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Showing posts with label Mathematics. Show all posts
Showing posts with label Mathematics. Show all posts

Monday, 13 July 2020

කන්දකාඩු, බටහිර වෙදමහත්තුරු හා දද සත

                        

                                                 සිංහල ලිත් ඉලක්කම්

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කන්දකාඩු, බටහිර වෙදමහත්තුරු හා දද සත

කන්දකාඩු ප්‍රශ්නය තරමක් බරපතළයි. ඒත් එය පාලනය කර ගත හැකි බව බලධාරීන් පවසනවා. එසේ ම වේවා කියා බලාපොරොත්තු වෙනවා. කන්දකාඩු කඳවුරට කොවිඩ් ඇතුළු වුණේ කොහොමද කියන එකයි ප්‍රශ්නය. අර නාවික කඳවුරේ රෝගීන් අවසන් වූ පසු කන්දකාඩුවට කොවිඩ් ගියේ කෙසේ ද? නාවික කඳවුරේ කොවිඩ්වලට හේතුව සුදුවැල්ලේ මත්ද්‍යව්‍ය භාවිතා කළවුන් බව කිව්වා. අප එය පිළිගත්තා. දැන් කන්දකාඩුවලටත් හේතුව සුදුවැල්ල කියන කොට එය විශ්වාස කිරීම පිළිබඳ ප්‍රශ්න ඇති වෙනවා. විශ්වාසය දැනුමක් ද වගේ ප්‍රශ්න මා අහන්නේ නැහැ. සියලු දැනුම් බොරු.  මා දන්නා දේත් බොරු. දන්නේ දැනුම නොවැ. ඒ කොහොම වුණත් රේඛීය චින්තනයේ ඕනෑම දැනුමක් විශ්වාසය මත පදනම් වෙනවා. ඒකත් දැනුමක් තමයි. ඒකත් බොරුවක්. මොනවා කරන්න ද? නිවන සම්මාබෝධ කරන තෙක් අපට බොරු කිය කියා ඉඳීම හැර වෙන කරන්න දෙයක් නැහැ. 

Tuesday, 7 April 2020

බටහිර වෛද්‍ය සභාවෙ බමුණු ආකල්ප

                     සිංහල ලිත් ඉලක්කම්


බටහිර වෛද්‍ය සභාවෙ බමුණු ආකල්ප 




අද බටහිර වෛද්‍ය විද්‍යාව විශේෂයෙනුත් බටහිර විිද්‍යාව පොදුවේත් කඩා වැටිලා.  තව මාසයක් දෙකක් යන විට බටහිර ආර්ථිකයත් කඩා වැටිල බව පෙනේවි. එය ඊනියා ධනවාදයේ කැඩී වැටීමක් නිසා නො වෙයි. ධනවාදයේ කඩා වැටීම නිසා නම් ඒකට විකල්පය කුමක් ද? සකර්බර්ග් හා වෙනත් වම්මුන්ට කියන්න පුළුවන් සමාජවාදය කියල ද? කියුබාව සමාජවාදී ද? ට්‍රොට්ස්කිවාදියකුගෙන් අහල බලන්න. සමාජවාදය කියන්නෙ මාක්ස්ගෙ හිතළුවක් පමණයි. සියල්ල හිතළු තමයි. සමහර හිතළු හරි යනවා (හරි කියන එක නොවෙයි, වැඩ කරනවා කියන අර්ථයෙන්) ඒත් මාක්ස්ගෙ හිතළු ව වැඩ කළෙ නැහැ. මාක්ස් පවු!

