For it behooves those going forward with this theory inquiringly and for the love of truth to use the new and surest methods found, not only for the correction of the old hypotheses but also of their own if they need it; and not to think it disgraceful (for it is a great and divine profession) even if they happen upon a correction for greater accuracy due to others and not only to themselves.
Ptolemy, Almagest, Great Books, Chicago, 1952, p. 135.
This is an investigation of original sources in astronomy and physics and additional material relevant to the history of those fields. The significant lack is an explicit history of either. The order is chronological by event or publication of the original material. Recommendations are always appreciated.
Hipparchus and Ptolemy are the only ancients to have compiled extensive and accurate catalogs of stars. That of Hipparchus, c. 129 bce, does not survive in written form, but might survive as the source for the sculpture known as the Farnese Atlas, now in a museum in Napoli. Schaefer argues that the date and accuracy of the depiction could only be based on the Hipparchus data.
A detailed look at a geometry of the solar system and how to calculate the positions of any of the planets for any date based on it. Not recommended reading for the casual reader. Before reading, review Euclidean geometry and the zodiac as well as read Appendix A.
Surprisingly, Ptolemy spends very little time discussing his choice of a geocentric universe and even notes that a rotating earth is in some ways simpler (see Science Quotes). He basically starts with the Aristotelian astronomy and then “adjusts” it to create a practical mathematics to fit the data. His primary concern was pragmatic, not theoretic.
The large emotional/religious/philosophical investment of the Renaissance is more Aristotelian with Medieval overlay than based on any special assertions made by Ptolemy.
This title, The Almagest, is redundant as Almagest is made up of the Arabic al, meaning “the”, and the Greek megiste, meaning “greatest”. That name being applied by the Arabs to a work known to the Greeks as The Great Astronomer.
Written for his son, it is a simple introduction to the construction and use of the astrolabe, a principal astronomical (and astrological) instrument of the day. Though the Middle English is difficult to wade through, it seems to be quite practical and could serve as a guide to anyone interested—though I might first look for a more recent publication with phraseology more suited to our age.
Like Ptolemy, Copernicus starts with the Aristotelian equation of perfection with circularity and argues for the sphericity of the earth. But he quickly points out that apparent motion can be achieved through motion of either of the bodies involved (an argument recapitulated by Doppler centuries later in a different context). He points out that the standard argument against rotation of the earth, that it would fly apart, applies even more strongly to the heavenly sphere as it must be moving immeasurably faster. He then points out a disagreement in the placement of Mercury and Venus as above or below the Sun, but if they revolve around the Sun, not only does that confusion go away, but it also explains why they are never observed far from the Sun as are the other planets. Placing the Earth on its own circuit around the Sun between that of Venus and Mars provides a natural explanation for the retrograde motion of the planets.
In the introduction Duncan asserts “the Gregorian calendar which was introduced in 1582 was based on Copernicus' figures”. If so, why was De Revolutionibus on The Index of Prohibited Books and why was Galileo excommunicated? By then Tycho Brahe also had demonstrated that the supernova of 1572 and comet of 1577 invalidated the idea of a separation between earthly corruption and heavenly perfection. The answer is that De Revolutionibus didn't appear on The Index until Galileo got into trouble in 1616.
Owen Gingrich in The Great Copernicus Chase recounts searching out every extant copy of first and second editions of De Revolutionibus. He could identify some owners and analyzed marginalia.
This is a curious pamphlet of only twenty-six pages. His “Coniectur” is astrological ('nuf said about that), but is based on his careful astronomical observations during the more than one year existence of this star. He first recapitulates the astronomical facts published earlier (De Stella Nova)—that this apparition was a star because “it shined without a taile or any scattered beams, (for then it had beene a comet)”, or parallax, whereby it might be a planet, or motion with respect to the fixed stars, whereby it could be any other object but a star.
Elsewhere in his writings he promoted what was known in Greek times as the Egyptian world view but is now known as the Tychonic system—that the planets revolve around the sun but that the earth is stationary and the sun revolves around it. In his zeal for observational accuracy (he was the greatest pretelescopic observer) he never got around to using his unprecedented data to do the necessary calculations; he hoped Kepler would do it for him.
