Today's the big day, the one that Ioannis and I have been planning since Munich. We invited the Berlin astrophotographers to join us at Lustgarten for a night of sidewalk astronomy.
When two guys set up a telescope in a public space, it's an odd thing.
When a bunch of people set up two telescopes, now people are wondering: "Just what are they looking at? I should take a try."
In the evening, we meet Ioannis and a few of his astronomer pals at a Brewery, a Brauhaus, to talk about the standard astronomer things: the size of the Universe, the tragedy of light pollution, and the miracle that we can use technology to learn anything at all about the world beyond Earth.
Victor says he brought a telescope that weighs 80 kg. Now that will attract some big attention! We order some typical Berliner beers, and then head over to our chosen spot.
As we begin deploying the telescopes, a few more people show up that responded to our event! They don't bring telescopes, but they do bring knowledge. We meet a few physicists that are very excited to learn about more about sidewalk astronomy.
And that's what it's all about. Creating conversations, strangers developing new common interests, realizing that because we live on planet Earth, we all share the same atmosphere, and a quick peek at Jupiter can remind us of that.
At the beginning, I find myself retelling the story of John Dobson. John Dobson was born in China and then moved to California. After getting a college education in Chemistry and holding a wartime job, he became a Hindu monk. While practicing at the monastery, Dobson was given this task: to reconcile the Vedantu teachings with the modern science of Cosmology.
This task led him to invent a new type of telescope. He built it out of cardboard and garden equipment, and soon found himself wheeling it into town to share with people on the street. He snuck out of the monastery so often that after 27 years, he was kicked out. At that point, he dedicated his life to the practice of sidewalk astronomy, founded the San Francisco Sidewalk astronomers, and dedicated the his life to "showing people what the rest of their Universe looks like".
We're so happy that in Berlin, so many people joined us to share in this tradition. Thank you Ioannis, Victor and friends for so generously hosting us on this night. I hope you had as much fun as we did!
Photo Credit: Ioannis of the Berlin Astrophotography Meetup
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!
Long ago, in Munich, I heard back from the Berlin Amateur Astronomers and Astrophotographers. They do observing events, hold lectures, and sometimes just get beers to talk about the stars. I was really excited to finally meet Ioannis and join the club for a couple of days.
In the evening, we meet Ioannis at Hackescher Markt for some Currywurst. We share stories of the wonders of the Universe. Ioannis is from Greece, and used to study black holes as an astrophysicist. When he realized he loved Berlin possibly more than black holes, he switched fields into programming and has stayed in this city now for 7 years.
We talk about sidewalk astronomy, and the great difficulty of inviting amateur astronomers back into the city centers to share their knowledge with the public. Ioannis says he's never tried sidewalk astronomy before, but he's very excited to see what it's like.
We walk over to the Berliner Dom, where we set up the scope. Groups of people are sitting all around, enjoying their beer in friendly circles. In a crowd like this, not many people will pass by, so I'll have to walk right up to each group and invite them over.
Our friend Dax meets us again and stays for a while.
We encouraged people to make sketches tonight, and we got enough data on Jupiter to watch Ganymede disappear behind the planet! Saturn again makes its appearance. Yesterday, we started spotting Titan, that faint bluish white.
One MoonGazer is a biologist from California. She says she's been to the Griffith Observatory, where John Dobson did so much of his famous work. But she said they never showed her Titan.
With a small group around us, it becomes so much easier to attract attention. I approach the groups sitting in the grass and point to the light in the sky.
"Hey guys, do you see that star? It's actually Jupiter, and my brother has a telescope set up over there, so you should go see it!" And that's generally enough of an argument for a Berliner. We try out our new Saturn facts and enjoy the fresh air.
As usual, the Earth turns toward sunlight and we ignore our obligation to sleep. By the time we get home, the moon is out, and our host Paulo thinks up the perfect place to spot it. Now it's 2 am and the entire BnB is outside looking at the waning gibbous.
Did I mention that tomorrow morning we're cycling to Potsdam (35 km) to see the Leibniz Observatory?
Photo Credit: Ioannis of the Berlin Astrophotographers.
Flixbus trips feel a little like spaceships, especially if you step onto an overnight bus. All sense of time and position is lost for the rest of the evening. We sleep in 20 minute increments.
The bus traveled from 7 PM to 7 AM, 8 degrees east in the same time zone. Since the Earth spins 15 degrees every hour (360/24hours), that means that in Berlin, the Sun sets about 30 minutes earlier than in Amsterdam.
