Some wrong notions
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There are some wrong ideas among people about scientific matters. It is the purpose of this essay to correct them.
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Galileo and falling objects
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Archimedes' principle
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Heat is not a material object
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Electricity is not a liquid or gas
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Atomic energy is not the energy of the atom
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Is atom a dangerous demon?
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Is radioactivity dangerous?
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Is it possible to change one element into another?
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Neutrino is not the neutron
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Heart is not the mind
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Energy and mass are the same.
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What is the aim of Science?
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1. Galileo and falling objects
For 2000 years since the time of Aristotle it was believed that heavy objects fall faster than lighter objects. Galileo dropped a heavy and a light object from the leaning tower of Pisa and proved that both reached the ground simultaneously. An idea that was believed for two thousand years was disproved by a simple experiment by Galileo. Through this Galileo emphasized the importance of experiments.
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But a stone and a feather will not fall down at the same time. Reason for this is the atmosphere. The feather will float in air and come down slowly. If we pump out the air from a glass bottle and create vacuum, stone and feather will fall down at the same rate in this vacuum.
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If an object moves under the influence of gravitation alone, its acceleration does not depend on its mass. This truth first discovered by Galileo later
became the seed for the birth of General Theory of Relativity in Einstein's hands.
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2. Archimedes' principle
Archimedes is a scientist who lived in Greece two thousand years ago. The King ordered Archimedes to find out whether his crown was made of gold or of some base metal. Archimedes was pondering over this. When he was immersed in his bath tub, he felt the upward pressure of water lifting his body. Immediately he knew how to answer the king's question. He is reported to have run along the street without clothes, shouting "Eureka, Eureka!"
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Many have heard this story. But they have not understood the principle discovered by Archimedes correctly. When we are immersed in water, the water level will go up. Everybody knows this. Many people think this is Archimedes' principle. It is not correct.
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When we are immersed in water, our weight will be less.
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This is Archimedes' principle.
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3.Is heat a material object?
In the seventeenth and eighteenth centuries, heat was considered to be a material object. It was believed to be an object called phlogiston that is invisible to the eye and later it was considered to be a weightless liquid called calorie. Finally only at the end of the eighteenth century and in the nineteenth century the full nature of heat was understood.
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Daniel Bernouli, Joule, Mayer, Helmholtz, Clausius, William Thomson and many more - through the efforts of these scientists, the truth about heat was brought out. What is that truth?
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All matter is made of atoms and molecules that contain atoms. Heat is nothing but the motion of these atoms or molecules. If their speed increases, heat increases. Therefore heat is a form of energy, not an object like phlogiston or clorie. Thermodynamics which is a part of physics is the science of heat.
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4.Electricity is not a liquid or gas
In the early researches on electricity done in the seventeenth and eighteenth centuries, electricity was considered to be a liquid or gas. What is its true nature? Benjamin Franklin (1706-1790) did quite a bit of research on this.
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All matter is made of atoms. Inside every atom, there are electrons and inside the atomic nucleus, that is at the centre of the atom, there are protons. Normally, the number of electrons and protons in an atom are equal. Since the protons have positive charge while the electrons have negative charge, the total charge of an atom is zero. In other words, an atom is electrically neutral. So, normally, all objects like chair and table do not have electric charge.
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But sometimes, some atoms take in more electrons than protons. Some atoms like the atoms of a metal like copper expel electrons from inside. So these atoms will be negatively or positively charged.
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The electric current that we generate in a metallic wire is caused by the motion of the electrons expelled from their atoms.
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5. Atomic energy is not the energy of the atom
It is atomic energy that comes out in all chemical reactions. For example, by burning combustible gases we obtain the energy needed for many purposes. This energy is released through the basic chemical reaction:
Carbon and Oxygen combine to form Carbon-dioxide, releasing energy.
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But what is commonly (wrongly) called atomic energy is the energy of the atomic nucleus. It is released in nuclear reactions such as
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Uranium nucleus and a neutron combine and the Uranium nucleus splits into Barium and Krypton nuclei. Two or three neutrons also come out. The energy released in this reaction is the destructive power of the nuclear bomb, which is wrongly called atomic bomb. If we release this energy in a controlled way, we get the nuclear reactor that is used for generating electric power.
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The energy released in nuclear reactions is about a million times more than the
energy released in a chemical reaction.
6. Is atom a dangerous demon?
Because of the terrible destruction caused by atomic bomb (more correctly nuclear bomb), many people are afraid of the word "atom". This is not wise.
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All of us, trees and plants, mountains, rivers, Sun, Moon, stars and everything that we see are made of atoms.
