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Science in Daily Life

– Pushpa Raj Adhikary

Most people in our society  take science as something strange and crazy,  which are the works of Newton, Einstein and few others persons known as scientists. The works of so-called scientists led to the invention of rockets and bombs which are threats to human civilization. Also science contradicts the age-old belief  on the existence of god, hell and heaven. Wrong notions about science and technological advancement are the main causes of our ignorance and backwardness.  As a consequence, we are suffering from poverty, shortage of food, diseases and lack of medical facilities, lack of drinking water, shortage of electricity and so many other  benefits, which people in the developed world enjoy.
We have to dispel our mistaken notion of science and technological advancement if we want to get rid of most of our problems related to underdevelopment. The history and survival of humankind is a story of the growth of science. The desire to survive led early human to learn to hunt. In that process, they devised tools. The discovery of agriculture led to the process of growing food through irrigation, farming and cropping. The curiosity to communicate with others led to the invention of language and the art of communication which continued to grow further in the form of written language, printing  and wireless communication. This was a revolution continuing still today in the development and spread of internet. The urge to go to different parts of the earth led to the growth of transportation. Now the movement of humans is not confined only on the surface of earth bu to the top of the mountain, deep inside the sea and as far as the planet mars. People are thinking about inter-space travel. There are many other fronts of developments which are the direct consequence of the development of science and technology. Notably among them is the advancement of medical science and medical technology.
Science is not something which concerns only scientists. We wake up in the morning and see that the sun rises or appears in the east. In the evening the sun sets or disappears in the west. We are all familiar with the changing seasons. Some parts of the earth have heavy rain whereas other parts have snow and very hot deserts. The nature of plants and animals, even the colour of human beings in different parts of the earth differs. We need water to drink .We don’t drink water from all sources. Water from some source may upset our stomachs. We have diseases like malaria, typhoid, and hepatitis and nowadays AIDS. Insects crawl on grounds, birds fly and animals and human beings walk on ground. Many animals live on grass and green plants but human beings need cooked food.
During winter nights, if you look at the sky, you see tiny twinkling dots known as stars. If you look more closely, you find several differences among the stars. Stars appear only in nights. Moon also appears only in nights but not at all nights. Sometimes our sun and full moon are covered by strange black shadows known as eclipse.

We all are aware of the phenomena described in the last two paragraphs. We can cite many other natural phenomena which happen in our daily life. During illness we take pills and capsules of medicine and get cured. Sometimes we do take medicine in the form of injection but how many of us and how often do we ask ourselves why and how different natural phenomena happen? Why sun always rises in the east and sets in the west? Why do we get monsoon more or less in the same time each year? Why we need medicine when we are ill and how medicines cure us? How different varieties of breads, cheese and butter which appear in our breakfast table are prepared? Very recently we have started showing concern for our environment. What has happened to our environment and how? Why the rapid industrialization has dismantled some of the natural resources?
Many of us take all things and happenings around us without any wonder. But there are persons who wonder about these things. They are curious to learn more about their surroundings and the happenings with the question “Why?” and “How?” They wonder why the sun shines and what cloud is like. They wonder why a book falls to the ground when we drop it. They wonder at the stars, planets, and the moon.They wonder as how star is born, how many stars are there, why there are patches in the full moon, how vast is the universe and so many other questions. Most discoveries came out because someone wondered.
But discoveries are not made by wondering alone. You may wonder and ask questions as “How?” and “Why?”But who answers theses questions? You observe, listen, feel and learn to satisfy your curiosity. By doing so you make some idea about something or some happening. In other words, you come out with some explanation.  If this explanation alone satisfies you, then you are not a scientist. The difference between a scientist and others lies here. A scientist likes to verify his/her understanding or explanation of something by experiment. In many cases we might have made a guess but we could not be sure. So we do the experiment and it can give us a true answer. Experiment and discovery go hand in hand.
A curious mind asks questions and comes across new riddles and puzzles. You may be bored and give up solving them. Others may come out with some valid explanations of these puzzles. But how do we know whether these explanations are correct? Those who continue to know the correct answers to these riddles and puzzles either by explanations or by experiments are scientists. Scientists have to correct their understanding or explanations and experiments again and again until they bring out the truth. Sometimes scientists discover the answers to their problems in a very short time. More often, they must experiment patiently and carefully for years before they find out what they want to know. They may do one experiment a thousand times, or a thousand different experiments just to discover one fact.
Now, if you are also intrigued to think like a scientist or think that you have a potential to be a scientist then think about the question, “Assume that the earth does not rotate around its axis. How will this affect us? Assume next that the earth does not go around the sun, what will happen?”
 
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Posted by on January 15, 2016 in Science

 

Face to Face with the Universe

– Pushpa Raj Adhikary

Former Dean and Controller of Examinations

We human beings live in a planetary system of a star which we call the Sun. Our sun is just one of the minor stars in the cluster of about 250 billion stars called the Milky Way. We live far from the bright and densely populated nucleus of the Milky Way. Earth is one of the nine planets which surround the Sun, and continuously revolves around the Sun in more or less a fixed path known as its orbit. The earth is surrounded by a gaseous ocean. We live on the bottom of this rather opaque gaseous ocean. The earth is also one of the billions of other planets in the universe, nothing more than a tiny speck of dust in the vast galactic island. What can we hope to learn of this universe from our galactic backwoods?

