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Claimed and Written by Ananth Somasundaram for PHYS2211
Claimed and Written by Ananth Somasundaram for PHYS2211


'''Alhazen''' was an Arab physicist, mathematiician, and astronomer who resided in Basra, Cairo. Alhazen had significant contributions in the fields of optics, astronomy, mathematics, meteorology, visual perception and the scientific method. He is considered to be the first theoretical physicist. Alhazen also was the earliest to discover that a hypothesis has the requirement to be experimented through trailed procedures or mathematical evidence.
'''Alhazen''' was an Arab physicist, mathematiician, and astronomer who resided in Basra, Cairo. Alhazen had significant contributions in the fields of optics, astronomy, mathematics, scientific method and visual perception. He is considered to be the first theoretical physicist. Alhazen also was the earliest to discover that a hypothesis has the requirement to be experimented through trailed procedures or mathematical evidence. Alhazen is considered by many to be the father of modern optics.


 
[[File:03-ahazen.jpg|100px|thumb|right|Alhazen]]
[[File:Max_Planck_1933.jpg|200px|thumb|right|Planck in 1933]]


==Early Life==
==Early Life==
Line 10: Line 9:
Alhazen was born in 965 CE in Basra, Buyid Emirate and passed away at the age of 75 in 1040 CE in Cairo, Egypt. He was born to an Arab family and moved to Cairo at an early age. When he moved to Cairo, it was under the rule of  Fatimid Caliph al-Hakim. Alhazen pitched a hydraulic project to improve regulation of the flooding of the Nile. After pitching the idea, Alhazen realized the impracticality of his plan. There is no concrete proof, but it has been told that the Caliph was upset at Alhazen for the failed plan and placed him under house arrest till the Caliphs death in 1040. During the house arrest, Alhazen wrote his famous [https://en.wikipedia.org/wiki/Book_of_Optics Book Of Optics].  
Alhazen was born in 965 CE in Basra, Buyid Emirate and passed away at the age of 75 in 1040 CE in Cairo, Egypt. He was born to an Arab family and moved to Cairo at an early age. When he moved to Cairo, it was under the rule of  Fatimid Caliph al-Hakim. Alhazen pitched a hydraulic project to improve regulation of the flooding of the Nile. After pitching the idea, Alhazen realized the impracticality of his plan. There is no concrete proof, but it has been told that the Caliph was upset at Alhazen for the failed plan and placed him under house arrest till the Caliphs death in 1040. During the house arrest, Alhazen wrote his famous [https://en.wikipedia.org/wiki/Book_of_Optics Book Of Optics].  


When Planck was nine years old, his father, who was a distinguished jurist and professor of law at the , received an appointment at the [https://en.wikipedia.org/wiki/Ludwig_Maximilian_University_of_Munich University of Munich], where a teacher by the name of Hermann Müller stimulated Planck's interest in physics. After graduating at the age of 17, Planck ultimately chose physics as his career path because he had become deeply impressed by the absolute nature of the law of conservation of energy. Planck describes why he chose physics:
===Contributions===
 
 
Alhazen had significant contributions in the fields of optics, astronomy, mathematics, scientific method and visual perception as mentioned earlier. He made the correlation that the angle of incidence and refraction does not remain constant. He also researched the magnifying power of the lens. Alhazens work significantly impacted other scientists of his time and future. His book of optics debuted many scientific facts which would be used later in the scientific world. Although Alhazen wrote as many as 200 books, as many as 55 have survived.  


''"The outside world is something independent from man, something absolute, and the quest for the laws which apply to this absolute appeared to me as the most sublime scientific pursuit in life.”''