Tuesday, 31 December 2019

රාජිත චම්පක ගානියා හා තවත් දේ

 සිංහල ලිත් ඉලක්කම්


රාජිත චම්පක ගානියා හා තවත් දේ


සජිත් බොහොම බරපතළ දේ ගැන කතා කරනවා. ජනාධිපතිවරණයෙන් පස්සෙ නැතිව හිටපු සජිත්ගෙ ඩයිනමෝව හා එංජිම නැවත ක්‍රියාත්මක වෙනවා වගේ. සජිත් ඒවා ගරාජයට දාලා තියෙන්න ඇති. දෙයියන්ගෙ පිහිටෙන් සජිත්ට හෘදයාබාධ නැහැ. ආතතියකුත් නැති පාටයි. ඔහු තාම තරුණයි. රාජිතට හා චම්පකට වඩා තරුණයි. ඔහු රාජිත හා චම්පක බලන්නත් ගිහින්. මට ඔහුගෙන් පොඩි ප්‍රශ්නයක් අහන්න තියෙනවා. ජාතික ගීය දෙමළෙන් ගැයීම ගැන ඔහු මොක ද කියන්නෙ. ඔහුත් හිටි ආණ්ඩුවකින් තමයි 2015 -2019 කාලයෙ ජාතික ගීය දෙමළෙන් ගැයුවෙ. ඔහු එය අනුමත කළ බවයි පේන්න තියෙන්නෙ. බොහෝ දෙනාට මතක නැති වුණාට ජාතික ගීය දෙමළෙන් ගැයීමට ජාතික ව්‍යාපාරයෙ සමහර ගිහි පැවිදි ප්‍රධානීන් ද එකඟ වුණා. 

Tuesday, 6 August 2019

රට ඉඳි හා ගණිතය


  සිංහල ලිත් ඉලක්කම්


රට ඉඳි හා ගණිතය 



පාස්කු ප්‍රහාරය පිළිබඳ වග කිවයුත්තන් එක්කෝ මළවුන් අතර නැත්නම් අත්අඩංගුවේ කියා ජනාධිපතියි අගමැතියි දෙන්න ම කිව්වත් තවමත් අත්අඩංගුවට ගැනීම් කෙරී ගෙන යනවා. සමහරවිට දැන් අත්අඩංගුවට ගැනෙන්නන් පාස්කු ප්‍රහාරයට සම්බන්ධ අය නොවෙන්න පුළුවන්. ඔවුන් සමහරවිට කාත්තන්කුඩියේ රට ඉඳි ගස් වවන්න ඇති. පොලීසිය ඒ නිසා අත්අඩංගුවට ගත්තා ද කියා දන්නේ නැහැ. කාත්තන්කුඩි පොලීසියට හෝ ත්‍රස්ත විමර්ෂණ ඒකකයට හෝ සහරාන් අත්අඩංගුවට ගන්න බැරි වෙලා තියෙන්නෙ සහරාන් ඔවුන්ගෙ ඇස්වලට වැලි ගහල පැනල ගිය හින්ද කියල තමයි කියැවෙන්නෙ. සහරාන් රට ඉදි ගස් වැව්වෙ නැති වෙන්නත් පුළුවන්. 

Wednesday, 5 June 2019

රාමළාන් හඳ

රාමළාන් හඳ 


අද රාමළාන්. ඒත් මා හඳ බලන්න පාතිමාට එන්න කියන්නේ නැහැ. එයට ප්‍රධාන හේතුව මගේ භාර්යාව සමගවත් හඳ බලන්න මගේ වයස අනුව හිතෙන්නෙ නැති නිසා. දෙවනුව හඳ බැලීමෙන් පමණක් සිංහල - මුස්ලිම් සහජීවනයක් (ඊනියා සංහිඳියාවක් නොව) ඇති කරන්න බැරි නිසා. ජඩමාධ්‍ය සුපුරුදු පරිදි මේ අදහස්වලට ප්‍රචාරයක් නොදේවි. දැන් පෝය හැටකට වැඩි කාලයක් ජනමාධ්‍ය මා අත්හැර ගොස්. ඊයේ මට කුලියාපිටියේ දී අවුරුදු තිහකට පමණ පසු හමු වූ අයකු ඇසුවේ මා දැන් නිහඬ ඇයි කියා. මා නිහඬ නැති බවත් ඒත් මගේ හඬ පිටවන්නට ඉඩක් නැති බවත් මා කී විට ඔහුට මා කියන දේ තේරුම් ගියා. එහෙත් මා කියන දේ සමාජයට නොගිහින් තියෙන්නේ නැහැ. ජඩමාධ්‍ය කුමක් කළත් ඒ අදහස් රටට යනවා.

