Knowing ourselves with Science

Nabin bhatta
B.SC. Physics 2nd year

Science is a Technical Subject. Science has always led Technology, made our life easier. We all say that our lives would have been quite difficult to imagine if the thing called Science was non-existent. But, amongst all the technicalities, the equations and logics, what does Science say about us as human beings? Some might even doubt that Science can answer such complex questions such as what is life itself. But turns out, Science is not only about Equations and technicalities after all. Science can often give us a profound Spiritual feeling.
Perhaps one of the most far reaching realizations of the human mind is the fact that everything is made from atoms. Almost everything you can touch, smell or see is made from atoms. That is a fantastic generalization, that approximately 100 elements of the periodic table make up everything. But even the different elements are not so different. In it’s core, every atom is made from three basic constituents; namely Protons, Neutrons and Electrons. But this fact carries several mysteries.
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For example, we don’t know why every Electron in the Universe should be identical. All we know is that they are Identical, and that they carry exactly the same charge and mass. One of the people crazy enough to try to answer that was the American Physicist John Archibald Wheeler. There is an anecdote that he once called his graduate student Richard Feynman in absurd hours of night to tell him that he had solved the problem of why every electron in the Universe is Identical. Wheeler told Feynman that the secret behind the puzzling similarity among the Electrons might be that “Every electron is the Universe is one and the same!” Now this is a crazy Idea, a really crazy one. But you see, Physicists don’t sit in their desks and think, “What crazy Idea can I think of today so that I can pull all the people to the edge of their seats?” Physics doesn’t work that way. You have to give the reasoning behind your argument, and do that by using Mathematics. And Wheeler did just that, he backed up his Idea mathematically. We live in a something called a four dimensional Space-time, but are allowed to perceive only a Slice of it at a given time. For example, you can only say that a cat landed onto the third floor at precisely 8:00 pm, you cannot ‘see’ at 8:00 pm what it did a while ago or what it will do some time later. So, the coordinates of the place where the cat landed, and the time at which the cat landed, together create what is called an ‘Event’ in Space-time. You can see several of those events at a given time, like the light bulb going off in the street, your neighbor turning the TV on etc etc. So all of these events combine to form what you call ‘Now’. So, Wheeler said, “There is only one electron in the Universe travelling in a complicated way, forming complicated knots. But we perceive it as many electrons because we can perceive only one Slice of Space-time at a given moment, so we cut through many many knots so it seems to us as if there were many electrons in the Universe.” But his ideas did have some serious difficulties on the practical grounds. For example, there are approximately 10^80 particles in the observable Universe and most of the matter is made up of Hydrogen (don’t let yourself fooled by noting that the things you see around you are not made from Hydrogen, Earth is only a tiny dot in the vast arena of Cosmos and most of the Universe ‘is’ made from Hydrogen). A Hydrogen atom has only one electron in it, so that makes at least 10^80 electrons in the Universe. So, if every electron is one and the same, it has to travel the Universe 10^80 times. The problem with this is that even if an electron travels with the speed of light (the highest speed possible), it would take much more than the lifetime of the Universe (which is 14 billion years) to do that. Wheeler’s idea failed on experimental grounds. But the point here is the Man’s courage to probe beyond what’s reachable. There have been many Curios and devoted people because of whom Science has progressed so much. Einstein is Einstein, not because his head was twice as bigger than other people around, but because he asked questions nobody had ever asked before which took him to places nobody’s mind had ever been before. And the depth of his answers is almost unbelievable!

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The atoms that we are made up of can be traced back to the interior of the Stars where light elements like Hydrogen and Helium are fused to make heavier atoms under great temperature and pressure. The Helium atoms themselves are created from the fusion of Hydrogen atoms. The first Hydrogen atoms were created at a very early stage of the Universe. The Stars in a sense ‘cook’ the heavy elements in their interior and when they explode in a Nova, the atoms are scattered throughout. Our Earth and the planets around us are also by-products of a Star explosion. The Earth cooled with time and the conditions began to support the evolution of first organisms. Consequently, the organisms started to become more and more complex and finally we Homo Sapiens were evolved. When something or someone dies, it doesn’t get lost at all. Everything is being recycled constantly. Atoms don’t like to stay in a place, they are constantly moving. With a single breath, you take in more atoms than the number of people who ever walked the Earth. So, it’s possible that you contain at least an Atom of every Human Being that has ever lived on Earth. The atoms that you Scratched from your nose today might have been in your Neighbor’s ear yesterday! In other words, you don’t really own the atoms in your body, you just borrow them. Most of us know that we all Humans are made from same kind of atoms, but what many of us don’t know is that we are made from the ‘Same’ atoms! Perhaps the meaning of life is to recycle Energy!
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A rose is red because the atoms in it reflect the light of frequency 4*10^14 hertz, and that frequency of light is what we call red. According to Physics, Color vision is a Physiological experience. There is nothing inherently ‘Red’ with the rose. There are organisms, including the color blind humans, who don’t see the rose as red colored. So, Color lies in the eyes of the beholder. The visible light (white light) is composed of many colors which range from red to violet. Most objects absorb some part of visible light and reflect other part of it. For example, hair appears black because it absorbs all the visible light that is incident upon in and the white things are white because they reflect all the colors of visible light towards the observer. But what about transparent things? There are objects that absorb and re-emit light. A green glass for example, absorbs all the visible light and re-emits the green light. The world is colorful because of the property of atoms to emit different frequencies of light. Since the color is relative, it has some interesting consequences. For example, the Fluorescent bulbs are rich in higher frequencies of light and hence blue and violet colors are enhanced under them.
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So when you do shopping in a Mall under fluorescent lamps, you might be disappointed with your choice when you see that dress in a broad daylight! It’s very interesting to think about Colors this way. But the Physics of it has perhaps a very important message inside it. The color of human skin, you see, is nothing but the combination of light reflected by it. A white person appears white because his/her skin is a good reflector than absorber. A black skin absorbs more light that the white one. So, if we think about it, how logical is it to distinguish people based on the frequency of visible light that their skin emits? Science says that it is very illogical. The atoms in all of us came from Stars, we all are Star Stuff!

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