Cosmology

For those interested in astrophysics and cosmology: some comments on their scientific status from professor Bartelmann, who teaches the cosmology course I'm taking here.

"Neither is a science in the traditional sense of the word, as no experiments are being conducted. One does not take a dust cloud, let it collapse into a star and observe when nuclear fusion begins. Nor does one repeat the Big Bang very often in laboratory settings to see how it generally works. Astronomy has the excuse of having very many stars to observe, and thus, assuming spacetime translation invariance, in a sense very often repeating the long-lasting experiment that constitutes a star's life, but cosmology has nothing to go by. Only one object to study, and both its temporal and spatial scales vastly larger than any that can be considered within human range."

Still, people do research on stars, and the universe, and the results seem to make sense, at least for a large part. Of course, the geocentric hypothesis also seems to make sense, for a large part. Only there we know where it doesn't anymore; dark matter, dark energy, and cosmological constants are still a lot more fuzzy in that respect.
Cosmology is one of the fields of research where I often start to wonder why one would go into it at all, except out of pure curiosity. The practical benefits of knowing that we are close to the dark energy-dominated epoch are hard to find, especially since 'close' means 'close on the cosmic time scale', which is about 10¹⁰ years (i.e., humankind will in all likelihood have eradicated itself before 'we' would actually enter this epoch).

The funny thing is that of the courses I'm taking here, so far, cosmology seems the most practical one. The reason for this is of course that it uses results from theories that are developed in the other courses, which are therefore much more mathematical, but it still feels refreshingly 'applied'.

Driving

Having failed my first driving exam, on Friday the 13th (what should I have expected :p), I set out in search of a German ending to my Dutch driving education. I went to two driving schools, and found out that finishing here would be about two to three times as expensive as in Holland. So I'll do the latter, but only in September, since I've already spent quite enough time in Holland for being on exchange.

One of the driving schools was located in Neckargemünd, a town about the size of Bilthoven, but considered a city nonetheless; they even have a city gate¹. I went there to get information, but found an old-fashioned classroom instead, stuffed with students, tables, chairs, blackboards with miniature traffic signs, two motorcycles, tyres, a tv set with old-fashioned videoplayer, and an old-fashioned, white-haired, white-sideburned teacher. I told him I would like to know how things would proceed here, were I to make an attempt at obtaining a driver's licence, to which he responded by getting an extra chair and introducing me to the class as Gasthörer.
What followed was a long and slow lecture on the laws regarding drunk driving in Germany. One of the students was asked to come up to the front and write down on the blackboard what the teacher was telling the students to copy into their notes. She must have found the task a bit boring, since she started drawing all kinds of decorations, like cars, bicycles, pigs on skateboards and pedestrians waving with flags.
Apparently, this is standard in Germany: driving schools arrange your theoretical exam, and don't let you take it without the standard 14 hours of instruction. Apart from that, there are 12 mandatory hours of Sonderfahrten, lessons at night, on the highway or in unknown terrain. This is what would make it rather time- and money-consuming for me to retake my exam here: I'd still have to go through those 12 hours, and take another theory test. In spite of the fact that a Dutch driving licence does allow one to drive in Germany...

¹They have only one gate, on the upstream (= non-Heidelberg) side of town, which made me wonder wether I was observing silent evidence to historical bullying on the part of Heidelberg, or just the consequences of modern city-planning. Or something completely different.

Courses

This semester, I'll be taking:

• Quantum Field Theory II. Still taught by Professor Schmidt , for whom I will still be typing up lecture notes. Basically a continuation of last term's course (QFT I).
  
• General Relativity. The professor teaching it seems to be taking a fairly theoretically minded approach, which might be good, but also means I will probably get more math than I like to work through.
  
• Cosmology. This will, based on the first week, be my favourite course. It's more accessible than the other two, I like the topic better, the teacher is a good lecturer, and for a change, I could actually work through the first exercise sheet with relative ease :).
  

All three professors have the relaxed attitude towards testing I mentioned last term: 'Just hand in your solutions to the exercises, and if necessary, we can do a small oral exam at the end of term.'

Jetzt ist Sommer

After a premature spring, summer, too, seems to have found a way to fool the climatological clock. Cycling to the university, at 9:00 in the morning, even the thought of taking a coat seemed ridiculous. Cycling home, at 11:30, I found that shadowy spots offered the most agreeable temperatures. Yesterday, the sun surprised me by going down around 20:15, which seemed quite inappropriate given the temperature.
Not that I'm complaining, mind you. The mountains around the city look lovely green, the Neckarwiesen are an incarnate invitation to procrastinate and the Neckar itself is simply beautiful in the sun, so life in Heidelberg seems good. I did mean the remark about the sunset being inappropriately early, though: if the day is hot, then the evening should be long enough to be enjoyed outside, and make up for the afternoon spent in siesta. This attitude also seems to be taken by the Spaniards in the Schlierbacher Schiff, who are talking of nothing but parties.

All in all, I'm getting the feeling that maybe winter has really been skipped. I wonder what that means for July...

P.S.: This message means I'm back in Heidelberg, safely, in one piece, and alive, but not kicking (although someone proposed I join some kind of fighting course in the university sports centre).

Easter

Χριστοσ ανεστι!

A voice, the source sometimes hidden behind the iconostasis, intoning the gospels in Greek, from time to time answered by a choir. Children playing, talking, mostly unchecked by their parents. People, holding candles (long hair is dangerous!), walking in and out all the time. Some are talking, once or twice someone goes out in haste to answer a mobile phone call, some sing along with the choir.

The Greek Orthodox Easter celebration I attended last Saturday in Utrecht was a good example of the Orthodox tendency towards piety and ritual, as opposed to the Western (both Protestant and Catholic) culture of scholarship and interpretation. No sermon, no explanation, but rituals, processions, and an affirmation of faith. The act of kissing the gospels is more important than being present during the rest of the service, which consists mainly of recitation of said gospels. Indeed, the number of people inside the church dropped markedly after this ritual, so that when at the end the remaining faithful went forward to receive communion, I felt quite alone in the back.
Quite in line with this general approach, almost all of the service was in Greek, even though probably about as many of those present understood Dutch as understood Greek. Only the Creed and the Lord's prayer were repeated in Dutch, as these were to be spoken along by the community.

This celebration seemed to have more characteristics of a social gathering than the traditional Calvinist church service that is my benchmark. It was, of course, still a service, but in such a way that walking in and out, and even talking, albeit softly, did not seem disturbing. It left, I think, more space for individual approaches, and would be very suitable for the modern Dutch, if it were less easily identifiable as a ritual.