Everybody knows the earth goes around the sun. The apparent shift in position of the nearer stars as our position changes (parallax) proves it. Also, under any other assumption the orbits of the planets make no sense.

When and why did it become reasonable to accept this Copernican world view? What were the objections to it and how valid were they, given the knowledge available at the time?

Prior to 1543 the main objection to the Copernican view was that it didn’t exist. What earlier claims of the earth moving had been made, and how seriously should they have been taken?

In 1835 the Catholic Church published the first Index Librorum Prohibitorum which did not ban the work of Copernicus. In 1837 Bessel measured the parallax of 61 Cygni. Was there any good reason to wait this long before accepting that the earth moves?

Tycho Brahe’s system had the moon and the sun revolving around the earth while the planets revolved around the sun. Is this (ignoring the stars) after a mere co-ordinate transformation identical to the Copernican view? Does the entire material universe bob two feet up and down every second or so while spinning in its entirety at many hundreds of revolutions per minute around my daughter’s perfectly stationary yo-yo?

The most obvious objection to Copernicus is common sense. You will find it in this morning’s San Francisco Chronicle, which contains predictions of what time the sun and moon will rise and set, not what time the earth rotates us into and out of their view.

Closely related to the common sense arguments are the arguments from the science of mechanics as it was known before the work of Galileo and Newton. Throw a rock straight up. Does it get left behind as the earth spins us along at thousands of miles per hour?

The scriptural reasons for denying that the earth moves were considered persuasive. Can we, or could they, have found these reasons valid without taking the strict fundamentalist view which leads to the conclusion that pi is exactly equal to three?

The Cassinis were the last prominent astronomers to hold that the earth stood still. Was it part of the French rejection of Newtonian dynamics at the time? Was absence of parallax his reason?

Parallax is a big sticking point. Why don’t the stars seem to shift position if the earth goes around the sun? Doesn’t Copernicus’s claim that they’re really really far away (now known to be true) sound really really lame?

The most persuasive argument against Copernicus - probably the reason Galileo recanted - was put forth by the Holy Fathers of the Italian Inquisition on February 16, 1600. On that day Giordano Bruno, continuing to claim that the earth moves around the sun, was burned at the stake.

ca 300BC Aristarchus proposes heliocentric theory

ca 130 Ptolemaic system developed

1543 Copernicus publishes and perishes
1578 Brahe develops the Tychonian system

1600 Burn, Bruno, Burn
1610 Kepler’s results published
1616 Copernicus to the index
1618 Kepler supports Copernicus, indexed
1631 Galileo’s Dialogue published
1633 Galileo recants
1680 Cassinian oval proposed for sun’s motion
1687 Newton publishes universal gravitation

1781 Herschel looks for parallax, finds Uranus

1835 Copernicus removed from index
1838 Bessel publishes parallax of 61 Cygni

"The Holy Bible", King James Version, 1991, Ballantine

Asimov, Isaac, "Asimov’s Guide to the Bible", 1981, Random House

Crowe, Michael J. "Theories of the World from Antiquity to the Copernican
Revolution", 1990, Dover

Durant, Will and Ariel, "The Age of Reason Begins", 1961, Simon and Schuster

Johnson, Paul, "A History of Christianity", 1977, Athenium

Galilei, Galileo, "Dialogue on the Great World Systems" revised & annotated
by Giorgio de Santillana, 1953, University of Chicago Press

Kuhn, Thomas S, "The Copernican Revolution", 1957 Harvard University Press

Kuhn, Thomas S., "The Structure of Scientific Revolutions", second edition,
1970, University of Chicago Press

Ley, Willy, "Watchers of the Skies", 1966, Viking

Lodge, Sir Oliver, "Pioneers of Science", 1960, Dover

Moody, Ernest A., "Galileo and his Precursors", in "Galileo Reappraised",
Carlo Golino, ed., 1966, University of California Press

Pannekoek, Anton, "A History of Astronomy", 1989, Dover

White, Andrew Dickenson, "A History of the Warfare of Science with Theology
in Christendom", abridged Bruce Mazlish, 1965, The Free Press

Chair: Nancy Cox

We’ve all been paying attention to the famous Leonids, and of course the Perseid meteors, but how long has humanity noticed meteor showers, and when and how did we figure out what they are? Also, let’s consider some of the major meteor showers through the year.

Meteors noticed for millennia – Babylonians 4000 BC

2000 BC – first systematic records – Korea & China

Lyrids 687 BC – "stars fell like a shower"

Aristotle: "hot exudates of the Earth"

Perseids active AD 36

Eta Aquarids 466 – "Countless small meteors flew west"

Orionids 585 – "Hundreds of meteors scattered in all directions"

Leonids 1002 – "scores of small stars fell"

These records are useful to trace changes in patterns of activity. For example, the Taurids used to be like the Perseids but now are weak. The Quadrantids, now one of the 3 most active, were missing in the Middle Ages. Roman times, Anglo-Saxon Chronicles, European fireball records.

Before that, little understanding.

Great fireball of 1783 investigated by Charles Blagden.

What meteors really are – investigated by Germans Heinrich Brandes (1777-1834) and Johann Benzenberg (1777-1846), who laid a foundation. They used parallax for meteor altitudes, estimating them to be 20 miles up.

November 11, 1799: Spectacular Leonid meteor storm observed by chance by Alexander von Humboldt while exploring South America. He noticed the storms appear on a regular basis, around every 30 years.

November 12, 1833: Immense Leonid storm – 200,000 meteors over 6 or 7 hours. Famous "Day of Judgement" picture. Olmstead again noticed the radiant effect.

The "August meteors" (Perseids) were well known by the early 1800s. (Brandes)

1839: First extensive catalog of meteor showers, by Adolphe Quetelet.

by 1857: diurnal variation in meteor rates noticed

1861: American Daniel Kirkwood first proposed the comet-meteor connection

Studies by 2 Italians: Giovanni Schiaparelli observed meteor storms and showers. He corresponded with Angelo Secchi, who published for him in 1866. Secchi observed Biela with its split mucleus in 1846, and calculated that meteors shine about 45-150 miles above Earth’s surface. From calculations of Perseids, Schiaparelli concluded those meteors are produced by the Great Comet of 1862 (P/Swift-Tuttle). Secchi observed meteor spectra. In 1871 Schiaparelli published his "Outline of an Astronomical Theory of Shooting Stars".

Leonids of 1866, and other comet/shower associations, predicted by H. Newton of Yale based on mathematical studies by John Couch Adams. Intensely observed.

Alexander S. Herschel (1836-1907), the least-known astronomical Herschel, designed a binocular spectroscope and observed Leonid spectra in 1866.

Review of other meteor/comet connections

Short period: 6 years. Did not return in 1865-6 and 1872. November 27, 1872: a fine meteor storm radiating near gamma Andromedae. Secchi observed their spectra. In 1885: 75,000 Andromedids/hour!

1890: British Astronomical Association founded. BAA Meteor Section coordinated efforts.

Alexander Herschel – Perseid spectra, accurate meteor paths, and with R. Greg published Catalogue of Meteor Shower Radiants.

William Denning – standard technique to plot meteor paths on gnomonic charts (still used). 9 charts also by T. Bachhouse, based on 10,000 stars. 1899: detailed catalog of 278 radiants. Lots of BAA information on how meteor showers behave.

1911: American Meteor Society established. Charles P. Olivier (1884-1975) wrote classic text on meteors based on amateur observations. Most professionals spent little time on meteors, preferring farther-out topics.

Cuno Hoffmeister 1930s Radiant Catalog: Meteorströme. He and Ernst J. Öpik believed their origin lay outside the solar system, which wasn’t ruled out till the 1950s.

1930s: Fred L. Whipple – meteor photography and patrols. The Harvard Meteor Project 1936-42. Peter Millman, Canadian professional astronomer, pioneered connecting meteor spectroscopy to the chemistry of meteoroids. He also photographed meteors.

Giacobinid meteor storm: photography of October 9-10, 1946, and 1957-58 events. International Geophysical Year.

1946: Jodrell Bank confirmed radar echoes from after-midnight Giacobinids. Detected daytime meteor showers. Bernard Lovell’s book "The Story of Jodrell Bank".

J. Prentice, director of BAA meteor section, handled many radio observations of several showers. Worldwide observations.

The "Super Schmidts" designed by Baker in the 1950s. 4 Super Schmidts operated by Harvard Observatory. With the dawn of the space age, they concluded there were not enough meteors to damage spacecraft including satellites.

1960: spectrum of a Lyrid meteor reveals 70 lines

Predicted from the perihelion passage of Comet P/Temple-Tuttle, after very little activity in 1899 and 1933. Even more spectacular than 1799, 1833 and 1966!! Very short peak. Seen on US West Coast ~60,000 meteors/hour!

Networks set up in Canada; US Midwest (Prairie network), Czechoslovakia. Recovered Lost City, Innisfree, and Pribram meteorites after tracking fireballs. Though very useful, none of these patrol networks survived the 1980s.

1980s: International Meteor Organization formed by Belgians.

1985-6: Return of Comet P/Halley, associated with eta Aquarid and Orionid showers.

Amateur observations continue to be very important worldwide, including photography and CCDs. They contributed a lot to the 1999 Leonids observations, and other showers.

Neil Bone, "Meteors", Sky & Telescope Observer’s Guides, 1993, Sky Publishing. Includes a chapter on the history of meteor studies.

Mark Littman, "The Heavens on Fire: The Great Leonid Meteor Storms", 1998, Cambridge University Press. Includes chapters on the history and mythology of meteors, and the figures whose discoveries advanced the field.

J. F. Burke, "Cosmic Debris: Meteorites in History", 1986, University of California Press.

J. Kelly Beatty and Andrew Chaikin, eds., "The New Solar System", 4th ed, 1999, Sky Publishing & Cambridge University Press.

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