OUR ATTEMPTS TO TURN NIGHT INTO DAY

Here, let us explore various sources of light.
A point to remember;
Normally, there are two processes which yield light.
1. When the charges vibrate(ions, electrons) light waves[electromagnetic waves] are emitted
2. When high energy electrons return to the low energy state, the excess energy is released as light.
But, in this article, we will simply say, when the atoms are agitated, light is given out.

1. Oil lamps and candles:
Here, oil and wax burn using atmospheric oxygen. It is a combustion process. Heat generated in the process agitates the vapour atoms around the wick. Hence light is emitted.

2. Incandescent lamps:
The tungsten bulb is the first electric lamp. Electric current is sent through the tungsten filament; Heated to very high temperature; tungsten atoms are agitated and emit light. A bulb surrounds the filament to keep away the oxygen. Hence, no burning here. It is the first incandescent lamp.

3. Fluorescent lamp:
A long tube or folded tube is filled with mercury. When electric power is given, the mercury is vapourised and the electric current (electrons) passes through it. The electrons collide with mercury atoms (agitation) which yields visible and ultraviolet light. The UV light is turned into visible light by the fluorescent coating on the walls of the tube. Hence the name fluorescent lamp.

Sodium, Neon, Mercury lamps:
Here, electric current pass through sodium, neon, mercury or argon vapours. The atoms are agitated and excited. Hence they give out the light of characteristic colours.

LED lamp:
In a diode, electron rich and electron starving materials are joined together. When the electron goes from the rich side to the poor side, light is emitted. Technically, we can say, the excited (high energy) electrons from one side go and relax (low energy) on the other side. The excess energy is released as light. It is the LED -light emitting diode.
Today LEDs are everywhere. (mobile, TV, computer, signal, all lamps)
The future seems to have arrived. Tomorrow, wallpaper, with embedded LEDs may glow. We need not have separate lamps.

SUN:
The sun, powerful and natural source of light. Atomic fusion takes place continuously in the sun. Heat energy is released in this fusion. This energy agitates the solar atmosphere molecules which emit visible light.
Our eyes have evolved to sense the sunlight. Hence the artificial lights must be similar to the sunlight. But artificial sources never match the sun.
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LISSAJOUS FIGURES

Definition: "When a particle is subjected to two sine wave motion or two oscillatory motion at right angles, the particle describes lissajous figures". We know sine wave motion and circular motion is basically same. Hence we draw two circles A and B perpendicular to each other. The circle B rotates twice faster than circle A. That is, frequency of circle B is two times than that of A. A particle at the intersection of two circles is subjected to two sine wave motion A and B at 90 degree simultaneously. The particle will describe figures depending on the frequency and phase of A and B . In our case, the ratio of frequency is 1:2 and the two waves are in phase. To draw lissajous figures : A moving point in both the circles are chosen. Here we should remember; during the time taken by the circle A to complete one rotation, circle B completes two. Hence the points are marked on the circles according to their speed. Then straight lines

THE PARABOLA

A jet of water shooting from a hose pipe will follow a parabolic path. What is the so special about parabola. Y= x^2 Draw a graph for the above equation. It will result in a parabola. This parabola is also called unit parabola. Any equation involving square will yield a parabola. Example: Y = 2x^2 +3x+3 (also called quadratic equation) X= 2 and -2, both satisfies the equation 4 = X^2. Parabolic equations always have two solutions. Any motion taking place freely under gravity follows parabolic path. Examples: An object dropped from a moving train, A bomb dropped from flying plane, A ball kicked upwards. If a beam of light rays fall on the parabolic shaped mirror, they will be reflected and brought to focus on a point. This fact is made use of in Dish Antenna, Telescope mirrors, etc. Inverted parabola shape is used in the construction of buildings and bridges. Because the shape is able to bear more weight. A plane

CASINO'S GAME

Let us find out how the casino survives with mathematics. Say, your friend invite you for a game of dice. You must bet (wager) 2 dollars. If you roll 'six' you will get back 8 dollars. The game will go on for 30 rounds. All sounds good. The probability of rolling 'six' is 1/6. Since the game will be played for 30 times, the 'expected win' is 30*1/6 = 5. That is, you are expected to win 5 rounds out of 30. Hence your gain will be 5 * 8 =40 dollars. ok. This also implies that you will loose 25 rounds. Hence your loss will be 25*2 =50 dollars. Your net gain will be gain-less = 40-50 = -10 dollars. For 30 rounds, the loss is -10 dollars, Hence, for one round =-10/30 = -1/3 dollars. There will be a loss of -1/3 or 0.33 dollars per round. It is not a fair game. Let us make a simple formula to calculate 'Pay out per round\. The probability for a win = p The pay-out in case of win = V No. of rounds = n The expect

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