In our short history of the existence on earth we had hardly had time enough to take stock of our immediate surroundings. We have just begun to know and understand ourselves. Thousands of years of human civilization are but a fleeting instance as compared with the periods of time in which matter evolves on the universal scale. Less than 500 years have passed since man first proved that this planet is a globe by circumnavigating it.  A century has passed since we discovered, at first by speculative reasoning, some of the laws connecting space, time, and motion. We have just begun to probe the secrets of the structure of the matter. Our knowledge of the universe is scanty indeed and we still have a lot more to learn. But we are inquisitive, have learned things step by step and continue to learn many more things about our universe by the same way and in course of time will unravel more mysteries of the universe.

Apart from the terrestrial landscape of mountains, valleys, flat plain, dense forest and oceans, man has been looking up at the twinkling dots in the sky for thousands of years. Some have compared these twinkling dots, known as stars, the twinkling eyes of the universe looking down on earth. Stars appear after the Sunset and must have looked very mysterious objects for early human beings. Beginning with idle stargazing, it has now turned to systematic observations, first with naked eyes, then with the simplest of instruments, and today with the help of giant telescope with lenses several feet in diameter and other sophisticated instruments. Now we can distinguish planets and stars.

In addition, we have identified various other objects scattered around the vast void of the universe. There are very big clusters of stars like our Milky Way. These clusters of stars are known as galaxies. The galaxies have hundreds of solar systems like ours. There are huge objects made of a gaseous material known as nebulae. Some objects are not visible to us but we feel their presence by detecting the noises they emit. These noises are known as radio waves and are detected and analyzed to understand about these noisy objects. We can measure how big a star is, how far one star is from another, and measure the distance of the farthest nebulae. So the old saying “Twinkle, twinkle little star, how I wonder what you are” is no longer true. Today we can say “Twinkle, twinkle little star, we know exactly what you are”. Stars are no wonders today and neither are they little. Other stars are several thousands to even hundreds of millions larger than our sun and are made of materials in plasma state.

The earth is surrounded by an ocean of colorless gases which we call air. Air mainly contains nitrogen and oxygen along with different other gases in traces. This air covering of our planet earth is known as the atmosphere and is spread up to 3,000 kilometers altitude above the earth. Clouds are usually observed at an altitude of about 80 kilometres. Somewhat higher, between 100 and 120 kilometres, meteors appear as shooting stars. A flying meteor is a complex phenomenon involving the interaction of a fast moving body carrying an electrical charge with the Surrounding air. Atmosphere gradually becomes less and less dense depending on the distance from the surface of the earth. Some strange lights (Northern and Southern lights) called Aurora Polaris occur in the uppermost layers of the atmosphere as high as 1,200 kilometres.

At an altitude of 3,000 kilometres above the surface of the earth, just outside the edge of the atmosphere, electrically charged particles from the outer space counter us. Earth is a huge magnet and its magnetic influence spreads in the surrounding space known as magnetic field. The charge particles which come from outer space towards earth are trapped by the earth’s electromagnetic field. They spiral along the earth forming three radiation belts. A disturbance in this belt causes disturbances in our radio, television and other means of communication.

From the surface of the earth we see the sky is blue and the stars twinkle. These phenomena do occur due to the earth’s atmosphere. So, how does the sky look when we watch it beyond the atmosphere? Astronauts and space travelers tell us that the sky looks totally dark and stars no longer twinkle. Rather they look like dull light-emitting objects. If we recall back, on March 18, 1965 an earth man named Alexei Leonov, citizen of the then Soviet Socialist Republic, first encountered the vast void of the universe face to face. Leonov became the first person from the planet earth to push himself away from his spaceship Voskhod 2 to drift out into the bottomless void known as space. Leonov was connected with a rope-like chord to keep from losing himself in the strange, weird void surrounding him.

Man is inquisitive by nature. As soon as we discover a new law of nature, we try to exploit it for our own ends. Having discovered the secret of lightning bolts we use it to produce electric light. By learning the laws of river flow we dug irrigation canals. We have harnessed the power of nuclear fission of uranium and will soon learn to tame the thermonuclear reaction which heats the sun and stars. No sooner do we discover the laws of the universe than we surely put them to work and make them serve us. We have understood the terrestrial laws and phenomena and made them serve us. So we can hope that by becoming the master of the universe one day we may be able to reconstruct the planetary systems, move stars about and regulate their brightness at our will.
 

 
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Posted by on May 23, 2014 in Science

 

The Omnipresent Force

– Pushpa Raj Adhikary

We call the pull of the earth on the bodies the force of gravity. The measure of this pull is called the weight of the body. There is no escape from the gravity and its eternal laws are valid even in the remotest parts of the universe. It equally pervades vacuum and the densest substance. There is no way of shielding from it or acting on it. Its action is less and less when we move away from earth but does not vanish completely. Gravity makes rivers flow down to the sea, keeps the atmosphere around the earth, and is the cause of tides in the oceans. We have to use force to overcome gravity if we want to move away from the earth.

Since time immemorial, living beings had to reckon with gravity, and learned to adapt to it. The force of gravity, which makes everything move towards it, was unexplained for ages. The first man to develop a scientific theory of gravity and apply it to study of the universe was the great Englishman, Sir Isaac Newton.

The anecdote that Newton discovered the law of gravity by watching an apple fall from a tree may or may not be true. It has been said that he invented this story to get rid of people demanding explanation of just how he discovered the great law. Today, any high school student knows this law with such an ease that it seems strange indeed that there was a time when learned men had not the slightest idea about it. However, it is not as it may appear to us and it took the genius of Newton to discover it.

