Medieval Islamic geometry & chimps using spears

070222_islamictiles_bcol5pstandard.jpgUpdated & expanded

There’s no connection between these two new papers, apart from my finding them both interesting. I’ll be writing more on both subjects soon, but meanwhile here are the abstracts and a few thoughts.

In the first paper, from today’s issue of Science, physicists Lu and Steinhardt, of Harvard and Princeton, respectively, describe geometric patterns from 15th Century mosques in Afghanistan, Iran and India, and say that the tiling patterns weren’t “discovered by the West” until about 500 years later:

The conventional view holds that girih (geometric star-and-polygon, or strapwork) patterns in medieval Islamic architecture were conceived by their designers as a network of zigzagging lines, where the lines were drafted directly with a straight edge and a compass. We show that by 1200 C.E. a conceptual breakthrough occurred in which girih patterns were reconceived as tessellations of a special set of equilateral polygons (girih tiles) decorated with lines. These tiles enabled the creation of increasingly complex periodic girih patterns, and by the 15th century, the tessellation approach was combined with self-similar transformations to construct nearly perfect quasi-crystalline Penrose patterns, five centuries before their discovery in the West.

As this paper shows, the contributions of the Arabs to the physical sciences, and the influence of the Arabs over pre-Renaissance Western thought, cannot be underestimated. By 1,200, when they made their “conceptual breakthrough, the Arabs had also made advances in biology that would not be paralleled in the West for centuries.

The Bush administration’s foreign policy is based on the idea of a “clash of civilizations”; that Islamic civilization was once great – during the ‘golden age’ of Islam, when Arab science and philosophy blossomed, Europe was still largely in the dark ages; that it eventually fell into decline, then got taken over and left behind by “the West”; and that “they” (Arabs/ Muslims) hate “the west” because of the humiliation and anger this caused. The matter is, of course, far more complex than that; I’m going to focus on Arabic science, but a little politics may creep in.

The second paper, about chimps manufacturing and using tools, was published online yesterday in Current Biology, and has received a lot of attention from the media.

Although tool use is known to occur in species ranging from naked mole rats to owls, chimpanzees are the most accomplished tool users. The modification and use of tools during hunting, however, is still considered to be a uniquely human trait among primates. Here, we report the first account of habitual tool use during vertebrate hunting by nonhumans. At the Fongoli site in Senegal, we observed ten different chimpanzees use tools to hunt prosimian prey in 22 bouts. This includes immature chimpanzees and females, members of age-sex classes not normally characterized by extensive hunting behavior. Chimpanzees made 26 different tools, and we were able to recover and analyze 12 of these. Tool construction entailed up to five steps, including trimming the tool tip to a point. Tools were used in the manner of a spear, rather than a probe or rousing tool. This new information on chimpanzee tool use has important implications for the evolution of tool use and construction for hunting in the earliest hominids, especially given our observations that females and immature chimpanzees exhibited this behavior more frequently than adult males.

The chimps were observed and filmed making and using the spears. (I’ve uploaded two of the film clips from the supplementary data onto YouTube.) In the first step of this process, they locate a potential nest cavity then select a branch of an appropriate size. The branch is then broken off, and trimmed off its leaves and side branches. In a quarter of cases, the spear was then used. On other occasions, the monkeys continued to trim one or both ends of the branch, and then the tip, before enlarging the nest cavity and using the spear to retreive the bushbaby.

This would appear to be the first observation of a non-human using a weapon to kill prey – the chimps used their spears to stab bushbabies hiding in trees cavities. However, crows, rooks, and jays have equally, if not more, sophisticated tool-using capabilities. The method of fashioning tools described here is very similar to the tool-making techniques of Caledonian crows; the similarity between the two is actually quite remarkable – the crows break branches to make hook-shaped tools, sculpt the hook very finely with the tips of the beak, then use the tools to retrieve food from cavities in trees, or from the soil. But although the authors mention owls in the abstract, there’s no discussion about tool-manufacture/use in birds elsewhere in the paper. There’s no mention of birds at Mixing Memory or Tetrapod Zoology either.


