Community Gardens Germany

 http://www.cityfarmer.org/german99.html

https://www.treehugger.com/german-allotment-gardens-kleingarten-4859448

https://www.dw.com/en/a-brief-guide-to-german-garden-colonies/a-39133787

Birds

Updating list of birds sighted.
Page references are, unless specified otherwise, to Lars Svensson et alia Birds of Europe Second Edition, Princeton Field Guides

Grey Heron (Ardea cinerea) (P p.84) before I bought the bird book in April 2021. Seen in the KGV behind my apartment.

Tree Sparrow (Passer montanus) (P p.372) on my kitchen window ledge April 2021. Perhaps house sparrow. Flew away before I could fully confirm. But seemed too small for house sparrow, and crisper, higher contrast markings than the illustrations on page 373 for house - more like tree.

Pigeon

Egyptian Goose (Alopochan aegyptica) May 2021 banks of Nidda River. Brown eye circle.

Common Swift (Apus apus) June 6 2021 by bird call along Lorscher Strasse.

give up and publish.

Frame the Cards

 Task: create a rectangle with playing cards of any one suit from A through 10 such that the total count of pips on each edge is the same. Here is an example that does not meet that restriction.

The total across the top is 20, bottom is 19, left side is 23, and right side is 22.

Here is an example that does meet that restriction.

All edges in this example total 20.

According to the source where I found this problem, Teaching Through Problems Worth Solving version 3.0 by Alicia Burdess and a few others, problem #27, Frame the Cards, there are 10 unique solutions to this problem. By unique I assume simple rotations and reflections are out, as would be a solution that simply swaps the position of two inner cards on the sides with four cards. I wanted to find solutions and, if possible, figure out an easily articulated rule for generating solutions.

First thing I realized was that only certain totals for each side are possible. The total of all numbers from one to ten is 55 (cue the standard math teacher story about a young Gauss). But each corner card would be counted twice in a total. The highest the corner cards could be is 10, 9, 8, and 7, totaling 34. But 55+34 is 89, and 89 isn't evenly divisible by 4, so that can't be a solution. The highest possible corner card total is 33, which would make the total on each edge 22, if we can work it out right.

Similarly the lowest total for corners is 10 (1+2+3+4), but that also gives a total count of 65 which isn't divisible by four; same problem as above. So the lowest workable corner total is 13, making each edge 17, if we can work it.

Because we need a total that is divisible by four, the total for the corners can only be 13, 17, 21, 25, 29, and 33. This significantly narrows down the possibilities if I want to try brute force solving.

If we start at the high end, the only way to make 88 is with corners 10, 9, 8, 6. I know I am aiming for a total of 22 to an edge, I know if I try 10, 3, 9 across the top that leaves 8 and 6 in the bottom corners. I would need another 8 to make that 22, so this isn't possible. It also starts me thinking about what corners are possible. What if the top were 10, 4, 8 and the bottom is 9, 7, 6. That would force the left edge to be 10, A, 2, 9 and the right edge 8, 3, 5, 6.

Great! I know it is possible to find a solution. Is there any other solution with these corner values? The only grouping I didn't try is 10, 6, which needs another 6, so that isn't possible. This must be the only solution with 22 to an edge.

So I realize that I can filter possibilities for appropriate corner combinations. Once I filter for the corner there must be a way to filter for the corner placements as well. If I consider the low corner total of 13 there are only three combinations to make this total; {1,2,3,7}, {1,2,4,6}, and{1,3,4,5}. Remember that a corner total of 13 forces an edge total of 17.

Since there are two edges (which I'm putting on top and bottom) composed of three cards, I need to be able to make the edge total two ways with the grouping of cards. There are a low finite number of distinct corner placements. In the first case, of {1,2,3,7} I can only have 1,2 and 3,7, or 1,3 and 2,7, or 1,7 and 2,3. There is no third card to bring 1,2 up to the target 17. Same for 1,3. Same for 2,3. So I can conclude it is not possible to work this puzzle with an edge total of 17.

