Jumat, 15 Oktober 2010

Ibn al-Haytham and the New Optics

Book review: Ibn al-Haytham and the New Optics
Ruveyda Ozturk*
Table of Contents
1. Prologue
2. Introducing Ibn al-Haytham and His Work
3. Ibn al-Haytham's Intellectual Legacy
4. Reflexsions on Scientific Methodology
5. The Mathematical Investigation of the World
6. Concluding Remarks
7. Table of Contents of the Book
8. Resources and Further Reading
* * *
Review of Ibn El-Heysem ve Yeni Optik (Ibn al-Haytham and the New Optics) by Huseyin Gazi Topdemir (in Turkish). Ankara: Lotus Publishing, 2008. Soft cover: 155 pages; ISBN- 13: 975-6665503; 16 x 24. 1. Prologue
The full name of our scientist is Abu Ali al-Hasan Ibn al-Hasan Ibn al-Haytham al-Basrî al-Misrî (965-1041). In medieval Europe, he was known as "Alhazen" (Latin form of "al-Hasan"). He was born in Basra, Iraq. He was a great mathematician, astronomer, physicist, and the founder of experimental science. He supported the results of his experiments with strong proofs. He began his scientific career in Iraq, where he envisaged the construction of a high dam on the river Nile near Aswan to regulate its waters. When the Fatimid Caliph al-Hakim (996-1021) heard about this project, he invited Ibn al-Haytham to Egypt, where firsthand observation convinced our scholar that such a construction was impossible. He then simulated madness and was put under house arrest until al-Hakim's death. After 1021, under the following Fatimid caliphs al-Zahir (1021-10367 and al-Mustansir (1036-1049), he recovered liberty and pursued his scientific activies.

Figure 1: Front cover of Ibn El-Heysem ve Yeni Optik by Huseyin Gazi Topdemir (Lotus Publishing, 2008).
Ibn al-Haytham was possibly the first to classify all even perfect numbers (i.e., numbers equal to the sum of their proper divisors) as those of the form 2k - 1(2k - 1) where 2k - 1 is a prime number. He also stated Wilson's theorem: If p is prime, then 1 + (p - 1)! is divisible by p (where "!" denotes the factorial function). It is called Wilson's theorem because of a comment by Waring in 1770 that the English mathematician John Wilson (1741–1793) had noticed the result. There is no evidence that Wilson knew how to prove it. It was Lagrange who gave the first known proof of the statement in 1771.
2. Introducing Ibn al-Haytham and his work
The number of written resources available in Turkish on one of the greatest scientists of all times, Ibn al-Haytham (Alhazen), is significantly limited and as such this work fills in a large gap by providing the readers with a wholesome text that sets out his major achievements and everlasting legacy. Ibn al-Haytham is renowned throughout the history of science as the ‘father of optics' for his brilliant contributions way ahead of his time which sometimes overshadow his many other important accomplishments, including the development of valuable experimental methods. The main purpose of this book is to introduce the life, works and scientific successes of "the greatest optician of all times" in eight detailed and comprehensive chapters.

Figure 2: Diagram of the physiology of the eye. Ibn al-Haytham's studies of the eye gave the first modern understanding of lens, retina and optic nerve, as well as the mechanics of vision and perception. (Source).
In the first chapter of the book of Huseyin Gazi Topdemir, which outlines Ibn al-Haytham's growing devotion to science through time, Ibn al-Haytham is characterised as one of the main contributors to the development of science in the Classic Islamic World, highlighted by his significant efforts in acquiring and mastering the prominent contributions of Ancient Greek science and philosophy. Due to his father's high position within the government, he received a high quality education, allowing him to become exceptionally well in conceptual and practical sciences and earning him the title of engineer in his earlier years. He traveled to a number of places and carried on his observations and studies in several Islamic countries, further expanding his knowledge base and common understanding. One of the earliest projects he undertook upon the orders of the Fatimid Caliph in Egypt Al-Hakim is the construction of a barrier that would stop the Nile River from overflowing. Even though he was unsuccessful in achieving this, the reasons of this failure remaining obscure, the models he developed were quite extraordinary and involved fine engineering.