Lu, P. J. & Steinhardt, P. J. (2007). Decagonal and quasi-crystalline tilings in medieval Islamic architecture. Science 315: 1106-1110. [Full text]

Pruetz, J. D. & Bertolani, P. (2007). Savanna chimpanzees, Pan troglodytes verus, hunt with tools. Curr. Biol. DOI: 10.1016/j.cub.2006.12.042. [Full text]


5 thoughts on “Medieval Islamic geometry & chimps using spears

  1. Being originally from Spain, I can appreciate how evolved Arab culture was during our “Middle Ages”. And hope Christians, Muslim and Jewish people can work together again.

  2. @mike radolf
    please show me one iranian geometric picture of pre-islamic origin. you are a liar, somebody that hates islam and because of that you don’t want to admit the souvereignity of islamic culture
    shame on you

  3. Islamic refers to a religion and political dominance.
    Islamic Architecture is mainly copied from India and its Hindu-Buddist culture. As new conquerors imposing the third Abrahamic Religion, Islam borrowed from the cultures it subdued and labeled it Islamic.
    Over its 1400 years of maddening ‘multiply and conquer’ excercise it has produced nothing authentic.
    Take Musa al- Khawarazmi, the “Great Islamic Mathematician”. There is nothing Islamic about Khawarazmi except that he, the Persian, is subdued to Islamic dominance. Khawarazmi’s essence is not Islamic or Arabic. His origins are of a totally different background which is not respected under Islamic conquering rules.
    Islam does this everywhere it lands. Spain is another great example. Islam disrespects other cultures, imposes its falsehoods distorting history, science and native lifestyles.
    Islam is the rape of mankind, culturally and intellectually; there is truly no other way to put it.
    Al Bakhtyasu ,Al-Nowbakht, Al-Masouyeh, Abdollah Ibn Moqaffa, Omar Ibn Farakhan Tabari, Ali Ibn Ziad Tammimi, Ibn Sahl, Yusof Al Naqel, Isa Ibn Chaharbakht, Yatr Ibn Rostam Al Kouhi and the latest was Abu Reyhan Birooni, the mathematician and famous translator of Indian books were all PERSIANS! with Islamic_Arabic Names.

    If this is called “hate” for putting the historic obvious of a ‘disrespectful ideology with a god-belief’ then you have to enlarge your vocabulary. There is life beyond your one word “hate” vocab.

  4. @ Muhammad Sulaimaan.
    Nobody replies because your request indicates your high level of ignorance and your mental state of mind conditioned to produce falsehoods instead of respecting history.

    Ever heard of the first batteries (sometimes known as the Baghdad Battery) in Parthian era or Sassanid era. Some have suggested the batteries may have been used medicinally. Other scientists believe the batteries were used for electroplating – transferring a thin layer of metal on to another metal surface — a technique still used today and a common classroom experiment.

    Yep! there is more than one Persian/iranian geometric picture of pre-islamic origin

    Ca. 1700 BC, Windmills developed by Babylonians. They are used to pump water for irrigation. Later on, Persian inventors develop a wind-power machine, a more advanced windmill than that developed by the Babylonians.

    After Islam

    The philosophy of the Islamic period was influenced by Greece, India and by Persia/Iran of the pre-Islamic period. Ibn Khurram writes in his book “al Melal wa al-Nehal” that Muhammad Bin Zakaria Razi took from ancient Iranian’s five principals in which he believed:

    Creator- Ahuramazda

    The same is mentioned by Massoudi in his book “Moruj-oz-Zahab.” Shahaboddin Sohrevardi in the preface to his philosophical book quotes old Iranian terms and expressions derived from Zoroastrians, Manians and Zarvanians.

    As far as I know…Ashuramazda isn’t a muslim and neither an islamic; neither was Zoroasthra. Contrary to what Islamic/Quran/Hadith writings claim: Earth being Flat!?? surely Ashuramazda would object to this Islamic Falsehood. In 6000BCE the ancient people knew of galaxies, planets, and Earth/Moon orbitting around the SUN!

    All Ancient Native lifestyles are aware of galaxies and planetary lifeforms. Maybe you should ask why the Abrahamic Religions deceived and still mislead mankind into falsehoods.

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