Cosmos: A Personal Voyage

| March 14, 2012 | 0 Comments

Cosmos: A Personal Voyage is a thirteen-part television series written by Carl Sagan, Ann Druyan and Steve Soter, with Sagan as presenter. It covered a wide range of scientific themes, including the origin of life and our place in the universe.

Ever since 1978 when Cosmos was produced it became famous for groundbreaking special effects and memorable soundtracks (including music by Vangelis). However, the real show stealer was Carl Sagan, who is one of only a few scientists who were truly popular outside the world of science. He was a truly amazing scholar who had an extraordinary passion for science and a talent to pass it to the wide audience.

The show had 13 episodes covering a variety of subjects including planets, stars, universe formation, science in our society, evolution and others.


Episode Guide


1)“The Shores of the Cosmic Ocean” (September 28, 1980)

Carl Sagan opens the program with a description of the cosmos and a “Spaceship of the Imagination”. The ship journeys through the universes’ hundred billion galaxies, the Andromeda Galaxy, the Milky Way, the Orion Nebula, our Solar System, and finally the planet Earth.


2) “One Voice in the Cosmic Fugue” (October 5, 1980)

Sagan opens the episode with a discussion of evolution through natural selection. Among the topics are also the development of life on the Cosmic Calendar and the Cambrian explosion, the function of DNA in growth, genetic replication, repairs, and mutations.  Also Sagan shares some speculations on alien life (such as life in Jupiter’s clouds).


3) “The Harmony of the Worlds” (October 12, 1980)

In this one Carl Sagan follows the development of astronomical observation. Beginning with constellations and ceremonial calendars and ending with the roots of the science of astronomy. Then the story moves to the debate between Earth and Sun-centred models: Ptolemy and the geocentric worldview, Copernicus’ theory, the data-gathering of Tycho Brahe, and the achievements of Johannes Kepler.


4) “Heaven and Hell” (October 19, 1980)

Sagan discusses comets and asteroids, giving a recent example of the Tunguska event. It moves to a description of the environment of Venus, from the previous fantastic theories of people such as Immanuel Velikovsky to the information gained by the Venera landers and its implications for Earth’s greenhouse effect. Environmental problems, including global warming are discussed as well.


5) “Blues for a Red Planet”  (October 26, 1980)

The episode, devoted to the planet Mars, begins with scientific and fictional speculation about the Red Planet during the late nineteenth and early twentieth centuries (H. G. Wells’ The War of the Worlds, Edgar Rice Burroughs’ science fiction books, and Percival Lowell’s false vision of canals on Mars). It then moves to Robert Goddard’s early experiments in rocket-building, inspired by reading science fiction, and the work by Mars probes, including the Viking, searching for life on Mars. The episode ends with the possibility of the terraforming and colonization of Mars and a Cosmos Update on the relevance of Mars’ environment to Earth’s and the possibility of a manned mission to Mars.


6) “Travellers’ Tales” (November 2, 1980)

The journeys of the Voyager probes is put in the context of the Netherlands in the seventeenth century, with a centuries-long tradition of sailing ship explorers, and its contemporary thinks (such as Constantijn Huygens and his son Christian). Their discoveries are compared to the Voyager probes’ discoveries among the Jovian and Saturn systems. In Cosmos Update, image processing reconstructs Voyager’s worlds and Voyager’s last portrait of the Solar System as it leaves is shown.


7) “The Backbone of Night” (November 9, 1980)

Carl Sagan teaches students in a classroom in his childhood home in Brooklyn, New York, which leads into a history of the different mythologies about stars and the gradual revelation of their true nature. In ancient Greece, some philosophers (Aristarchus of Samos, Thales of Miletus, Anaximander, Theodorus of Samos, Empedocles, Democritus) freely pursue scientific knowledge, while others (Plato, Aristotle, and the Pythagoreans) advocate slavery and epistemic secrecy.