===University Education and Career===
==Book Of Optics==


Planck entered the University of Munich in the fall of 1874, however found very little encouragement to pursue a future in physics. He spent a year at the [https://en.wikipedia.org/wiki/Humboldt_University_of_Berlin University of Berlin], where he had the opportunity to be taught by great research scientists [https://en.wikipedia.org/wiki/Hermann_von_Helmholtz Hermann von Helmholtz] and [https://en.wikipedia.org/wiki/Gustav_Kirchhoff Gustav Robert Kirchoff], however he was very unimpressed by their lectures. He returned to Munich and received his doctorate of philosophy in July 1879 at the age of 21. The following year he finished his dissertation at Munich and became a lecturer. He spent five years teaching at the University of Munich, then was appointed Associate Professor of Theoretical Physics at the University of Kiel, with the help of his father. Two years later he married Marie Merck in 1887, and they went on to have four children, Karl (1888), the twins Emma and Grete (1889) and Erwin (1893), of whom only Erwin was to survive past the First World War. In 1889, he succeeded Kirchoff and became a professor at the University of Berlin, where he came to venerate Helmholtz as a mentor and colleague. Though he had only nine doctoral students altogether, his lectures on all branches of theoretical physics went through many editions and exerted great influence in that particular field. He remained a professor in Berlin until his retirement in 1926.  
As mentioned earlier, Alhazen's most significant contribution was the Book of Optics which was created in a span of 10 years with 7 volumes. This book was also translated into Latin at the end of the 12th Centruy. This book influenced Johann Kepler and Leonardo da Vinci.  


==Scientific Contribution==


===Black-Body Radiation===
===Theory Of Vision===


While teaching in Berlin, Planck studied thermodynamics - in particular examining the distribution of energy according to wavelength. By combining the formulas of [https://en.wikipedia.org/wiki/Wilhelm_Wien Wilhelm Wien] and Rayleigh, Planck announced a new formula referred to as Planck's radiation formula. Two months later, Planck introduced the quanta of energy by making a complete theoretical deduction of his formula and giving up classical physics. He knew how the entropy of the radiation had to depend mathematically upon its energy in the high-frequency region if Wien’s law held there. He also saw what this dependence had to be in the low-frequency region in order to reproduce the experimental results there. Planck guessed that he should try to combine these two expressions in the simplest way possible, and to transform the result into a formula relating the energy of the radiation to its frequency. He presented his theoretical explanation involving this quanta of energy on December 14, 1900 at a meeting of the Physikalische Gesellschaft in Berlin. He announced his derivation of the relationship which was centered around the idea that the energy emitted by a resonator could only take on discrete values or quanta. The energy for a resonator of frequency is hv where h is a universal constant, known as Planck's constant.  
Alhazen performed experiments on colors and light, reflections, and optic illusions. He would view the refraction of light rays through transparent mediums such as air and water and would record the laws of refraction. He was noted to be the first person to perform experiments on the dispersion of light into colors. He was noted to be extremely close to discovering the theory of magnifying lenses. This theory was officially created three centuries later. Alhazen was the first scientist to consider horizontal and vertical components of refracted and reflected light rays.


The discovery of Planck’s constant equipped him to define a new universal set of physical units (such as the Planck length and the Planck mass), all based on fundamental physical constants. Planck’s work on the quantum theory was published in the Annalen der Physik. His work is summarized in two books Thermodynamik (Thermodynamics) and Theorie der Wärmestrahlung (Theory of heat radiation).
Alhazen proposed an intromission theory which said that from all points of a colored body, light and color along every straight line can be produced from that single point. By stating this, Alhazen realized that his theorem had a loop hole: he couldn't explain how a coherent image formed from many independent sources of radiation. Essentially, every point on an object would send rays to every point on the eye. To fix this problem, he stated that only perpendicular rays from the point would be received by the eye. He stated that perpendicular rays are more powerful than oblique rays. He also stated that there was only one perpendicular ray that enters the eye at an point and all the perpendicular rays converge on the center of the eye. Parallel rays are refracted through the eye and perceived as if perpendicular. Johannes Kepler used Alhazen's theory to build off his own theory of retinal imaging which would address the problem of correspondence of points on an object and places in the eye. Alhazen was the first person to experiment and prove that light travels in straight lines and experimented with refraction and reflection.  


