WILL YOUR APARTMENT SWAY WITH WIND?

Yes, if you happen to live on the hundredth floor. Tall buildings oscillate up to few meters due to wind and earth-quack. It may be uncomfortable for dwellers. It may even be dangerous. There is a physics technique to prevent this vibration.

Tall towers can be considered as an inverted pendulum. It will oscillate with its own natural frequency due to natural forces. Now select a pendulum of the same frequency and attach a suitable weight. Hang this pendulum in the top portion of the tower. When the tower swings in one direction, the pendulum will swing in the opposite direction. That is, tower and pendulum will execute opposite oscillations. Hence the building's energy will be dissipated through the pendulum and the swings of the building will come to a stop (damped) quickly. Hence this pendulum is called 'Tuned mass damper" (TMD). [Matching the frequencies is called tuning].

In Taiwan, there is a skyscraper by name Taipei-101. It has 101 floors. There is a TMD. It weighs 660 tonne -the world's biggest. It is a tourist attraction and also has a Muscat. The oscillations of this TMD during an earthquake has been vidoegraphed and the video clip is available on the net.

TMD was also used in standing rockets to arrest the vibrations. It is used in ships for stability. TMD is also found in Mobile towers, electrical cables, electrical towers (pylons), cars and so on.

It is etched in our minds that our concrete houses are fixed to the ground. But, sometimes it is not.
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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

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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

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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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