8 ) “Journeys in Space and Time” (November 16, 1980)

Ideas about time and space are explored in the changes that constellations undergo over time, the redshift and blue shift measured in interstellar objects, time dilation in Albert Einstein’s theory of relativity, the designs of both Leonardo da Vinci and spacecraft that could travel near light speed, time travel and its hypothetical effects on human history, the origins of the Solar System, the history of life, and the immensity of space. In Cosmos Update, the idea of faster-than-light travel by wormholes (researched by Kip Thorne and shown in Sagan’s novel Contact) is discussed.


9) “The Lives of the Stars” (November 23, 1980)

The simple act of making an apple pie is extrapolated into the atoms and subatomic particles (electrons, protons, and neutrons) necessary. Many of the ingredients necessary are formed of chemical elements, formed in the life and deaths of stars (such as our own Sun), resulting in massive red giants and supernovae or collapsing into white dwarfs, neutron stars, pulsars, and even black holes. These produce all sorts of phenomena, such as radioactivity, cosmic rays, and even the curving of spacetime by gravity. Cosmos Update mentions the supernova SN 1987A and neutrino astronomy.


10) “The Edge of Forever”   (November 30, 1980)

Beginning with the origins of the universe in the Big Bang, Sagan describes the formation of different types of galaxies and anomalies such as galactic collisions and quasars. The episodes moves further into ideas about the structure of the Universe, such as different dimensions (in the imaginary Flatland and four-dimensional hypercubes), an infinite vs. a finite universe, and the idea of an oscillating Universe (similar to that in Hindu cosmology). The search into other ideas such as dark matter and the multiverse is shown, using tools such as the Very Large Array in New Mexico. Cosmos Update shows new information about the odd, irregular surfaces of galaxies and the Milky Way perhaps being a barred spiral galaxy.


11) “The Persistence of Memory” (December 7, 1980)

The idea of intelligence is explored in the concepts of computers (using bits as their basic units of information), whales (in their songs and their disruptions by human activities), DNA, the human brain (the evolution of the brain stem, frontal lobes, neurons, cerebral hemispheres, and corpus callosum under the Triune Brain Model), and man-made structures for collective intelligence (cities, libraries, books, computers, and satellites). The episode ends with speculation on alien intelligence and the information conveyed on the Voyager Golden Record.


12) “Encyclopaedia Galactica” (December 14, 1980)

Questions are raised about the search for intelligent life beyond the Earth, with UFOs and other close encounters refuted in favor of communications through SETI and radio telescope such as the Arecibo Observatory. The probability of technically advanced civilizations existing elsewhere in the Milky Way is interpreted using the Drake equation and a future hypothetical Encyclopedia Galactica is discussed as a repository of information about other worlds in the galaxy. The Cosmos Update notes that there have been fewer sightings of UFOs and more stories of abductions, while mentioning the META scanning the skies for signals.


13) “Who Speaks for Earth?” (December 21, 1980)

Sagan reflects on the future of humanity and the question of “who speaks for Earth?” when meeting extraterrestrials. He discusses the very different meetings of the Tlingit people and explorer Jean-François de La Pérouse with the destruction of the Aztecs by Spanish conquistadors, the looming threat of nuclear warfare, and the threats shown by destruction of the Library of Alexandria and the murder of Hypatia. The episode ends with a overview of the beginning of the universe, the evolution of life, and the accomplishments of humanity and makes a plea to for mankind to cherish life and continue its journey in the cosmos. The Cosmos Update notes the preliminary reconnaissance of planets with spacecraft, the fall of the Berlin Wall and the end of apartheid in South Africa, and measures towards the reduction of nuclear weapons.


14) “Ted Turner Interviews Dr. Sagan”

Some versions of the series, including the first North American home video release (though not the DVD release), included a specially-made fourteenth episode, which consisted of an hour-long interview between Sagan and Ted Turner, in which the two discussed the series and new discoveries made in the years since its first broadcast.



  1. More information about Carl Sagan and Cosmos
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Category: Physics & Science Documentaries

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