on the weekend before easter we were in kaiserslautern. the main reason for our visit was to attend a team meeting for matheraum, but then we also visited rebekka and m. i haven’t seen rebekka for … i don’t know how many years now. (ignoring a “train incident” where she saw me, but i didn’t saw her while changing trains in mannhein or so.) definitely longer as this blog exists, i.e. before 2007. anyway. even though the weather wasn’t too great most of the weekend, we were lucky to get a glimpse of kaiserslautern with sun on both friday and sunday (on sunday we met rebekka and m.).

on saturday, we went to the japanese garden. while inside at least it didn’t snow (it waited until we left), but the weather wasn’t very great and also the cherry blossom didn’t bloom yet. still, it was a nice experience:

next time i’ll go there, there should better be sun and cherry blossoms :-)

today, we were on muottas muragl. luckily, this morning, the weather was much better than predicted by the weather report yesterday: it was sunny! during the late morning, it once again became cloudy, but before, we had some really great views while strolling a bit on the philosopher’s trail:

while being in tromsø, we did two longer excursions by car. driving on icy and snowy roads is not exactly our favorite thing, but since it is quite common in scandinavia (and also canada), we thought it might be not too bad. and in fact, it was quite ok, probably thanks a lot to the great winter tires our rental car had. most of the time we had no problems at all, only noticing that braking could take a little longer than usual. only in two situations we experienced trouble: one time, in a roundabout, the car started steering somewhat different than i intended it to go. well, i managed to take control of the situation, but it was not exactly good anymore :) the second situation was when turning the car, it ended up in a situation where we couldn’t drive forward anymore due to wheelspin. well, driving back a bit more and then steering differently solved that as well. alltogether, i would say driving in this conditions is not too bad, and after driving for some days, i felt quite safe.

kvaløya.

our first longer excursion led us to the island kvaløya, an island adjacent to tromsøya, the little island tromsø is located on. we started a bit late, when sunset already had begun (i.e. somewhen around 1 am). we basically circled the southern part of the island.

eastwards.

our second excursion led us east of tromsø. we began driving over to tromsø’s mainland and continuing to breivikeidet, from where we crossed the ullsfjorden via ferry to svensby in lyngen, and then continued to the east side. there, we followed the lyngen fjord southwards until we finally reached the southmost point of our voyage, nordkjosbotn. from there, we drove up north again, this time along the balsfjord, and finally continued back to tromsø.
this time, we started much earlier, and so also got some sunny views. unfortunately, most of the time, we were covered by clouds…

last week, we visited tromsø in arctic norway for a couple of days. it is one of the largest cities north of the arctic circle, featuring a university (which, among many other subjects, also has a mathematics department – to my knowledge, the only one north of the arctic circle).

tromsø during daylight.

here are some impressions from tromsø during daylight. at this time of the year, there’s not too much daylight – the sun rises around 10 am, and is gone by 4 pm. the photos feature the tromsø gallery of contemporary art, the polaria aquarium whose form represents ice floes, the rica ishavshotel with its interesting form, the polstjerna (a seal hunting ship) museum, and some views on tromsø’s harbor, in part from the tromsø bridge:

tromsø at night.

most of the time, we saw tromsø during night. this is how it looks. the first picture shows the public library.

the last four pictures depict one of the hurtigruten ships, the trollfjord which was stopping by in tromsø one night. we used the chance to explore the ship a bit and have a nice midnight snack on-board.

northern lights over tromsø.

unfortunately, we only saw an aurora once during our stay. but it was a beautiful one! we were standing close to the public library, and later to the city hall:

polaria.

we also visited the polaria, the northernmost aquarium featuring bearded seals. here are some impressions from their feeding and training session:

tromsø airport.

finally, on our last day in tromsø, the weather was fantastic. that is, there was a lot of sun and not many clouds around noon. we were already at the airport at that time, but still managed to take some nice pictures:

a happy new year to everyone!

we spend the last couple of days of the last year in braunwald, glarus, for a short skiing vacation. the weather was great, much better than announced. it was sunny most of the time:

