one would find many stores to buy electronics. I have went there and indeed saw many technology company office buildings, but there wasn't really any electronics store to be found. Then I discovered two malls, but they were just filled with stores that focused around fashion, food, hairdressing, random junk. There were Apple and Huawei booths, but they only sold the phones and the most popular accessories. I asked some people but they had no idea where I could locate electronics.

I have later just asked a local from where I could order it online. I have ordered a couple of things from AliExpress, but they do not ship to China. The local told me that I should try jd.com or taobao.com. For both of them I would need an AliPay account, however. So I ended up just asking the local to order it to his address and I payed him cash. We have ordered Monday afternoon. To my surprise he was in the lecture hall with my keyboard already the day day after and said that it got delivered to him in the morning. I am pretty amazed how that that went with the regular shipping.

I have talked about this a bit more, and it seems that it is just the same as in Germany: people order all their stuff online, so there is on real need for actual stores anywhere. There are just stores for things that one cannot order online that well, clothes and food.

• I have the feeling that this trip was very resource intensive. The biggest ones are likely the 23 hours of flight that I took. But then also the many plastic bottles, the daily replaced towels and all the food that I I ordered but could not eat because I completely underestimated the size of the servings. My ecological impact from the supercomputer simulations is likely to be staggering as well already, so this trip might not have such a huge impact. Still I feel sorry that I spent so many resources during this trip.

• A friend of mine asked me to send her a postcard. It turned out to be extremely difficult to purchase one. The gift shops at the Great Wall and the Forbidden City did not have them. At the Old Summer Palace I could not find one. At the Hubei Provincial Museum in Wǔhàn they had postal cards, but only very thick ones with 3D effects. Finally at the New Summer Palace I managed to purchase a postal card. It already had stamps worth 5 CNY on it, and apparently that is what one needs to ship it to Germany.

As I had purchased it on my last day, I did not have the time to find a regular mailbox. I wanted to give it to the reception but then forgot about it. Before I entered security at the airport I asked at the information booth and they did not know about a mailbox. Behind the security I found a "China Post" booth with a mailbox! Now the postcard was on its way. It has "Germany" written on there in four languages: German, English, French, Chinese. It took 17 days to arrive in Germany.

• One of the summer school students had a cold. He then wore a facial mark such that he would not spread the germs. The lady that filmed the lectures was wearing one on one day and then a colleague was filming the day after. It seems somewhat customary in China that people who are sick wear these masks to limit the spreading of the common cold.

• In the subway I saw a commercial for sunscreen with an LPF of 130. From the picture of a very pale woman and what people told me the very bale skin is associated with beauty there, just like it was centuries ago in Europe.
• Extremely few people are obese in China. I noticed this when I first arrived there and also realized this the other way around when I was back at Düsseldorf airport.

## Conclusion

This has been an amazing trip. Sometimes exhausting, often rewarding. I have eaten many dishes that were new to me, have seen a bunch of amazing places and streets. During the conference and the Summer School I met many interesting people and became friends with a bunch of them. All in all I am grateful that I was given the opportunity to experience this trip and that it went mostly smoothly.