SCIENCE CAPSULES

    Visible light, X-rays , sunlight, radio waves, television waves, wifi signals, blue tooth signals, cell phone transmission and GPS.  All are purely electromagnetic waves made up of electric and magnetic fields.  We just want to know how they are created and propagated.      Imagine a positive and negative charges separated by a distance.  An invisible line of electric force connects both of them.  If we oscillate one of the charges, line of force oscillates and creates a wave like form. ( If you oscillate a rope tide at one end, a wave ripples through the rope)      That is, electric field oscillates or changes with time.  According to Maxwell's fourth law, a changing electric field produces changing magnetic field perpendicular to it and encircling it.  So a magnetic field wave is produced.      Again Maxwell's third law says, "changing magnetic field produces circulating electric ...

Long ago, in the absence of money, exchange of goods was in practice.  Next came coins made using precious metals like gold , copper.  After the advancement of printing technology, paper money came into being and gained currency.   Paper money is still holding forte.      Next we had plastic card with our information encoded in magnetic strips.  Later the electronic chips were embedded in them.  Plastic credit cards ushered in a cash free era.  In the computer age money took digital form .  That is electronic form.  Our bank accounts, balances, deposits, everything were  digitized.  Instant transferring of money became a reality.  Opening deposit accounts, getting credits, payments were a snap.  The world was taken over by electronic commerce.       Then, electronic wallets in smart phones.  Sending money from one phone to another was possible.  It helped even small tra...

  To shed your weight, you have to spend energy.  Let us analyze the energy thread bare.   If you have energy, we can do work.  Hence energy=work.   What is work?  Physics says:  If a force acts on a body and it moves to a certain distance, the work is said to be done by the body.  Energy=work=force*distance. What is the force?  Newton second law says,  force= mass*acceleration. So, energy = mass*acceleration*distance we know Acceleration= velocity/time Velocity = distance/time putting everything in energy equation, we get,   energy= mass*distance^2 /time^2     So distance and time plays more important role in energy than mass     Mass : Small children requires less energy and less food to function.  But a heavy adult requires lot of calories through food.        Distance and time : If you want to spend less energy, walk slowly.  That is, take a long time t...

  Consider the alphabet L and consider the matrix grid of 4X4.    Blacken the cells in the shape of L .  Next write 1 in blackened cells and 0 in empty cells. Write digit in the cells from left to right and top to bottom in a single line as a binary digits.   1000100010001111 Convert the binary number to ordinary number of base 10. 34959 Now the picture or letter L is digitized.  Any picture can be digitized as given below. Once we convert the picture into numbers, we get lot of advantages. 1. They can be instantly transmitted. 2. errors in the pictures can be detected and corrected. 3. requires less storage. 4. two pictures can be compared.  For example, two signatures can be compared.      We  have seen that by blackening the cells we can create drawings.  We know that the spreadsheet is made up of cells.  By colouring each cell suitably, we can create any colour picture, even your photo. ...

     In this information era, many things have become cheaper and almost free.  Access to movies, music, books, magazines, articles, information have become cheaper.  Publishing and distribution of all the above have become free.        Voice calls and data are getting cheaper by the day.  Remember the "telegram" days when we paid for each word to be sent.  Now sending even video is free.      Mails are free.  Storage for our documents are free.  Creating tools like photo editor, video editor, drawing tools, music creators, blog tools etc, are free.       Today we have 3D printer in which molten plastic is used to mould objects of our choice.  Plastic comb, footwear and a pet house have already been fabricated.        Experts forecast: In future we will have what is called " molecular assembler " controlled by a computer.  It can fabricate food,...

  Automobile engines, ovens, chemical reactions work due to heat.  How to see , feel and understand the heat ?       We know all the substances are made up of molecules.  When the molecules are in motion(moving, vibrating, rotating etc.,) the substance is said to carry heat energy.        Take a hot tea in a cup and put a cold spoon in it.  We know the spoon will be heated up.  What happens?  The molecules are in fast random motion in the hot tea.  These molecules collide with the molecules of the spoon and set them in vibration.  Now we say heat is transfered from tea to spoon.       As a speed of the molecules increases(kinetic energy), the heat content of the substance increases and we say the temperature increases.       Even at freezing point (at 0 degree c), the molecules really do not freeze but move at low speeds.  When all the molecules come to stan...

    100, 1100100, 64,25      all represents the number  hundred in  different numerical languages.     We count the minutes as 1,2,3...60 and mark it as one hour.  Again we start counting the minutes from 1.  So the minutes and seconds are having the base of 60 or radix 60. We count the inches 1,2,3 ....12 and mark it as 1 foot. It is having base 12.      In our day today life, we use numbers of base 10. (tenary numbers or decimal numbers) We are used to this 10 number system and very comfortable with it.  But a number system can have any base.     Unary numbers  uses only one digits.    1-----l    2-----ll    3-----lll    4-----llll You know using this unary numbers is highly difficult. Next we have binary numbers using only two digits. 0,1,10,11,100  These numbers are widely used in all digital devices.  the signal like ...