Author: Ben

Dresden was an interesting city to visit. The first thing we visited, mostly because it was near where we happened to get off the tram, was the Frauenkirche. The Frauenkirche was destroyed during World War II, then rebuilt in 1994. From the inside, it looks completely different from any other church I’ve been in before. It is painted in pastel colors and is very cylindrical, rather than being a long rectangular room like most churches. Despite being a Lutheran church, it is fairly decorated.

The next thing we visited was a mural of the kings of Saxon. Each king was painted in period-appropriate fashion or armour. Their names were also painted beneath them. There was a long period when they had epithets, but then they stopped using them. The change in fashion of the hats was also noticeable.

After the mural, we went to the Mathematisch-Physikalischer Salon. There, the main exhibit was clocks. Wall clocks, pocket watches, table clocks, and astronomical clocks, all of them were there. Many had heavily decorated cases. Some moved on the hour or quarter hour. Aside from clocks, there was a mechanical calculator built by Blaise Pascal. Mechanically, it could only add, but through complementary numbers, it could subtract as well. There was a digital display explaining how it worked as well. There were also globes, both terrestrial and celestial, there. There was an entire room devoted to them and a world clock that told the time at every longitude. It did so by having the hour hand point down at all times and rotating the wheel the clocks were mounted to. In the globe room, there were a pair of globes each a meter in diameter, one celestial and one terrestrial. Celestial globes display stars and constellations based on location. Terrestrial globes display maps of the earth’s surface. The last thing in the globe room was an explanation of various projections – the cylindrical projection, the conical projection, and the flat projection. Each one captures a different band of latitudes most accurately – cylindrical projections are most accurate near the equators, flat projections are most accurate near the poles, and conical projections are most accurate in the band between flat and cylindrical projections.

The last thing we did that day was go to the Volkswagen transparent factory. We had been planning to take a guided tour, but we were too late. There was a free to access part where Volkswagen’s plans for electric cars were discussed. It seemed like just an ad, rather than imparting much useful information.

We went to Berlin over the weekend. One of the museums that we saw was the German Spy Museum. It was a very interesting and amusing place.

The first thing we noticed was that the museum offered free WiFi. You probably know that for security reasons, you shouldn’t use public WiFi for anything private or secure, like banking. That’s in things like coffee shops, where their business probably isn’t knowing things that they shouldn’t. Spies are in that business. I tunnel all my internet usage through a VPN, encrypted, and I didn’t connect to their network, even though I wasn’t doing anything that used authentication. I really didn’t trust their network.

They also offered free phone charging. Are you starting to see a theme here? Non-wireless phone chargers necessitate plugging a cable into the phone. Most phones allow data syncing over a cable. The data sync port is the charging port. Looking at the phone chargers in the lockers, you can’t tell what they’re plugged into, meaning they could be plugged into a computer. It would also be remarkably easy to destroy a phone by using too high of a voltage in the charger. This is normally impossible to do accidentally, but by cutting the cables and splicing in a stronger power source, it would be possible. Anyway, if a malicious actor has physical access, there’s really nothing that can prevent data destruction, and very little that can prevent data theft, most of which destroys the data.

Interestingly, the charger cables supported the old apple charger that was last used for the iPhone 4s and iPad 3rd generation. Neither of those are seen commonly anymore.

Later in the museum, there was an interactive ‘How secure is your password?’ display. You type in your password, and it tells you how long it would take to brute-force your password and if it’s a common password. The common password part didn’t catch correcthorsebatterystaple (https://www.xkcd.com/936/), but that’s not even the biggest problem. You just typed your password into a computer that you don’t control. The answer to ‘How secure is your password?’ is now ‘It’s not’.

You might think that based on this post, the German Spy Museum is a bad idea, but it’s really not. It was very interesting, and I learned a good bit. If you do go though, be careful. They probably aren’t actually using these security holes, but it’s good to be on the safe side.

