WHY THE SATELLITES ARE NOT FALLING DOWN ON US?

A fast running bi-cycle hit by an object may not fall down. It gets stabilized due to gyroscopic effect. A boat or ship tilted by the strong wind will not turn turtle because it is so designed to stabilize itself. A space station orbiting around the earth may get hit by a rock. It may slow down. But it will not plummet to the earth. It automatically get stabilized. Let see how.

A satellite is taken by the rocket and pushed into the orbit. The satellite is given a preciously calculated velocity called 'orbital velocity'. If the velocity is slightly less than the orbital velocity, it will fall down on the earth pulled by gravity. If the velocity is more, it will fly away from the earth or earth's gravity.

Any orbiting or rotating body have what is called "angular momentum'. given by the formula
Angular momentum = mass * velocity* radius of orbit
This quantity is always remain constant and conserved. As the radius increases, the velocity has to increase to keep the momentum constant. Consider a spinning dancer. As the dancer brings the stretched arms close to her body, she spins even faster.(The distance decreases, speed increases).

If the space station or satellite is hit by a rock accidentally, its speed will decrease, and it will start falling down. But immediately, the principle of conservation of angular momentum comes into play. That is, the space station's speed will get increased as the distance decreases. The station will get back the required speed and will stay in the orbit. Hence "angular momentum" plays the main role in orbital stability.

The earth goes around the sun in slightly elliptical orbit. When the earth is close to the sun, it moves fast. When it farther from the sun, it slightly slows down. All because of angular momentum principle.
It seems that, nature has given laws to stabilize our vehicles. And the nature's intent is not to destabilize our life.

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THE EARTH, A SUPER ORGANISM

JOIN MY COURSE: "Become a programmer in a day with python" A man called 'love lock' (what a name) proposed a theory called Gaia theory, named after Greek Goddess. It says, "Earth is a self-regulating organism like a human being. The organic life in it interacts with in-organic matter and maintains atmosphere, temperature and environment". Hence the earth is still suitable for the life to thrive. Imagine, in a particular place, there are lot of flowers. Some flowers are white and some are darkly coloured. We know, white reflects light and heat while dark absorbs the same. White flowers can thrive in hot climate. But dark flowers requires cold climate. The absorption and reflection balances and the environment reaches average, warm temperature at which both the flowers can co-exist. This is the essence of "Gaia" theory. On our earth, the oxygen constitute 20% of the atmosphere. The oxygen level is always mai

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

DISORDER IS THE "ORDER OF THE DAY"

Imagine a balloon full of air. The air molecules are moving randomly inside the balloon. Let us pierce the balloon with a pin. The air rushes out. Why should not the air molecules stay inside the balloon safely and ignore the little hole? That is not the way the world works. The molecules always "want to occupy as many states as possible". Hence the air goes out in the open to occupy more volume. The things always goes into disorder (entropy) and the disorder increases with time. The above statement is what we call "second law of thermodynamics". Consider a cup of coffee on the table. Suppose the heat from entire room flows to your cup of coffee, the coffee will boil and the rest of the room will freeze. Freezing means bringing things to order and arrangement. It violates the second law. Hence it will never happen. Hence heat must flow from high temperature to low temperature and not the other way. The air molecules in y

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