Newton’s studies convinced him that not only earth attracts an apple but an apple also attracts the earth. In fact, every material body attracts other material bodies towards it. But then why the apple moves towards the earth but not the earth towards the apple? This attraction or pull or force exists between the earth and all heavenly bodies too. This is known as the force of gravitation.Any material object attracts all other material objects and this attraction is in proportion to the weight of an object. The heavier a body, the stronger is the attraction. The weight of the earth is enormous compared to the weight of an apple or a man. Hence, the attraction exerted by the earth on other objects is also very strong compared to the attraction of an apple on earth or by a man on earth. This attraction of the earth makes every body move towards earth. The attraction between two material bodies increases if they come closer or if their weights are increased.

About seventy years before Newton’s time, the great German Scientist Johannes Kepler discovered the law as how planets moved around the sun. But in Kepler’s time nobody knew why the planets moved as explained by him. Newton, with the help of the law of universal gravitation, could explain why the planets moved around the sun as explained by Kepler. The universal law of gravitation found another brilliant confirmation in the discovery of the planet Neptune. Astronomers had long discovered that the planet Uranus occasionally appeared to stray from its orbit. Sometimes it would slow down its motion and again it would go faster as if drawn by some invisible force. The law of gravitation predicted that the anomaly in the motion of Uranus was due to the presence of another planet farther from Uranus and soon astronomers discovered a new planet Neptune.

For many decades Newton’s theory of Gravitation appeared perfect. But then facts began to accumulate which could not be explained by the law of universal gravitation alone. One of these is the Seeliger paradox. This paradox goes this way. The universe is infinite and is infinitely variable. Its lifetime too, is unlimited. It is more or less filled with material bodies and so can be assumed to possess some mean density of matter. Seelinger decided to apply the universal law of gravitation to determine the gravitational force which an infinite universe would exert at any point within it. This force was found proportional to the radius of the universe. As the radius of the universe is infinite, so the force would be. But this is not the case. Does it mean that the law of Universal gravitation is not valid on universal scale?

Another phenomenon in which the conclusions of gravitational theory did not quite agree with observations was found in the displacement of the orbit if the planet Mercury. Very accurate calculations of the orbit of Mercury reveal that the point closer to the sun suffers a precession or displacement. For a long time this precession of the orbits of Mercury remained unexplained. It took a revolution in science to explain it, and the revolution was carried out by a young German Scientist, Albert Einstein.

It is a long known fact that if a gun fires at a distance we see the flash of light some time before we hear the sound. This tells us that sound travels in a far less speed that the light. It was possible to measure the speed of sound in the surface of the earth as 330 meters per second. But it is much harder to measure the speed of light because light travels with an incredible speed of 3,00000 kilometers per second. A ray of light can circle the earth in just over 0.1 second i.e. one tenth of a second. For a long time people were unable to measure the speed of light. It was finally measured by observing the eclipses of the satellites of the planet Jupiter from two points on earth’s orbit around the sun, when the earth was closed and farther from Jupiter. Today it is measured in laboratory conditions to a high degree of precession by means of rotating mirrors. In fact, not only light but all electromagnetic waves travel with light’s speed as the electromagnetic field moves through space.

But how do electromagnetic fields propagate through space? Does gravitational force also propagate through space in the form of gravitational field? If so, how fast does a gravitational field travel? As fast as sound in air, light in vacuum or with some other speed? Can the attraction between the bodies happen directly without the participation of the intervening medium? Do the gravitational force and gravitational field also propagate with the same speed of light or have a finite velocity? A new scientific theory was needed to explain the propagation of electromagnetic field through space and its foundation was laid in 1905-1915 by Albert Einstein in his special and general theories of relativity based on the geometries of Lobachevski and Riemann.

One of the fundamental conclusions of the special theory of relativity, which defines the interconnection between space and time, is the equivalence of mass and energy. The theory states that a moving body carries kinetic energy, hence its mass is greater than when it is at rest. The greater a body’s latent energy is, the greater is its mass. A cup of hot coffee is heavier than cold coffee in the same cup. The famous equation E=mc2 is Einstein’s formula of mass-energy equivalence.

But what is meant by a body’s mass? The mechanical concept of mass states that mass is a measure of a body’s inertia. Hence, mass can be expressed in terms of force and the acceleration which it imparts to the body. In physics, mass measured in this way is known as inertial mass. But mass can also be measured from Newton’s formula of gravitation. This mass of bodies which may be at rest relative to one another is known as gravitational mass. The physical interpretation of inertial and gravitational mass are different but quantitatively have, to date, been found to be the same no matter how they are measured. This led Einstein to think that inertia and gravitation must have a common origin. So, if a body’s inertial mass varies with the velocity of motion, then, he reasoned, the gravitational mass should also vary with the velocity of motion.

Einstein’s identification of inertia and gravity on the basis of the equality of inertial and gravitational mass of great significance. It enabled him, in 1915, to develop the general theory of relativity, which is the modern theory of gravitation. This modern theory offers a much more exact and profound explanation of the properties of the bodies than Newton’s theory. Einstein’s theory was a revolution in physics which provided explanation for many hitherto unexplained phenomena. But it would hardly be useful to present the theory in common language as it contains largely mathematical, extremely complicated equations belonging to the class of non-linear differential equations in spite of the clarity of its physical meaning.

