Last quarter, I've been on a soccer team which was playing indoors, but this quarter we didn't have enough players so I am on another one (and maybe next quarter I'll play for both ;)). This team ("physics force" :)) plays on Astroturf outside. And this artificial grass is really different!

When you fall down you can't really scratch your knee because it's so soft (it still hurts though ;)). There's not only green artificial grass, there are small black beads between the blades; I couldn't find out what the role of the black particles is, but they seem to fill up the space between the blades to make everything still a bit softer. Every time the ball bounces, it briefly leaves a black trace in the air - those are the small black particles (it looks a bit irritating).

Coming home, I had to pour out the black beads from my shoes! They were everywhere...



An example of the advantages of being abroad and having somehow less "duties" is the huge choice of sports you're faced with. Actually, Göttingen does have a great sports center as well, but I didn't find time to try everything (and I heard that surfing might get a bit complicated...). 

So I started with rowing, some soccer, still running and yesterday I went kickboxing for the first time of my life! A friend of mine is doing it and there's one free time you can join a lesson (afterwards it's about 100$/month with about five lessons a 45 min a week). I had no idea what to expect, so I was a bit confused when I got gloves when I came in. The interpretation of "kickboxing" is quite literally (not kicking boxes, but a large bag), so we basically boxed a huge bag in front of us and hit it with a kick. Doing that with a high speed for quite some time is sufficiently exhausting :) (I shouldn't forget the usual fitness "torture" in form of push-ups and crunches we did.)

I absolutely dislike boxing since people hurt each other on purpose and others watch it, enjoy it and cheer. (Seems to me like re-invented gladiator games) However, this kickboxing was a lot different and mainly concerned about fitness. I can definitely recommend it, but probably I won't join (there's sailing on Saturday ;)).


I cleaned my glasses several times...

... and I was still confused what these people were doing in front of my window:

At the same time it was super loud so I couldn't really ignore it (but it sounded fun, so I was okay with it ;)). But people were wearing these super protective suits and you can do a 360°-overhead-turn with it! They tried to play soccer which worked out (you usually crash a lot while playing soccer and these costumes are an invitation to do that ;)).


The fractal dimension of crumpled paper

This is my homework for the class "Complex Fuids" I take during this quarter:

You see six paper balls of different sizes starting approximately with a diameter of 0.5 cm up to 4.5 cm (the last one at the bottom). They are all made of the same paper.

Why do we care about paper balls of different sizes of the same material? Well, of course it's just a demonstration how to determine the "fractal dimension" of a sample. Indeed, the ball lives in three dimensions as we look at it, but in which direction can you walk if you're on the ball itself? And how complex is the paper crumpling compared to the pattern of a snow flake?

To measure this degree of complexity we use the fractal dimension which is e.g. 3 for a normal filled sphere (until you leave the sphere, then there's no shape any more) or 2 for a flat piece of paper etc. For fractals it happens to be a non-integer value, a fraction. Mathematically the fractal Dimension D is just m~r^D with the mass m and the distance to an origin point r. I obtained the fractal dimension of the balls by comparing the increase in diameter to the size of the paper I used for it, plotted the graph and fitted the data. The fractal dimension turned out to be around 2, with an uncertainty of 0.5 ;)



The Kavli Institute for Theoretical Physics (KITP) has a really fancy and new building directly opposite of the Engineering building I work in (which is really neat as well; it's called the California NanoSystems Institute (CNSI)). However, the KITP has a grand piano and a small electric piano in one if its seminar rooms! I asked people over there if I could just go in and play, and, yes! that's possible and I've done it a couple of times (to be honest, I only used the electric piano with the smallest volume possible ;)).

That's an example for the auditorium of the KITP I visited yesterday for a talk on the modeling of bacteria growth which was super interesting. Apparently, their straight, cylindric shape is a result of the Gaussian curvature and the pressure acting on the bacteria. Each single phenomenon can not explain the straight growth, so they're coupled, but it further investigation is needed to find out, how their interplay works exactly.


