- Jose Arrieta

# The Münster (in Westf.) Hbf. Series

## Part 1

The school year started and as children in Munster start their education, teachers all around get asked the question: Why do we need to learn how numbers are ordered?

The question is shared in schools all around Germany but in Munster, it clings louder. The pupils will give the example of the newly rebuilt and impossible to expand Munster Bahnhof.

2-3, 4-8, 9-11-12, 14-17 go the Gleise in Munster. From this IQ test is numerical series, It is clear that whoever decided that 8 follows 4, and 17 follows 14 had both: 1) become a contributing member of society and 2) completely disregards how numbers are ordered.

This fact, the willful disregard of order and tradition is of utmost importance in the growth of mathematics. One might surmise that whoever thought 8, 11, and 12 go together and 14 precedes 17 might have a direct implication that might have inspired a young Gerd Faltings while pondering his decision to study mathematics at WWU and eventually rise to the top of the field.

As school starts, and pupils ask why order matters, we might actually come to see that it does not. At least not all of the time.

## Part 2

In a train station, the lowest track number is usually to the side closest to the center of the city. If all train stations were created equal, one. would have track 1 next to the street, then tracks 2 and 3 following it.

Not all train stations are created equal. And some are just strange. Munster central station follows the standard logic, track 17 is the furthest to the city center, yet, there is no track 1. The trophy for closest to the city is given to track #2. but that is just where the fun begins.

If we were to ask you what number goes after 4 and you told me 8. I would have reasons to doubt your saneness. Yet, in Munster, as we all know, 8 comes after 4. What goes after 8? Nine obviously but after 9 things go crazy, in the same platform we have not 10 but 9, 11, and 12. By now, you will think I am joking, just like a sword, or a coin a train platform has just two sides. Not in Munster.

Many a bewildered tourist have wondered where the mysterious Gleis 11 lies at Munster Hbf. As the locals well, know, it lies between platforms 12 and 9. To make this happen, track 10 had to banish. Our whole system of numbers is base 10 but in Munster, this number did not matter. Enshrined between 9 and 12 lies 11. Interestingly, the joint platform "9 11 12" has a sort of palindrome of emergency numbers in one platform. First the American and then the European! Indeed, it is not only in London's King Cross, that numbers make funny things when tracks get close to 10.

Thirteen is an unlucky number. Many buildings and most planes miss the floors and rows with that number. That is somehow normal. And obviously, Munster also lacks track #13. The story is getting long, and I did promise 17 tracks, thankfully, to avoid my random babble, the architects deemed that track 17 should share the last platform with track 14.

## Part 3

The Online Encyclopedia of Integer Series is amazing, it includes not only the Fibonacci numbers, and the Primes, but thousands and thousands that appear in mathematics and nature. One series that did not appear until yesterday goes: 2, 3, 4, 8, 9, 11, 12, 14, 17. Sure, there is nothing special about it. It grows monotonically, there are some gaps, but that is it. So, why the fanfare?

Well, this is a somewhat out-of-place series. It is the track numbers of all tracks in Munster Central Station, the biggest city in Westfalia, Germany. The nine numbers in this series provide a lot of information about the city. It is clear that it believes it has the potential to grow, indeed, one could add 8 extra tracks without needing to repaint track 17. It also tells us a bit about the intransigence of tradition.

Why? The station is close to finishing a rebuilt that took the better part of a decade. On the Eastside, and close to the city, a shopping center was built to improve the Sunday shopping portfolio of Munsterland. This shopping center blocks any growth of the station East from track 2 and thus track 1 is out of the question. On the West, A stream of buildings erupts directly after track 17. No chance of expansion there. In between? No. There is even one platform that has three tracks in itself. The third platform joins tracks 9, 11, and 12. To allow for this marvel of engineering, track 11 only runs South of Munster. All other tracks go both ways.

funnily enough, the numbers are a relic of a past. It is unclear to me whether a track 1 or 10 ever existed. But what seems clear is that at the time when the city decided to remodel the station, it also decided that a. numbering from 1 to 9 was out of the question. As every good Munsteraner knows, after 4 goes 8, after 9 11/12, and after 14 goes 17. To commemorate a series of numbers that has been ingrained in every Munsterlander, the OIES has accepted my request of including this unique piece of number theory in their encyclopedia.