 
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Posted by on July 20, 2012 in Science

 

अन्तरिक्ष–विज्ञान सम्बन्धमा केही चर्चा

– निर्मलमणि अधिकारी

विश्वका प्रायः सबै पाठशालाहरुमा निकोलस कपर्निकस (सन् १४७३– १५४३) लाई सर्वप्रथम सौरमण्डलको विज्ञान–सम्मत अध्ययन गर्ने वैज्ञानिकको रुपमा मान्यता प्राप्त छ। अन्तरिक्ष विज्ञानसम्बन्धी चर्चा अधिकांशतः आरम्भ गरिन्छ उनैको नामबाट। पछि केप्लर, ग्यालिलियो, न्यूटन आदि वैज्ञानिकहरुले यिनैको सिद्धान्तको अनुशरण गरेका हुन् भनिन्छ। ग्यालिलियो ग्यालिलि (सन् १५६४– १६४२) टेलिस्कोपको आविष्कार गर्ने वैज्ञानिक हुन् र यिनले परावर्तित प्रकाशद्वारा अन्तरिक्षको विशिष्ट अध्ययन गर्न सकेका छन्। यी वैज्ञानिकहरुको योगदानलाई म आदर गर्छु र उनीहरुप्रति मेरो सम्मान छ। तर मलाई चित्त नबुझेको कुरोपनि यहीँनेर छ। प्राचीन भारतवर्षका वैज्ञानिकहरुलाई आधुनिक विश्व-समुदायले चटक्कै बिर्सेको छ र ती प्राचीन वैज्ञानिकहरुले आफूले गरेका आविष्कारको श्रेय पाइराखेका छैनन्। पख्नोस्, वेदसम्म पुग्नुअघि पहिले त केही शताब्दीअघिको कुरा गरौं।

माथिनै उल्लेखित छकि कपर्निकसको समय थियो सन् १४७३– १५४३ र ग्यालिलियोको समय थियो सन् १५६४– १६४२। जबकि पाँचौं शताब्दीका (अर्थात्, कपर्निकसको तुलनामा करिब एक हजार वर्ष प्राचीन) भारतवर्षीय वैज्ञानिक आर्यभट्टको पुस्तक ‘आर्यभट्टीय’मा अन्तरिक्ष विज्ञानको जति तथ्य लेखिछाडिएको छ; त्यो हेर्दाखेरिमा स्पष्ट हुन्छकि आधुनिक विश्वका सबै पाठशालाहरुमा आर्यभट्टलाईनै सौरमण्डलको विज्ञान–सम्मत अध्ययन गर्ने पहिलो वैज्ञानिकको रुपमा मान्यता दिनुपर्ने हुन्छ। आर्यभट्टको वैज्ञानिक सिद्धान्तलाई आज उनीभन्दा धेरैपछिका कपर्निकसको सिद्धान्त भनेर पढाइनु अन्यायपूर्ण कार्य हो। आर्यभट्टीय पुस्तक अहिले पनि प्राप्य छ (यसलाई पश्चिमाहरुलेचाहिँ सन् ९५० को भन्दछन्) — जसमा उनले सूर्यग्रहण र चन्द्रग्रहणको वैज्ञानिक कारण दिएका छन्। पृथ्वीले सूर्यलाई घुम्दछ र त्यसै कारणले दिन–रातको भेद हुन्छ भनेर लेखेका छन्। सोही पुस्तकमा आर्यभट्ट लेख्छन्— चन्द्रमा तथा अन्य ग्रहसँग आफ्नो प्रकाश छैन र तिनीहरु सूर्यको प्रकाशले प्रकाशित हुन्छन्। उनले दूरदर्शकयन्त्र पनि बनाएका थिए भनिन्छ। यसरी अहिले सर्व–स्वीकृत ‘सूर्यकेन्द्रित सिद्धान्त’का जनक आर्यभट्ट हुन् र कपर्निकस, ग्यालिलियो आदिचाहिँ त्यस परम्पराका उत्तराधिकारीमात्र हुन् भन्ने छर्लङ्ग देखिन्छ। तर विद्यालय, उच्चविद्यालय तथा विश्वविद्यालयहरुमा किन पढाइँदैन त आर्यभट्टको योगदान ? कम्तीमापनि नेपाल–भारतका विद्यालय, उच्चविद्यालय तथा विश्वविद्यालयहरुमा त पढाइनै पर्छ उनको बारेमा।

चन्द्रमामा मानव बस्ती बसाल्ने कल्पना गर्न थालेको छ आधुनिक मानवले। मिति सन् १९५७ अक्टोबर ४ मा तत्कालीन सोभियत संघद्वारा स्पुतनिक–१ मानवनिर्मित प्रथम अन्तरिक्षयान प्रक्षेपण गरेपछि आधुनिक विज्ञानको अन्तरिक्षसम्बन्धी अध्ययनको नयाँ अध्यायको आरम्भ भएको थियो। सन् १९५९ मालुना–२ चन्द्र धरातलमा पुग्योभने सन् १९६१ अप्रिल १२ मा सोभियत रुसले युरी गागरिनलाई अन्तरिक्षमा पठायो। सं.रा. अमेरिका सन् १९५८ जनवरी ३१ मा एक्सप्लोर–१ प्रक्षेपण गरी अन्तरिक्ष विज्ञानको क्षेत्रमा प्रवेश ग-यो। सन् १९६९ जुलाइ १६ मा केप केनेडीबाट नील आर्मस्ट्रङ्, एडविन एल्ड्रीन र माइकल कलिन्सलाई लिएर उडेको ‘अपोलो’ अन्तरिक्षयान चन्द्रमामा पुग्न सफल हुनुलाई आधुनिक विज्ञानको महान् उपलब्धि मानिएको छ। त्यसपछिका दिनमा अन्तरिक्षतर्फ धेरैओटा अन्तरिक्षयानहरु प्रक्षेपण गरिएका छन्। अन्तरिक्ष विज्ञानका क्षेत्रमा भए–गरेका उपलब्धिहरुप्रति गर्व गर्न हिच्किचाउनु पर्दैन। साथसाथै गर्वयोग्य कुरो योपनि छकि हाम्रा प्राचीन शास्त्रहरुमा अन्तरिक्ष विज्ञानको भण्डार छ।