San Diego!

Thanks to Martin Luther King, the last Monday was an official holiday and I spent the long weekend in San Diego - at least from Saturday afternoon until Monday noon because it takes about six hours to go there by train. But the trip is absolutely worth it since the railroads are directly at the Pacific! The view is fantastic! (Also, the seats are larger than the usual ICE seats in Germany and you've got more space.)

USS Midway Museum.
San Diego is famous for surfing and lots of fun beach activities, but since it was a bit cold and the beaches are actually in La Jolla which is outside San Diego, we visited the USS Midway Museum. The USS Midway is an old aircraft carrier which was alive during the Cold War. Now you can actually walk on the carrier and see lots of small airplanes which were stored on the carrier. It's impressive what people can make up to destroy others.


Get ready...

... there is only one month left to be prepared and equipped for Valentine's Day! Don't miss it! Check it out now, it's like tomorrow! Imagine you would think about it a week before, that's way too late!

In China, there's a similar Day, called the "Singles Day" at the 11th November (because of some 1s in the date) where singles (and also everybody else) goes to parties etc. That day became the largest online-shopping day in the world!



When I think of lithium, batteries and rechargeable batteries come to my mind. If I think back to the periodic table, there are some typical alkali metal properties, i.e. it's flammable and coated by a layer of oxid when exposed to air. It also burns read when lit.

But a few days ago I heard for the first time in my life that lithium is used as a drug against bipolar disorder, hyperactivity, mania, etc., so basically to calm people down. I haven't understood the exact mechanism yet, but what people know, is, that it works.

I learned this during a talk given by Matthew Fisher who is a physics professor here at my university. He used to be interested in condensed matter systems and now changed his field of study to interdsiciplinary neuroscience. There's an article in the "New Scientist" about him and his theory (Is quantum physics behind your brain’s ability to think?).

So, what's the point? Lithium occurs in two isotopes, Lithium-6 and Lithium-7. Their chemical properties are really close to being exactly the same because they have the same outer electron shell. Thus, one would expect the same therapeutic effect for Lithiums as a drug. Nowadays, a mixture seems to be most common for medication.

But, about 20 years ago,  there was a study with female rats which showed that one of the isotopes (as far as I remember Lithium-6) made rats even more active and Lithium-7 made them calm down. So the resulting behavior had the opposite effect! How can that be possible if the chemical properties should be the same?!

The answer might lie in the time for the nuclear spin of a solve lithium-ion to entangle to the surrounding water molecules. This time is highly different for both isotopes (10s and about 5 min!). If this time difference would account for the rats' opposing behavior, there would be quantum effects involved in the brain. There are not many other molecules in the human brain which indicate the relevance of possible quantum processing; nevertheless, there is one large phosphor complex which has an "entanglement time" of about 10 min as well and it's properties are studied.

Since physics is still an experimental science, we have to wait for the rat experiment to be conducted (which should happen in the next year at Stanford).



There are many hiking trails around Goleta and Santa Barbara, which caused the evolution of not a only a website on his topic (here), but also a book(e. g. "Day Hikes around Santa Barbara" by Robert Stone). For the last weekend we picked a trail which was going to lead (or better: was supposed to lead us) to the so called "Cathedral Peak".

The "path" to Cathedral peak.

The elevation gain is about 3300 ft (about 1 km) which is a lot for a total trail length of about four miles (6.4 km). But since the trail was described as "for families", "any level" and "fun for beginners" we planned to take it. As it had to happen, every trail was clearly marked except the Cathedral trail. We found a really small path which was going up at the side of a creek we defined as the Cathedral peak trail (that turned out to be right!).

The trail itself held its promise in being rather a climbing parcour than hiking, but that was lots of fun. We went up to the deep-hanging clouds, but at some point we couldn't make out the path any more because the rocks were so large and huge. Thus, we turned around and took one of the many trails back.