Wednesday, 24 October 2018

අපේ ම නොවන අපේ ගණිතය


අපේ ම නොවන අපේ ගණිතය



අප කලින් දවසක (!5 වැනි දා) කතා කළා ගණිතයේ සාපේක්‍ෂ බව ගැන. ප්ලේටෝගේ සිට මෙයිසු ද කවු ද දක්වා බටහිර දාර්ශනිකයන් හිතන්නෙ ගණිතය අපෙන් තොරව පවතින බවත්  එය සත්‍ය බවත්. ප්ලේටෝ විඥානවාදියකු ලෙස හංවඩු ගැසුණත් ඔහුත් ද්‍රව්‍යවාදියෙක්. ඔහුගේ අර සුප්‍රසිද්ධ ගුහාවේ කතාවෙන් කියැවෙන්නේ ඊනියා යථාර්ථයක් පවතින බවත් අපට දැනගැනීමට හැකිවන්නේ එහි හෙවනැල්ල පමණක් බවත්. මේ ඊනියා යථාර්ථය අපට දැනගැනීමට නොහැකි බව ඔහුගේ කතාවෙන් කියැවෙනවා.

Monday, 23 July 2018

සාධන හා පෙන්වීම්


සාධන හා පෙන්වීම්



ගණිත ප්‍රශ්න පත්‍රවල තියෙන්නෙ සාධනය කරන්න පෙන්වන්න කියල. මේ දෙකෙන් කියැවෙන්නෙ දෙකක් වුවත් ගණිතයේ දී පිළිතුරු දෙන්නෙ එකම විධියට. පෙන්වන්න කියන එක සාධනය කරන්න කියන එක තරම් දැඩි ව කළ යුතු දෙයක් නො වෙයි. එහෙත් පෙන්වීම කෙතරම් දුරට සාර්ථක ද කියල කියන්න බැහැ. සාධනය නම් නිවැරදි ද කියලා සාමාන්‍යයෙන් කියන්න පුළුවන්. සාමාන්‍යයෙන් කියල කිව්වෙ වරතමානයෙ ඉදිරිපත් කරන පරිගණක ආශ්‍රිත සාධන, පිටු දහස් ගණනක් දිවෙන සාධන නිවැරදි ද කියල කියන එක තරමක ප්‍රශ්නයක්.

Thursday, 7 January 2016

අමරතුංග මහතාගේ ගණිතය හා යථාර්ථය (2016 ජනවාරි 06 විදුසර ලිපිය)

අමරතුංග මහතාගේ ගණිතය හා යථාර්ථය

ඩී එස් සී උපාධිධාරී සේවාර්ජිත (සම්මානිත) මහාචාර්ය අශෝක අමරතුංග මහතාට තමා කලින් කියා ඇති දේ අමතක ය. ඔහු අසංගතව ඇතැම් කරුණු සඳහන් කරයි. ඔහු දැන් කතා කරන්නේ යුදෙවු ක්‍රිස්තියානි සංකල්පයක් වූ ජීවිතයේ ඊනියා අරුත ගැන ය. එය සිංහල බෞද්ධ චින්තනයට පටහැණි ය. කෙසේ වෙතත් ඔහු ප්‍රෝටීන නෑමුම ගැන කතාකිරීමට ජනප්‍රිය ඉංගිරිසි පොතපතින් සිංහලට පරිවර්තනය කර විදුසර පුවත්පතෙහි පළ කරයි. ඔහු එහි දී ගණිතය ගැන ද සඳහන් කරයි. පසුගිය දෙසැම්බර් 30 වැනි දින ලිපියෙන් ඔහු මෙසේ කියයි.

Tuesday, 28 February 2012

Mathematics and Physics(NP)