The analysis for the 17 edge case was fairly quick, because there are so few combinations of cards for the corners. But the number quickly increases with higher numbers. I need a better way to analyze this.

Next higher than the 17 edge is an 18 edge. This requires corner cards totaling 17, which can be made in nine ways, with {1,2,4,10}, {1,2,5,9}, {1,2,6,8}, {1,3,4,9}, {1,3,5,8}, {1,3,6,7}, {1,4,5,7}, {2,3,4,8}, and {2,3,5,7}. As before there is no third card to bring 1,2 or 1,4 or 2,4 up to the required 18, so the first combo is out. On the other hand, at first glance {1,2,5,9} looks like a possibility.

I'm not thinking of a good way to do this analytically, so I will use a Python script (running on my TI-84 Python Edition) to identify quintuples of interest. I will use for loops to run through all quintuples, and test for possibility of generating the desired edge total. I won't brute-force for all solutions this way, but rather will narrow down the possible corner combinations to look at. I'm hoping I will see some pattern in those numbers.

Weimar Food Memories April 2022

Food on Weimar trip, April 2022.

Tuesday 19 April

36 Pho 

Kaufstraße 5 order pho nam and a Saigon beer

I liked. Portion seemed small (is that possible for a bowl of noodle soup?) so I supplemented with their baked spring rolls and dessert of a tapioca/sweet potato/banana/and a few other ingredients. Perfect. 

Wednesday 20 April

Bratwurst stand

Formosa

Tofu with hundred year eggs. Beef soup with noodles. Buns with bean paste.

Thursday 21 April

Erbenhof breakfast buffet good variety.

Scharf Ecke

Rinder gulasche (Seiko schweine schnitzel)

Creperie du Palais

Adventures in Disability

 On Wednesday 4th of May while bicycling to work I had a mishap which toppled me. In the fall I apparently twisted my leg to the point that I was unable to walk. I immediately notified my employer that I would not be in due to a accident on my commute (I had been told several times over my stay in Germany that an accident during a commute is considered a workplace accident and has more extensive insurance coverage than any other routine mishap).

My wife had visited an orthopedist not far from the accident location, so using my (damaged) bicycle as a support I hobbled over there without an appointment. It's not their fault that my German is so weak, but the people in that office have minimal English, so communication was not free-flowing. At any rate, the doctor saw me.

At each stage I emphasized this happened during my commute to work. They took x-rays (which are called Röntgen, corresponding to the Japanese word for x-rays, so I understood) and after a while the doctor told me - the good news is no bones are broken; the bad news is there is damage to the medial collateral ligament (MCL) and perhaps the cruciate ligaments as well.

He prescribed an analgesic called Novalgin, had a nearby orthosis shop bring a pair of crutches, told me to get an MRI (called MRT in German, the T being for tomography), and said he would see me again after the MRT.

First problem. I tried to arrange the MRT, and the facility he suggested had no openings until early June. So I searched and found they had other branches, and one had an appointment the next day. Booked online, because that allows me to compensate for my language failings and translate things. But when I went for my appointment, it turned out I had booked a different branch. Yikes! But the receptionist was VERY friendly and rebooked me for that facility on Saturday. This place was relatively nice because it is so accessible by public transportation (my ability to walk was severely limited), so I went ahead.

Saturday the MRT went mostly as expected. Check in, and go to one waiting room. Later be ushered to another waiting room closer to the MRT machines. Dump all metal-containing objects in a locker and lay down on the MRT platform. They did not fully support my leg, so once the procedure started I could feel that I was trembling a little bit. After about ten minutes, done.

Tuesday I saw my orthopedist again. No surgery needed. Prescription for a knee brace orthosis. Instructions to put limited weight on the leg, if I don't feel pain.

