XVI C: Everthing in the universe is made of math-including you and I.

 
XVI (C):Everything in the universe is made of math- including you and I.
  [Contd.A Journey to the Wonderland of Math.by Ajay Kumar Chaudhuri.]
               Marvellous gifts of ghostly Quantum Mechanics.

              The first quarter of the twentieth century has witnessed two revolutionary and mind bending discoveries which dealt a severe blow to our idea of classical physics (Newtonian mechanics,Thermodynamics and Maxwell`s theory of electromagnetism which prevailed till the beginning this century). Those are : Theory of Quantum Mechanics# propounded by the eminent German physicist Max Plank (1857-1947) and the Theory of Relativity  put forward by the legendary scientist Albert Einstein (1879-1955). We consider these two theories as pillars of modern physics as they can explain virtually everything about the universe. General Relativity gives us the picture of very big like our universe while Quantum Mechanics provides us the picture of very small  such as microscopic world of atoms and subatomic particle  (with which an atom is made of).
             The theme of quantum mechanics is incredibly bizarre:The same object can exist in more than one place at the same time.There are virtual particles appear out of  empty space and then disappear again  but which is in reality will be determined by the observer. Moreover a particle may behave like a wave also, think as you like. It is accepted now that all the energies known to us,are carried by their respective particles,known as quantum particles, from the matter to the point where there effects are perceived.
            A very familiar example:Light is a form of energy which gives us perception of vision, is carried to us by the particle,called "Photon" which behaves like a wave ( like ripples when a stone is thrown in to a pond) also.
           The idea of quantum theory is difficult to swallow for ordinary people like us. But we may get some solace for this quandary from some quotes of pioneers and stalwarts in the field of this strange but fascinating area of physics:
           "I think I can safely say that nobody understands quantum mechanics"-----Richard Feynman.
            "Quantum mechanics makes absolutely no sense"-----Roger Penrose.
            "If it is correct, it signifies the end of physics as science"-----Albert Einstein.
            "I do not like it and I am sorry I ever had anything to do with it"-------Erwin Schrodinger.
            "If quantum mechanics has`t profoundly shocked you,you haven`t understand yet.----Neils Bhor.
              Yet, many such best quantum thinkers had contributed a lot towards developments and advancement of this ludicrous subject.Nowadays we are enjoying the nectarous fruits of their diligent efforts.       
                                

                Can you imagine today without a computer or without your smart phone? The names “laser”, “MRI Scan”, “GPS guide” etc. are not only very familiar to us bu t also very useful in many ways to fulfill our various practical needs.

Today we are very much dependent on computer, be it for our every day requirement in almost all walks of life or for fundamental research.

Basically, the entire computer industry is built on quantum mechanics, depending on the wave nature of electrons*. From this quantum mechanics we get a clearer picture of a material particle. It advocates the dual nature of a particle, that is, a particle can behave as it is a wave too.

Depending on this property we can manipulate the electrical properties of Silicon** mixing just a right tiny fraction of other elements. Stacking up layers of Silicon doped with different elements allows us to make transistors on nanometer or very tiny scale. Millions of these  packed together in a single block of material make the computer chips that power all the technological gadget that are so central to modern life. Desktops, laptops, tablets, smart phones, even small household appliances and kids’ toys are driven by computer chips that simply would not be possible without our modern understanding of quantum physics.
              [# There is 'Quantum' in the centre stage of "Quantum Mechanics"(or Quantum Theory or Quantum Physics). But what is 'Quantum'? It means 'amount' in Latin but at present it stands for smallest possible discrete unit of any entity such as energy or matter.In1900 Max Plank proposed that electromagnetic waves,such as radio waves,visible light,infrared,ultraviolet rays(both are not visible to our eyes),microwaves etc.are emitted in discrete packets of energy which he called 'Quanta'.  Literally 'quanta' is the plural form of 'quantum'. He also contemplated, this quanta can take on certain  discrete values which are multiples of a certain constant(a fixed number). Now this constant is famously known as 'Plank Constant'.(This constant denoted by h whose value in metre- kilogram-second is approximately  6.62607004 × 10⁻³⁴ joule∙second)

* Electron: In 1897, J.J. Thompson along with some British Scientists discovered it as a constituent elementary particle of all matters having an electrical charge and insignificant mass. This particle was named “electron” and its charge was arbitrarily assigned as negative. Today this electron has many roles to play in our daily life, in particle physics, chemistry and many electrical appliances including devices for recreations. It is also used in radiation therapy, particle accelerator. Moreover, it is involved in enormous nuclear explosions due to fusion of hydrogen atoms in to helium atom in the cosmological nuclear furnace at the core of all active stars.

