Person: Brahe, Tycho
Tycho Brahe was a Danish astronomer who is best known for the astronomical observations which led Kepler to his theories of the Solar system.
Mathematical Profile (Excerpt):
- He is now known as "Tycho" since that is the Latinised version of his name that he adopted when he was about fifteen years old.
- For simplicity we shall use the name Tycho throughout this biography.
- Tycho was one of twin sons, but his twin died shortly after birth.
- A strange episode occurred when Tycho was two years old.
- Jorgen Brahe commanded Tostrup Castle, and it was in that castle that Tycho lived from the time he was taken by Jorgen until he was six years old.
- We should not give the impression that he did not travel during this time, for his parents had many administrative duties which took them away and it is likely that Tycho sometimes went with one of them.
- About a year after Tycho moved to Vordingborg with his foster parents he began to attend school, almost certainly attending that attached to the local cathedral.
- Tycho attended this school until he was twelve years old, then began his university studies.
- On 19 April 1559 Tycho began his studies at the University of Copenhagen.
- The second observation he recorded was a conjunction of Jupiter and Saturn which proved significant for Tycho's subsequent career.
- While in Rostock he was involved in an argument with another Danish student and in the resulting duel Tycho had part of his nose cut off.
- A consequence of this was that Tycho developed an interest in medicine and alchemy.
- Tycho had been working on improved instruments for observing for a while, but when in Augsburg he designed some of his own and managed to obtain a patron to underwrite the cost of a major new instrument.
- Peter Ramus was also on a visit to Germany and while in Augsburg he learnt of Tycho's great quadrant leading to meetings at which the two engaged in deep astronomical discussions.
- Tycho began constructing another instrument, this time a large celestial globe made from wood.
- They also built an alchemy laboratory there since alchemy was becoming a major interest for Tycho.
- The star is now usually known as 'Tycho's supernova'.
- It turned Tycho's interest back to astronomy.
- The Landgraf Wilhelm IV of Hessen-Kassel had founded an observatory at Kassel about 15 years earlier and Tycho was very impressed by the methods used there.
- Leaving Kassel, Tycho visited Frankfurt, Basel and finally Venice before returning to Denmark by the end of 1575.
- By this time he had made a decision to leave Denmark and to settle in Basel, but King Frederick of Denmark was not going to lose his most eminent scientist easily so he made offers to Tycho to entice him to set up an observatory in Denmark.
- At Uraniborg Tycho made twenty years' worth of astronomical observations.
- We should note that Tycho's design was influenced by buildings he had seen in Venice, and was also constructed in a highly geometrical form.
- One of the most exciting astronomical events which Tycho observed from Uraniborg was a comet which he first spotted on 13 November 1577.
- From his observations Tycho was able to show that the comet was certainly further away than Venus.
- In 1584, with the observatory of Uraniborg now too small to house all his instruments, Tycho built a second one named Stjerneborg adjacent to Uraniborg.
- This was the time when Tycho was most active in producing major new instruments.
- The ten-year process had considerable consequences for progress of Tycho's theoretical work during his life.
- Thus, as was also the case in the earlier study of fixed stars, Kepler's belief that Tycho's observations could be trusted to better than two minutes is amply confirmed.
- Tycho is perhaps best known today for his theory of the solar system which is based on a stationary Earth round which the Moon and Sun revolve.
- The other planets, according to Tycho's theory, revolve round the Sun.
- In his younger days Tycho had been convinced by Copernicus's Sun centred model but his firm belief that theory must be supported by experimental evidence led him away.
- The problem was, of course, that in the Sun centred model of Copernicus a parallax shift should be observed but despite his attempts to measure such a shift, Tycho could detect none.
- We know today that it is the second of these which is true, and that the scale is such that Tycho would have had no hope in measuring parallax with his instruments.
- Despite the quality of Tycho's measurements, this value in about 100 times smaller that Tycho's observational errors.
- Tycho was not the first to propose the Earth centred model with the planets rotating round the Sun for Erasmus Reinhold had done so a few years earlier.
- He had two sons; Tycho, born in 1581, and Georg in 1583.
- Tycho, however, presented a patent which gave Uraniborg something like university status, and the director something like the status of the head of a university.
- It also stated that succession to the headship would give preference to "Tycho Brahe's own".
- In his younger days Tycho had been a fair man in his dealings with others.
- However in the 1590s Tycho's nature seemed to change and his treatment both of the inhabitants of Hven and of his student helpers at Uraniborg became unreasonable.
- Tycho closed down his observatory on Hven in 1597 (the last recorded observation is on 15 March that year), and moved to Copenhagen.
- Tycho intended that this work should prove the truth of his cosmological model, in which the Earth (with the Moon in orbit around it) was at rest in the centre of the Universe and the Sun went round the Earth (all other planets being in orbit about the Sun and thus carried round with it).
- Tycho began observing again in Prague.
- He received support from Rudolph for Kepler and himself to compile a new set of astronomical tables based on Tycho's recorded observations over 38 years.
- However, Tycho died eleven days after dining at the palace of Peter Vok Ursinus Rozmberk as a result of adhering to the etiquette of the day and refusing to leave the dinner table before his host.
- Tycho's observations of planetary positions, which were made using instruments with open sights (a telescope was not used for astronomy until about 1609), were much more accurate than any made by his predecessors.
- They allowed Kepler, who (unlike Tycho) was a convinced follower of Copernicus, to deduce his three laws of planetary motion (1609, 1619) and to construct astronomical tables, the Rudolphine Tables (Ulm, 1627), whose enduring accuracy did much to persuade astronomers of the correctness of the Copernican theory.
- However, until at least the mid-seventeenth century, Tycho's model of the planetary system was that favoured by most astronomers.
Born 14 December 1546, Knutstorp, Skane, Denmark (now Svalöv, Sweden. Died 24 October 1601, Prague, Bohemia (now Czech Republic).
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Tags relevant for this person:
Astronomy, Origin Denmark, Physics
Mentioned in:
Chapters: 1
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References
Adapted from other CC BY-SA 4.0 Sources:
- O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive
