From BER (Flughafen Berlin) to Spandau: S9 all the way. I couldn’t find the Berlin Express line. This is slower but there’s enough to do and see: read, revise, see Berlin go by. There’s the Bundestag, the distinctive tiled interior of Hackerscher Markt station. The Hauptbahnhof looks imposing but its glass roof is fragile. The panes are individually cut to fit into the curved roof. When panes break it’s difficult to replace them and wood is used instead.

A man sat down next to me. He wore Jeans, he was young. He started looking at me and smiling and I noticed he was building up to something. Then he suddenly asked me about how I was using the camera on my iPad to broadcast myself. I told him I was only watching a recorded classroom video on Chinese Grammar, not broadcasting myself. He seemed disappointed and moved away.

Later a girl ran down the carriage and started throwing herself around the pole in the middle of the carriage. I couldn’t understand what the girl was saying or shouting. She spoke in vowels with no consonants. I couldn’t understand her but her mother could. She swung herself around the pole then climbed up to stand on a little ledge next to the doors pulling herself up by the grab rail. And then, just before the doors closed she’d press a light sensor that looked like a button: the doors would close and she would look around proudly.

The next morning I’m on the S9 in the other direction from Spandau to Messe-Süd after taking a regional train from Dallgow-Döberitz for two stops. I’ve started to worry about the passports that I’ve left in my Hotel-Pension. What if someone was to steal them? What would I do? Staying in Germany would be easy enough, I’ve got an ID card, but what about getting back to the UK? Did I make a passport copy as the passport office urged in its letter accompanying the new non-EU UK passport? I feel tempted to go back but resist the urge. It’s strange how worries arise. (Applying for an emergency document looks easy enough in retrospect.)

Three men sit opposite me, I think they may be bound for Innotrans as well. They seem to be seated in age order from left to right. The ‘middleman’ wears a mask. The oldest of them has the best bag. It looks comfortable to wear, featuring back support: wisdom with age? He browses his phone.

What is it about three suited men that prompts you to think about absurdity and silliness? Perhaps it’s because you were just listening to Jay Garfield talking about the nature of the world and how you can only see what you construct. Dogs perceive smell volumes, bees perceive UV light and other spectra.

Just as we can do far more than dogs and bees, dogs and bees can do far more than we can do… The only world anybody can represent is the world as constructed by their sensory motor system and that’s true of a dog, a bee and a person…

https://www.samharris.org/podcasts/waking-up-conversations/do-you-really-have-a-self

There’s more space here than in England. There are more platforms, the platforms are constructed from solid material. The air feels fresher, cooler. Bigger trees line the track. Milder graffiti lines the inside of modern overpasses (more concrete, less brick) that the train passes under.

At the fair a first pass through the halls is almost overwhelming. There are so many stands and people. Everyone is there to pitch, to put their best foot forward. There’s excitement in the air. Some stands have coffee bars, some bars have baristas. The exhibitor staff are buzzing with nervous energy, you can sense the adrenaline. I get lost. There are stands focusing on train interiors, bits and pieces of fabric, fire-proofing. There’s a section focused on seating: chairs for drivers, passenger seats. There’s a lot of stuff around data. “Get your data into shape for passenger flow management,” suggests the marketing material for a particular one-man stand.

Fasteners, fancy Velcro, more seating solutions, cushions, fire proofing, thermoplastic solutions. Sensors to be installed under seat cushions in order to stream data into dashboards for passenger monitoring.

Someone runs up to me as I type on my phone: “Railway Gazette, are you from Railway Gazette?”

In and between exhibition rooms are cold, tiled hallways, halls of escalators, cafe and snack places. I pass back through a coffee place which seems popular. Someone is doing accounts on a checked table.

All the places have city names, I walk past a staff room, Trier 3. More food. Two lonely ice cream machines. A cleaning lady sitting on a bench with pink gloves. A hot dog stand.

There’s a stand with a dipping bath and an ultrasonic cleaning exhibit. The booth looks lonely even though the company is No 1 worldwide for damage restoration, it says.

A stand focusing on “Wheel & Rail Integration Diagnostics’ stands out in yellow and black. Their slogan: “It’s not about data it’s about information.”

A company exhibiting engine starters has a clear mission: “Starting Diesel Engines since 2007, American Solutions for Modern Rail, made in USA.”

Later, in the Alte Nationalgallerie, I discover the 1847 painting “Die Berlin-Potsdamer Bahn” by Adolph Menzel and a portrait of his foot.