Let me first deal with banter of Prof. Carlo Fonseka as it is relevant to our discussion. I am younger now than when I went to the UK to write that thesis, does not mean that I am younger due to the air travel. After coming back to Sri Lanka I grew older until about the year 1980, repeating like many others what the westerners had taught me. My so called research confined to some peripheral problems in western science without challenging its concepts or theories. However, after that year new ideas came to me in a “procession” and it is generally believed that it is the young who are endowed with new ideas. I have been able to think a fresh creatively since then, and I am happy that I am growing younger, though many, especially in the academia may not like my original ideas. Prof. Carlo Fonseka does not belong to that category and that is one of the reasons I respect him.
Prof. Fonseka does not seem to have grasped the essence of time dilation in Special Relativity. It is essentially regarding the time interval between two events as measured by observers moving relative to each other. In special relativity objects cannot travel with velocities faster than light though there appear to be evidence recently to the contrary. For a particle travelling with a velocity less than that of light the time as measured by a clock moving with it (proper time) increases and a person does not become younger by going in an airplane. The clocks that were taken round the earth referred to by Prof. Fonseka registered different times due to general relativistic effects and rotation, and is not related to the so called twin paradox in special relativity. In any event my being younger now has nothing to do with traveling in airplanes with or without that young lady called Bright.
What I said on imposing ideas is the following. “After coming back from the UK to Sri Lanka then known as Ceylon in another Air Ceylon airplane (could have been the same airplane) I have realized that the westerners have imposed their needs on us through colonialism.”. Prof. Fonseka states that “In any case, my position has nothing to do with westerners having "imposed their needs on us through colonialism’ as claimed by Prof. Nalin”. Prof. Fonseka is of course entitled to think that way but it is not a secret that the schools we attend, the universities where we study and of course the books we read have an immense influence on us unless we for some reason or other make a deliberate attempt to break away from that influence and succeed. What are (western) schools and universities for if not for imposing not only western needs, but also western attitudes, western knowledge, western culture etc.? Personally I am aware how I changed from my semi rural and semi urban knowledge and attitudes to western scientific knowledge and attitudes at schools and the universities, and then how I went back to my cultural identity having realized the inadequacies, weaknesses, inconsistencies, inhumanness etc. in the western Chinthanaya that gave rise to western science. There are many people who talk of Principle of Superposition in Quantum Physics without realizing that it cannot be explained in western thinking. Quantum Physics may be working but as Feynman has said nobody (in the western sciences – my emphasis) understands it. How does one understand that a particle can exist at two or more places simultaneously in Aristotelian logic? At home and the village temple I was brought up in a culture that did not seek comfort but emphasized on avoiding “kamasukhallikanuyogaya” and also “attakilamtanuyogaya” and taught me of “alpecca” and sallahuka” form of life. My upbringing as a child did not allow me to be “bahubhandika”, and today I have no problem in traveling by bus and sparingly using my old car bought in 1978 (before 1980). Full option cars are not for me now, and I am reminded of the “nembiliya” in this regard. “Nembiliya” is used to separate rice from other material found in rice and having constructed and developed it to a certain level, Sinhala people did not want to “improve” it to a full option nembiliya, wasting energy and resources. The concept of comfort is determined by culture and it is not only the bodhisathva who find “dukkha” in comfort. In my series on so called scientific knowledge I will go into detail on this and show how a Science based on Sinhala Buddhist culture or Tamil Hindu culture is different from western science.
Prof. Fonseka says “For my part, my understanding of what the Buddha taught about the way to achieve well-being and happiness through the elimination of greed, hatred and delusion is quite compatible with my understanding of the modern scientific outlook.”. However, greed, competiveness, sensory pleasures etc., are behind modern western consumerism and living in general and more and more possessions will not guarantee happiness to people. It will only destroy the natural resources, increase competitiveness, and I do not think that I have to elaborate on this. In connection to what Buddha had taught there are many scholars who would be happy to show that Buddhism is (western) scientific and rational meaning conformity with Aristotelian logic. It is not so, and I remember Prof. Fonseka himself trying to present Kalama Sutta as evidence for the so called scientific method. However, he has now realized that there is a Part II to Kalama Sutta referring to the Vinnus .
Prof. Fonseka states: “Prof. Nalin’s answer to his question about the effectiveness of western physics based on western mathematics is their ‘abstractness’”, and that in his view “the effectiveness is the outcome of their concreteness and empirical nature.” However the question I asked was "why western mathematics ‘the subject in which we never know what we are talking about, nor whether what we are saying is true’ has been so effective in western physics" It is different from Prof. Fonseka’s formulation. Western Mathematics is very abstract and western Physics is abstract to a very high degree. It is said that we do not know what we are talking in Mathematics nor whether what we are saying is true, but I presume that Physics is trying to arrive at truth. How can Mathematics with those properties be so effective in Physics as such? On the other hand, if I were to ask Prof. Fonseka why western Mathematics is not effective in Physiology what would his answer be? Concreteness was and is not the hallmark of western science that looks for generalized theories. Even the patients in western medicine are generalized patients and not concrete patients. Finally this talk of empirical nature becomes a travesty when it is claimed that if the appearances (what is grasped through the sense organs) are true, then there is no need for a science. It is said that one starts with observations (experiments, controlled experiments,) then theorize and come back to observations to test the theories. Observations are appearances and how does one know that the theories are true or let us say approaching the truth by comparing the deductions from theories with observations?