तर, हाम्रा प्राचीन शास्त्रहरुमा अन्तरिक्ष विज्ञानको भण्डार भएको कत्तिपनि मेसो नपाएका तथा “नील आर्मस्ट्रङ्हरु चन्द्र धरातलमा पुगे अरे ….” भन्दाखेरिमा पनि ट्वाँऽऽ परेर बस्ने व्यक्तिहरुपनि थुप्रै छन्। धर्मशास्त्र भन्नेबित्तिकै नाक चेप्राउने उल्लुहरुको संख्यापनि कम छैन। अनि, शास्त्रलाई पोको पारेर पुजामात्र गर्ने, पढ्न–गुन्नचाहिँ नखोज्ने प्रवृत्तिपनि देखिएकै छ।

चन्द्रमामा पहिरो गएर विचित्र किसिमको शब्द भइरहने गर्छ तथा त्यहाँ सात किसिमका पत्थरहरु छन् भन्ने तथ्य ऋग्वेद र शुक्लयजुर्वेदमा उल्लिखित रहेको पाइएको छ। (यहाँ त्यो ‘पहिरो’लाई सामान्य अर्थमा बुझ्ने गल्ती नगरौं नि !) आधुनिक अन्तरिक्ष विज्ञानले पत्ता लगाएको कुरा पनि यस्तै छ। यसरी सो वैदिक तथ्यलाई आधुनिक अन्तरिक्ष वैज्ञानिकहरुले पनि पुष्टि गरेका छन्। वेदमा भनिएझैं नै धातु खानी भएको तथ्यपनि क्रमशः प्रमाणित भइरहेका छन्। विश्वको सबैभन्दा पुरानो शास्त्र ऋग्वेदको भनाइ आधुनिक वैज्ञानिकहरुको खोजीले पुष्टि हुनुको ठुलो अर्थ छ। यसले इंगित गर्ने संकेत पनि निक्कै महत्वपूर्ण छ।

वेदमा “यां चन्द्रमसि ब्राह्मणा दधुः” भनी ब्राह्मणहरुले पृथ्वीको भाग चन्द्र धरातलमा लगेर राखेको प्रागैतिहासिक कालको ‘इतिहास’पनि भेटिइएको छ। यस तथ्यले के देखाएको छभने नील आर्मस्ट्रङ्हरुलाई चन्द्र धरातलमा पुग्ने प्रथम मानवको मान्यता अहिले मिलिरहेको छतापनि उनीभन्दा हजारौं वर्ष अघि (कुनै युगमा) ऋषि एवम् ब्राह्मणहरु चन्द्र धरातलमा पुगेको हुनुपर्छ। अझ आश्चर्यको कुरो लाग्नसक्छ तपाईंहरुलाई— वेदमा अन्तरिक्षयान निर्माण गर्ने र विभिन्न लोकमा यात्रा गर्ने प्रविधिको बयान गरिएका ऋचाहरु हामीसँग छँदैछन् र यदि त्यसकालागि खर्च हुने अरबौं रुपैयाँ उपलब्ध हुनसक्दा हामीले त्यस्ता अन्तरिक्षयानहरु निर्माण गर्न सकिन्छ। आर्य परम्पराका शास्त्रहरु वेद, उपनिषद् आदि र ‘विज्ञान’ बीचको अन्तर्सम्बन्ध बुझ्न नसक्दा हामीलाई भइरहेको घाटाको पत्तो कतिलाई होला ? अनि ख्याल रहोस्— यदि आधुनिक प्रविधिपनि लिन नसक्ने र परम्परागत प्रविधिपनि बिर्सने होभने समयको प्रवाहमा गतार्थ (आउटडेटेड) भई कालान्तरमा समाप्तै हुने नियति भोग्नुपर्छ नि !

 
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Posted by on July 20, 2012 in Science

 

Mathematics: Exciting or Hard?

