====== Tycho Brahe ======

**Tycho Brahe** (December 14, 1546 - October 24, 1601) was a Danish (Scanian) nobleman, astronomer, astrologer, and alchemist. He was granted an estate on the island of Hven and the funding to build Uraniborg, an early research institute, where he constructed large astronomical instruments and conducted many precise measurements.

As an astronomer, Tycho aimed to merge the geometrical advantages of the Copernican system with the philosophical benefits of the Ptolemaic system into his own model of the universe, known as the Tychonic system. From 1600 until his death in 1601, Johannes Kepler assisted him and later used Tycho's astronomical data to develop his own theories. It was common in Scandinavia to refer to him simply as "Tycho" rather than by his surname "Brahe."

Tycho is credited with the most accurate astronomical observations of his time. His detailed data was instrumental in Kepler deriving the laws of planetary motion. Tycho's approach involved cataloging the planets and stars with unprecedented accuracy to determine the validity of the Ptolemaic versus Copernican systems.

On April 19, 1559, Tycho began his studies at the University of Copenhagen, where he initially studied law per his uncle's wishes. His interest in astronomy grew, particularly after an eclipse on August 21, 1560, which inspired him to study the subject further. He acquired an ephemeris and books such as Sacrobosco's *Tractatus de Sphaera*, Apianus's *Cosmographia seu descriptio totius orbis*, and Regiomontanus' *De triangulis Omnimodis*.

Tycho believed that systematic and rigorous observation, combined with highly accurate instruments, was essential for progress in astronomy. He improved existing instruments and developed new ones, achieving remarkable accuracy in naked-eye measurements of planetary parallax. His sister, Sophia, assisted him, and these meticulously guarded measurements later became the basis for Kepler's work.

During his student years, Tycho lost part of his nose in a duel with Manderup Parsbjerg, which led him to develop an interest in medicine and alchemy. He wore a replacement nose made of silver and gold, but modern investigations suggest he might have used a copper prosthetic. Tycho's work as an observational astronomer was unparalleled before the advent of the telescope.

Tycho's observations included measuring Earth's axial tilt as 23 degrees and 31.5 minutes, claiming greater accuracy than Copernicus by 3.5 minutes. His records of Mars's motion were crucial for Kepler's discovery of planetary motion laws, supporting the Copernican heliocentric theory.

Tycho proposed the Tychonic system, where the Sun orbited the Earth, and other planets orbited the Sun. This model offered a compromise for astronomers who were hesitant to accept the Earth's motion. It gained traction after 1616 when the heliocentric model was officially opposed by the Catholic Church. Tycho's system also eliminated the need for transparent rotating crystalline spheres used in other models.

Tycho accounted for atmospheric refraction affecting star observations near the horizon and used the new technique of prosthaphaeresis for mathematical calculations.

===== Astronomy =====

On November 11, 1572, Tycho observed a bright new star in Cassiopeia, known as SN 1572. This supernova challenged the Aristotelian view of celestial immutability and supported Tycho's argument that the star was distant, not in the Earth's atmosphere. He published a book, *De Stella Nova* (1573), coining the term "nova" for a "new" star. This discovery solidified his commitment to astronomy.

Tycho's supernova discovery inspired Edgar Allan Poe's poem *Al Aaraaf*, and some speculate it was the "star that's westward from the pole" in Shakespeare's *Hamlet*.

===== Heliocentrism =====

In the Tychonic system, objects on blue orbits (the moon and the sun) rotate around the Earth, while objects on orange orbits (Mercury, Venus, Mars, Jupiter, and Saturn) rotate around the Sun. A sphere of fixed stars surrounds everything.

Tycho rejected the heliocentric model proposed by Copernicus, believing that if the Earth were in motion, nearby stars should shift position relative to background stars. However, this parallax effect could not be observed with the naked eye or early telescopes due to the vast distances involved. The Tychonic system became a major alternative to Copernicanism after Galileo's observations of Venus's phases in 1610.

King Frederick II of Denmark and Norway financed the construction of two observatories for Tycho on Hven: Uraniborg and Stjerneborg. Uraniborg also housed a laboratory for alchemical experiments. Tycho left Hven in 1597 due to disagreements with Christian IV and moved to Prague in 1599. Supported by Rudolf II, he built a new observatory in Benčič nad Jizerou before returning to Prague until his death. Tycho prepared astrological charts and predictions for his patrons, including Frederick II and Rudolf II.

===== Astrology =====

Tycho Brahe accepted astrological prognostications, believing in their influence on terrestrial events while remaining skeptical of multiple interpretative schemes. He produced astrological interpretations for events such as the supernova of 1572 and the comet of 1577 and provided predictions to his patrons. Tycho's philosophy included a belief in correspondences between heavenly bodies and terrestrial substances, reflected in his construction of Uraniborg as both an observatory and alchemical laboratory.

He defended astrology and alchemy in his lectures and emblems, emphasizing the relationship between the macrocosm and microcosm.

===== Final Years =====

Tycho died on October 24, 1601, following a bladder rupture at a banquet. It was said that he did not leave the banquet to avoid perceived rudeness. Recent investigations suggest he may have died from mercury poisoning rather than a urinary issue, possibly from a mercury-containing medicine. There is speculation about possible murder, but no solid evidence supports this.

===== Surprising Element Found in Traces of Tycho Brahe's Alchemy Lab Confounds Scientists =====

*CNN - July 27, 2024*  
Tycho Brahe, known for his pre-telescope celestial discoveries, also worked as an alchemist. Researchers analyzing glass and pottery shards from the site of his demolished Uraniborg have uncovered new clues about his alchemical work. The secretive nature of Brahe's alchemical practices has long been a historical mystery.