That's not the only unusual thing about the sky this morning. At 7AM, above the bus station, is the waning gibbous directly overhead.
A few days after the full moon is usually the end of the moon cycle, because with each passing day, the moon rises about 49 minutes later in the evening, every evening.
(24 hours in a day/29.5 days Full Moon to Full Moon = 49 minutes)
And THAT'S why the moon is in the sky during the day today, because it revolves around the Earth! It's just harder to notice because the contrast makes it pale in the sky, and just blends in with the clouds. But there is a time in the morning, if you can get underneath the shadow of a building or some tall trees, that you can see the moon quite clearly during the day.
It's really delightful. And it's the perfect time to share it with people who are on their way to work.
So that's what we got to do, after traveling through time and space to show up on the lawn of Tiergarten. When you balance the bike's kickstand on soggy ground, it's making a risky landing. Once the bikes start to tip, they can't easily be stopped, so you might as well let gravity win.
A number of people stopped to join us and see what we were looking at. It's difficult to posture yourself to offer a view - two in every three people have earbuds in, and "why are these weirdos out here with a telescope this early in the morning? I'm on my way to work."
Not everyone is in a rush though, and we get plenty of people to see what we were pointed at.
Well it's the craters on the moon during the day! A cool trick - you can use a red filter to bring out more of the shadows at the terminator line, just like you would see them at night. It also works great for full moons, since the striae of craters pop out as a much lighter tone in the red filtered light. The monochromatic light will surprise people, so you can even show them the difference, before and after, if you have the time to shuffle the eyepiece around. Low magnifications also look great for the daytime waning gibbous. The moon resembles a dimpled golf ball hovering in the blue.
10 am. It's time to meet our hosts and go back to sleep. The planets are up tonight, and we're gathering a group at Alexanderplatz in the evening.
See you there!
It's the first moon night of our Apollo 11 celebration. On this day, the astronauts left for the moon on a Saturn V rocket.
50 years later, a partial lunar eclipse is visible from Amsterdam.
Entering Rijksmuseum, we walk right up to Jupiter high in the sky. As we're setting up, a few people who heard about our event approach us! Advertising works!
When I visited in Amsterdam in 2015, I remember, like everyone else, taking a picture in front of the I AMSTERDAM letters. A big plaza that's totally crowded, day and night.
It turns out they removed the landmark because the entire place was swarmed with a critical mass of tourists. Now that the letters are gone, the park is a calm and peaceful but very central location in the city.
Our friend Ammar joins us and ends up hanging out with us for the whole night! So now, we begin to gather people who are nearby to look through the telescope. It's a quiet, more neighborly affair, and the crowd is made up of a mix: a few visitors as well as a few Dutch residents.
An English family passes by with three daughters. All of them are excited to look through the telescope, so I lower the tripod way down. The first girl looks through, and that's when I realize: they know all the basics! I try to tell them about Jupiter's clouds, but they already know what they're looking at. Do any of you know what a lunar eclipse is? It's when the moon passes in front of Earth's shadow. One of the girls, Ellie, even leaves us with a sketch of Jupiter, as she saw it with her very own eyes!
The full moon, at 52 degrees latitude, is much lower in the sky than in Philly (40 degrees). Hold your fist out at arm's length. That's how much lower!
So when the moon peeked out from the horizon of the buildings, the eclipse was in full swing. An abnormal crescent shape hung in the sky, with the two points facing straight up. A few people passing by thought it was a cloud.
Earth's shadow has an interesting fluffy appearance. Unlike the moon's terminator line, which gives us the crisp shadows we love to look at, Earth's shadow does not have a crisp boundary. It isn't as dark either: you can easily see the eclipsed portion of the moon as well as the eclipsed portion.
The night ticks on, and Saturn emerges. Standing back, the two planets plus the eclipsed moon form a long arc in the sky: the disk of the Solar System, and some of the best urban viewing we've ever done. It feels as though the entire ecliptic is in a special alignment.
"On July 24 we returned to Earth. We landed in the Pacific Ocean. We were invited to take a tour and I was amazed: everywhere we went people said: 'We did it, we did it, you and me, the inhabitants of this Earth.' " - Michael Collins, Apollo 11 Astronaut
We've been spending time in Brussels with our friend David, and something showed up in the mail today! An Omegon Pro Carbon-Fiber tripod!
Remember when we teamed up with Omegon back in Munich? They noticed how we've been hauling heavy duty telescope equipment across the continent, and offered to donate a smaller tripod to the cause!
It's made of carbon fiber, lightweight at only 1.3 kg. The tripod legs are a series of four twist locks, which are easily deployed in a couple of seconds. Fully extended, the tripod stands 1.5 meters tall! It's the perfect piece of hardware for a tour, and it's already giving me new ideas for more astronomy related travel.
Sidewalk astronomers need lightweight equipment to make their treks across the city. I can't wait to get this guy deployed on the next clear night. We will probably see it in action once we reach Antwerp.
Kilometers cycled: 105
About two years, ago, my friend David from Belgium visited Philadelphia for a weekend. He found me set up on the corner of 4th and South with a pair of binoculars. It was in Philadelphia that he met his first flat-earther "in real life". In the same night, he actually met quite a few more. That night, I was able to show him the moons of Jupiter, the four famous points of light all in a straight line. Tonight, we visit him, and take a trip together to his local observatory a few towns over.
Tonight, another observatory! Grimbergen Volkssterrenwacht is one of Belgium's public observatories. This is an astronomy venture run by three people - their mission is to broadcast science to the public and especially to children. Phillippe is at the door as we arrive, and greets us "These guys look like they come from Philadelphia!"
Phillippe says we are only a few miles away from the largest planetarium in Belgium. It helps to have a planetarium for communicating astronomy, but it also helps to have something different. He shows us a "constellation clock". On this massive circular wheel, the milky way and all the stars visible from Belgium are painted. Each constellation is lit up by a button on an old-fashioned control box. The technology is Thomas Edison: push a button, complete a circuit, and the stars of that constellation will light up. On this wall, there are over 1,200 individual stars drilled into the device, and the stars were chosen to represent as accurately as possible what you can actually see in Belgium under the influence of light pollution.
As we venture upstairs, we pass by a number of murals that help depict the scale of the Solar System and the Universe. If the earth is the size of a baseball, then you can only fit a small fraction of the sun on the wall, from floor to high ceiling.
At the end of the tour, we reach the inner Sanctum, where the other astronomers are hanging out and drinking coffee. One astronomer, Chris, is working at his computer on a Virtual Reality replica of the Apollo 11 mission. You can listen to the radio recordings, sit inside the cockpit, and watch as the rocket orbits the moon and experiences an Earthrise. The entire experience is so detailed, I can't wait until people see it with goggles on!
To end the night, our friend David looks at Jupiter through a 50 cm telescope. I easily notice the red spot, but we are reminded that right now Jupiter sits so low on the horizon that its best secrets are washed out by the atmosphere, and are invisible to any telescope.
David meets the Moon Men in Philadelphia, looks through a Galileo-sized instrument, and then two years later, he sees the same object through a telescope large enough to climb inside.
Galileo didn't invent the telescope. Actually, he was far from the first person to own one - records show that even the Pope probably had one before he did! What was different was the high magnification of his instrument.
All of this started because of a 1608 patent application by Hans Lipperhey for a spyglass "with which one can see all things very far away as if they were nearby". Through the combination of two lenses, he achieved magnifications between 3X to 4X. Lipperhey wrote to the noblemen in The Hague, and was invited to demonstrate his instrument, capable of "seeing all things very far away as if they were nearby". Two weeks later, at least two more people came forward claiming they had also invented the telescope. Immediately, people all over the continent understood the wartime advantage of owning one, for example: counting the number of archers stationed at a wall before your siege begins. So there were a wealth of pre-Galilean telescopes - Galileo's contribution was his improvement to high powered optics (21X magnification), and his consistent, detailed observations of the sky, which he conducted in the years 1609 and 1610.
Today we are visiting Sterrenwacht Middelburg, situated around the corner from the home where Lipperhey invented his spyglass. Middelburg is known worldwide as the birthplace of this invention. The observatory houses some powerful instruments as well as some important ones. Rijk-Jan, one of the astronomers, invited us for some coffee and to share a conversation about sidewalk astronomy. The Dutch people are overall very familiar with astronomy. The University at Leiden exports astronomers all over the world. SterrenWacht Middelburg does a number of events outside town hall: with Dobsonians, with solar telescopes: the best time to show someone the Universe is when they are simply walking by.