A YouTube Video of Planck's logic in Black-Body Radiation and the beginning of quantum mechanics can be found [https://www.youtube.com/watch?v=YEn-vX4duUc here].
Alhazen also researched the process of sight and the structure of the eye along with image formations in the eye. He went into the detail of the structure of the human eye and went to consider how the anatomy would behave functionally as an optical system. Alhazen built off of [https://en.wikipedia.org/wiki/Ptolemy Ptolemy's] optic studies.  


==Later Life==


===Second Marriage and World War I===
===Alhazen's Problem===


In 1909 Planck's wife Marie passed away, presumably from [https://en.wikipedia.org/wiki/Tuberculosis tuberculosis]. In 1911, Planck married his second wife, Marga von Hoesslin, who bore him a third son, Hermann, the same year. By the time of the German annexation and [https://en.wikipedia.org/wiki/World_War_I World War I] in 1914 (which Planck initially welcomed, but later argued against), he was effectively the highest authority of German physics, as one of the four permanent presidents of the Prussian Academy of Sciences, and a leader in the influential umbrella body, the [https://en.wikipedia.org/wiki/Kaiser_Wilhelm_Society Kaiser Wilhelm Society]. By the end of the 1920s, [https://en.wikipedia.org/wiki/Niels_Bohr Niels Bohr], [https://en.wikipedia.org/wiki/Werner_Heisenberg Werner Heisenberg], and [https://en.wikipedia.org/wiki/Wolfgang_Pauli Wolfgang Pauli] had worked out the "[https://en.wikipedia.org/wiki/Copenhagen_interpretation Copenhagen Interpretation]" of quantum mechanics, and the quantum theory which Planck’s work had triggered became ever more established, even if Planck himself was never quite comfortable with some of its philosophical implications.
Alhazen's problem encompasses drawing lines from two distinct points on the plane of a circle meeting at a point on the circumference and making equal angles with the normal at that point. Alhazen used this in the realm of optics to solve problems when given a light source and a spherical mirror, to be able to find the point on the mirror where the light reflected to the eye of an observer. Alhazen then proceeded to derive a formula for the sum of [https://en.wikipedia.org/wiki/Fourth_power fourth powers].  


===Nobel Prize in Physics===
[[File:Abhishek_main_squeeze.jpg|200px|thumb|right|Alhazen's Problem]]


Planck was just 42 years old in 1900 when he made his famous discovery of the black body radiation law. This was not only Planck's most important work but in addition it marked a turning point in the history of physics. In 1918, this discovery won him the Nobel Prize in Physics.


===World War II===
===Scientific Method===


Planck was 74 years old when the Nazis seized power in 1933, and he typically avoided conflict with the Nazi regime, although he did organize a provocative official commemorative meeting after the death in exile of fellow physicist Fritz Haber. He also succeeded in secretly enabling a number of Jewish scientists to continue working in institutes of the Kaiser Wilhelm Society for several years.
Alhazen believed in reliance on experimentation and controlled testing for his scientific observations. Alhazen especially preferred combining classical physics along with mathematics which helped him believe in his theories of color, vision and light.  


The “Deutsche Physik” movement attacked Planck, [https://en.wikipedia.org/wiki/Arnold_Sommerfeld Arnold Sommerfeld] and Werner Heisenberg among others for continuing to teach the theories of [https://en.wikipedia.org/wiki/Albert_Einstein Einstein], calling them "white Jews". When his term as president of the Kaiser Wilhelm Society ended in 1936, the Nazi government pressured him to refrain from seeking another term. At the end of 1938, the Prussian Academy of Sciences lost its independence and was taken over by Nazis, and Planck protested by resigning his presidency. He bravely refused to join the Nazi party, despite coming under significant political pressure to do so.