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In order to release atomic energy (more correctly, nuclear energy), one has to use high technology and work very hard.
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So, nuclear bomb is the terrible demon, not atom.
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7. Is radioactivity dangerous?
Yes, radioactivity is dangerous. But only if it is above a certain limit.
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Radioactivity is of three types - alpha, beta and gamma. If these particles enter our body in large number, it is dangerous.
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Cosmic rays are entering our body all the time. Further, there are radioactive elements in surrounding rocks and the Earth. Radioactivity from these are also entering our body. All of these are dangerous. We cannot stop the cosmic rays or the natural radioactivity around us. But all these are entering our bodies below the danger limit and so human beings and other forms of life are prospering on the Earth.
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For cancer treatment, radiation is used in a very controlled fashion. X-rays also are like gamma rays. All these must be used only when it is absolutely necessary and under medical supervision.
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8. Is it possible to change one element into another?
Five hundred years ago, before progress was reached in the knowledge of elements, compounds and their reactions through research in chemistry, many attempts were made to change base metals like lead into gold. It is this kind of wrong research called alchemy, that evolved into chemistry. Later it was realized that elements like lead or iron cannot be turned into another element and this was accepted as a basic principle of chemistry.
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This principle was disproved by the discovery of radioactivity. Radioactivity itself is a reaction in which one element changes into another element. Marie Curie, Pierie Curie, Rutherford and many other scientists worked very hard to discover these truths. This modern alchemy is the story of radioactivity. In all nuclear reactions one element changes into another.
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Example of a chemical reaction:
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Example of a nuclear reaction:
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9.Neutrino is not neutron
Neutron is an elementary particle that is present in all atomic nuclei. It is a dangerous particle like alpha, beta and gamma rays.
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Neutrino is different from neutron. It is not present in atoms or nuclei, but is emitted when some heavy nuclei decay. Neutrinos are completely harmless since they do not interact with our body.
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Both neutron and neutrino are electrically neutral.
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Neutrinos are born through the decays of other elementary particles or through nuclear reactions inside the Sun and stars and so exist in large numbers throughout the Universe. Every second about a trillion neutrinos enter our body and go out. They do not interact with any material object. So they do not do any harm to us.
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Until recently, neutrinos were believed to be massless particles just like photons which are the particles of light. In 1998, it was discovered that neutrinos do have mass. This discovery is expected to lead to revolutionary changes in physics and cosmology. There is much more to discovered about neutrinos. Worldwide it is an important field of research.
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India-based Neutrino Observatory (INO) project was planned in Tamil Nadu 20 years ago. But some "wise" men have created obstacles. These obstacles will be overcome.
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10. Heart is not the mind
Many people think that our mind is in the heart. Heart is nothing but a pump. But it is an important organ since it pumps blood throughout our body.
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Our mind resides in our brain. Brain is an essential organ for the body. Actually brain is a computer made of trillions of neurons. The brain controls all other organs such as eye, ear, hands, legs, heart, digestive system etc.
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Not only that, all our memories and thoughts, the writings of authors, discoveries of scientists - all these appear in the brain and get processed there. Further, all our emotions love, hate, kindness, anger, and fear are generated in the brain only.
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It is strange that our language is struck with such phrases as kind-hearted!
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The brain made of trillions of neurons is a gigantic computer. In comparison, even the fastest and biggest computer made by man is only a toy.
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11. Are energy and mass different?
Einstein's famous equation
shows the equivalence between energy and mass. We can convert mass into energy and vice versa. In the equation c is the speed of light which is 300,000 km per second. When we take the square of c, it becomes a very big number. So a very small mass is equivalent to a very large amount of energy.
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12.What is the aim of Science?
What is the nature of the Universe? Sun, Earth, Moon, Planets, stars, trees, plants, animals, human beings - what are these? It is the aim of Science to answer these questions.
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Today Science has grown enormously. Scientists have studied the history of the Universe for the past 140 billion years. Starting with the Big Bang, how stars, galaxies and planets were formed, how in one of the planets, life started and how it evolved into human being - this history is now in text books of students.
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Scientists have made an inward bound journey also. They went deeper and deeper into matter, animate or inanimate, and discovered that matter is made of layers like elements, atoms, electrons and quarks and have discovered the forces that activate all these layers.
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This is the aim of Science.
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Making technological products such as TV and cellphone is not the aim of Science. These are nothing but toys that come out as side products.
Our weight = true weight - weight of water of same volume as ours.
All electricity is nothing but the electrons in the atoms.
Energy and mass are not separately conserved. Energy can be created or destroyed. Same is true of mass. Only the combined energy-mass has the property of conservation or indestructibility.