– Pushpa Raj Adhikary
Traditionally mathematics has been an integral part of the courses in natural sciences and engineering everywhere. But experience has taught us that learning mathematics has never been a priority of majority students. The high rate of failure in mathematics of mathematics majors as well as Engineering students confirms this fact. Perhaps the motivation and encouragement given to learn mathematics are not sufficient.
Although mathematics is considered the most prestigious subject in the school curriculum at any level, it continues to be a subject taught more for enabling students to get through the examinations only. It is taught in an authoritarian fashion. There is least worry about motivation. At most, all emphasis is on solving tedious and rather complicated problems with little explanation on the inherent beauty and logic of the methodologies involved and their practical implications. Mathematics is one subject where the gap between the intended and the implemented objectives is wide. As a consequence, mathematics is considered a most difficult subject and is considered as a useless, boring and hard subject. Also, it is considered as abhorred by a majority of the educated people. This attitude of parents and educated people in the society is creating a negative impact upon the younger generation that it is a difficult and not so useful subject. This causes great panic among the students to study mathematics.
Part of the reason why mathematics puzzles the majority of persons is that it is hard for them to decide what kind of thing mathematics is. Is it a science? Is it an art? Is it a language? In fact mathematics is all three. Among all the existing sciences, it is the science which is least restricted to any one particular area of the world, real or imagined. It is hard to say all that mathematics is. The famous philosopher Bertrand Russell said that pure mathematics is something which we can talk about without understanding what it is.
Some parts of mathematics can be useful to any intelligent person. They help one to make better decisions. They help anyone to see the structure of the world more clearly and help in common activities. Graphs and tables summarize a lot of information. To be able to read a graph or a table makes the information accessible. Estimating is a technique of making good rough guesses about numbers. Models, plans, schemes, maps, diagrams are the representations or pictures of the real world. In all these activities, the results are not obtained without hard work. Moreover, such mathematical scales are a part of any skill/aptitude test for a job or for advanced study in any discipline.
Mathematics contains ideas that can be, and deserve to be, communicated to a wider public. But mathematicians claim that math is not a spectator sport. You cannot understand math, or enjoy it, without doing it. A mathematician who tries to communicate his subject to the layman soon finds himself in trouble because if he sticks to the truth he cannot communicate, and when he tries to communicate, he strays from the truth. Talking without being understood is pointless, lying is painful, so most often mathematicians abandon the attempt to communicate mathematics to others.
But this is not the case in other branches of science. Not only a geneticist doing research in recombinant DNA research knows about DNA but many others know what DNA is. Likewise, you need not be a Physicist or a Chemist to know that matter consists of atoms. But the reverse is true in case of mathematics. When mathematicians, physicists or electrical engineers talk about anything, sooner or later they scribble down formulas. To them formulas are the most precise and economical way of expressing their thoughts. Without formulas they think they cannot communicate well. But showing a formula to someone who can’t remember the symbols is something like encountering nightmares. An English major student once asked a mathematics professor to suggest him a book of geometry written in plain English without any mathematical formulas and symbols. Can mathematician write such books for students majoring other subjects?
Formulas do not scare only non-mathematicians, but sometimes even to the persons of science. Michael Faraday, best known English investigator for his pioneering work connecting magnetism and electricity, wrote the following to one of his junior, James Clark Maxwell:
When a mathematician engaged in investigating physical actions and results has arrived at his calculations, may they not be expressed in common language as fully, clearly, and definitely as in mathematical formulae? If so, would it not be a great boon to such as I to express them so?
If formulas in mathematics and other physical sciences are considered weapons of intimidation by others, cannot they be replaced by common language? But to explain the mathematical formulas in details, words are often clumsy and sometimes ambiguous.
Having talked about something on the nature of mathematics, now let us answer the question, “Is mathematics exciting?”. Today mathematical methods not only pervade the whole world of physical sciences and engineering but such diverse branches of knowledge as the social sciences, management  sciences, psychology, economics, biology, linguistics, and military affairs. Why mathematical methods are so popularly used is because it has ability to reduce complex problems into a set of simple step-by-step solutions. In the absence of such a technique, problem solving would mostly be a trial and error or a subjective matter.
We are living in the greatest age of mathematics ever seen. Mathematics started being more abstract since the beginning of twentieth century and many feared whether mathematicians would be working on silly intellectual exercise. Since World War II, it has became a single unified discipline having profound influence in the development of human civilization. So, learning and creating mathematics is a worthwhile way to spend life.
Now, to the second question: “Is mathematics hard?  Unfortunately most people confess that they are not good at mathematics.  You may not find a single good mathematician who claims that mathematics is easy for him or her. While mathematics is intensely enjoyable, it also requires hard work and discipline. Very bright students who are good in mathematics at high school do not graduate in mathematics courses and still a few eventually get their PhDs. The truth is that one should be driven to study mathematics and it is literally difficult to convince that they could shine in this discipline. But the fact is: it is exciting. The earlier frustration of learning mathematics should not deter anyone in the thrills of learning and creating new mathematics. Mathematicians are the only people who, by their mathematics, help to create new technologies and knowledge to enhance human civilization further.
 
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Posted by on May 22, 2012 in Science

 