This has been draft for three years. I'm fully healed. I may edit this later. I had to switch to an Unfal doctor (accident) because it was a work related injury. Found a good doctor in Bockenheim (not far from me) who was teach doctor for a few professional teams, and same building had a PT guy, Schmidt. They were good. Back in USA, not much from PT people, but on my own began regular Pilates and TRX work, and my knee is back as good (or better?) than before.

Calculus Problem From OpenStax

 I was trying to explain to someone how I got a solution to OpenStax Calculus Vol 1 section 4.1 (related rates) exercise 43, so first I did a google search to see if there was a posted answer. I found two answers posted, and I disagreed with both of them, and they also disagreed with the OpenStax solutions (which only had a numerical answer and not an explanation).

So I worked it again, and my work agrees numerically with the OpenStax answer and I'm satisfied. If anyone else is searching for the supporting work, this post is an attempt to document that.

First, the problem: A batter hits a ball toward second base at 80 ft/sec and runs toward first base at a rate of 30 ft/sec. At what rate does the distance between the ball and the batter change when the runner has covered one-third of the distance to first base? (Hint: Recall the law of cosines.)

Whatever triangle we construct to visualize this set up has sides along the line from home to 1st base, and from home to 2nd base. The third side of the triangle is from the runner's position to the ball's position. Since a baseball "diamond" is actually a square, we can say the angle between the 1st baseline and the line passing through home and 2nd base is 45 degrees (or Pi/4).

If r is the runner's distance from home and b is the ball's distance from home then Law of Cosines tells us the relationship to d, the distance between runner and ball, is d²=r²+b²-2r*b*Cos(π/4). At the instant the runner is 1/3 the distance to 1st base r=30 (1/3 of 90 feet). This implies time t=1. This tells us b=80. We can calculate d=62.497

If we differentiate that equation relating d, r, and b (with respect to time, as r, b, and d are functions of time) we get d*d' = r*r' + b*b' - Cos(π/4)*(r*b' +b*r'). The problem statement tells us r'=30 and b'=80. Substituting in known values and solving for d' we get d'=62.497.

The solutions manual gives 62.50, which is the same answer to two decimal places precision.

Berlin Food Memories April 2022

Notes on most of our restaurant experiences during a one week trip to Berlin. 

Sunday 10 April

Mogg, Auguststr. 11-13, is a limited-menu sandwich shop in the Old Jewish Quarter. They're located in a building which was formerly the Jewish Girls School (Ehemalige Jüdische Mädchenschule). The building dates to 1927, That, of course, was closed down as Jews were deported to be murdered under National Socialist policies. After the war the building saw a number of uses. More recently it was refurbed and now houses a number of small restaurants and art galleries. 

We went back a few times over six days. We had both Rubens and Pastrami. Both are on a German rye bread, square loaf, sliced thickly (about 2 cm). Generous portion of meat, nice balance of cheese, dressing, and sauerkraut. Side of cole slaw and half of a small pickle. Seats were in demand, and we were lucky to get in when we went. If you can, I recommend you make a reservation.

On the way back to our hotel we noticed Wiener Brot Holzofenbäckerei at Tucholskystraße 31. The shop window is only a couple meters wide, but we liked the look of what we saw and went in. Good choice! The pastries are, not as is common in US bakeries, overly sweet. This allows the flavors of the fillings (fruit, cinnamon, chocolate, poppyseed) to come through clearly. Over several visits we tried strudels, struesels, and rolls. Hard to say a favorite, but I'll give my top three as the sour cherry streusel, and the cinnamon and chocolate rolls. This place is well worth going out of your way for a treat. They have a cute logo of a fox (with long eyelashes) carrying a baguette in its mouth. I would have bought one, but they don't sell t-shirts.

Monday 11 April

Jewish Museum cafeteria inside the Berlin Jewish Museum (Jüdische Museum Berlin) there is a well-reviewed cafeteria. The offerings seems to change, and the day we visited the items on the printed menu were not available. They did have daily specials, and we tried the cauliflower curry soup, and tandoori chicken. The soup was good, the chicken not so much. Although I would go back for the soup, I don't know how to be certain what offerings they have on any given day. Hit or miss.