Copyright Prof. Nalin De Silva

Mathematics and physics

Home  » Opinion » Mathematics and physics

February 12, 2012, 6:46 pm

The miraculous power of western physics based on western mathematics has enabled Prof. Nalin de Silva to respond on the 10th of February to my article on mathematics and physics published in The Island on the 9th of February. As Sir Arthur Clarke said, any sufficiently advanced technology is indistinguishable from magic (Clarke’s 3rd Law). Having informed us that he went to the UK many moons ago by an airplane Prof. Nalin says that he is "much younger now" (sic) than he was then. I believe this was a slip i.e. a small unimportant mistake, and what he really meant to say is that he is now "much older", but with my friend Nalin you never can tell. From past experience I know that when he uses a word it means just what he "chooses it to mean, neither more nor less". That is why for years I have avoided arguing with him although I often read the lucubrations of his lateral-thinking mind.


Relativity


In the present context because Prof. Nalin went to and returned from the UK by air to write a thesis on Relativistic gravitational effects in Astrophysics, I must bend over backwards to make sense of his claim that he is much younger after he came back than before he went. If I have got it right, according to Einstein’s theory of special relativity, the passage of time can be slowed down. If time can indeed be slowed down it is not intrinsically absurd to suppose that it might even be reversed. So Prof. Nalin’s claim that he is younger now than when he went to the UK can be understood in terms of the following popular limerick:


There was a young lady called Bright,


Who travelled much faster than light.


She set off one day


In a relative way,


And came back the previous night.


Buddhism


Leaving banter on one side, in his response to me, Prof. Nalin refers to a Bodhisatva, dukkha, anicca, and avidya. Obviously he is steeped in Buddhist thought and if he says that he prefers his understanding of Buddhist doctrine and cultural ethos to every other approach to life in this world, who am I to contradict him? For my part, my understanding of what the Buddha taught about the way to achieve well-being and happiness through the elimination of greed, hatred and delusion is quite compatible with my understanding of the modern scientific outlook. This implies that acceptance of my understanding of what the Buddha taught does not require the rejection of my understanding of the modern scientific outlook. In any case, my position has nothing to do with westerners having "imposed their needs on us through colonialism" as claimed by Prof. Nalin. I know that he genuinely believes that my position is due to my lack of sufficient intelligence to understand these matters in the way his first-class mathematical brain does. That is why when exasperated by what he regards as my invincible stupidity and intractable obstinacy, he occasionally calls me a matta (i.e. a dullard) to my face. Who knows, he may well be right!


Abstraction & Empiricism


Prof. Nalin’s answer to his question about the effectiveness of western physics based on western mathematics is their "abstractness". My view is that the effectiveness is the outcome of their concreteness and empirical nature. Sense perception (as opposed to abstract thinking) if not the sole legitimate source of knowledge, is critically the final court of appeal of the validity of modern science. For example, Einstein’s counter-intuitive claim about the relative nature of time, that is to say that the passage of time can slow down, was empirically tested in 1971. Four identical atomic clocks were sent on flights twice around the world, two eastwards and two westwards. Their times were compared with a matched clock on the Earth’s surface in the United States. It was found that the moving clocks had lost a fraction of a second compared with the grounded clock in accordance with the theory of special relativity. (See: 50 physics ideas you really need to know by Joanne Baker, Quercus, page 163. www.quercusbooks.co.uk)



Carlo Fonseka

Mathematics and Physics

I am afraid my senior colleague and friend Prof. Carlo Fonseka has not answered my question. The question I posed in my letter to the editor on 6th February 2012 was "why western mathematics ‘the subject in which we never know what we are talking about, nor whether what we are saying is true’ has been so effective in western physics" Without answering the question Prof. Fonseka make certain statements (The Island - 9th February 2012) , which are not that relevant. However, I will deal with them with pleasure.


Prof. Fonseka says to “seek comfort” he has “to understand what is happening” in his “environment in terms of cause and effect relationships i.e. gain knowledge about how nature works”. The comfort referred to by Prof. Fonseka may not be the same as what some others may mean by “comfort”. For example a Bodhsathva would have a different objective in life and there are many others who see “dukkha” in “comfort”. There are different attitudes to life in different cultures but unfortunately we are now dominated by western idea of “seeking comfort”. The knowledge systems created by people differ due to these differences among others, and it has to mentioned that Medieval Europe with attitudes based in Catholic culture was not able to create western science. It needed a revolution in Chinthanaya as I call it, in the sixteenth century.


