Results 1 to 23 of 23

Thread: Book recommendations on the history of astronomy

  1. #1
    Join Date
    Apr 2020
    Location
    Garland, Nebraska
    Posts
    22

    Book recommendations on the history of astronomy

    Found myself wondering how long a society would have to observe the night sky before catching on to the whole precession of the equinoxes thing. Can anyone recommend good reads on the history of astronomy? "The Story of Astronomy" by Couper and Henbest looks like it might be pretty good. "Episodes From the Early History of Astronomy" by Aaboe also looks good. Thanks.

  2. #2
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    22,082
    Quote Originally Posted by jascryan View Post
    Found myself wondering how long a society would have to observe the night sky before catching on to the whole precession of the equinoxes thing. Can anyone recommend good reads on the history of astronomy? "The Story of Astronomy" by Couper and Henbest looks like it might be pretty good. "Episodes From the Early History of Astronomy" by Aaboe also looks good. Thanks.
    There are a lot of good books on broad topic of pretelescope astronomy. Owen Gingrich had some good things to say on the detection of the precession.
    Forming opinions as we speak

  3. #3
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    22,082
    Quote Originally Posted by jascryan View Post
    Found myself wondering how long a society would have to observe the night sky before catching on to the whole precession of the equinoxes thing. ...
    BTW, have you seen things written about "trepidation"? Because dates were known for the chaldean values for the location of the Vernal Equinox, and the date for Hipparchus and Ptolemy, but Ptolemy got his numbers from Hipparchus 150 years earlier, it seemed as though the progression was at a largely inconstant rate.
    Forming opinions as we speak

  4. #4
    Join Date
    Apr 2020
    Location
    Garland, Nebraska
    Posts
    22
    I did read the wiki entry on the discovery being credited to Hipparchus before I started looking for a good book. [URL="https://en.wikipedia.org/wiki/Axial_precession"] Trepidation theories were mentioned for a couple different cultures. A short review of Gingerich's work indicates I might prefer a little more science in my science than he. Pretty sure I didn't do that hyperlink right. Thanks for pointing me in a direction.

  5. #5
    Join Date
    Aug 2003
    Location
    The Wild West
    Posts
    9,491
    Quote Originally Posted by jascryan View Post
    Found myself wondering how long a society would have to observe the night sky before catching on to the whole precession of the equinoxes thing.
    As you likely know, Hipparchus discovered this around 130 BC (which is pretty amazing!). I've read a lot of "popular" astronomy/astrophysics books, and most include a brief intro history bringing the discussion to "what's been found out more recently," which I was typically more interested in. I don't recall any addressing this particular phenomenon. Steven Weinberg's 2015 book To Explain the World: The Discovery of Modern Science was quite good nevertheless.
    Everyone is entitled to his own opinion, but not his own facts.

  6. #6
    Join Date
    Apr 2020
    Location
    Garland, Nebraska
    Posts
    22
    Thanks Cougar. That does look like a good read. Weinberg is certainly prolific.

  7. #7
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    22,082
    Quote Originally Posted by jascryan View Post
    ... A short review of Gingerich's work indicates I might prefer a little more science in my science than he. Pretty sure I didn't do that hyperlink right. Thanks for pointing me in a direction.
    You might like the three volume set from 1975 by Otto Neugebauer: "A History of Ancient Mathematical Astronomy" from Springer-Verlag. Neugebauer has a number of other books also covering Babylonian and Classical Greek astronomy. G.J. Toomer's translation and explanation of Ptolemy's "Almagest" might also be of some use on this topic.
    Forming opinions as we speak

  8. #8
    Join Date
    Apr 2020
    Location
    Garland, Nebraska
    Posts
    22
    Holy cow antoniseb! I don't even know where to start. Firstly, Thanks! I just lost an hour of my life down the Otto Neugebauer rabbit hole, and it was fun. Secondly, holy cow, $854 for a used version at Amazon! Good thing there's free shipping. Tertiarily, the book is CLEARLY the tome on the history of mathematical astronomy. 13 pages of Table of Contents. 1209 pages long. The guy is funny as well. I love the first two sentences of the Introduction, "Many things are omitted here. The reader who wants to hear about Archimedes taking a bath or about the silver nose of Tycho Brahe can find innumerable books which dwell on these important biographical matters." Nextly, when looking for a book on ancient astronomy, check the bibliography to see if Neugebauer is cited. Or skip that that and just read Neugebauer. The trouble with that is I haven't used anything more complicated than geometry for a number of years now. Wait, I did measure the height of a tree of few years ago. I guess that's Trig. And finally, thanks again!

  9. #9
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    22,082
    Quote Originally Posted by jascryan View Post
    ... $854 for a used version at Amazon! ...
    Just as a heads up, all of the diagrams referenced in volumes 1 & 2 are in volume 3. Don't skimp and skip buying volume 3.
    Forming opinions as we speak

  10. #10
    Join Date
    Sep 2004
    Posts
    4,913
    Gerald Hawkins's Stonehenge Decoded did wonders for my imagination and enlightenment as a child. Strongly recommend it.
    Do good work. —Virgil Ivan "Gus" Grissom

  11. #11
    Join Date
    Dec 2006
    Location
    Canberra
    Posts
    2,193
    Quote Originally Posted by antoniseb View Post
    BTW, have you seen things written about "trepidation"? Because dates were known for the chaldean values for the location of the Vernal Equinox, and the date for Hipparchus and Ptolemy, but Ptolemy got his numbers from Hipparchus 150 years earlier, it seemed as though the progression was at a largely inconstant rate.
    An excellent book, Early Astronomy: From Babylon to Copernicus, by William O'Neil, argues to the contrary that Ptolemy did not get his numbers from Hipparchus, but actually made a major mistake. Hipparchus correctly calculated the rate of precession as about one degree per 72 years, but Ptolemy somehow gave the wrong figure of one degree per century, leading later astronomers to wrongly wonder why the speed was changing, as developed in the false "trepidation" hypothesis.

    It seems likely that Hipparchus used the total lunar eclipse of 14 September 134 BC to measure the exact stellar position of the equinox, and hence see how far it had moved over the two centuries since Babylonian calculations.

  12. #12
    Join Date
    Oct 2001
    Location
    The Space Coast
    Posts
    4,639
    Quote Originally Posted by Robert Tulip View Post
    It seems likely that Hipparchus used the total lunar eclipse of 14 September 134 BC to measure the exact stellar position of the equinox, and hence see how far it had moved over the two centuries since Babylonian calculations.
    What made him suspect it moved in the first place?

    CJSF
    "Off went his rocket at the speed of light
    Flying so fast there was no day or night
    Messing around with the fabric of time
    He knows who's guilty 'fore there's even a crime

    Davy, Davy Crockett
    The buckskin astronaut
    Davy, Davy Crockett
    There's more than we were taught"

    -They Might Be Giants, "The Ballad Of Davy Crockett (In Outer Space)"


    lonelybirder.org

  13. #13
    Join Date
    Dec 2006
    Location
    Canberra
    Posts
    2,193
    Quote Originally Posted by CJSF View Post
    What made him suspect it moved in the first place?

    CJSF
    It is likely that there was extensive ancient knowledge of precession. Babylonian astronomers could predict eclipses for a thousand years before Christ, which gives a handy way to measure the position of the equinox when the eclipse happens close to the equinox dates.

    As an example, Philo of Alexandria writing at the time of Christ states that Passover always occurs with the Sun in the constellation of Aries. That means the Passover full moon is seen in Libra. However, with the blood moon in 4BC, although barely eclipsed in the middle east, the calculation would have determined its occurrence, and the moon was seen in Virgo due to precession, when tradition said this Passover full moon should be in Libra. This may be the source of the "event in the heavens of great significance, the moon seen at the foot of the woman", mentioned in Revelation 12.1 in the Bible.

    Such use of star positions for seasonal dating appears in Works and Days by Hesiod, with the rising and setting of the Pleiades used to define seasons to sow and reap, but over time these calculations cease to work. Similarly temples aligned to the position of stars rising on the horizon had to be demolished and rebuilt every few centuries, as extensively documented by Sir Norman Lockyer.

    So it is likely that Hipparchus was looking forward to observing the 134 BC total lunar eclipse because he had earlier star maps from Babylon and Alexandria that enabled comparison of the equinox position. (link)

  14. #14
    Join Date
    Apr 2020
    Location
    Garland, Nebraska
    Posts
    22
    Roger E Moore: I think I remember seeing the movie some time back. We might be similarly aged. I'm 46 or 7, can't remember.

    Robert Tulip: Bummed I couldn't find a table of contents. Or the peek inside kind of stuff Amazon and Google do. Do you recall the Indus valley civilization being mentioned? The Hawaiians? The Mayans? It does seem like there is some lively disagreement over whether Ptolemy knew his stuff or not. All the academics seem to respect Hipparchus' work.

    CJSF: Your question totally gets to the nature of what I was wondering. Say you're a Polynesian around 1200 years ago? You learn the Navigator's stories from your dad/grandpa. You pass them on to your kids. One of your progeny eventually sees that the vernal equinoxical(is that a word?) doesn't come up in the same place that he was taught it should. What's the thought process behind trying to justify the passed down knowledge with the current observationo?

  15. #15
    Join Date
    Mar 2007
    Location
    Falls Church, VA (near Washington, DC)
    Posts
    9,016
    Quote Originally Posted by CJSF View Post
    What made him suspect it moved in the first place?

    CJSF
    If Hipparchus knew about the changes mentioned in posts 13 and 14, it could easily have been a motive for closely checking his observation against similarly precise ones from his Greek predecessors. The Egyptians certainly saw some changes in star azimuth at rising and setting points, but they may or may not have fully understood the pattern of motion over the whole sky. Hipparchus was able to recognize a slow rotation of the entire celestial sphere around the ecliptic pole, with the stars remaining apparently fixed on that sphere.

  16. #16
    Join Date
    Dec 2006
    Location
    Canberra
    Posts
    2,193
    Quote Originally Posted by jascryan View Post
    Bummed I couldn't find a table of contents. Or the peek inside kind of stuff Amazon and Google do. Do you recall the Indus valley civilization being mentioned? The Hawaiians? The Mayans? It does seem like there is some lively disagreement over whether Ptolemy knew his stuff or not. All the academics seem to respect Hipparchus' work.
    Table of contents is attached.
    Attached Images Attached Images

  17. #17
    Join Date
    Jul 2005
    Location
    Massachusetts, USA
    Posts
    22,082
    I had a few (2 or 3) books by Robert R. Newton more or less on this topic... they were a bit sensationally titled. One was "The Crime of Claudius Ptolemy". Basically it was looking at how Ptolemy plagiarized Hipparchus, and trepidation was his main starting point for his evidence. I think I sold those books at a yard sale years ago, but they should still be available on the used book market.
    Forming opinions as we speak

  18. #18
    Join Date
    Apr 2020
    Location
    Garland, Nebraska
    Posts
    22
    Quote Originally Posted by Robert Tulip View Post
    Table of contents is attached.
    Thank you!

  19. #19
    Join Date
    Mar 2007
    Location
    Falls Church, VA (near Washington, DC)
    Posts
    9,016
    Quote Originally Posted by jascryan View Post
    Found myself wondering how long a society would have to observe the night sky before catching on to the whole precession of the equinoxes thing. Can anyone recommend good reads on the history of astronomy? "The Story of Astronomy" by Couper and Henbest looks like it might be pretty good. "Episodes From the Early History of Astronomy" by Aaboe also looks good. Thanks.
    Check out this one:
    http://members.westnet.com.au/gary-d...on/page9f.html

    From this and other sources I would say "It takes as long as it takes," depending on how good an understanding the society has of the celestial position geometry that is involved. When the Greeks had achieved that understanding, around 400 to 300 BCE, it took only a couple of centuries to pick up on the whole picture of precession. The Babylonians, without that sort of understanding, apparently did not recognize it, despite their great success at the same time in predicting lunar eclipses and other periodic phenomena. Mr. Thompson quoted Owen Gingerich as saying the Babylonians could get good predictions by recognizing the pattern over a few centuries without necessarily making precise position determinations.

  20. #20
    Join Date
    Mar 2007
    Location
    Falls Church, VA (near Washington, DC)
    Posts
    9,016
    In all fairness to those with whom Mr. Thompson disagrees, let me offer a caveat. Like all of us he is not perfect, and part of Appendix 1 has problems. He asserted that there was practically no precessional movement of Sirius as seen from the latitude of Cairo, because of something about its motion which he did not make clear. I analyzed it as follows, and I am confident in my opinion that he is mistaken on this detail.

    Copied from my post of July 26, 2011:

    I was too rusty on spherical trig to do analytic calculations, so I chose to plot the positions on a globe, using a plotting tool that came with the globe. I plotted the ecliptic using the intersection of the prime meridian and the equator as the March equinox point, and used the intersection of the Antarctic circle and the 90 degrees W meridian as the south ecliptic pole. Using that point as the center I drew a circle of position with ecliptic latitude 40 degrees south for Sirius. I marked the star's present position on that circle and then stepped off 30 degree intervals of ecliptic longitude to look back 1/12 of a precession cycle at a time. Then I plotted a great circle through the star's position and inclined 60 degrees to the equator to represent the horizon as seen from Cairo. That circle intercepted the ecliptic at the Sun's position on the heliacal rising date, and it was a simple matter to measure the Sun's ecliptic longitude, and thus the date. I am backdating the Gregorian calendar to the ancient times to keep the equinox around March 21.

    Date________Sun longitude___Heliacal rising date

    AD 2000_______122______________July 25
    147 BC________100_______________July 3
    2294 BC________82______________June 13

    So far I have disregarded the proper motion of Sirius, because over this interval it will not cause major errors at this level of precision. Before looking further back, I applied the proper motion. I got my proper motion information from the Sky Catalogue 2000.0, and it was in good agreement with a chart published in Sky and Telescope in June 1972. I feel confident that those are reliable sources.

    Continuing my plotting to include the proper motion I got the following:

    4441 BC_______61_______May 22
    6588 BC_______44_______May 5
    8735 BC_______22_______April 12
    10882 BC______-4_______March 17
    13029 BC_____-69_______January 14

    The minus signs indicate west of the equinox point. Thing start getting weird when Sirius is approaching the polar regions.

    These are the dates when the Sun and Sirius are on the horizon simultaneously. I would estimate about a week to 10 days later to have a decent chance of seeing Sirius in a clear sky. My dates are reckoned by extrapolating the Gregorian calendar back, to keep the spring equinox about March 21. Clearly the heliacal rising date was getting progressively later relative to the equinoxes and solstices. Some sources state that the date stayed nearly fixed in mid to late July over the millenia, but that could only happen by using the Julian calendar and ignoring the timing of the seasons. Such writing adds confusion to studying this topic. Perhaps the Egyptians really were not paying attention to the exact times of solstice and equinox. In principle it might get out of sync with the flood cycle, but for all we know the timing of the flood could have drifted because of climate change in east-central Africa, where the Nile originates.

  21. #21
    Join Date
    Mar 2007
    Location
    Falls Church, VA (near Washington, DC)
    Posts
    9,016
    Quote Originally Posted by Robert Tulip View Post
    It is likely that there was extensive ancient knowledge of precession. Babylonian astronomers could predict eclipses for a thousand years before Christ, which gives a handy way to measure the position of the equinox when the eclipse happens close to the equinox dates.
    Do the surviving Babylonian writings say that they did any such measurements with any great precision?

    As an example, Philo of Alexandria writing at the time of Christ states that Passover always occurs with the Sun in the constellation of Aries. That means the Passover full moon is seen in Libra. However, with the blood moon in 4BC, although barely eclipsed in the middle east, the calculation would have determined its occurrence, and the moon was seen in Virgo due to precession, when tradition said this Passover full moon should be in Libra. This may be the source of the "event in the heavens of great significance, the moon seen at the foot of the woman", mentioned in Revelation 12.1 in the Bible.
    This particular apparition of the Moon and the subsequent writing about it occurred more than a century after Hipparchus's discovery. I cannot see this as supporting an inference that it was likely that Jewish congregations before Hipparchus were aware of precession. A "may be" about Revelation, with all of its mysteries, is hardly sufficient for astronomical inferences, at least in my opinion.

    Such use of star positions for seasonal dating appears in Works and Days by Hesiod, with the rising and setting of the Pleiades used to define seasons to sow and reap, but over time these calculations cease to work. Similarly temples aligned to the position of stars rising on the horizon had to be demolished and rebuilt every few centuries, as extensively documented by Sir Norman Lockyer.

    So it is likely that Hipparchus was looking forward to observing the 134 BC total lunar eclipse because he had earlier star maps from Babylon and Alexandria that enabled comparison of the equinox position. (link)

  22. #22
    Join Date
    Mar 2007
    Location
    Falls Church, VA (near Washington, DC)
    Posts
    9,016
    I just now used Stellarium to plot the heliacal rising dates for Sirius over more than a complete precession cycle centered on the present date, as seen from Cairo, Egypt. They are at intervals of 2,150 years, about 1/12 of the precession period, or "ages" for short. Gregorian dates before 1582 are estimated from the Sun's ecliptic longitude and could be off a day or two because of orbital eccentricity effects. In my opinion these are trifling uncertainties for the purpose of this exercise. Attached is a PDF of my work.

    Note that the progression of the heliacal rising date is nonlinear, ranging from about two weeks to more than two months per age. This is a consequence of the combination of great circles (ecliptic and horizon) and a small circle (precessional trek of Sirius) with the horizon steeply inclined to the other two. For the classical period of ancient Egypt the rate was about three weeks, not far from the rate at which the Julian and Gregorian calendars diverge. Thus the Julian date did not change much during this era.

    Stellarium plots the proper motion of the bright stars, and Sirius is moving south rapidly. The years 13,080 and 10,880 BCE straddled the date at which Sirius was farthest south in declination. At those times it rose shortly before culmination, not far from due south. One cycle later its proper motion will carry it a few degrees farther south, keeping it invisible from Cairo for about 4,600 years. The two latest years listed are when it culminates on the horizon.

    From this table it should be clear that Sirius precesses with respect to the equinox at all times, and that anyone who says otherwise is misconstruing heaven only knows what. The more I worked on this, the more outraged I got that Mr. Thompson made such a blunder in what looks like an otherwise good presentation.
    Attached Files Attached Files
    Last edited by Hornblower; 2020-May-16 at 09:14 PM. Reason: Add mention of attachment

  23. #23
    Join Date
    Mar 2007
    Location
    Falls Church, VA (near Washington, DC)
    Posts
    9,016

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •