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.
Astronomy
04/17/2016
04/10/2016
Episode 3.9: Islamic Astronomy
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.
04/03/2016
Episode 3.8.1: Supplemental-South American Astronomy
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.
03/27/2016
Episode 3.8: The Great Syntaxis
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
Claudius Ptolomaeus
Full Ptolemaic Cosmos (Simplified Model)
Ptolemaic Model w/Equant and Eccentric for a Single Minor Planet
Animation of Minor Planet Retrograde Motion
03/20/2016
Episode 3.7: Hellenistic Astronomy from Aristarchus to Hipparchus
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)
Hipparchus
Conic Sections
Deferent-Epicycle Model of Planetary Motion
Eccentric Circle Model of the Sun's Motion
Equivalence of Deferent-Epicycle and Eccentric Models to produce motion.
03/14/2016
Episode 3.6.1: Supplemental-Rounding the Earth
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.
Eratosthenes
Diagram of Eratosthenes' Method of Measurement
Diagram of Posidonius' Method of Measurement of the angle of Canopus
al-Biruni's Method of Measuring the Height of a Mountain
Diagram of al-Biruni's Method of Determining the Radius of the Earth
03/06/2016
Episode 3.6: The Geometer's Universe
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
Eudoxus of Cnidus
Graphic of a Eudoxian Set of Spheres
A late medieval representation of Aristotle's Spheres
02/28/2016
Episode 3.5.1: Supplemental-Mesoamerican Astronomy
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)
The Caracol at Chichen Itza
Upper Tower Window Alignments-Caracol
Foundation Base Astronomical Alignments-Caracol
El Castillo-Chichen Itza
Temple of the Inscriptions-Palenque
Sarcophagus Lid of Pacal at Palenque
02/21/2016
Episode 3.5: The Necessary Tools
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.
Circular Star Calendar
02/14/2016
Episode 3.4.2: Supplemental-Unscripted Thoughts on LIGO
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.
LIGO Sites in Washington and Louisanna
LIGO Interferometer Diagram
Gravitational Waves Produced by Orbiting Balck Holes
Processed Version of LIGO Detection Signal
Tweet from Lawrence Krauss
02/07/2016
Episode 3.4.1: Supplemental-Native North American Astronomy
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.
Bighorn Medicine Wheel (credit: Wikipedia Commons)
Bighorn Medicine Wheel Alignment Diagram
01/31/2016
Episode 3.4: Wanderers
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)
Image Displaying Mars' Retrograde Motion
01/24/2016
Episode 3.3.1: Supplemental-Ancient Chinese Astronomy
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.
Image of the top of a clothes hamper found in a Chinese tomb displaying the 28 lunar lodges, the character for the North Pole and the Cerulean Dragon
01/17/2016
Episode 3.3: Sun Cycles
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.
Gnomon Diagram
Ming Dynasty Gnomon with Shadow Length Measuring Scale
Sextant
The Celestial Sphere
The Path of the Sun on the Ecliptic through the Zodiacal Constellations
01/11/2016
Episode 3.2.1: Supplemental-Ancient Egyptian Astronomy
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.
Get, Nut and Shu
Horus, Osiris and Isis
The Great Pyramid at Giza
01/03/2016
Episode 3.2: Moon Motions
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.
12/29/2015
Episode 3.1: Looking Up
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.
Circumpolar Star Tracks
12/25/2015
Episode 3.0: Beyond the Horizon
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.
Preparing to Set Sail