Face to Face with the Universe: A search for vacuum

– Pushpa Raj Adhikary
All of us have seen a pipe fitted with a piston. When the lower end of the pipe is dipped in water and the piston is pulled up, water rises in the pipe. This is the way ink is filled into a fountain pen and liquid medicine is pulled in a hypodermic syringe.
No water rises in a pipe when dipped in water, but water can be made to rise up in a pipe once the piston fitted on it is pulled up. How do you think a piston is capable to pull water up in a pipe? When medieval scholars saw that water follows a piston up a pipe , they found a simple, though hardly convincing, explanation. They reasoned that the piston, when pulled up, also pulls the air contained in the pipe, so a void or nothingness is created and water, in turn, rises up to cover this void or vacuum. Although a simple explanation was found out, it was not less than a horror for them to conceive the idea of the vacuum.
In 1643 AD, an Italian scientist, Evangelista Torricelli, carried out an experiment. He took a meter (33 foot) long glass tube with one end sealed and filled it with mercury. By closing the open end with the thumb he carefully lowered this end into a cup filled with mercury. Once the tip was dipped well into mercury, he removed his thumb and held the tube upright. Some mercury from the tube flowed out into the cup and a gap appeared in the upper end of the tube.
Torricelli reasoned that the upper end of the tube was sealed off from the atmosphere and no air could pass into it through the glass walls or the mercury. Therefore, it didn’t contain air or anything, hence an empty space or a total vacuum is created. The space above the mercury column has been named as “Torricellian vacuum”.
Today any physicist will tell you that a Torricellian vacuum is not a real, absolute vacuum. For one, it contains mercury vapour. Secondly, there are molecules of nitrogen, oxygen and even carbon dioxide. These gases are dissolved into mercury and they readily evolve from mercury to spread into the space over mercury.  Every earthly material, even metal, glass, wood or plastic, contains some gases. These gases readily diffuse into a vacuum. This process is analogical to the bubbling of gas in a bottle of coca or soda. As long as the bottle is closed, the pressure inside the bottle is above the normal pressure of the air in the atmosphere. The gas is dissolved in the water and nothing reveals its presence. When you open the bottle, the pressure drops and the bubbles of gases pop out in the surface as if the liquid in the bottle were boiling.
The physicists could also tell you of the difficulties which they encounter in their attempts to produce and, even more so, maintain a high vacuum. When scientists began sending high altitude rockets up to take samples of air in the upper layers of the atmosphere, they thought the job would be quite simple. The scientists have metal cylinder of suitable size with airtight valves, pump all air out of it, place it into a rocket and shoot it two or three hundred kilometers up where automatic devices would open the valves, let the air outside flow into the cylinder and close it again. A parachute would carefully bring the sample back to earth. This, however, is easier said than done.
A process, similar to the boiling of liquid and bubbling of gas in a bottle of coca, though not so violent, takes place in the materials of which a rock is built by the time it reaches an altitude of 250-300 kilometers. Even in a laboratory, with ingenious devices designed to create an ultrahigh vacuum in a glass or metal cylinder, it is impossible to maintain the vacuum for very long as gases begin to evolve from the cylinder walls, and air even filters through them from outside. So you see that it is not easy to bring an air sample from a very high altitude.
Can complete vacuum be found anywhere in the universe above the layer of air which we call atmosphere? A trip beyond the atmosphere is necessary to find out, and we need suitable vehicle to embark upon such a journey. A balloon, evidently, will not do.  A balloon could take up to 20 kilometers which means that the atmosphere up there is still fairly dense. If we ride in a gondola even up to eight or ten kilometers high above sea level, the air would be so rarefied that we cannot take normal breathing.

 We can say that the emptiness of outer space is as illusory as the emptiness of Torricellian vacuum. Our dream of finding total emptiness or absolute vacuum ends in void.

Clouds present another tangible and visible indication of atmosphere. Clouds generally appear at an altitude of 80 kilometers from the surface of the earth. Somewhat higher, between 100 to 120 kilometers above the surface of the earth, meteors appear as shooting stars. And it is a proof that the atmosphere, which is unable to support our breathing, is still sufficiently dense at an altitude of 120 kilometers from the surface of the earth. The aurora Polaris (northern and southern lights) which occur in the uppermost layers of the atmosphere, have been observed as high as 1,200 kilometers.
It can be said that neither lighter than air balloons nor heavier than air aeroplanes can be used to study the upper layers of the atmosphere. The atmosphere, which surrounds our earth, has no sharply defined boundaries. It becomes less and less dense the higher we go, and somewhere between 2,000 to 3,000 kilometers up it gradually thins out into interplanetary gas.
Once the atmosphere vanishes completely at a sufficient height above the earth, would there be vacuum from there and afterwards? At a height of 3000 kilometers above the surface of the earth, just outside the edge of the atmosphere, we encounter electrically charged particles. These electrically charged particles are known as elementary particles because they are the building blocks of matters which make our universe. These elementary particles come from different sources like sun, stars and other energy emitting bodies found in the universe. These elementary particles are trapped by the magnetic field of the earth and spiral along the earth. There are three such belts of elementary particles of high energy which surround our earth.
There was a time when scientists compared the earth with a large nut encased in a thin gaseous shell. Today we know that the atmosphere is extended only up to 2000 kilometers up and it trails away into the gas filling interplanetary space. The earth is surrounded by a great halo of radiation, about 50,000 kilometers in diameter consisting of electrically charged elementary particles gyrating around the magnetic force of the earth.
So, where do we look for a total vacuum? Beyond the atmosphere or even beyond the 50,000 kilometers boundary of the charged particles? If we move away from the earth beyond 50,000 kilometers, say, to the moon, are we able to get a total vacuum? Moreover, the moon does not have an atmosphere surrounding it and no magnetic field to trap elementary particles and make them move around it. But the rockets which reached the moon as far back at 1959 A.D. had detected an increase in charged particles near the moon.
Can we detect a vacuum even far away from moon, or say, very very far away, beyond our solar system? It is known that the interplanetary space is pervaded by a tenuous gas with over a hundred molecules in every cubic centimeter. But even if there were no molecules of gas, could the outer space be empty? The answer is still no because it is pierced by the charged particles which come out of the radiation of the stars. We know that light rays, x-rays, infrared and ultraviolet rays the whole gamut of electromagnetic radiation – are of material nature and can be treated as streams of tiny particles, photons, possessing mass, velocity and energy. We can hardly regard space as empty through which endless streams of particles pass. To add to this, we have gravitational field which interact in space. We can note here that gravitational fields are omnipresent. Every material particle, be it a tiny molecule or a giant star, emanates a field of gravity. It attracts and is attracted by other material bodies.
We can say that the emptiness of outer space is as illusory as the emptiness of Torricellian vacuum. Our dream of finding total emptiness or absolute vacuum ends in void.
 