Even if we forget these differences and go with Prof. Fonseka’s idea of “understanding” what is happening in the environment and gaining “knowledge about how nature works”, and assuming that western Physics tries to gain knowledge about how nature works, the question is how could it be done with Mathematics ‘the subject in which we never know what we are talking about, nor whether what we are saying is true’ in the words of Bertrand Russell. In Mathematics one is not bothered to “know” whether the axioms of the particular branch one studies is “true”, and all that one is interested is in obtaining some other propositions from those axioms using formal logic. My question is if western Physics tries to “gain knowledge about how nature works” how can it do the same with western Mathematics.


Prof. Fonseka says: “ I have gradually realised that the most reliable knowledge available to me has come from the collective experience of human beings living in the east or west, north or south who have observed aspects of the world with their five senses, used their reason to figure out causal explanations for their observations and then checking the validity of their explanations by putting them to the test of experience. Experience has shown humankind that in formulating causal explanations (hypotheses) the use of formal systems of reasoning has greatly contributed to the reliability and usefulness of the final outcomes. One such formal system is mathematics,” Now this is nothing but what was called scientific method before Popper and much water has flown under the Kelani Bridge as well as the Tower Bridge in London since then. As I am discussing these under my series of articles “on so called scientific knowledge I do not want to delve into it now. However I would like to ask how one knows that A = A as assumed in formal logic, in a world of “anicca”. With A = A there is no change (motion), and I have dealt with this problem in an article on “The logic of change”, published in “Kalyani” the journal of the University of Kelaniya.


Incidentally what Gödel proved was that any formal system that incorporates Arithmetic contains statements that are “Mathematically true” which cannot be deduced from its axioms. Prof. Fonseka may think that western Mathematics is “reliable” but then there were so many other systems that could be considered as reliable. It is true that I went to the UK many moons ago in an Air Ceylon airplane to write a thesis on “Relativistic gravitational effects in Astrophysics”. I had been interested in western Physics and Mathematics as a young person and situation demanded that I gain postgraduate qualifications to continue as a lecturer and I had to make that trip to the UK. However, I am much younger now and air travel is not a necessity at present. I seek no employment in any capacity nor any qualifications in western Science. In any event the motion of airplanes was based also on Newtonian Gravitation, which had been discarded as a “Theory of Gravitation” and shown that there was no gravitation as such by Einstein more than fifty years before I got into that airplane. However, the western scientists have still not discarded it and it is continued to be taught in schools and universities. So much for the “scientific method” and “reliable knowledge”.


People invent, construct instruments, concepts, theories etc., depending on their needs and it is needless to say that needs differ from culture to culture. After coming back from the UK to Sri Lanka then known as Ceylon in another Air Ceylon airplane (could have been the same airplane) I have realized that the westerners have imposed their needs on us through colonialism. I do not want to say there was the “dandumaonara” of Ravana constructed most probably due to some need of that society as an alternative to the airplane, but I can assure Prof. Fonseka who hold a very high position in an institution of the western medical profession, that there are hundreds of western medical doctors who have more faith in Sinhala Nila Vedakama than in western Medicine, probably because the former is more “reliable’, and moreover that some of them practise it.


Now since Prof. Fonseka has not answered my question I give my answer to the same. Western Mathematics is very abstract and western Physics is the most abstract among the western Sciences. Western Mathematics has not been very successful in western Physiology or western Biology for that matter, and the main reason for the effectiveness of western Mathematics in western Physics is this abstractness. Of course there is another reason for the effectiveness. Even in western Physics “we never know what we are talking about, nor whether what we are saying is true”, gravitation on which I worked for my thesis being the best example. However, that does not imply that “we know what we are talking about, and what we are saying is true” in other western sciences or for that matter in any “knowledge constructed by human beings due to Avidya. (Avijja paccaya sankara).(12/02/10)