Allied bombing campaigns against Berlin during the Second World War forced Planck and his wife to leave the city temporarily to live in the countryside, and his house in Berlin was completely destroyed by an air raid in 1944. He continued to travel frequently, giving numerous public lectures, including talks on Religion and Science (he was a devoted and persistent adherent of Christianity all his life).
==Alhazen Wrap Up==


===Death===
Not only was Alhazen heavily involved in optics, he was also heavily involved in the research of celestial objects/astronomy, number theory, geometry, philosophy, and theology. His work is very highly regarded that a crater on the moon is named after him. For number theory, Alhazen contributed his work on perfect numbers. He is a highly regarded physicist whose work can often be overlooked easily. 


[https://en.wikipedia.org/wiki/World_War_II World War II] brought further tragedy. Planck’s house in Berlin was completely destroyed by bombs in 1944. His younger son, Erwin, was implicated in the attempt made on Hitler’s life on July 20, 1944, and in early 1945 he was killed at the hands of the Gestapo. Planck’s will to live was greatly crushed by this act. At war’s end, American officers took Planck and his second wife, Marga von Hoesslin, whom he had married in 1910 and by whom he had had one son, to Göttingen, West Germany. Planck died here on October 4, 1947 at the age of 89.


== See also ==
==Connectedness==


[https://en.wikipedia.org/wiki/Max_Planck Max Planck's Wikipedia Page]


[https://www.youtube.com/watch?v=YEn-vX4duUc YouTube Video] regarding the beginning of quantum mechanics
How is this topic connected to something that you are interested in?


[http://hyperphysics.phy-astr.gsu.edu/hbase/mod6.html Black-Body Radiation]
Alhazen sparked interest in me due to my heavy interest in the way light works. I've always been interested in refraction and reflections and also how light travels in a straight line.  


===Further reading===


[http://hyperphysics.phy-astr.gsu.edu/hbase/mod6.html HyperPhysics: Black-Body Radiation]


==References==
== See also ==


===External links===


http://www.famousscientists.org/max-planck/
[https://www.youtube.com/watch?v=ljgWdMkZbsg Book of Optics Video]


http://www.nobelprize.org/nobel_prizes/physics/laureates/1918/planck-bio.html
[http://micro.magnet.fsu.edu/optics/timeline/people/alhazen.html Alhazen's work and contributions]


http://www.britannica.com/biography/Max-Planck
==References==


http://www.physicsoftheuniverse.com/scientists_planck.html
https://www.youtube.com/watch?v=ljgWdMkZbsg
http://www-history.mcs.st-and.ac.uk/Biographies/Al-Haytham.html
http://www.photonics.com/Article.aspx?AID=36717
https://en.wikipedia.org/wiki/Alhazen#Book_of_Optics
http://micro.magnet.fsu.edu/optics/timeline/people/alhazen.html

Latest revision as of 13:40, 4 December 2015

Claimed and Written by Ananth Somasundaram for PHYS2211

Alhazen was an Arab physicist, mathematiician, and astronomer who resided in Basra, Cairo. Alhazen had significant contributions in the fields of optics, astronomy, mathematics, scientific method and visual perception. He is considered to be the first theoretical physicist. Alhazen also was the earliest to discover that a hypothesis has the requirement to be experimented through trailed procedures or mathematical evidence. Alhazen is considered by many to be the father of modern optics.

Alhazen

Early Life

Alhazen was born in 965 CE in Basra, Buyid Emirate and passed away at the age of 75 in 1040 CE in Cairo, Egypt. He was born to an Arab family and moved to Cairo at an early age. When he moved to Cairo, it was under the rule of Fatimid Caliph al-Hakim. Alhazen pitched a hydraulic project to improve regulation of the flooding of the Nile. After pitching the idea, Alhazen realized the impracticality of his plan. There is no concrete proof, but it has been told that the Caliph was upset at Alhazen for the failed plan and placed him under house arrest till the Caliphs death in 1040. During the house arrest, Alhazen wrote his famous Book Of Optics.