On Saturday, we went to Jena and Weimar. Jena is a large university town, and Weimar is where the Weimar Republic, the government of Germany between the World Wars, was based. Weimar was also the home of Goethe, an author, and Schiller, a playwright.

Jena still has some remnants of the old city wall, including the Johannistor, which is the only remaining gate. It’s said that for students, walking through the Johannistor brings bad luck on exams.

Weimar was an interesting place to go. There were quite a few open pedestrian areas that didn’t seem to have a border with actual roads and many of the squares had grilled bratwurst stands.

Weimar is also where the Bauhaus art style started. Bauhaus places priority on utility and is similar to modernism. There is a Bauhaus museum in Weimar, but we didn’t visit it because we were getting tired of walking around.

Today, we visited CERN. Visits and guided tours are free, although guided tours book up very fast in the summer. Tickets aren’t available for a guided tour on a certain day until 15 days before, and in summer can be booked up in seconds.

First, we went to the globe, where there is an exhibit called the Universe of Particles. In the exhibition, there were various displays of things that are connected to CERN, like papers about the Higgs-Boson particle, an original proposal for the internet, and the first particle accelerator. There were also touch-screen displays showing graphics about the accelerators and a projected film about the development of particles right after the Big Bang.

Once we were finished with the Universe of Particles, it was nearly time for our tour. Nate didn’t come on it, since the minimum recommended age for the tours is 12. The three of us got our visitors badges, then waited until we were told to go into a presentation room, where the basic structure of the tour was introduced and another guide tried to fix the tech problems that come with conference or meeting room screens. He got it working, and we were given a presentation on what CERN is.

After that, the tour group was split up into two groups that did the tour in opposite orders. We started by going to look at the first particle accelerator at CERN, the Synchrocyclotron. It was constructed in 1957, right after CERN was created. The walls of the building it’s in are 5 meters thick!

After looking at a presentation about the Synchrocyclotron projected onto it, we went into the other permanent exhibit, the Microcosm. At the beginning of it, there was a map of the accelerators and an explanation of where they get the protons that they accelerate – They are extracted from hydrogen.

The next part of the permanent exhibit showed the acceleration pipe. It’s only around 60 cm in diameter. Inside, there are two pipes that are only a couple cm in diameter, which is where the proton beams go. Around that are superconductor coils that produce the magnetic field, using 18500 amps, which are surrounded by insulation.

After seeing the acceleration pipe, we looked at a cross-section of a detector. It has several detection layers – the pixel detector to detect the location of the particles coming off of the collision, a magnetic field to cause the particles to turn to detect the velocity of the particles as well, surrounded by crystal detectors that measure the energy of the particle by turning the energy into light, surrounded by muon detectors. The detectors are very large – the CMS is the smallest, and it is 15 meters high and 21 meters long.

We went to the Alhambra yesterday. We had to wait two weeks to get tickets, so it is a popular place to go even in the off-season. The weather was not great, although it did clear up later in the day.

The Alhambra is one of the more famous pieces of architecture in Spain. It dates back to 889 AD, although the complex has been added to and changed in many ways over the years. It was originally a small fortress, but fell out of use until the 14^th century, when an emir of the Nasrid dynasty rebuilt it and added a large palace complex around it. The palace is the place that shows the most of the architecture and carving, although other parts of the complex display similar designs. Most of the artwork in the palace is just designs or Arabic calligraphy, but there are 3 paintings that show people in the top of alcoves.

The Alhambra complex has an impressive water system. There are fountains all over the place, and since this is on top of a large hill, the fact that they had running water in the 14^th century is quite impressive. There are a few staircases where there are water channels down the sides or the centre. Many entrance arches have niches in the walls for water bowls, which shows how much significance water has in this culture where they live in a very dry environment. There are also various pools in courtyards that at the time, would have reflected the architecture and been very peaceful places. Since the palace was built, fountains were added in the 16^th century, making the water less still and reflect the architecture less.