The Contributions by the Danish astronomer Tycho Brahe (1546-1601) to science and society, are vital to understanding the movement of the planets and the cosmological concept we have today.
Tycho Brahe was born into an aristocratic family that had political, economic and social control in Denmark for 200 years. For reasons that are not clear, Tycho was raised by his paternal uncle since he was two years old.
It was Jørgen Thygesen Brahe, his uncle, who sent him to study Laws at the University of Copenhagen. It is there that Tycho, in addition to studying law, studies a variety of other subjects that lead him to become interested in Astronomy.
In 1560, a year later from his arrival in Copenhagen, he experienced an event that would guide the rest of his days towards the observation of the Cosmos: a solar eclipse. He was surprised by the fact that the eclipse had been predicted, although predictions, based on observation data, were for an earlier day. At this point, he realized that with more accurate observations, predictions would be made more accurately.
After enrolling at the University of Leipzig in 1563, he observed a conjunction between Jupiter and Saturn, whereby he understood that the Nicolaus Copernicus (1473-1543) and Claudio Ptolomeo (90/100 d.C.-170d.C.), used to predict conjunctions, were imprecise. Here begins his progress in the astronomical field.
The most remarkable scientific contributions of Tycho Brahe
1- Supernova
From ancient times, based on the axiom of celestial immutability over the Aristotelian worldview, it had been argued that the world behind the moon's orbit was eternally unchanging.
In 1572, Tycho observed a new star in the constellation of Cassiopeia to which he named"nova stella"and today we know as Supernova.
During the eighteen months in which the new star was visible, Brahe made strict observations and measurements that indicated that there was no daily parallax between the star and the background of fixed stars. This implied that the nova stella was beyond the Moon and the Earth's orbit.
Tycho not only had discovered a new star, but also beat all Aristotelian doctrine and its spherical finitism.
2- Uraniborg or Castle of the heavens
Emperor Frederick II delivered the Island of Hven, and a large amount of annual money, sufficient to carry out the construction of Uraniborg. It was this, the last primitive astronomical observatory before the invention of the telescope in 1608, being the first modern observatory hundred percent financed by the government.
Uraniborg Palace
The Uraniborg palace receives its name from Urania, muse of astronomy. And here is where Tycho Brahe, realizes most of his observations and also develops new astronomical instruments of great size.
3- Astronomical measuring instruments
From that solar eclipse of 1560, Tycho insatiably sought the precision of his observations, as well as an excellence in the records of them. In order to perform this task, it was necessary to apply and improve various astronomical measurement instruments. Here are some of the devices with which Brahe observed the skies night by night:
From left to right: Quadrant, Armillary Sphere and Sextant
4- 1000 stars
All his instrument design, allowed him to measure the position of stars and planets with a precision much superior to the one of his time. In this way, he developed a stellar catalog of more than 1000 fixed stars.
5- Refraction of light
The refraction of light was first perceived by Tycho Brahe. He corrected the astronomical measurements of this effect and also produced a complete table of it.
6- Model of the Universe of Tycho Brahe
To explain the model of the universe of Tycho Brahe, we must first understand the ideas of his predecessors in this subject.
Claudio Ptolomeo (90/100 d.C.-170d.C.), in his astronomical treatise Almagest , Presents us with a model of geocentric universe in which the Earth was the center of the Universe and remained motionless, while the Sun, the Moon, the planets and the stars, revolved around him.
On the other hand, the Polish astronomer of the Renaissance, Nicholas Copernicus (1473-1543), formulates the heliocentric theory of the solar system. This heliocentric model proposes that the Sun is the center of the universe and that orbiting around it are the Moon, Earth, Mercury, Venus, Mars, Jupiter and Saturn.
In 1577 appeared a comet in the sky that served to him to Brahe like questioning of the traditional vision of the cosmos. Through the observation of this fact, summing up all the researches done during twenty years in the Uraniborg observatory, it exposes a model of the intermediate universe between the Ptolemaic geocentric model And the heliocentric universe of Copernicus.
