[HN Gopher] Galileo's handwritten notes found in ancient astrono...
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       Galileo's handwritten notes found in ancient astronomy text
        
       Author : tzury
       Score  : 211 points
       Date   : 2026-03-05 16:47 UTC (2 days ago)
        
 (HTM) web link (www.science.org)
 (TXT) w3m dump (www.science.org)
        
       | macintux wrote:
       | I have had the experience of serendipitous discovery when
       | researching relatively recent history. To find Galileo's
       | handwriting 400 years later, effectively engaging in both
       | agreement and debate with Ptolemy through the latter's work...
       | even though he specifically was looking for it, it still must
       | have been surreal.
        
         | divbzero wrote:
         | > _even though he specifically was looking for it_
         | 
         | The historian was looking for conceptual connections between
         | Ptolemy and Galileo, but the discovery of Galileo's handwriting
         | in Ptolemy's book seemed to be a surprise.
        
           | macintux wrote:
           | I interpreted the fact that he was reviewing multiple copies
           | of the same text as him searching for Galileo's notes, but I
           | suppose it's possible that the motivation was the possibility
           | of discrepancies between printings.
        
             | SiempreViernes wrote:
             | The Almagest was hand written about 1400 years before
             | Galileo lived, so it's not so much looking at different
             | printings as at different editions that are based on
             | different set of copies of the copies of the copies etc,
             | further many editors would try to "fix" the ancient work,
             | removing material they didn't like and adding their own
             | stuff or material from other works... it can get very
             | messy.
        
             | 2b3a51 wrote:
             | Owen Gingerich was a historian of astronomy who did a
             | census of printed early editions of Copernicus' book _De
             | revolutionibus_. He found a tradition of students copying
             | annotations from teachers readings into their own copies of
             | the book. I recollect that he was able to trace various
             | traditions of commentary each stemming from a well known
             | astronomy teacher.
             | 
             | I suppose that checking early printings of key works
             | looking for annotations is a pretty standard thing to do
             | now.
        
         | Diederich wrote:
         | > I have had the experience of serendipitous discovery when
         | researching relatively recent history.
         | 
         | I would really love to hear about this. (:
        
           | macintux wrote:
           | Nothing all that exciting, just pleasure from finding a photo
           | in a local newspaper of my great-great-grandfather's
           | (approximately, I don't remember the specifics at the moment)
           | car being pulled by horses out of a local river, or
           | researching a family name I found in a cemetery and finding
           | interesting tidbits about their history.
           | 
           | Probably the most impressive effort I stumbled upon was a
           | woman from rural Indiana who collected (and typed up)
           | thousands of pages of local history & genealogy in the
           | mid-20th century. Was interesting reading personal accounts
           | of Morgan's Raid, for example.
        
       | mrose11 wrote:
       | What a wild find. Good for the historian.
        
       | behnamoh wrote:
       | That's not "ancient". That word often means thousand(s) of years
       | ago.
        
         | jswelker wrote:
         | I clicked just to make this same pedantic comment, fellow
         | traveller.
        
         | kgeist wrote:
         | >The pages belonged to The Almagest, in which second century
         | polymath Claudius Ptolemy described his vision of an Earth-
         | centered cosmos.
         | 
         | Where's the article wrong?
        
           | josefx wrote:
           | Galileos notes where found in a 16th century print of The
           | Almagest.
           | 
           | If you copy the pythagorean theorem onto a page and cross it
           | out, would you be "defacing an ancient text"?
        
         | ant6n wrote:
         | pedantry works best when correct.
         | 
         | "Ancient history is a time period from the beginning of writing
         | and recorded human history through late antiquity."
         | 
         | Perhaps you are mixing up "ancient" and "prehistoric".
        
           | brabel wrote:
           | Galileo lived in the 16th century. Late antiquity ends around
           | the end of the Western Roman Empire I think, which was before
           | 500AD!?
        
             | edgyquant wrote:
             | But the text his notes were found in is ancient
        
               | lostlogin wrote:
               | No it isn't, unless you date reprints to first edition
               | publication.
        
       | ffsm8 wrote:
       | Not particularly important, but the title adding "handwritten"
       | implies that they had non-handwritten notes too...
        
         | mock-possum wrote:
         | Dictated? Transcribed?
        
           | dotancohen wrote:
           | He who is valiant and pure of spirit will find the holy grail
           | in the castle of aaaeeerrrrr...
        
         | sjdrc wrote:
         | Or it implies they were handwritten by Galileo himself vs his
         | words written by someone rlse
        
       | ocean2 wrote:
       | Galileo Galilei, and yet people still refer to him by his
       | firstname alone. It's painful to read.
       | 
       | It is, as if we refer to Isaac and Albert when speaking about
       | Gravity and Relativity.
        
         | yapfrog wrote:
         | https://en.wikipedia.org/wiki/Galileo_Galilei#Name
         | 
         | Surnames are optional in Italy at that time. Galileo is how he
         | refers to himself and how people refer to him.
        
         | spockz wrote:
         | There are many Isaacs and Alberts. How many notable Galileo(s,
         | not to use Galilei) do we have?
        
         | 9dev wrote:
         | His name works like "Bostoner from Boston", so it was
         | reasonable for him at the time to refer to himself as just
         | Bostoner.
        
           | srean wrote:
           | I have always been intrigued by the similarity of Italian
           | naming conventions and that of the Arabs and Persians.
           | 
           | Resident of, son of, father of, family of. Leonardo of Pisa
           | of the family of Bonacci being another well known one.
           | 
           | I suppose it is not specific to those cultures and was a more
           | widespread convention.
        
         | pmontra wrote:
         | In Italy it's extremely usual to refer to the greatests of the
         | great people of those ages by their given name: Leonardo,
         | Galileo, Dante, Michelangelo. It's testament to their
         | greatness. There is only one Dante that matters, so there is no
         | need to add Alighieri but if you do nobody notices anything
         | strange. It's only a bit redundant. Using only the surname
         | would be unusual.
        
       | gignico wrote:
       | It's unbelievable how that 16th century book looks like it is
       | written in LaTeX. Or plain TeX, probably, given its age XD
        
         | weinzierl wrote:
         | Not at all surprising. There were some _" unshakable truths"_
         | in typesetting that basically held up from Gutenberg until the
         | Internet came along. Knuth (partly through his friend Zapf) is
         | well aware of them and respected them in TeX.
         | 
         | It's relatively recent that we've found out some of these _"
         | universal"_ rules might not have been so important all along
         | and together with technology as another factor things changed.
        
         | cladopa wrote:
         | Not that surprising if you consider that books before the
         | Gutenberg printing press were artisans work of art that
         | required years of work of specialists.
         | 
         | In other words: Today some of those will cost more than a
         | Ferrari to make. They use Vellum paper that is much better that
         | today's but require killing hundreds of animals each.
         | 
         | Only very rich people could afford that. I had access to
         | European books collections of the 16th that are in Color, much
         | much better than any normal book we have.
         | 
         | If you think about that it is normal. Color require more
         | printing plates in a printer, but just changing your ink if you
         | do it manually.
        
           | saalweachter wrote:
           | > They use Vellum paper that is much better that today's but
           | require killing hundreds of animals each.
           | 
           | Yes, but also, it's more of byproduct. You raise sheep for
           | wool, they're going to lamb every year, you eat most of the
           | lambs, someone buys some of the skins to turn onto vellum.
           | 
           | The processing to produce vellum would be expensive, and not
           | something every shepherd would be making at home, but the
           | input sheepskin would be plentiful.
        
         | Aerolfos wrote:
         | Really? Because what TeX did was make it possible to write
         | "proper" books or formal texts via a computer - that was the
         | whole point
         | 
         | A 16th-century formal book like this _would_ be the gold
         | standard to replicate if you want to make  "serious" texts. And
         | yes, in scientific literature, the "serious" text is a narrow
         | target and far narrower than you might expect from the possible
         | variation in a handmade artisanal work. Mostly because when
         | everything is "custom", standardization and regular structure
         | is exceptional
        
         | tristramb wrote:
         | It's not unlikely that Donald Knuth looked at examples of 16th
         | Century typesetting when he came to design TeX. Or looked at
         | examples of typesetting that had been influenced by 16th
         | Century typsetting.
        
           | ternaryoperator wrote:
           | He studied them diligently. His book Digital Typography gives
           | lengthy accounts of his research and includes photographs and
           | examples of how he chose various aspects.
        
       | teleforce wrote:
       | Fun facts, the patron of Almagest Abassid Caliph Al-Ma'mun was
       | also the founder of Baitul Hikmah in Baghdad that was
       | aggressively translating important foreign manuscripts due to
       | weight gold equivalence for Greek/Indian/etc manucsripts
       | translation compensation [1],[2].
       | 
       | According to history, the Caliph once back off his plan of
       | conquering Constantinople (that were later achieved by Ottoman
       | Caliph Fatih) due the Roman (Byzantine) offered him an offer he
       | cannot refused, the original copy of Ptolemy Almagest as
       | important part of the truce arrangements. He certainly capable of
       | overcoming and conquering the Constatinople since during his
       | time, Afghanistan was conquered under Islamic rule for hundred of
       | years that modern Russia and USA cannot achieved. The fact that
       | his mother Marajil, was a princess originally from Afghanistan.
       | This is where the popular saying that asserted only Afghanistan
       | people can conquer Afghanistan. Point in case, the most recent
       | Afghanistan conqurer was Mughal Empire, who was originated from
       | Indian sub-continent Afghanistan. During his time, Al-Khwarizmi
       | published his infamous Algebra book namely Kitab al-Mukhtasar fi
       | Hisab al-Jabr wal-Muqabalah (The Concise Book of Calculation by
       | Restoration and Balancing), where we got the word algebra, and
       | from his name Al-Khwarizmi now we have the word "algorithm" [2].
       | 
       | In addition to having translation Baitul Hikmah in Baghdad, Iraq
       | and in other Islamic knowledge center in Toledo Spain (before
       | fall to Spanish Christian and started the European Renaissance),
       | the Islamic civilization also engaged in contributing to science,
       | math, astronomy, etc. Al-Haitham (Alhazen), the founder of
       | optics, and he's also the founder of modern scientific
       | methodology [3].
       | 
       | Having said that, there several Islamic astronomers
       | (Arab/Persian/etc) already proposing against the geocentric idea
       | that most probably that was inspired Galileo. I think he most
       | probably did not come with the original idea of heliocentric
       | model and the Islamic astromoners mosy probably have proposed it
       | before Galileo, but he failed to credit them properly as normally
       | practiced by European scientists at the time.
       | 
       | [1] al-Ma'mun:
       | 
       | https://en.wikipedia.org/wiki/Al-Ma%27mun
       | 
       | [2] Graeco-Arabic translation movement:
       | 
       | https://en.wikipedia.org/wiki/Graeco-Arabic_translation_move...
       | 
       | [3] Ibn al-Haytham:
       | 
       | https://en.wikipedia.org/wiki/Ibn_al-Haytham
        
         | darkwater wrote:
         | > Al-Khwarizmi published his infamous algebra book
         | 
         | Math can be hard, but calling that book "infamous" is a bit too
         | much... /s
        
         | graemep wrote:
         | There are a number of factual mistakes, misleading/unclear
         | statements and speculation in your "fun facts".
         | 
         | Al-Ma'mun failed to conquer Byzantium and died while preparing
         | his next attempt to do so: https://en.wikipedia.org/wiki/Al-
         | Ma'mun
         | 
         | He cannot possibly have been the patron of the Almagest as
         | Ptolemy lived centuries before he did. Maybe you mean of a
         | translation.
         | 
         | Everyone knows Galileo did not originate a heliocentric model,
         | because he was promoting the Copernican model.
         | 
         | Heliocentric models had been proposed by ancient Greeks, but
         | the Copernican model was a huge advance. There is big
         | difference between just speculating that the sun was the centre
         | of the the universe and an actual mathematical mode.
         | 
         | There is a lot more to the scientific method than al-Haytham's
         | minor contribution:
         | https://en.wikipedia.org/wiki/Scientific_method
        
           | teleforce wrote:
           | >He cannot possibly have been the patron of the Almagest as
           | Ptolemy lived centuries before he did. Maybe you mean of a
           | translation.
           | 
           | The Almagest version of the Galileo notes are Latin
           | translation of the Arabic translation by Gerard of Cremona in
           | Toledo around 1175. This makes Al-Ma'mun the patron of
           | Almagest [1].
           | 
           | >Heliocentric models had been proposed by ancient Greeks, but
           | the Copernican model was a huge advance. There is big
           | difference between just speculating that the sun was the
           | centre of the the universe and an actual mathematical mode.
           | 
           | The Islamic scholars were not speculating they were the
           | original and earlier researchers of the heliocentric model
           | that Copernicus and Galileo were famous for. It's not
           | exxageration that both very highly dependent of Islamic
           | scholars work on the required mathematics and the earlier
           | astronomy works as the OP article indicated. Most of these
           | original works by Islamic have been lost and many have not
           | throughly studied. I will argue that Copernicus himself
           | probably plagiarated some if not all his works from the
           | Islamic scholars wothout properly attributing the original
           | Islamic scholars' sources. Heck the so called telescope
           | invention by Galileo was invented by Islamic scientists
           | several hundreds years before him [2].
           | 
           | >There is a lot more to the scientific method than al-
           | Haytham's minor contribution
           | 
           | Al-Haytham is father of scientific methods, nothing minor
           | about that.
           | 
           | The will and audacity to whitewash Islamic scholar
           | contributions are beyond believe. They even had to change the
           | name from Ibnu Sina to Avicennia, Al-Haytham to Alhazen, Ibnu
           | Rush to Averroes, etc.
           | 
           | [1] Gerard of Cremona's Latin translation of the Almagest and
           | the revision of tables
           | 
           | https://journals.sagepub.com/doi/10.1177/00218286221140848
           | 
           | [2] How a Muslim invented the Telescope centuries before
           | Galileo:
           | 
           | https://www.secondgoldenage.com/p/how-a-muslim-invented-
           | the-...
        
         | hiro1986 wrote:
         | Beyond the facts corrected by other user, graemep, the
         | translator school was in fact established after the christian
         | kingdom of Castile conquer the city of Toledo, and the king
         | Alfonso X [1], actually is what is studied as main promoter of
         | it. [1]
         | https://en.wikipedia.org/wiki/Toledo_School_of_Translator
         | 
         | Then, first heliocentrism with some approximations of size and
         | distance, as far as I know was Aristarchus of Samos, but there
         | is not much that we know about it. [2]
         | https://en.wikipedia.org/wiki/Aristarchus_of_Samos
        
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