To come. Or possibly other selections, depending on further investigation.
To come.
To come.
There's a Nova episode that examines the life of Newton and shows how deeply he was engaged in alchemy—a discipline not yet quite separated from chemistry. His theology was also not quite straight Church of England, leading to some danger from the authorities, yet he thought his legacy would rest on his religious writings—who now knows he even wrote anything on theology?
The title derives from Koestler's contention that not only does science not move in the direct, straight line of advancement so often portrayed in history synopses, but that the perpetrators themselves are often totally unaware of what they are doing and its consequences. After a cursory look at the Greeks, he examines in detail Copernicus, Tycho, Kepler, Galileo, and Newton. Copernicus, for example, described the orbits as ellipses, but insisted on trying to construct them from epicycles and Galileo rejected Kepler's ellipses.
Fallacies vs. truths: Copernicus developed the solar-centric idea sui generis; not only was the idea as old as Aristarchus and Hipparchus and even Pythagorus, but it was actively discussed in the sixteenth century—Copernicus developed the philosophical ideas into a mathematical model. Kepler was a modern scientist; only in so far as he abandoned cycles only after the accuracy of Tycho's data forced him to look at ellipses, but he never abandoned his idea that the five perfect solids governed the structure of the planetary orbits—even though he could never get them to work within the ellipses. Galileo's scientific importance lies in his defense of Copernicus; that's only where his fame lies—his true importance is in the treatise on mechanics at the end of his life that gave Newton the rules he needed to marry to Kepler's laws of planetary motion to produce the concept of universal gravitation. Newton developed the three laws of gravitation; Descartes actually formulated the first law, momentum in a straight line, where both Kepler and Galileo assumed circular motion as the default.
His argument is mostly against a straw man. For one thing, science as we now describe it, didn't even exist at the time of the men in question; it only developed in the mid nineteenth century with such men as Lyle and Darwin, resulting from the ferment in the half-century before Lyle (see Linneaus, Hutton, and Howard). And all scientists are acutely aware of the dead ends and false starts of their activities. Unlike most scientific works, Kepler recounts much of his process of failure before success. Nonetheless, Koestler's book is an interesting history of and insight into the development of cosmology.
An extra lecture which was not included in his textbook, it took the form of a recapitulation of Newton's geometrical derivation of planetary motion with one exception. Feynman confessed that he was unfamiliar with one geometrical technique Newton used because it was something that was no longer studied after the invention of calculus, which Newton lacked at the time of the Principia. Honoring that lack of knowledge, Feynman invented another geometric demonstration.
Though it had long been accepted that the Copernican cosmological system was the correct model of the universe, rather than the Ptolomaic, it was not until 1851 that anyone was able to demonstrate that the earth rotates on its axis, creating the apparent motion of the stars and planets around the earth. In that year Leon Foucault created a working model in his basement and was able to obtain the use of a large hall for a public demonstration. The crucial feature of his pendulum was its torsionless mounting system. Pendula were well known in clocks; but those are constrained to operate in the same plane as the clock itself. Foucault's pendulum was free to swing in its own plane while the earth rotated underneath it.
Now every science museum mounts a large pendulum with a circle of blocks that get knocked over as the pendulum makes an apparent circle, when it is actually maintaining the same plane and the earth is spinning underneath. This can be seen most clearly (in a thought experiment) by mounting a pendulum at the North Pole, where it will describe a complete circle in twenty-four hours. As the latitude decreases, the period of revolution increases. In the Southern Hemisphere the apparent direction is reversed (counter-clockwise) and at the South Pole will again traverse the circle in one day.
I include this book, not because of any great importance of the atomic bomb as science, but because the first third of the book is a particularly clear exposition of the process of science—the give-and-take, the publish one small piece here that lets someone else publish another small piece that lets…. Eventually all these small pieces coalesce into a significant scientific achievement (see Oreskes). This particular story starts with Rutherford in the nineteenth century and includes the Curies, Einstein, Bohr, Heisenberg, and others, culminating in Lisa Meitner's paper in Nature just before the second half of The Great War. The remainder of the book is a history of technology and politics.