Unfortunately we chose one which led us to pools whose depth we didn't know and the walls to the left and right of it were too steep for climbing. In addition to that we couldn't go back because we had to jump down a short part to continue at all. Some other hikers showed us small hand and foot holes in the rock where you could climb. But they were tiny... I never thought I was going to make it, it was definitely beyond my limits and skills, but with a high level of concentration and unknown muscle strength I didn't fall into the pool :) When I looked back I couldn't remember how that worked out. Once I read somewhere that you do sports to find your limits and go further - that's the case.

That was one of the rather spectacular "hikes" I had so far - somehow I can recommend it, but you have to prepared for everything.


Long days and free food

I have to admit that my blogging frequency definitely went down during the last few weeks. One reason was traveling but then really long days came up and I didn't dare to calculate the hours I worked per day. I absolutely don't want to complain because what I do is fun, but research also really performs magic with your time!

Concert hosted by the International Students Association.

An example for these days was Friday: I started working a few minutes before 8 am and I got a second breakfast at 9:30 am which is a free breakfast in the Engineering building sponsored by the Engineering department (free food is a very effective way in the United States to get people attracted and away from work). I'm glad I had another break around noon when the "Physics Circus" (I already wrote about that) presented how this quarter and its physics shows were going to look like.

My afternoon was one meeting after another with lots of fruitful and great discussions. In the evening the International Students Organization hosted a concert in the University Center where some awesome a cappella groups presented songs - and there was a free menu with three courses! The concert makes this day kind of less exemplar. Usually I start my next lap of image processing ;)

In general, it seems to me that food is a lot more expensive around here than in Germany. To illustrate that I estimated the average for the money I spent on groceries in Germany which is about 30-40US$/month and here ... well, it's at least twice this amount - including "free days" like the one sketched above ;)


It never rains in Southern California... nearly

I'm sure you know Albert Hammond's song "It Never Rains in Southern California" (youtube). Until today I would have kind of agreed, but then this happened:

We had at least seven hours of rain and spending only a few minutes riding my bike got my socks wet for the day (at least all physicists get a shower ;)). Around noon the sun was shining again which reminded me of the typical German weather around April.

However, some people say we're going to get more rain than usual here, because the El-Nino phenomenon is apparently really strong this year. But this is not an easy topic and I searched around the Internet and the correlation between El Nino and more rain in California does not seem to be clear at all. There seems to be more rain with El Nino, but nobody understands the phenomenon so well that there's a distinct link.

Nevertheless, we definitely need the water here! So whatever the cause is and how wet any socks might get, it's welcomed.


Christmas and New Year's Eve

Happy New Year! I hope you all had a nice Christmas and New Year's Eve. Since I stayed in the US for Christmas we had something like an international Christmas party with people from China, Denmark, Germany, Turkey and the US. The improvised version of German "Bratäpfel" (baked apples with raisins and marzipan) worked out and afterwards we played "wichteln" (similar to "secret Santa") which was lots of fun as well.

Times Square on the 30th Dec.

For New Year's Eve I went to New York, but I didn't stand at the Times Square for the famous Ball Drop because it was just too crowded. However, we had a great view on the NY sky line from the Central park - there was a huge public party without security checks and nobody threw any firework at somebody else or the like. (There wasn't even a lot of alcohol around! Indeed, there are some rules about drinking alcohol in public, e.g. you can drink but you have to cover the bottle.) Looking at the skyline was nice, but it didn't change at all after midnight since there were no fireworks near the sky scrapers. So we just turned around and saw a really long and well planned firework in Central Park. (At first, we thought we had a super good point to watch the firework, but for some reason not many people chose the same point, which was a clear clue that there was not going to happen anything concerning fireworks in downtown...)

At the very second the fireworks stopped everybody rushed to leave the Central Park and the Times Square so the public transport system was a bit crowded as well, but everybody got in! The city's cleaning machines were immediately starting to eliminate all traces from the party and NY looked the very same in the morning as the day before.