Tuesday 12 April

There is a big deal in Berlin popular culture (maybe in German popular culture) for a dish called curry wurst. The legend is that it was invented in Berlin, and now there is a lot of buzz about various curry wurst shops. We went to one of the famous ones Konnopke's Diner. They are convenient by public transit, located underneath the U-Bahn tracks at Schönhauser Allee.

Okay, so now I've eaten official (East) German currywurst. And I don't see what the big deal is. It's a boiled bratwurst, cut into chunks, smothered in ketchup, and sprinkled with what seems to be canned curry powder. Some people claim, quite passionately, that this one was the best, but I can't see why any boiled bratwurst smothered in ketchup wouldn't serve just as well.

Rausch Schocoladehause is a fine chocolatier located at Charlottenstraße 60. They have three stories open, with the first devoted to sale of chocolate goods, the second where you can custom order a particular blend of ingredients at a particular "darkness" level. The third level (in European numbering, the second floor) has a cafe. We ordered coffee and cake. Quite delicious. Quite pricey. Nice for a splurge, but I wouldn't eat here on a regular basis. The store is decorated with a number of sculptures made of milk chocolate. Prominently displayed in the cafe is a chocolate Titanic. Wow! I hope their air conditioning system never breaks down.

Down the street from the New Synagogue we noticed a wall decoration characteristic of Thailand. On investigation it turned out to be the front of a Thai restaurant, Kamala at Oranienburger Str. 69. Their menu looked authentic enough (many of the Asian restaurant menus we had been seeing had odd combinations of offerings that left us unsure of what cuisine the chef actually knows how to make) so we gave it a try. From the street you take a few steps down to the restaurant door. Inside the restaurant is in three or four levels, with a few tables on each. Still concerned about COVID we liked that we could be mostly isolated in our own room (it was not crowded on our visit). Although the menu has many offerings, it seems that for the most part they have a few sauces which you can order with a few different proteins. We both ordered a Phanäng curry, mine with chicken and my wife's with duck. We were both satisfied. It had just enough spiciness to leave a little tingle in the mouth, and good balance of flavor. 

Wednesday 13 April

After touring the Pergamon we felt we needed a snack, so we went to their cafeteria. It was a warm day and they were only seating outside on the terrace. This was nice because it overlooks the Spree River, and was quite pleasant surroundings. We ordered a Flamkuchen, a thin-crust German version of pizza. It was good enough. This was the only place where the waiter solicited a tip, and I gave them none.

For dinner I went to Pho at Linienstraße 134, a moderate walk from our hotel. I chose outdoor seating, and soon realized that many other people in outdoor seating are smokers. Oh well. Their menu adopts the conceit of an airline ticket. Cute. I ordered the summer rolls and a bowl of pho. The summer rolls were mostly okay, but in making them there were too many layers of the rice wrapper, making an unchewable chunk at one end. The pho was okay. I would have liked more vegetables in the broth. It had a good level of spiciness for my taste.

Thursday 14 April

After touring the Memorial to Murdered European Jews, we went to Noodles Plus at  Hannah-Arendt-Straße 1. The menu had a mix of Chinese-looking items, and some with atypical ingredients, like peanut sauce. We ordered a dim sum assortment (four each of 3 different dumplings) and I tried their mapo dofu. Both were good.

Friday 15 April

Encouraged by favorable online reviews, we tried Bentokado at Eberswalder Str. 5. When we got there, we saw the sushi fish did not look particularly fresh, so opted against any of the sushi offerings. I ordered the miso ramen, which was okay. My wife ordered the shiitake vegan udon, which she said was very strange. She was very unhappy with her choice. She had been looking forward to ordering a Japanese cake for dessert based on the photos on the website, but on seeing the actual options changed her mind. Essentially, the name (which could translate from Japanese as "lunch box corner") is not at all what their menu is about.