Figure 3: The visual system according to Ibn al-Haytham. This diagram of the two eyes seen from above, shows the principal tunics and humours and the optic nerves connecting the eyeballs to the brain. (Source).
Huseyin Gazi Topdemir notes that Ibn al-Haytham spent a significant part of his life in Cairo copying scientific texts and earned his living by reproducing them. As a result, he had an enormous knowledge base and was directly aware of almost all previous scientific studies. In parallel, Ibn al-Haytham carried out imperative studies in optics but also made substantial findings in other scientific fields, including astronomy and geometry and has left behind a number of significant works. His most prominent publication was Kitab al-Manazir (The Book of Optics), one of the most original scientific text of all times. This book was published in a number of different languages starting with Latin and left an extraordinary impact on Middle Age Europe and onwards. It has been an important source of reference and inspiration for many scientists within the field of optics. In this book, Ibn al-Haytham successfully rejected well-established ancient beliefs by using creative thought and criticising the works and findings of his predecessors, establishing a bridge between Ancient Greek knowledge and Middle Age Latin Science. He developed a number of new theories by undertaking independent studies instead of using prior works as authority to provide basis and proof.

Figure 4: Four stamps on Ibn al-Haytham and his work issued by Qatar in 1971, Pakistan in 1969, by Jordan in 1971 and Malawi in 2008. (Source).
Hüseyin Gazi Topdemir states that Ibn al-Haytham demonstrated admirable courage and determination in deeply analysing the works of other highly regarded scientists like Aristotle, Euclid and Ptolemy and by being able to point out their mistakes. One of the main aspects which distinguished him from other scientists of his time was that he directed his focus to one specific field instead of keeping a wide array of study interests. Most of his studies in other fields were related to his optics studies and did not evolve around making new discoveries or providing further proof for a finding. For example, in investigating the refraction of light, he analysed the reasons behind the refraction of light in the atmosphere and as a result obtained the pre-requisite knowledge on astronomy. Another example of his optics related findings includes the discovery of the geometrical problem known as the Alhazen's problem which aimed to prove that light rays which approach the light axis parallel will meet at one point on the axis in dinted mirrors. The author explain this problem with this equation: H (x2-y2)-2Kxy+(x2+y2) (hy-kx)=0.
As a result of his keen focus on this field, he became the most prominent figure in the history of optics until the 17th century and his findings changed the science of optics radically.

Figure 5: The crater Alhazen on the surface of the moon (Lat: 15.9°N, Long: 71.8°E, Diam: 32 km, Depth: 2.17 km) named after Ibn al-Haytham. (Source). See FSTC, http://MuslimHeritage.com/topics/default.cfm?ArticleID=815Illustrious Names in the Heavens: Arabic and Islamic Names of the Moon Craters.
The second chapter of the book entitled ‘Doctor Mirabilis' shows the influence of Ibn al-Haytham on well-known scientists following him. Topdemir puts forward that Roger Bacon, who was identified as a Doctor Mirabilis (Exceptional Scientist) of the Middle Ages obtained most of his ideas on light and sight from Ibn al-Haytham, like other 13th and 14th century researchers, including John Pecham and Witelo. All their works are full of references to Ibn al-Haytham's studies, especially to Kitab al-Manazir which aimed to expose all the characteristics of light through observational and experimental investigations and mathematical explanations, analysing the accumulated knowledge, problems and suggested solutions of the Old Ages. The author suggests that Ibn al-Haytham's works successfully achieved their purpose of presenting an understanding of the science of optics which was wholly true, independent of past authorities and based solely on experimental and mathematical inductions.
3. Ibn al-Haytham's intellectual legacy
In the third chapter, Topdemir suggests that studies made on the history of scientific development shows that scientific development was an activity that took place subsequently in between the East and the West throughout world history. He puts forward an interesting argument by suggesting that the high level interaction between different cultures resulting from science show that it is a field on which humanity unites. He asserts that by the 8th century, Muslims had established themselves as the intellectual leader of the world, acquiring the scientific and philosophical legacy of the past. This legacy was embraced by Muslim scholars who utilised the Arabic translations of ancient works to make fresh, original contributions. As such, he argues that it is not surprising for Ibn al-Haytham to have started his studies by an analysis of the knowledge inherited from the Greeks. However he also benefited greatly from the culture of scientific research and development existent in the Islamic world during his times. Topdemir links Ibn al-Haytham's success to two main dimensions, including the application of existent methods to new fields and enhancement of factual knowledge through a process of analysis and secondly on developing new experimental processes.

Figure 6a-b: Two medieval illustrations depicting two consecutive theories of vision: (a) the Greek optical theory according to which rays come out of the eye and go to fill the object; and (b) the modern theory expounded by Ibn al-Haytham based on a correct vision theory establishing that vision occurs because the eye can see the object from the light that flows from it. (Source).
The author also mentions treatises written by other Muslim scholars before Ibn al-Haytham, including the Banu Musa Brothers' Kitab al-Hiyal which included immaculate designs and mechanisms still applicable today. He emphasises that Ibn al-Haytham was born into a technologically enhanced society and a culture which embraced scientific thought. Another example provided is that of Thabit Ibn Qurra (829-901) who was one of the foremost mathematicians of his times and successfully translated many Greek works into Arabic, also using them as a valuable source in his findings. By employing these reputable models, especially those of the well-established scientist Al-Kuhi, Ibn al-Haytham was able to develop a geometrical concept on quadrilaterals to determine the outcomes of applying different forces to certain objects. Ibn al-Haytham was further influenced by Ibn Sahl who arguably developed the rule on the refraction of light in his studies in geometric optics.
4. Reflexions on scientific methodology
The in his fourth chapter of the book authored by Topdemir shows that Ibn al-Haytham also developed pioneering concepts on the nature and methods of science and provides a few worthy examples. He states that Ibn al-Haytham was adopted a holistic approach to science and to correctly depict scientific methodology in terms of classical scientific understanding. He was also one of the first scholars of his times to exhibit a modern research approach by focusing on one specific area and to use experimentation as both a tool for discovery and verification. He had a clear understanding of the importance of mathematics, more specifically of geometry, in scientific explanation and demonstration as evident from his quadratic theorem. In his studies, he did not only provide experimental proofs but also made available causal explanations. The author also presents simple details of his fundamental works and the operations of his models giving citations from Ibn al-Haytham's various works to highlight the everlasting effect and relevance of his methods and thoughts. He allows the reader to see that the methodologies and practices Ibn al-Haytham developed were generally at a higher level than those following him like Francis Bacon in the 16th century. It is obvious from his works that he not only valued the observational, experimental and mathematical aspects of science, but at the same time, highly regarded its historical development.

Figure 7a-b: Two views of the frontispice of the first edition of the Latin translation of Ibn al-Haytham's Book of Optics, Opticae Thesaurus...Libri Septem, nunc primùm editi. Eiusdem liber De Crepusculis & Nubium ascensionibus. Item Vitellonis...Libri X. Omnes instaurati, figuris illustrati & aucti, adjectis etiam in Alhazenum commentariis, a Federico Risnero. Basel: Episcopius, 1572. (Source) - (Source).
Further, Topdemir argues that Ibn al-Haytham also used the techniques of induction and deduction in an acute and careful manner in the light of experimental determination. According to Ibn al-Haytham, science is the activity of expressing facts consistent within concepts under a mathematical light attained from observation and experimentation. As pointed out by the author, this is very similar to the modern day understanding of science. Ibn al-Haytham had suggested a two phase system of arriving at fundamental data, made up of analysis and synthesis and has identified lack of satisfactory observations as the main reason behind wrongful findings which was a common reason for failure in problem solving in Middle Ages optics. He also successfully pointed out the significant problem of generalisation from insufficient data and tried to overcome this by very elaborate and detailed experiments. Consequently, Topdemir argues that even though he lived in the 11th century, Ibn al-Haytham implemented investigations and practices achievable by the use of modern age methods.
Figure 8: The anotomy of the eye by Kamal al-Din al-Farasi based on Ibn al-Haytham's investigations. Kamal al-Din Abu'l-Hasan Muhammad Al-Farisi (1267-ca.1319/1320) was a prominent Persian Muslim physicist, mathematician, and scientist born in Tabriz, Iran. He made a major contribution to the science of optics. (Source).
5. The mathematical investigation of the world In the fifth part of the book, the author gives an explanation of the relationship between geometry and optics as understood in those times and outlines the important respects of Ibn al-Haytham's work in order to allow us to appreciate the extent of his capabilities and the significance of his studies. Ibn al-Haytham also referred largely to the works of other scientists in his fields using them as a resource but also improving on the ideas presented. He undertook to complete Apollonius' work on the conics, the eighth book of which was missing, by analysing the first seven articles and determining the missing content through the method of analysis, synthesis and renewal. He also criticised and amended some of the works of Euclid on geometrical drawing.