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Posted by on March 29, 2012 in Science

 

Mathematics and Nonmathematicians

— Pushpa Raj Adhikary

For most mathematics is like an iceberg, a small visible portion above water and nine times as much submerged below, invisible. Most of us who have come to know a little of mathematics, under rather uncomfortable conditions, have no idea what mathematics is the way it is hard for us to form a clear idea about the submerged part of the iceberg. The best thing to do about an iceberg is to take an about turn to go to the opposite way. Most of us do the same about turn in case of mathematics as well. 
Have those who take an about turn to go the opposite way ever tried to fathom what the subject is really about, what their own misimpressions are, and what sense it makes to those interested? Perhaps what puzzles non-mathematicians is the difficulty to realize mathematics. The explosion of the first atom bomb in 1945 was a reality out of a very famous mathematical equation of Einstein which says that E is equal to M C squared. If it makes no sense to you or to all non-mathematicians, it is because you never bothered to learn more about mathematics than what you know.
All the intelligent non-mathematicians may say, so what if I cannot make sense of the mathematical equation of Einstein while I know those disciplines of knowledge where mathematics has little or no use? But it is time to remind them that mathematics is no longer a subject they can dismiss easily. Mathematics is increasingly becoming important not to science and engineering but in industry, business, military affairs and many other human activities and innovations of new technologies in almost all areas of human endeavor. Space and deep sea explorations for tapping entirely new sources of energy, food and raw materials necessary to continue our development are impossible without the development of mathematics. So, there is a growing need for more and more persons to enhance their knowledge of mathematics. Mathematics no longer remains a subject of intellectual pursuit for a few but knowledge essential to create and respond to your daily requirements.
Why mathematics puzzles non-mathematicians is because they find it hard to decide what it actually is. Is it science? It is an art? Is it a language? In fact, mathematics is science, language, and art. Among all existing sciences, mathematics is the most general science. It is not restricted to any particular area of knowledge, real or imaginary. Mathematics deals with any objects, or observations, real or imaginary, and any thought however abstract it is. Numbers can count not only motor cars and people, but stars on the sky and molecules on a drop of water. No other science is as general as mathematics.
Mathematics is an art where creativity of highest order can be displayed by means of language, symbols, and a combination of both. Mathematics is also an art of reasoning and deduction. From such statements which are assumed to be true, we deduce, by reasoning, other statements that must inevitably follow them. For example, from the fact that 2 plus 5 equals seven, and some other statements, it can be deduced that 2222 plus 5555 equals 7777. No other art equals mathematics in the way of skillfully and correctly deducing.
Mathematics is also a language, the language of expressing scientific ideas. Natural laws are expressed correctly in the language of mathematics. Moreover, it is a language of calculation. In mathematics, any idea can be named, discussed, analyzed, and calculated (in exact reasoning process). Alfred North Whitehead remarked that a mathematician has weighed the earth and counted billions of molecules in a drop of water. In fact, no other language has such a degree of freedom, as in mathematics to use words or symbols for any idea one chooses. Precise deductions with these words or symbols lead to the calculation one desires. But let me remind the readers that mathematics in not only the language of calculation. Lots of calculations take place in an ordinary language, too. For example, removing ambiguity from sentences to make their meaning clear also needs calculations. 
Some people have found out what mathematics is about, and what power it has. For such people mathematics is the most exciting instrument of human mind. But we can say that most people have not understood this. Education in mathematics, up to now, has not been able to impart this degree of understanding to know what mathematics is about.
The root cause of the trouble in understanding mathematics lies in the introduction to mathematical ideas which we experience as we grow up. The introduction usually begins with arithmetic. In the age where the idea of numbers is introduced, a child may not be able to conceive the idea of 2: which represents two eyes or two hands that we possess. Again the number 3 which is larger than 2 by 1, and any other latter numbers, seem inconceivable for a child unless he/she is matured enough to count. Education in mathematics begins at an age when a person does not know very much, nor is he/she able to know much. Besides, mathematical ideas are introduced not in a systematic manner but in bits and pieces which make little sense to the learners. Moreover, the authoritarian manner of the teacher “do this and this and never mind if you do not understand” would contribute a lot for the general dislike for mathematics at the earliest opportunity. Those who continue the study of mathematics do so because it helps them to secure higher percentage in the tests/examinations and is necessary to study various branches of science and engineering afterwards. The worldwide trend of decline in the number of graduates majoring mathematics confirms that majority of young people shun this field. This is definitely not an encouraging sign at the age of rapid technological developments, and when we are faced with a hoard of problems. 
We are actually talking about non-mathematicians. So, as a non-mathematician have you ever reflected: “How much mathematics do I have to know? Can mathematics actually be useful to me?” If you are an intelligent person holding a responsible position, you need to know a host of things like how to read graphs and use tables, apply a few formulas, estimate the values of different items, take samples and make models and diagrams, determine chances, predict the future, and make appropriate decisions. All these are essential daily activities. Graphs and tables summarize a lot of information, and so do other mathematical ideas. These ideas help you to understand real world in much better way than without any mathematical ideas. As an intelligent non-mathematician you can think now how mathematical reasoning would help you and how much effort you have to make for acquiring broad and clear worldview.
 
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Posted by on July 21, 2011 in Science