In this context, it will be interesting to know that in this vast universe there are only so far known 92 naturally occurring elements. All matters are composed by combinations of two or more of those elements, starting with the lightest elements hydrogen ending with the heaviest radioactive element Uranium. Again these elements are made up of many elementary particles like electron.

Ancient Greek philosophers thought that the smallest unbreakable part of all matters is the particle, as they named “atom”. But in 1911 Earnest Rutherford of the University of Cambridge conclusively proved that an atom is breakable. He showed that an atom is like a hollow sphere having positively charged compact mass of an elementary particle, named as “proton”, at the centre of the sphere, called “nucleus”. It was found that an electron and a proton has exactly equal and opposite electrical charge and they exist in an atom in exactly in equal numbers. As a result an atom is electrically neutral. Surprisingly it was also found that the electrons are revolving round the nucleus, as if, a tiny solar system within the tiniest part of an element, namely, the atom.

Then another important elementary particle discovered was “neutron”, whose mass is equal to that a proton but having no electrical charge. These neutrons reside in the nucleus of an atom and act as a glue to hold the protons together.

The list of such elementary particles has been lengthened with discovery of more particles, like antimatter of proton and electron as “anti-proton” and “positron” respectively, the neutrino” which penetrates everything in its path including us in unimaginably large numbers but without any feeling or pain, the “photon” – the carrier of light energy etc. The search is still going on particularly to catch hold of the mysterious “God’s particle” which is believed to be responsible for mass of any matter.

** Silicon: Silicon is the second most abundant element in our Earth’s crust and eighth most abundant in the Universe. Oxygen (47.3%) and silicon (27.7%) together make up 75% of our planet’s crust. Most of crust’s silicon exists as silicon dioxide ((Si O₂). We are familiar with this as sand or quartz. Quartz (crystalline Silicon dioxide) has been known to people for many thousands of years.

Silicon is hard, relatively inert metalloid and in crystalline form is very brittle with a marked metallic lustre. It is classified as a metalloid, since it processes chemical properties in between those of typical metals and nonmetals.

Silicon is an excellent example of a semiconductor, means, a good medium for control of electric current. Silicon chips are the basis of modern electronic and computing for its unique property of a semiconductor.]

                 Perhaps all of us have witnessed a “Laser Show” in a ceremonial event or show of a musical fountain in an amusement park and many other innumerable entertainments related to light or light and sound both. This is a gift of quantum mechanics to us.

A LASER show is actually an artificial performance of light, for the purpose of entertainment. Duration or length of the LASER show depends on the theme of the spectacle and thus always different. But what does “LASER” actually mean? It is an abbreviated form of “Light Amplification by Stimulated Emission of Radiation”.

Scientists have found many uses for lasers.

When you go to a Supermarket for shopping, you must have noticed that the barcode scanner is used during billing. This is the first application of laser in the daily lives of general population, introduced in 1974.

             Then comes the first successful consumer product based on laser in the laser disc player introduced in 1978. By far the largest single application of laser is in optical storage devices such as compact Disc and DVD players, in which a semiconductor laser less than a millimeter wide scans surface of the disc.

The second largest application is the fibre - optic communications, such as for our telephonic conversations. Fibre optic cables are a major mode of communication, partly because multiple signals can be sent with high quality and low loss by light propagating along the fibre.

Nowadays, we are very much familiar with xerography, also commonly known as ‘photocopy’. This is actually an application of laser in printing. Xerography, also known as electrophotography, is a printing and photo copying technique that works on the basis of electrostatic charges半. The xerography process is the dominant method of reproducing images and printing computer data and is used in photo copies, laser printers and fax machines, The term derives from Greek word ‘Xerox’, meaning dry and ‘graphs’ meaning writing. Xerography was invented late 1930 s by an American patent lawyer named Chester Carlson.
             [半 Electrostatic charges: Electric charges are basic property of electron, proton and other subatomic particles.When two substances of different materials are rubbed together, electric charges are generated on the surfaces of those two bodies by friction.We have many experiences of this phenomenon in our everyday life:when you brush your dry hair with a plastic comb,small pieces of paper will be attracted by the comb.The same thing may occur ,the dry hair starts falling apart from each other or it may be in strands and start moving apart.If it is done in a dark room you will notice sparkles.The reason behind all these phenomena is the generation of static electric charges.Here comb is negatively charged as electrons from hair travel to the comb and hair itself gets positively charged by losing electrons. 
            Lightning is a very good example of static electric charge.The positive and negative charges within two clouds causes flow of electric current.We see  passage of this current as streak of lightning.Again if this flow of electric current occurs due to accumulation of opposite charges in a cloud  and  something on Earth, such as a tree or a tall building, we call it 'Lightning Bolt'. A typical lightning bolt may contain as high as one billion volts and current of 10000 to200000 amperes.Can you imagine?]

In manufacturing industry, lasers are used for cutting, bending, and welding metal and other materials and for marking.

                 Lasers are used by the military for range finding, target designation, illumination etc.

In science lasers are used for many purposes and in research work. One of the more common is laser spectroscopy which is very helpful for understanding basic atomic processes.

One of the most important modern therapies is the laser therapy which was not known before 1962. While history of laser beings in 1951, though the theoretical concept of laser was first given by Albert Einstein in 1917, the first application is reported by Dr. Leon Goldman in 1962.

But what is a laser therapy? Laser therapies are medical treatments that use focused light. Unlike most light sources, light from a laser is tuned to specific wave lengths. (It is to be borne in mind that the elementary particle photon is the carrier of light energy, which by quantum theory, behave like a wave too and in this case in the form a transverse wave). This allows it to be focused into powerful beams. Laser light is so intense that it can be used to shape diamonds or cut steel.

In medicine, lasers allow surgeons to work at high levels of precision by focusing on a small area, damaging less of the surrounding tissues. A person having a laser therapy may experience less pain, swelling and scarring than with traditional surgery.

             Laser therapy is used nowadays in the treatment of our various diseases and physical disorders excellently, such as: shrink or destroy tumors, polyps or precancerous growth, relieve symptoms of cancer, remove kidney stones, remove part of the prostate, repair detached retina, improve vision, treat hair loss resulting from alopecia, a disease which causes hair fall, or aging, treat pain, including back nerve pain.

Laser can have a sealing effect and may be used to seal nerve ending to reduce pain after surgery, blood vessels to reduce blood loss, lymph vessels to reducing swelling and limit the spread of tumor cells. Laser may also be useful in treating the very early stages of some cancers.

Laser therapy is also used cosmetically to remove warts (a disease of skin growth caused by some types of the virus), moles, birthmarks and fun spots, remove  hair, lessen the appearance of wrinkles, blemishes or scars, removal of tattoos.

                 Yet lasers also proved their usefulness in non-practical applications, especially in the realm of art and entertainment. First and foremost a laser beam is a wand of light and light itself can be beautiful as well as practical. The sight of deep red sunset or a multicoloured rainbow often inspires feeling of happiness, romance and even love.

So, it may be said undoubtedly that no other scientific discovery of the 20^th century has been demonstrated with so many applications as laser.

The word “MRI Scan” is indeed very familiar to us. Any time you or your loved ones undergoes MRI scan, quantum physics to thank for the proper diagnosis and hopefully successful recovery of them. But what does MRI mean. It is the acronym of “Magnetic Resonance Imaging”. It relies on a quantum mechanical phenomenon called “Spin”. We know spin of a top, a wheel or a planet. But this spin gives the atomic nuclei of human body their own magnetic fields, which are obtained by imaging here.

                The development of MRI Scan represents a huge milestone for the medical world, as doctors, scientists and researchers are now able to examine the inside of the human body accurately using a non-invasive tool.

The following are just some of the examples where an MRI Scanner is used.

Abnormalities of the brain and spinal cord; tumors, cysts and other abnormalities in various parts of the body; injuries or abnormalities of the joints, such as back pain; certain types of heart problems; diseases of the liver and other abnormal organs; causes of pelvic pains in women; suspected abnormalities in women undergoing evaluation for infertility.
             But we should not forget to be thankful to math for such incredible advancements and achievements of quantum mechanics which has given us so many precious gifts.Mathematics is regarded as "the queen of the sciences". Yet this queen sometimes seems to beg from her subjects viz. the various branches of science only to return it for their welfare and embellishment.In fact,science and math. go hand in hand and complement each other.

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