Figure 9: Photography is the result of combining several technical discoveries. Long before the first photographs were made, Ibn al-Haytham invented the camera obscura and pinhole camera. According to the Hockney-Falco thesis, some artists used the camera obscura and camera lucida to trace scenes as early as the 16th century. (Source).
The sixth chapter discusses Ibn al-Haytham's astronomical studies and shows that he also had an interest in this field. His book Fi Hay'at al-'alam (On the Configuration of the World) had a significant impact on the astronomers of the Middle Ages and the Renaissance, especially on Peuerbach's book The New Planet. The author again provides some basic information about the development of astronomical models and the continuous change in astronomical theory throughout history to better enable readers to understand the context and impact of Ibn al-Haytham's studies. He also effectively utilises explanatory images, diagrams and passages as well as depictions of the mentioned scientists to maintain the attention and certify the understanding of the reader throughout the book.
The seventh chapter, titled ‘Ex Oriente Lux' (The Light Comes from the East), suggests that the truthfulness of this statement has been definitively reflected through Ibn al-Haytham's life and works. The author applauds his success in putting forward a wholesome optics theory, overcoming the confusion and lack of clarity associated with this science in those time by utilising fundamental principles and significant techniques. After dismissing the emission theory which suggested that the eye emitted the light rays, Ibn al-Haytham moved from the assumption that light proceeded to the eye from each point on an object to develop his own basic theory. Regardless of a few downfalls, his optics theories were exceptionally successful and were accepted as authority in both the Eastern and Western worlds until the 17th century. Topdemir asserts that the main factor behind this success was his courage in using creative thought and producing independent models, instead of accepting existent theories on their face. He developed many original notions about the nature of light rather than simply refuting previous studies and extensively used experiments to prove his ideas. The author suggests that his book even today is a valid source of clear and comprehensible information on the rules and developments of optics, further signifying the scope and success of his studies.

Figure 10: Harold Anderson, Alhazen Studied the Recreation of Light (1936) (Size: 15"x20"); fine advertising for eyeglasses. (Source).
The final chapter starts with the details of the knowledge sovereignty held by the Muslims over the Medieval Era. It is stated that where the Muslims were making many original and unique contributions to science, the popular studies of the West were simply encyclopaedic works. According to Topdemir, Muslims inspired the renewal of the tradition of scientific thought in Europe. In his final analysis of Ibn al-Haytham's influence, the author points out that the main indicator of a scientist's authoritative power in his field is not only the directive force of his thoughts and ideas but at the same time, the unhesitant embracement of his mistakes of those following him. Ibn al-Haytham's Kitab al-Manazir had a large influence on the study of optics in his era and specifically inspired many scientists including Bacon, Pecham and Witelo. It is clear that until the 17th Century, all the main arguments, technical framework, controversial aspects and suggested solutions in the field of optics were advanced by Ibn al-Haytham. The author notes that the enormous value extended to scientific thought and scholars in the Middle Age Islamic World also had a substantial role in Ibn al-Haytham's success. As a result, his influence was not limited to his time or the Western world but also had a large impact on the studies of following Islamic researchers like Kamal Al-Din al-Farisi.