In this new model of Tycho Brahe's universe, the Sun and Moon revolve around the immobile Earth, while Mercury, Venus, Mars, Jupiter and Saturn revolve around the Sun.
We now know that this theory does not correspond to reality, since our solar system consists of a center (Sun) and 8 planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune) that revolve around the Sun We also know that our solar system has other astronomical objects, satellites, minor planets, among others.
Kepler, Brahe's successor
We can not speak of Tycho Brahe, without naming who was his successor: Johannes Kepler (1571-1630). We speak of a German astronomer and mathematician, Brahe's collaborator and one of the Most important scientists in history .
There is evidence that the relationship between astronomers was not cordial. Apparently, Tycho refused to teach Kepler, the complete set of observations of the path of the planets, their records and astronomical observations.
It was not until after Brahe's death that Kepler gained access to all the information baggage of Tycho, which allowed him to continue investigating, so that after several years he could come to enunciate his three laws on the movement of the planets.
Although the Danish astronomer was not aware, formulating the physical problem of planetary movement is one of the most important contributions that has left as a legacy to modern science.
Rudolph Tables
Time before his death, Tycho Brahe, entrusted to Kepler the task to finish the tables Tudolfinas, calls of this way with the intention of homenajear to the emperor Rudolph II.
Brahe developed them to compile new stellar position charts. He yielded to Kepler, all his astronomical data with the responsibility of demonstrating the validity of Tycho Brahe's model of the universe versus that of Nicholas Copernicus.
The publication of this star catalog was carried out by Johannes Kepler in the year 1627.
Kepler's three laws
With the help of Brahe's records of astronomical observations throughout his life, Kepler was able to deduce the real planetary orbits, until he realized that the orbits of the planets were elliptical and not circular perfect as was believed until the moment. This was thanks to his study on the elliptical orbit of Mars.
Between 1609 and 1619, Kepler constructed his three laws, based on a heliocentric vision where the planets move in elliptical trajectories and not in epicycles (from Greek, epi, about, and kyklos, circle, which means about the circle).
- Kepler's First Law
"The planets have elliptical motions around the Sun, which is located in one of the 2 foci containing the ellipse."
- Kepler's Second Law:
"The areas swept by the radii of the planets are proportional to the time spent by them in traversing the perimeter of those areas."
- Kepler's Third Law:
"The square of the periods of the orbit of the planets is proportional to the cube of the average distance to the Sun"
These laws made it possible to understand the laws of planetary motion. In a model where the stars rotate elliptical around the Sun at different speeds.
Law of universal gravitation
They must think that Tycho Brahe had nothing to do with the Law of universal gravitation of Isaac Newton , But the reality is that yes, it had a lot to do.
Our way of understanding the solar system and the whole universe was built by great minds, among which are Copernicus, Brahe, Kepler and Newton. Each of them played a crucial role. Let us first take Tycho as the great observer of the firmament in times when the telescope did not exist. Over several years of work, he collected large records of his observations of planetary movements.
Then, Kepler, based on the knowledge acquired by Brahe, ends by developing his three laws. Later, Isaac Newton by induction comes to make his three simple laws of motion and, finally, the Law of universal gravitation.
References
- John Robert Christianson; On Tycho's Island: Tycho Brahe and His Assistants, 1570-1601.
- Encyclopædia Britannica; (7-20-1998); Uraniborg. Retrieved from britannica.com.
- ROTATION, C. Wilson, Michael Hoskin; (2003), Planetary Astronomy from the Renaissance to the Rise of Astrophysics, Part A.
- Astronomiae Instauratae Mechanica, Smithsonian Institution. Recovered from sil.si.edu.
- Dreyer, Tycho Brahe: A Picture of Scientific Life and Work in the Sixteenth Century, Edinburgh 1890. Reprinted New York 1963. Retrieved from sites.hps.cam.ac.uk.
- Chapman,"Tycho Brahe in China: The Jesuit Mission to Peking and the Iconography of the European Instrument-Making Process, Annals of Science 41 (1984), pp. 417-433. Retrieved from sites.hps.cam.ac.uk.
- Victor E. Thoren; The Lord of Uraniborg: A Biography of Tycho Brahe.