Copyright Prof. Nalin De Silva

Wednesday, 22 February 2012

Mathematics and Physics

Prof. Carlo Fonseka’s article on the nature of Mathematical Knowledge that appeared on 5th February 2012 in “The Sunday Island” prompted me to pen these words. We as students knew that (Pure) Mathematics consists of the set of propositions of the form p implies q, and in fact one of the questions set by my respected teacher late Prof. Douglas Amarasekera for the final examination in the year I sat (in 1967) was on this proposition, which I must say that I answered with delight. I do not know what exactly Prof. Amarasekera had told Prof. Carlo Fonseka on Mathematics and Logic but all that I have to say is that Mathematics cannot be reduced to Logic. Bertrand Russell who himself undertook the task of showing that Mathematics could be reduced to logic with his friend A . N. Whitehead failed in his attempt. Later with his incompleteness theorems Gödel showed that the celebrated Hilbert Programme also failed and since then we know that the formalist methods though used in Mathematics are strictly speaking do not hold water. Western Mathematics is another system of knowledge created by human beings mostly of the male variety just as much Vedic Mathematics is, which is different from the former, and interested readers on this matter may refer to articles by Prof. Raju, though he does not seem to have grasped the idea of culture dependence of knowledge systems created by human beings.

I am a fan neither of western Mathematics nor of western Physics, though I have a very limited knowledge in both, but could Prof. Carlo Fonseka or anybody else explain why western Mathematics "the subject in which we never know what we are talking about, nor whether what we are saying is true", has been so effective in western Physics in which many people appear to think that they know what they are talking about.(12/02/06)


Nalin De Silva

Sunday, 22 January 2012

Z score and populations

I would not have written this if not for the explanations given by Prof. Thatil on the Z score. He has referred to the formula used by the panel of experts on pooling of two populations and said that it is not correct to pool them and then find the Z score of the pooled populations. Instead he suggests that the Z scores of different subjects of the two populations should be taken as they are and then add the Z scores of the three subjects each student has sat and then find the average of the three Z scores. The panel on the other hand pools the populations that sat the old syllabi and new syllabi examinations, find a Z score in each subject for the pooled populations and then take the average of the three Z scores to determine what is called final Z score of a student.
However it is the addition of Z scores in separate subjects that is questionable rather than the pooling of two populations. What is forgotten in the whole exercise is that what we are interested in selecting the students who performed better at the GCE (A/L) examination. Even if we have a group of students who sat for the same three subjects in the new syllabi how are we going to select the better students? Consider the following two cases. Sandun obtains 90 marks for Combined Mathematics 80 for Physics and 40 for Chemistry, while Sanduni obtains 60 marks for Combined Mathematics 70 for Physics and 85 for Chemistry. If we go by the aggregates of marks Sanduni is the better student. If the Z scores are considered this order may be reversed. However we cannot select the better student even by adding the respective Z scores. How does one compare the Z score in Chemistry with that in Physics? In other words how many marks in Chemistry are equivalent to say 70 marks in Physics?
If Sandun has 90 US Dollars, 80 Pounds and 4000 SLRupees  and Sanduni has 60 US Dollars, 70 Pounds and 8500  SLRupees we can find out who has more money by converting each currency to a common currency using the current exchange rates and then adding the money in the common currency. My question is what the exchange rates are as far as marks obtained in different subjects are concerned. I do not think that the Z scores give an "exchange rate" in respect of marks obtained in different subjects.
This problem arises not only at selection of students to the Universities but even at term tests in schools. We may say Sanduni came first and Sandun came second by just adding the raw marks. However it may not be so and I suppose in order to overcome this problem some schools adopted a method called scaling of marks in the fifties. The idea was again, I am assuming as I had not discussed this problem with any of the teachers, to find exchange rates between marks in different subjects. It may not be a bad idea for the experts in Statistics to find these exchange rates at least from a literature survey, if they are available, to be used at future examinations.
Though Prof. Thatil may not have realized it, when we calculate the average mark in a subject that is examined using more than one question paper we pool two or more populations and obtain the combined average. For example, though the same students sit for Combined Mathematics I ("Pure Mathematics") and Combined Mathematics II ("Applied Mathematics") they cannot be considered as one population. They are two populations but we consider them as one population for the purpose of calculation of the average mark in Combined Mathematics and then calculating the mean and variance in order to find the Z scores in Combined Mathematics. It would have been better if we have an exchange rate for conversion of marks from Combined Mathematics I to Combined Mathematics II and vice versa but until such exchange rates are found we may have to pool populations whenever pooling is better than any other method available. 

Copyright Prof. Nalin De Silva