A small room houses a 16" Meade Schmidt-Cassegrain, staring out the window toward the southern sky. Unfortunately due to its location, the window overlooks some lights and windows which must ruin the astronomy. That's when Rijk-Jan shows me something I've never seen before. He flips a circuit breaker on an electrical box next to the telescope, and every street lamp in view of the telescope simply turns off! Astronomers who are reading, imagine the trust and opportunity to work so closely with town officials for that!
The Philly Moon Men advocate about light pollution, and actually, due to its dense population, the Netherlands has some of the worst light pollution in all of Europe. Its cities are comparable to New York or Philadelphia. Still, in the smaller town of Middelburg, the constellations are visible.
Rijk-Jan takes us to display cases with mannequins of Galileo and Hans Lepperhey. He opens up the display with his key, and robs the mannequin of his prop. The prop is actually a French refractor built in the year 1690. He allows us to hold it, and shows us some features of its design. The telescope has a third lens inside, called a field lens, that provides an upright image to the user. With a field lens inside a telescope, if you look at mountains, the mountains are not upside-down. The field lens is removeable as well, so that the telescope can be used at night-time in low light conditions.
We return to the coffee shop, and Rijk-Jan gives us a book that will turn me into a quick expert on telescopes. A thick text "The Origins of the Telescope", filled with all the evidence and debate of just how this important device came into existence. Thank you to all the astronomers at SterrenWacht Middelburg for helping us with our education!
Next we walk outside to the old foundations of Lipperhey's home. From this site, we use the old French refractor to look at the wind vane on top of the Abbey, just as, according to legend, Hans Lipperhey did over 400 years ago. The refractor in Rijk-Jan's hand represents already 80 years of innovation over Lipperhey's invention. The field of view is quite small, but the clarity of the image is surprising, with a bit of chromatic aberration but nothing that gets in the way of making an observation.
Feeling inspired, Rijk-Jan decides to take the ancient telescope home for an evening, and make a sketch of the telescope.
The next time you visit a science museum and see a telescope hanging in a display case, remember that it probably still works!
Rotterdam -> Vlissingen
Kilometers Cycled: 110
Actually, I wouldn't recommend it - every night, we stay up until 3am, then sleep for a few hours before cycling to our next destination. A bicycle tour on its own is tiring!
From Rotterdam, we head south along the coast. All of Netherlands is a single bike lane, paved with stone. The street signals are designed to inform exactly who has the right of way, and there are no stop signs, only "don't hit the bicycles". The bicycles are the stop signs.
Halfway through our trip, the wind picks up. Against the wind, it's a struggle to maintain 15 km/h. In the other direction, it's easy to cruise at over 25 km/h. We know this because and one point we had to turn around and detour! We pass underneath towering wind farms, the shadows of the blades crashing onto the roadway.
Our ride took us across the famous dike system, that protects the Netherlands from the Atlantic Ocean. These structures are massive, and looking at them from a distance makes you feel like you are in the future.
The wind created a long day's trip for us, but as soon as we arrive, our host Froukje was preparing dinner under the windmill. The miller, who runs the windmill, brings us inside, and shows us wooden gears twirling under wind power, same as they did 320 years ago. From the rumbling of the building, you can feel the strength of the wind acting on the three-story long sails. This mill was used to grind grain into a fine powder, and explains how the workers would adjust their tools to the speed of the wind. Minute to minute, you can hear the gears speeding up or slowing down. Then, the miller walks over to a rope system, and with one hand, stops the entire show. A clever system of wood and friction holds the windmill still. Pulling the rope the other way, the windmill is free, and instantly it begins to turn in the wind.
Neighborhood kids put up posters for the Moon Men, and she had invited the entire town to come see our telescope in front of the windmill. Barbequed pizza, potato salad, and a sunset on the Atlantic ocean. By the time we are finished eating, we have quite a crowd to entertain. Froukje was so excited to share the telescope, she figured that giving all the townspeople a chance to meet each other would be a good thing, it would help people come together to understand each other.
Jupiter is high enough in the sky that we can view it as soon as twilight dwindles, which is right now a bit after 10 pm. Close to midnight, Saturn is ready as well, and we spend the evening toggling back and forth between the two planets. Everyone sees Jupiter's moons, everyone has more questions. It is like a hero's welcome for the town to come out and take a look. Hey, if you know a bunch of people who have never looked through a telescope before, we want to visit you!