In the final part of the part of our biography of Johannes Kepler, we look at his scientific work from 1612 to his death in 1630 including the Epitome of Copernicus, Harmonice Mundi and the Rudolphine Tables. We consider the accusations of witchcraft against his mother, Katharina, and a number of other personal tragedies. In conclusion we discuss the Somnium, Kepler's work of science fiction.
In part three of our biography of Johannes Kepler we look at his years in Prague and the scientific work he did there including Astronomiae Pars Optica, Dioptrice and Astronomia Nova. We discuss how he arrived at his first two laws of planetary motion and his description of how lenses produce images in various optical systems including the eye. We also follow the personal tragedy of the death of his son Frederick, how wife Barbara and the chaos that eventually engulfed Prague.
In part two of our biography of Johannes Kepler we look at the mathematician and astronomer's time in Graz and with Tycho Brahe in Prague. We specifically look at Kepler's role in the conflict between Brahe and Nicolas Reimars Bar (aka, Ursus).
Part 1 of our biography of of Johannes Kepler covering his early life from his seminary schooling to his time in Graz. We discuss his school in the lower seminary at Adelburg, the upper seminary at Maulbronn and at Sift at the University of Tubingen. After this we follow him to his assignment at the Protestant school in Graz and his work as the district mathematician. IN this we examine his attitudes on astrology and the publication of the Mysterium Cosmigraphicum.
This week we dock in Venice for a question and answer episode wherein I talk about podcasting, understanding quantum mechanics, the origin of the universe, and the evidence for human activity causing climate change. I also address questions about how doing the podcast has affected my teaching and where some of the strange things in academia come from. Then there's the story of the time I ran out of food but was saved by a do-it-yourself carwash in the middle of nowhere.
A discussion of the astronomical observation of Galileo Galilei and the escalating conflict with the Aristotelian Scholastics that dominated the Italian universities in the late 16th and early 17th centuries. Specifically, we discuss the 1604 nova and Galileo's telescopic observations of 1609 including those of the Moon, Jupiter and the phases of Venus.
NAAP Ptolemaic Phases of Venus Simulation
NAAP Copernican Phases of Venus Simulation
In this episode we look at the work of Johannes Kepler and his three Laws of Planetary Motion. We discuss the principles that motivated his work and his idea that forces were responsible for the motion of the planets around the Sun.
In this final episode devoted to the life of the Danish astronomer, Tycho Brahe, we look at his conflict with Nicolaus Reimers Bar (aka Ursus) as well as a number of other factors that led him to depart the island of Hven and eventually land in Prague where he would spend the last two years of his life.
This week we look at the construction of Uraniborg on the island of Hven and the astronomical work done on it. We also discuss the ideas that informed the facility's founding and the social structure that supported its construction and operation. Tycho's observatory and laboratory was the premier scientific research institution of its time and it marked a transition in how science was done throughout Europe.
This week we look at the scientific work of Tycho Brahe and his Tychonic Model of the solar system. Included in the discussion are his researches and observations on the island of Hven as well as his work in the court of Holy Roman Emperor Rudolph II.
This week we evaluate the Copernicus heliocentric model of the solar system and compare it to Ptolemy's geocentric model. We then look at the model's reception by Erasmus Reinhold, Gemma Frisius, Michael Maestlin and Tycho Brahe. We conclude with Brahe's observations of the supernova of 1572 and the Great Comet of 1577.
To see a simulation showing the equivalence of the various models, click on this link. The yellow dot is the Sun, the blue dot is the Earth and the red dot is Mars.
Link to NAAP Copernican Orbit Simulator
Link to NAAP Ptolemaic Model Simulator
A continuation of the the biographies of Nicolas Copernicus and Georg Joachim Rheticus from the time of the two men's meeting through the end of Rheticus' life and the publication of his trigonometric tables. Rheticus' work on the Narratio and the publication will be discussed as will the tragic outcomes of his career. The timely encounter with Valentin Otto is also covered.
The first part of a biographical examination of the two men who started the Scientific Revolution; Nicolas Copernicus and Georg Joachim Rheticus.
In this episode we take a look at the scientific work of Nicolas Copernicus including the Commentariolus and On the Revolutions of the Heavenly Spheres. We look at the foundational principles of Copernicus' Heliocentric System and how it explains the motions of the planets.
Link to Interactive Planetary Simulation from the Nebraska Astronomy Applet Project
A more in-depth look at the lives of Georg Peuerbach, Johannes de Regio Monte (aka, Johanes Muller, aka Regiomontanus) and Cardinal Basilios Bessarion with a specific focus on the years between 1454 and 1476. The development of the Epitome of the Almagest is discussed as is the role of astrology in late medieval and early modern culture, specifically in relation to the practice of medicine.
In this episode, we discuss the transition of European astronomy from the 13th century to the end of the 15th century. We spend some time taking a look at the effects of The Great Mortality on the institutions of Europe and consider the factors of the rediscovery of atomism, the development of the printing press, the Fall of Constantinople and the rise of the new universities of central and eastern Europe in creating the conditions that would allow for new ideas to develop and spread. We then conclude by looking at the work of Georg Peuerbach and Johannes Muller (Regiomontanus) that brings a full and complete understanding of the Hellenistic model Ptolemy.
In this episode we look at subdividing the day with the development of time keeping devices from the gnomon and sundials to atomic clocks.
We look at the development of the modern western calendar from prehistory through the time of the Roman Kings to the reforms of Julius Caesar (the Julian Calendar) and Pope Gregory XIII (the Gregorian Calendar). Modern attempts at calendar reform are also discussed including the World Calendar and the International Fixed Calendar.
