Brahe and Kepler in Prague

Tycho Brahe and Johannes Kepler at Pohorelec and in bronze

Tycho Brahe and Johannes Kepler were astronomers and astrologers at the imperial court of Rudolf II, who, in 1583, had moved his seat of government from Vienna to Prague. With this move, he had further irritated the Habsburg clan, who already regarded "their" melancholic emperor as blödhäuptig (silly-headed). As Golo Mann writes, "Rudolf possessed high intelligence when the urge of the moment did not cloud it." He was particularly interested in the science of his time, like alchemy and astrology.

As the best solution to the Rudolf problem, the Habsburgs considerably reduced his financial support. So the emperor was forced, although a fervent Catholic himself, to make a pact with the Protestant Bohemian estates. Their quid pro quo was financial support for the court in exchange for curbing religious liberties.

Rudolf's Letter of Majesty in the Czech language

So on July 9, 1609, Rudolf guaranteed in his Letter of Majesty to the followers of the Bohemian Confession, the Czech Hussites and brothers in faith, "From this day forth no one ... shall be pushed aside by [his] religion and forced to another faith by force or in any conceived way."

The document guaranteed the Ultraquists* not only freedom of religion but also the privilege of building churches and establishing schools. Prague University became Protestant.
*receiving the Holy Communion under both Species

©P. Habison

This situation culminated in a fight between two prominent brothers, Emperor Rudolf II and the younger Archduke Matthias. In the end, Rudolf was forced to abdicate.

Brahe and Kepler met for the first time on February 6, 1600, well before the fraternal quarrel, at Benatek Castle, Brahe's residence, located 50 km outside Prague.


Why do I write all this? Red Baron spent five days with a group on a guided tour of Prague and its surroundings. When I first read the announcement of "Tycho Brahe und Johannes Kepler in Prag," I was all excited. Studiosus, one of the better German tour organizers, offered this one-time specialized trip.

In what follows, I will no longer delve into the historical context on the eve of the Thirty Years' War, but rather focus on the tour. My German-speaking friends may read the full story and history here.

As usual, Studiosus had all well organized. At times, three guides looked at the overall organization, explained the implications of Brahe's and Kepler's discoveries for the development of astronomy, and showed us the beauties of Prague. The organizer was a man from Budapest speaking fluent German*, the astronomer-physicist was from Vienna, and the local guide was a Bohemian lady from Prague.
*His German was too good, clearly indicating that he was foreign (cf. My Fair Lady, the story about the Hungarian professor)

St. Norbert, in his recess, just does not get it.

In general, English was the language of conversation in shops and restaurants, but our three guides spoke German, the classical lingua franca of the bygone Danube Monarchy. I was moved.

The beautiful Elbe Valley

Coming from the Berlin wedding, I had a night-over at Dresden and took the train along the Elbe River to Prague the following morning.

Distinguish the famous Bastei bridge.

It was a pleasant ride along the Elbe Valley, passing the famous Elbe Sandstone Mountains.

The train named Berliner departed from Kiel on the Baltic Sea, passed through Berlin and Dresden, and had only a 10-minute delay when we reached Prague.

First impression: Prague's Wenceslas Square by night

The following morning started with a series of lectures by Dr. Peter Habison on Brahe and Kepler.

©P. Habison

Tycho Brahe became famous as an astronomer when he discovered and described the supernova of 1572. Its luminosity was so high that he could observe the bursting star with the naked eye.

©P. Habison

He also observed and described the 1577 comet.

A sextant

A replica of a Brahe quadrant at Benatec Castle

Brahe observed all his astronomical data, including the movement of the planets, with the naked eye, using well-adjusted sextants and quadrants.

Commemorative plaque for Smetana above the entry to Benatec Castle

Most people visit Benatec Castle not for Brahe but for Bedřich Smetana. The composer of "The Moldavia" lived here from 1844 to 1847.

Back to our protagonists. Enter Kepler. He needed Brahe's precisely measured data badly for the exact calculation of Mars's orbit. Initially, Brahe refused to part with them. You will find the full dramatic interhuman story between those two giants of science on Wikipedia.

Eventually, Kepler got the data following Brahe's death in 1601. He dedicated the publication to Emperor Rudolf.

In 1609, Kepler finally published his Astronomia Nova, in which, based on Brahe's precise observational data, he calculated the slightly elliptical orbit of Mars. In his book, Kepler also formulated two of his laws as there are:

1. Planets move in elliptical orbits with the Sun at one focus.
2. The speed of the planet changes at each moment so that the time between two positions is always proportional to the area swept over on the orbit between these positions.

Only a few contemporary "scientists" understood and
appreciated Kepler's Astronomia Nova (©P. Habison)

Only 75 years later, Isaac Newton fully understood Kepler's writings by applying to the orbiting planets in Kepler's Laws one of the basic principles in physics, the Conservation Laws, in this case, the conservation of angular momentum. In 1684, Newton published the paper De motu corporum in Hyrum.


In the following, I would like to share some of my photos from our guided tours.

A visit to the castle

Approaching St. Vitus Cathedral at the castle grounds

A look into the choir that was still finished in the Middle Ages

St. John of Nepomuk's drama in three acts is shown in one painting in the St Vitus Cathedral:
1. Nepomuk hears the Queen's confession.
2. King Wenceslaus demands that Nepomuk divulge the secrets of the Queen's confession.
3. Nepomuk refuses, is thrown from Charles Bridge, and drowns in the Moldavia River.

Crowds of tourists pass the great hall at the castle
on their way to and from the site of the 1618 defenestration.

Recovering with an Apfelstrudel (the best!) at the Castle Café

Changing of the guards at the castle

View from the castle onto the roofs of Prague.
         Note the site of the German embassy in the back of the Palais Lobkowicz.

Last view of the castle from Wallenstein's Gardens.

Downtown

An original vestige of Prague's University, founded in 1348

Today's entry to the Universitas Carolina

A traffic light at Charles Bridge channels the crowds of tourists.

Muzeum Speculum Alchemiae

Making gold

A problem everywhere: No drinks, no noise?

Library of the Strahov Monastery

"Science is difficult but fertile."

The interior is awe-inspiring...

... and the view down onto the Golden City, too.

Passing the Loreto Church ...

...discovering German street names ...

... and arriving at Tycho Brahe's house in the Castle Quarter, "The Golden Griffin."
Dr. Peter Habison gave an outdoor lecture.

The Klementinum

The National Library of the Czech Republic

Breathtaking views from the astronomical tower (see above) on
Baroque St. Nicolas Church, Tyn's Church, and the Powder Tower

The Hradčany hill with the castle and St. Vitus Church are to the west.

Pinkas Synagogue, Old-New Synagogue, and Old Cemetery

On the walls of the Pinkas Synagogue are written the names of all the Czech Jews
 who perished in the Holocaust.

The Thora shrine at the Pinkas Synagogue is flanked
with the names of concentration camps

The Old Jewish Cemetery...

... of the 15th century.

The oldest tombstone of Avigdor Kara from 1439

Rabbi Loew's tombstone of 1609

Interior of the Old New Synagogue where Rabbi Loew taught.

Rabbi Loew's seat in front of the Torah shrine, untouched.

The Golden City is a place to visit.
**