Figure 11: Ibn al-Haytham depicted on an Iraqi 10,000-dinar note.
6. Concluding remarks
Overall, the book presents a fair and balanced summary of Ibn al-Haytham's studies, focusing on his major achievements. The basic scientific explanations on relevant issues provided by the author raise the understanding of readers while giving them background information to better comprehend the extent of Ibn al-Haytham's successes. The book is well referenced and contains a large number of explanatory diagrams, images, posters and helpful citations from Ibn al-Haytham's works. However it lacks information on Ibn al-Haytham's life and practices, which might set a better light on his aspirations and determination in scientific research and discovery. It is easy to read and follow and as a whole provides reliable and noteworthy details about a great man who should be taken as an example by any student of science.

Figure 12a-b: Views from the recent edition in facsimile of a manuscript of Ibn al-Haytham's book Mahiyat al-athar alladhi yabdu 'ala wajh al-qamar (The Trace on the Moon's Face) edited by Yusuf Zidan (Alexandria: Alexandria Library, 2002).
In the Genius Arab Civilization, A. I Sabra stated, "Ibn al Haytham's most important contribution were in the fields of optics, mathematics, and astronomy. His most important single work is the comprehensive Kitab al-Manazir (the Book of Optics). Until the revival of optics in Persia, towards the end of thirteenth century, Ibn al-Haytham was mainly known to the Islamic world as mathematician and as an astronomer, but his best-known and most influential work in Europe was the Optics. It was largely on these bases of his book that George Sarton described Ibn al-Haytham as "the greatest Muslim physicist and one of the greatest students of optics of all times." Other optical subjects of Ibn al-Haytham include: "On the light of the Moon, that argues that the moon shines like a self luminous object, though its light is borrowed from the Sun; On the Halo and Rainbow; On Spherical Burning Mirrors; On Paraboloidal Burning Mirrors; and On the Shape of eclipse, which examines the camera obscure phenomena.
7. Table of contents of the book
Table of Figures
Table of Pictures
Chapter 1: A Life Devoted to Science
Chapter2: Doctor Mirabilis
Chapter 3: The Intellectual Inheritance that Nurtured Ibn al-Haytham
Chapter 4: Knowledge, Science and Methodology
Chapter 5: Mathematics and Nature
Chapter 6: A New Design of Universe
Chapter 7: Ex Oriente Lux
Chapter 8: Paradigm and Development
8. Resources and further reading
  • Al-Khalili, Jim, The first true scientist.
  • Sabra, A. I., ed., The Optics of Ibn al-Haytham, Books I-II-III: On Direct Vision. The Arabic text, edited with Introduction, Arabic-Latin Glossaries and Concordance Tables. Kuwait: National Council for Culture, Arts and Letters, 1983.
  • Sabra, A. I., trans., The Optics of Ibn al-Haytham. Books I-II-III: On Direct Vision. English Translation and Commentary. 2 vols, Studies of the Warburg Institute, vol. 40, London: The Warburg Institute, University of London, 1989.
  • Sabra, A. I., ed., The Optics of Ibn al-Haytham. Edition of the Arabic Text of Books IV-V: On Reflection and Images Seen by Reflection. 2 vols, Kuwait: The National Council for Culture, Arts and Letters, 2002.
  • Salih, H., Al-Amri, M., and El-Gomati, M., The miracle of light, in A World of Science (UNESCO), A World of science, vol. 3, no. 4, October-December 2005, pp. 2-7.
  • Smith, A. Mark, ed. and trans. (2006), written at Philadelphia, "Alhacen on the Principles of Reflection: A Critical Edition, with English Translation and Commentary, of Books 4 and 5 of Alhacen's De Aspectibus, the Medieval Latin version of Ibn-al-Haytham's Kitab al-Manazir, 2 vols", Transactions of the American Philosophical Society (Philadelphia: American Philosophical Soc.) 96 (2–3).
  • Sopieva, Natasha, Ibn Al-Haitham the Muslim Physicist.
  • Steffens, Bradley, Ibn al Haytham The First Scientist, Morgan Reynolds Publishing, 2007. Visit the website of the book: Ibn al-Haytham.
  • [Wikipedia], Alhazen (retrieved 18.10.2009).
  • Zahoor, A., Abu Ali Hasan Ibn Al-Haitham (Alhazen) (965 - 1040 C.E.)
* Reviewer, FSTC, Sydney, Australia.

by: Ruveyda Ozturk, Thu 29 October, 2009