We look at the rediscovery of astronomical texts by western Europe from the time of the Plague of Justinian to the Great Mortality. The work of Martianus Capella, Isidore of Seville, Gerard of Cremona, Averroes and Johannes of Sacrobosco is examined and placed in a wider historical context.
A brief scientific biography of the Islamic physicist, Ibn al-Haytham (Alhazen). We look at his work in optics, mathematics, astronomy and the development of a method of scientific inquiry.
In this episode we look at the astronomical work done during the Golden Age of Islamic Science. This includes the work sponsored by the Abbasid caliph al-Ma'mun, the work of al-Balkhi, al-Battani, al-Biruni and ibn al-Haytham. We conclude with material covering the Andalusian Revolt and the Maragha Revolution.
In this episode we look at the role of astronomy in the culture of the Inca Empire and Kogi Tribe. We examine the Cusco, Coricancha and the ceques and huacas that embody Inca religious practice along with the city of Machu Picchu. Finally, we look at the woven universe of the Kogi tribe of northern Colombia.
A look at the work of Ptolemy's Mathematical Treatise, otherwise known as the Almagest. Hipparchus, precession, the Library of Alexandria and the broader Greco-Roman world are also discussed.
Link to NAAP Ptolemaic Orbit Simulator
We look at the failure of the Eudoxian model of homocentric spheres and the models of Aristarchus of Samos, Apollonius of Perga and Hipparchus to proposed to replace it. We also discuss the ideas of scientific realism and instrumentalism with respect to Hellenistic astronomy.
Link to the University of Nebraska's Geocentric planetary orbit simulator (flash required)
A look at the evidence gathered by the Greek, Hellenistic and Arabic natural philosophers that determined the size and shape of the Earth. Aristotle's lines of evidence are discussed as are the measurements of Eratosthenes, Posidonius and al-Biruni. We also take a look at the myth that it was Columbus who first thought the Earth was round and how it arose.
A look at Greek astronomy from the time of Hesiod and Homer to the spherical model of Aristotle. The writings of Thales, Empedocles, the Pythagoreans and Plato are considered before moving to the sphere's of Eudoxus and Callipus and the synthesis of physics and astronomy by the tutor of Alexander the Great.
Link to Eudoxus' Spheres Animation
A discussion of some aspects of Mesoamerican astronomy including the Mayan calendar with its Calendar Round and Long Count Calendar and the cities of Chichen Itza, Palenque, Teotihuacan and Tenochtitlan.
The Exploratorium's Page on the Caracol at Chichen Itza (Highly Recommended)
In this episode we look at the practice of Babylonian astronomy and the tools that made it possible: cuneiform writing and arithmetical mathematics. We discuss the circular star calendars of the MUL.Apin as well as the Enuma Elish.
Some unscripted thoughts about the detection of gravitational waves via direct observation by LIGO. We briefly discuss some aspects of Einstein's Theory of Relativity, how interferometers work and what the significance of the detection is. We also look at how experimental science is done and communicated.
This week we look at the narratives, sites and artifacts of the native North Americans in their practice of religion and astronomy. We look at the traditions Chumash tribe of California, the kivas and spirals of the peoples of the Four Corners region including the Hopi, Navaho, Zuni and Anasazi, the Medicine Wheels of the central plains and the mounds and woodhenges of the Cahokia site of Mississippian peoples of Illinois.
A discussion of the motions of the planets in the night sky and some of the cultural associations that go with them. Observations such as retrograde motion, maximum elongation of Mercury and Venus, astronomical conjunction and opposition are discussed.
Link to Animation of Mars' Retrograde Motion (NASA)
In this episode we discuss the astronomy of the early dynastic period of China including the Xia, Shang and Zhou dynasties. Specific attention is paid the the idea of the Mandate of Heaven and its relation to circumpolar astronomy.
An examination of the motion of the Sun through the sky. We discuss the use of the gnomon through history to make measurements and the Sun's path through the Zodiac on the ecliptic with special attention paid to the equinoxes and solstices. We conclude with an discussion of the yearly calendar in many cultures.
This episode focuses on the practice of ancient Egyptian astronomy and its relationship to the culture's religion and agriculture. Particular attention is paid to the motions of Sirius, the Great Pyramid at Giza, the "Stretching the Cord" ceremony and the association of the pharaohs with the Sun and heavens.
In this episode we consider observations of the Moon and the role it has in keeping time and representing resurrection in the heavens. Defined are both sidereal months and synodic months and well as lunar calendar years.
This episode is a guided tour of the night sky looking in each of the cardinal directions. East, or orient, for rising; West, or occident, for setting; north for the circumpolar stars and south for the Zodiac.
In the introductory episode of our new season, we lay out the course for our next journey into the realm of cosmology. We will begin with the by considering our modern disassociation with the sky and unfurl our sails to reconnect in the ways the most ancient astronomers did. Our mission is to seek answers to the question, "What is our place in the cosmos?"
Grab your "go bag" and let's get ready to sail!
Music provided by Blue Dot Sessions.
![Link to Interactive Planetary Simulation from the Nebraska Astronomy Applet Project](<a href="http://astro.unl.edu/classaction/animations/renaissance/configurationssimulator.html"><img src="http://astro.unl.edu/classaction/animations/renaissance/configurationssimulator.jpg" alt="Planetary Configurations Simulator (NAAP)" title="Planetary Configurations Simulator (NAAP)" style="border-style: none"/></a>){kind=link}