Contributions

Alhazen had significant contributions in the fields of optics, astronomy, mathematics, scientific method and visual perception as mentioned earlier. He made the correlation that the angle of incidence and refraction does not remain constant. He also researched the magnifying power of the lens. Alhazens work significantly impacted other scientists of his time and future. His book of optics debuted many scientific facts which would be used later in the scientific world. Although Alhazen wrote as many as 200 books, as many as 55 have survived.


Book Of Optics

As mentioned earlier, Alhazen's most significant contribution was the Book of Optics which was created in a span of 10 years with 7 volumes. This book was also translated into Latin at the end of the 12th Centruy. This book influenced Johann Kepler and Leonardo da Vinci.


Theory Of Vision

Alhazen performed experiments on colors and light, reflections, and optic illusions. He would view the refraction of light rays through transparent mediums such as air and water and would record the laws of refraction. He was noted to be the first person to perform experiments on the dispersion of light into colors. He was noted to be extremely close to discovering the theory of magnifying lenses. This theory was officially created three centuries later. Alhazen was the first scientist to consider horizontal and vertical components of refracted and reflected light rays.

Alhazen proposed an intromission theory which said that from all points of a colored body, light and color along every straight line can be produced from that single point. By stating this, Alhazen realized that his theorem had a loop hole: he couldn't explain how a coherent image formed from many independent sources of radiation. Essentially, every point on an object would send rays to every point on the eye. To fix this problem, he stated that only perpendicular rays from the point would be received by the eye. He stated that perpendicular rays are more powerful than oblique rays. He also stated that there was only one perpendicular ray that enters the eye at an point and all the perpendicular rays converge on the center of the eye. Parallel rays are refracted through the eye and perceived as if perpendicular. Johannes Kepler used Alhazen's theory to build off his own theory of retinal imaging which would address the problem of correspondence of points on an object and places in the eye. Alhazen was the first person to experiment and prove that light travels in straight lines and experimented with refraction and reflection.

Alhazen also researched the process of sight and the structure of the eye along with image formations in the eye. He went into the detail of the structure of the human eye and went to consider how the anatomy would behave functionally as an optical system. Alhazen built off of Ptolemy's optic studies.


Alhazen's Problem

Alhazen's problem encompasses drawing lines from two distinct points on the plane of a circle meeting at a point on the circumference and making equal angles with the normal at that point. Alhazen used this in the realm of optics to solve problems when given a light source and a spherical mirror, to be able to find the point on the mirror where the light reflected to the eye of an observer. Alhazen then proceeded to derive a formula for the sum of fourth powers.

Alhazen's Problem


Scientific Method

Alhazen believed in reliance on experimentation and controlled testing for his scientific observations. Alhazen especially preferred combining classical physics along with mathematics which helped him believe in his theories of color, vision and light.


Alhazen Wrap Up

Not only was Alhazen heavily involved in optics, he was also heavily involved in the research of celestial objects/astronomy, number theory, geometry, philosophy, and theology. His work is very highly regarded that a crater on the moon is named after him. For number theory, Alhazen contributed his work on perfect numbers. He is a highly regarded physicist whose work can often be overlooked easily.


Connectedness

How is this topic connected to something that you are interested in?

Alhazen sparked interest in me due to my heavy interest in the way light works. I've always been interested in refraction and reflections and also how light travels in a straight line.


See also

Book of Optics Video

Alhazen's work and contributions

References

https://www.youtube.com/watch?v=ljgWdMkZbsg http://www-history.mcs.st-and.ac.uk/Biographies/Al-Haytham.html http://www.photonics.com/Article.aspx?AID=36717 https://en.wikipedia.org/wiki/Alhazen#Book_of_Optics http://micro.magnet.fsu.edu/optics/timeline/people/alhazen.html