It's a two hour bike ride on two hours of sleep. It's so tough to get out of bed. I ride through Kruezberg, I ride through Tiergarten, and then I get a flat.
That's flat tire #8 for this bike tour. Somehow, some way, the largest bicycle shop on Earth is 500 meters away. Think Walmart. They actually have an entire test course for off-roading in the back of the store.
Flat fixed, I pick up the bicycle path to Potsdam, and start speeding south. When I arrive, I am received by Sarah Honig, the outreach coordinator at the Leibniz Institute. This observatory campus was constructed in 1913, away from Berlin, due to the already problematic glow of light pollution.
As we walked through the campus, she explained the activities of 200 scientists, astronomers, and engineers to study faraway galaxies and also to build the equipment that studies them. It's the current HQ for the 4Most large telescope project. We pass through the optical labs, buried in the basement for thermal and vibrational stability. Vacuum chambers, integrating spheres, and optical tables, looks like home to me.
Then we move up the road, on spectrograph weg. This street has a 50 meter long graph that plots the spectral output of the sun. There are so many precise lines, it's more data than what you would see in a rainbow!
We enter the room of the one of the "smaller telescopes". The entire floor sits on three large steel screws, forming an 8 meter wide elevator. The floor can travel up two stories, all just to bring the astronomer's eye to the eyepiece. The telescope towers way above, and feels more like a rocket than a lens.
We discuss sidewalk astronomy. Sarah mentions that perhaps sidewalk astronomy hits an important blind spot. We want to engage the people who may not necessary have the idea to visit an observatory or a museum.
Finally, one final bike ride down the road, to visit the Great Refractor and the Einstein Tower. The domes here are so large that from the outside, the buildings remind me of the Pantheon in Rome. In a way, the buildings serve the same function: reverence of the sky above. Check out my bicycle for scale in the pictures below.
The Einstein tower is special because it was actually a failed experiment. One of the most sensitive solar telescopes at the time, it was designed to test Einstein's prediction about gravitational redshift: that light from the sun, due to Earth's gravity, appeared 0.01 Angstrom redder than could be explained by any other physics. What they realized is that other effects in the atmosphere of the Sun registered as far larger shifts on this instrument. A failed experiment doesn't mean failed science however, and this observatory is still engaged in active research, which is why I can't get a tour! I reflect briefly on the significance of Berlin to astronomy overall, and then turn back for home.
On my way back, I realize something truly crazy: Neptune was discovered around the block from our room! The New Berlin observatory was demolished in 1915, but the site and the event remains. The site of the discovery of Neptune, dimmest planet in the Solar System, in the center of a major city. From the same spot, it's tough to even see Saturn, a planet that has been known since before written history. What's the difference between now and 1846? A whole bunch of light bulbs.
I don't want this city to lose the night sky, but we are headed there so fast. Isn't there any way we can convince people to turn off the lights?
Then in the evening, we went to a bridge packed with people enjoying the evening and drinking. We set up at the foot of the bridge while Jupiter was just overhead. We worked our way across the bridge as the sky spun, shifting over to Saturn as the evening burned on. Eventually, the police come by and politely tell everyone to leave and quiet down, but not before they caught a look at Saturn themselves!