Astrometeorology 7, Brahe's Star Castle
In the 1500s Europeans were starting to pull away from Rome's monopoly on power and thought. Tycho Brahe was a rich aristocrat who became fascinated by Arab and Persian astronomy. He shared the Islamic motive of learning how the universe ticks (literally) so we could predict and align our activities better with the universe. His aristocratic rank enabled him to get a commission from King Frederick of Denmark to build an official observatory, initially to improve timekeeping.

From David King's history:

He became interested in astronomy after observing a conjunction of Jupiter and Saturn, the cause, he thought, of the great plague in 1563. He found that planetary tables were in error by several days, and there and then decided to make their improvement his prime concern.

In 1576 Tycho started building his Star Castle, following Islamic architecture and Islamic instruments as seen at Maragha, but with improved and enlarged instruments for better accuracy.







The function of the domes is unclear. King says they housed some of the instruments, guarding against wind and weather.... but the drawings from Tycho's book seem to show solid roofs, not retractable or glass roofs. Two of the circles have semi-open 'gratings' over them, which would probably be sufficient. The big dome has a semi-open chamber at the top, but the ribs would block practical use.

The floor plan of the underground part is clear. An adit on the left led downstairs to the rectangular middle part, which served as a residence for the technician. Passages from the middle led to the observation chambers, which might have housed instruments.



I've included several of the instruments aboveground for visibility.

First, the default structure was just a rotatable globe with some kind of mounting on top. The globe was protected by a cone when not in use. Experimental instruments could be mounted on the globe and rotated to various angles. An astronomical breadboard.



There were several armillary spheres, mainly for calculation and visualization, not for sighting.



The Islamic instruments had alidades instead of lenses. Tycho continued the practice, and improved the accuracy with a vernier marking on top, anticipating the tick marks in later sidereal time instruments.

One of the Maragha instruments:



Tycho's version of a simple altitude sight:



This machine had a fine worm-gear crank to adjust with greater precision:



The Quadrant Magnus, with both altitude and azimuth adjustments:



Quadrant in use, sighting a star through the alidade:



The Sextant had three axes of adjustment, altitude and azimuth and a separate rotation of the alidade.



The Sextant in use:



An equatorial instrument pivoted on a 23 degree axis, anticipating the more complex equatorials of the 1800s. It had two independent alidades, for use in opposite directions.



Polistra thinks this instrument would have been hard to use!



What happened to the Star Castle? Again from David King:

Tycho had an imperious and fiery disposition which made him many enemies among the nobles of Denmark, especially those who envied him his large estate and high salary. After his benefactor's death, these individuals naturally counselled the young King Christian against his father's astronomer, already in some disfavour for having ill-treated one of his tenants.** After the coronation of King Christian in 1596, Tycho found his allowances gradually curtailed, even to the pension, so that he felt, as never before, that both he and his work were unwanted.

Eventually, his troubles became so acute that he was happy to leave Hveen, taking with him servants, students, instruments, and printing-press. After a short stay in Copenhagen, he left Denmark for ever, seeking safe domicile in Rostock, Wandsbeck, and Wittenburg until, worn out in body and spirit, he settled in Prague.

The castle's decay was hastened by his successors, who appear to have pulled down some parts in order to provide building material for new dwelling-houses. By 1652, there was scarcely any trace of the original buildings.

Tycho thus fits firmly into the tradition of Follies that serve science. Follies fade quickly after the rich owner dies, but the contributions to the work of other scholars remain and grow.

An institution that fades can't undergo the Parkinson process. Unlike bureaucracies and foundations, it can't turn to crime and corruption. The product grows without interference from the now-corrupt institution.

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** Footnote: Can you imagine a modern aristocrat receiving disfavor for ill-treating one of his tenants? Now it's the other way around. Aristocrats lose Share Value when they accidentally treat their tenants and employees decently. Only ill-treatment is allowed.

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Keeping track of the links so far:

Intro: Opening the doors again

2: James Ferguson

3: From Ferguson to Kepler

4: Maragha and astrolabes

5: Qibla

6: Back to Europe

7: Brahe's star castle (this item)

Labels: 2000=1000, Entertainment, Equipoise, Metrology, Parkinson

  ¶ 2:09 PM