(sorry for the photo quality. i only took my tiny compact camera with me…)

it was also the first time i ever stood on skis. after a couple of skiing lessons, i even managed to get down the little hill (school to braunwald) and – with a lot of help – the bigger hill (grotzenbüel to school). it was great, even though i was pretty dead afterwards. skiing is quite exhausting, especially with regard to some muscles which i don’t really need for my daily life :)

last week i was in leiden, attending a workshop on post-quantum crytpography and quantum algorithms at the lorentz center. it was a collection of talks and working in smaller groups, where we discussed certain topics, such as quantum attacks on ideal lattices in more detail, trying to find a way to use quantum computers to speed up attacks against primitives of post-quantum cryptography. as this is somewhat close to my research – i work on analyzing a quantum algorithm with pawel wocjan and am working on lattices and lattice reductions – i was very happy to attend this meeting. especially since there were not just some mathematicians, but also a lot of experts on various aspect of quantum computers and quantum algorithms. now i also know a lot more about quantum computing, both from the theoretical side – like having been explained grover’s algorithm, which is another of the fundamental quantum algorithms next to the period-finding algorithm family starting with shor’s algorithm – and the practical side – what the current technology with regard to building quantum computers is, and how people writing compilers for quantum computers can suffer and how complicated it can be to turn a “simple” algorithm into a circuit. i think this was one of the most productive workshops i’ve ever attended.
unfortunately, i neither took my camera with me (the little one i had with me last week, since it is somewhat broken (the sd card slot won’t keep the card anymore, similar to what is described here), nor did i really had time to take any pictures, as i spend most awake hours doing mathematics. i took a few shots with my mobile phone on the excursion/conference dinner on wednesday, which happend to be on a boat going through grachten around leiden and the city and also happened to be a very decicious and very spicy asian food buffet. and later, there was a great dessert buffet. one of the best and original conference dinners i had for quite some time :)

this week, i was attending a conference on monte verità in ticino.

ascona.

on tuesday we shifted the afternoon lectures by two hours to be able to exploit the great weather to visit ascona:

bellinzona.

on wednesday, we went on an excursion to bellinzona. unfortunately, the weather was not so great. we began with a tour through castelgrande and continued with a short city tour. here are some impressions:

last weekend we travelled to dresden. with perfect weather, we (re-)explored the city and parts of the sächsische schweiz. we first started with a hop-on/hop-off sightseeing tour which led us among other things to the blue wonder, schwebebahn dresden, the funicular railway, the “balcony of dresden” (luisenhof), the dresden-neustadt station’s entrance hall and the “toilet cinema”. some impressions from these places can be seen below:

here are also some shots from during the night, mainly showing dresden downtown:

finally, we did an excursion to the sächsische schweiz, namely to the bastei and the adjacent neurathen castle. from there, we descended down to rathen and took a paddle wheeler from there back to dresden. here are some impressions. (you can see “our” paddle wheeler in the photos above, it was the “pillnitz”.)

as you can see, we had a great time with perfect weather. most of the time during the excursion, there wasn’t a single cloud on the sky!

yesterday we were on an excursion, which led us from our home to some nice places between lake constance and schaffhausen with a final stop in baden before we returned home.

we first traveled to tägerwilen to look at a small design settlement with eight houses, where different materials were used. unfortunately, the weather wasn’t very great at that point, and it was not very easy to take good pictures there anyway… afterwards, we walked over to gottlieben and waited for our boat.

we traveled by boat on lake constance and the rhine to schaffhausen. the weather was still not great, it was cloudy, but at least it wasn’t raining. when approaching schaffhausen, the clouds started to rip apart.

in schaffhausen, the clouds began to clear up. we explored the old town a bit.

finally, we walked up to the munot, a fortification built during the 16th century. from there we had a great view – some of the above photos were taken from there or from the way up/down.

finally, we proceeded by train to waldshut to drink coffee, and continued by train to baden to eat dinner. at least, that was what we planned to do in baden. turns out that the city center is essentially dead from 6 pm on, except fast food “restaurants” or pubs. we had to walk quite some distance outside of the city center to find something to eat; we ended up in an italian restaurant chain near the kantonsschule. on the way back, two of us who had to travel westwards wanted to take bus 3, which would have allowed them to arrive home earlier than if they would take the later bus which would be perfect for us. bus 3 is supposed to leave at the same stop. unfortunately, unknown to us and also to google maps, apple maps, map.search.ch etc., there are two stops called “kantonsschule”. at the time we located the second stop on a map, their bus was already gone… really great. anyway, we eventually got back to the main station, and were able to depart in direction of our beds after this long day…

last weekend, we were in brand, austria. the weather was great, despite the mixed forecast.

lünersee.

on the first day, we visited the lünersee, a water reservoir for the lünerseewerk power plant. it is a beautiful mountain lake which can be accessed by a cable car. here are some photos:

dorfbahn/panoramabahn.

during summer, there are two cable cars in brand itself, namely the dorfbahn and the panoramabahn. the dorfbahn starts directly in the town, while the panoramabahn starts at the end of the dorfbahn and crosses a valley. the view is really magnificent! there is a nice and easy walking trail from the top of the panoramabahn back to the top of the dorfbahn, which we took. here are some impressions: