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Ancient Tablet Reveals Babylonians Discovered Trigonometry (sciencemag.org)

An anonymous reader quotes a report from Science Magazine: Trigonometry, the study of the lengths and angles of triangles, sends most modern high schoolers scurrying to their cellphones to look up angles, sines, and cosines. Now, a fresh look at a 3700-year-old clay tablet suggests that Babylonian mathematicians not only developed the first trig table, beating the Greeks to the punch by more than 1000 years, but that they also figured out an entirely new way to look at the subject. However, other experts on the clay tablet, known as Plimpton 322 (P322), say the new work is speculative at best. Consisting of four columns and 15 rows of numbers inscribed in cuneiform, the famous P322 tablet was discovered in the early 1900s in what is now southern Iraq by archaeologist, antiquities dealer, and diplomat Edgar Banks, the inspiration for the fictional character Indiana Jones.

Now stored at Columbia University, the tablet first garnered attention in the 1940s, when historians recognized that its cuneiform inscriptions contain a series of numbers echoing the Pythagorean theorem, which explains the relationship of the lengths of the sides of a right triangle. (The theorem: The square of the hypotenuse equals the sum of the square of the other two sides.) But why ancient scribes generated and sorted these numbers in the first place has been debated for decades. Mathematician Daniel Mansfield of the University of New South Wales (UNSW) realized that the information he needed was in missing pieces of P322 that had been reconstructed by other researchers. He and UNSW mathematician Norman Wildberger concluded that the Babylonians expressed trigonometry in terms of exact ratios of the lengths of the sides of right triangles, rather than by angles, using their base 60 form of mathematics, they report today in Historia Mathematica.

17 of 83 comments (clear)

  1. We need more information by DontBeAMoran · · Score: 5, Funny

    Ancient tablet reveals Babylonians discovered trigonometry.

    What kind of tablet was it? iPad or Android?

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    1. Re:We need more information by future+assassin · · Score: 3, Funny

      it was a Chinese WinAll tablet running Babynix.

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  2. Oh please. by Anonymous Coward · · Score: 5, Insightful

    Equating a table of pythagorean triples to Euclid is like equating the wheel that Oog invented in 50,000 BC to a Ferrari.

    Babylonians don't get credit for trigonometry for being the first to use the concept of similar triangles.
    Persians don't get credit for all of algebra because they were the first to write down the quadratic formula.
    Aristotle doesn't get credit for absolutely all of math and logic because he invented modus ponens.
    Eudoxus and/or Archimedes don't get credit (though arguably they should) for inventing calculus for discovering the method of exhaustion.

    On the other hand, Euclid *does* get credit for inventing synthetic geometry and (basic) number theory, because Elements actually contains fleshed-out theories that still form a major part of what would be taught in a beginning course today.

    1. Re:Oh please. by Puff_Of_Hot_Air · · Score: 4, Insightful

      Where did you get Euclid from? No one is talking about Euclid except you. No one is suggesting the Babylonians were the first to "invent" trigonometry (mathematical concepts aren't invented, hence why you can't patent them). They were the first to use them, but we already knew that. What's interesting about this if that they used them way before we knew, but also that they were able to perform pratical trig (with triangles), in a completely different and novel way, without angles. What's more, this approach has pratical advantages over our current methods (albeit somewhat redundant since the calculator).

  3. Time travel by jfdavis668 · · Score: 4, Informative

    The Babylonians didn't invent trigonometry, they invented time travel. They went into the future and stole trigonometry from us.

  4. Re:But they couldn't tell anybody about it. by Orgasmatron · · Score: 5, Interesting

    There is a version of that story in the Sumerian literature too. Here is the Electronic Text Corpus of the Sumerian Language (ETCSL) link:

    http://etcsl.orinst.ox.ac.uk/cgi-bin/etcsl.cgi?text=t.1.8.2.3#

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  5. All comments above suck. Hope better ones follow. by Anonymous Coward · · Score: 3, Informative

    There's a lot to be said, but Slashdot has been infested with such hilarious Redditors. I never thought I'd miss the days when Digg commenters infested slashdot. Says something when the likes of Digg is far preferred to the likes of Reddit.

    moving on...

    the famous P322 tablet was discovered in the early 1900s in what is now southern Iraq by archaeologist, antiquities dealer, and diplomat Edgar Banks

    From Plimpton 322 wiki,

    According to Banks, the tablet came from Senkereh, a site in southern Iraq corresponding to the ancient city of Larsa.

    So my comment isn't earth shattering, but at least you're smarter than you were a moment ago, unlike after reading any of the comments above mine. Go home Redditors, you're drunk.

  6. Re:Not trig as we understand it today. by Puff_Of_Hot_Air · · Score: 4, Informative

    The tablet doesn't really contain trigonometry as we understand it today. There is no concept of angle, for instance.

    That's absolutely true and also why the discovery is so interesting. It is trigonometry. Trigonometry without angles. The authors have a YouTube video which is very informative Here. There are so many interesting things about this. Angles are not needed to work with triangles. The sexagesimal numbering system had many advantages over our current decimal system from an application perspective. It's just a whole new way of thinking about trig. Anyway, it's well worth 20 minutes of your time.

  7. Re: ok. go with it. the Babylonians beat the Greek by Paradise+Pete · · Score: 2

    My penis. However, I wrote the formulas in the snow with my piss

    So you wrote it in shorthand?

  8. Re:What a misleading post by Puff_Of_Hot_Air · · Score: 2

    Clearly you have spent approximately 0 seconds reviewing this study. It is a table (much like a sine or cos table back in the pre-calculator era), and the missing bit was really just an explanation as to the why of the table. These guys have "reverse engineered" that with a combination of math (how the numbers are related) and an understanding of how the sexagesimal system and babloynian use of it influenced their practical use of math.

  9. Re:Babylonian Crackpottery by TechyImmigrant · · Score: 4, Funny

    If it was not peer-reviewed, it is ancient crackpottery. Literally. Just saying.

    Or ancient cracked pottery.

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  10. Re:Invented by Hognoxious · · Score: 2

    Does it have rounded corners?

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  11. Re:But they couldn't tell anybody about it. by michelcolman · · Score: 2

    So not only did they have tablets, but they had different and incompatible operating systems as well?

  12. Re:Not trig as we understand it today. by Anne+Thwacks · · Score: 5, Informative
    If you can't figure out how high up a wall a 10' ladder goes at a 70 angle, it's not trigonometry!

    That is what it does do. However, it requires that you have a ladder an integer number of units high, and place the bottom an integer number of units from the wall, and those integers must be in a predetermined ratio.

    Basically, it is a list of triangles like 3,4,5 and 13,12,5 but, because they used base 60, there are a lot more of them in a given range.

    However, the strategy for finding the answers in the table, and the way in which the table is laid out, are way more useful to builders and surveyors than the tables we used prior to calculators being invented, and the answers (for the values in the table) are more accurate than many tables generated before the use of computers, as the method relied entirely on manipulating integers, rather than 4 figure log tables generating decimals to a fixed number of figures by expounding a power series to a limited number of terms.

    I was skeptical at first, but I am inclined to agree that it actually IS a different trigonometry, and it gives useful and practical results - but it does so by not solving the general case. However, it covers most cases that would be encountered by people using the technology of the day. (eg pyramid builders, land surveyors, and very probably boat builders). It is likely woefully inadequate for celestial navigation, but I have not tried it ;-)

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  13. Re:But they couldn't tell anybody about it. by Orgasmatron · · Score: 4, Informative

    134-155. "Chant to him the holy song, the incantation sung in its chambers -- the incantation of Nudimmud: "On that day when there is no snake, when there is no scorpion, when there is no hyena, when there is no lion, when there is neither dog nor wolf, when there is thus neither fear nor trembling, man has no rival! At such a time, may the lands of Shubur and Hamazi, the many-tongued, and Sumer, the great mountain of the me of magnificence, and Akkad, the land possessing all that is befitting, and the Martu land, resting in security -- the whole universe, the well-guarded people -- may they all address Enlil together in a single language! For at that time, for the ambitious lords, for the ambitious princes, for the ambitious kings, Enki, for the ambitious lords, for the ambitious princes, for the ambitious kings, for the ambitious lords, for the ambitious princes, for the ambitious kings -- Enki, the lord of abundance and of steadfast decisions, the wise and knowing lord of the Land, the expert of the gods, chosen for wisdom, the lord of Eridug, shall change the speech in their mouths, as many as he had placed there, and so the speech of mankind is truly one.""

    Enmerkar is building a tower/temple to the goddess Inana at Eridu. He asks her for permission to collect a tribute from Aratta. The messenger is told to threaten to destroy Aratta and disperse the people if they don't pay up, and to chant a song asking Enki to fix the languages - "change the speech in their mouths, as many as he had placed there".

    Sumerian translations aren't perfect, so we aren't positive if Enki is to fix the languages that he had broken earlier, or break the single language now.

    Oh, and towards the end, writing gets invented. The messages back and forth get longer and longer until the poor messenger can't remember it all - "The messenger, whose mouth was heavy, was not able to repeat it." - so the king invents writing, which makes the messenger positively giddy. That is in lines 500-514.

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  14. The Babylonians were very sophisticated by davide+marney · · Score: 2

    I took an undergraduate degree in History solely for the opportunity to study the Code of Hammruabi, which, along with the Pentateuch of the Bible, is one of the earliest systems of law ever recorded. Only later as a much older man was I able to afford going to Paris to see one of the actual steles on which the Code was inscribed, which was an unforgettable experience (it's a solid piece of obsidian over 7 feet high, with deeply-cut symbols that look like they were made about a year ago. These were people who didn't believe in Agile, not even for a moment!)

    I am not terribly strong in mathematics, but I was able to follow the gist of the paper, and I do think their interpretations about the Babylonians preference for exactitude and integer divisions aligns quite well with the precision of their legal work.

    From a purely academic perspective, it was an enormously sophisticated and skilled culture for its time.

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  15. Re:Not trig as we understand it today. by zippthorne · · Score: 2

    It's stuff I didn't know, pertaining to history and mathematics. I'd say it counts more as news than some trial baloon or fud about how much the next iPhone will cost.

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