Scientific Facts

Space Shuttle: OK here is the deal with the space shuttle. It has three rocket engines in the back, but there's absolutely no room inside for all the fuel it needs to launch itself up into space. All of that fuel is stored outside the shuttle, in the big brown cylinder, called the external tank.

The tank containing all the rocket fuel weighs seven times more than the space shuttle itself! That's a lot of really heavy fuel, and the space shuttle engines aren't quite strong enough to push the combined weight of the shuttle and the big bloated external tank up off the ground.

That's what the two long white solid rocket boosters strapped onto the sides of the external tank are for. They lift the tank! Fortunately, it was not necessary to strap an infinite series of smaller and smaller rockets to the sides of the solid rocket boosters.

It is not widely known that just behind the main flight deck of the space shuttle is a small Starbucks adapted for use in zero gravity.

Drinking Alcohol: The fetus is at risk when the mother consumes alcohol during pregnancy.

The risks include overt birth defects and a less obvious group of effects known as Fetal Alcohol Spectrum Disorders (FASD). Disorders may range from minor anomalies, for example of the face, through to adverse effects on brain development, including mental retardation.

Alcohol consumption during pregnancy can also cause spontaneous abortion, slower fetal growth in the womb, premature birth and low birth weight.

It is dangerous to sleep in an unventilated room with fire burning inside because the fire produces carbon monoxide and carbon dioxide gases. Carbon monoxide is poisonous and can cause death.

Electric Bulb: The filament of an electric bulb is made of tungsten because it has a high melting point and can be heated to a high temperature to emit light.

Pitcher: Water kept in an earthen pitcher becomes cold, because the pitcher has minute pores on its surface which absorb water. Water in the pores evaporates when it comes in contact with air, and produces a cooling effect.

Sliced Apple:  A sliced apple, when exposed to air, turns brown after some time as it contains iron which gets oxidized and gives the fruit a brownish color.

Freezing Compartment: The freezing compartment inside a refrigerator is at the top because the air in contact with it becomes cold and heavy and sinks downwards, cooling the rest of the compartment.

Copper Vessel: A copper vessel left in the air for a long time turns green. This is due to the formation of copper carbonate when copper reacts with carbon dioxide and moisture present in the air.

Wick: A wick in a stove keeps burning continuously as kerosene rises in the wick due to capillary action.

Earth Rotation: The Earth rotates on its axis from west to east. This rotation makes the Sun and the stars appear to be moving across the sky from east to west.

The Sky: The sky appears blue because the light of the Sun is spread or scattered by the dust particles in the air. In space the sky would appear black as there are no dust or air particles to scatter the light.

Food Cooking: Food is cooked quickly in a pressure cooker because the boiling point of water increases at high pressure. Food cooks faster at high temperature.

>>  In mountainous regions, the atmospheric pressure is less than it is at sea level. Water, therefore, boils at a lower temperature (less than 100° C) and food takes more time to cook.

>>When ice floating in a glass of water melts, the level of water remains unchanged because as a solid, ice displaces an equal volume of water.

>> A man weighs more at the poles than at the equator because the polar radius of the Earth is less than the equatorial radius. Hence the gravitational pull is more at the poles than at the equator.

>> Standing in double-decker buses, particularly on the upper floor, is not allowed because on tilting, the centre of gravity of the bus gets changed and it is likely to overturn.

>>The boiling point of seawater will be more than the boiling point of pure water because the former contains salt and other impurities.

>>An ordinary clock loses time in summer because the length of its pendulum increases, and therefore, its time period also increases. The pendulum takes more time to complete each oscillation and thus loses time.

>>Whenever there is water loss from the body, secretion of saliva is reduced resulting in dryness of the mouth and stimulating the sensation of thirst. Intake of fluid then helps in restoring the loss of the water.

>>A swimmer just out of the river feels cold particularly if it is windy, because of the evaporation of water from his body surface. The evaporation is more on a windy day.

>>Alcohol is sometimes rubbed on the body of a person suffering from fever. As soon as it is applied on the body, it evaporates taking away some heat from the body. Since evaporation has a cooling effect, the body temperature can be reduced by rubbing alcohol.

>>Soft iron is used as an electromagnet because it remains a magnet only while the current passes through the coil around it and loses its magnetism when the current is switched off.

>>The person jumping out of a moving train is carried forward in the direction of the train because the person himself is in motion sharing the velocity of the train and will continue in its state of uniform motion unless it exercises some force to prevent it (Newton's first law of motion).

>>A lightning conductor is fixed to tall buildings to protect them from the destructive effects Of the lightining

>> An electric bulb makes a bang when it is broken because there is a vacuum inside the electric' bulb; when the bulb is broken air rushes in at great speed from all sides to fill the vacuum. The rushing of air produces a noise generally referred to as the "bang".

>> A small space is left between each set of two rails of railway line to allow for the ­expansion in summer.

>> Moisture gathers on the outer surface of a glass tumbler containing cold water because its water vapours present in the air get cooled and appear as droplets of water on coming in contact with the cold surface of the glass tumbler.

>> The launching of Earth satellites should be from a place near the equator to take the full advantage of the Earth's movements. The regions of the Earth closer to the equator are moving faster through space as compared to regions elsewhere. Thus at the equator rockets would start off with a speed of nearly 1600 km/hour.

>>In deserts, day temperatures are very high and night temperatures are extremely low ­because the specific heat of sand is very low. It, therefore, absorbs the heat readily and its temperature rises by a large degree during the day. At night sand radiates the heat readily, making the temperature low.

>>White roof keeps the house cooler in summer than black roof because white roof reflects more and absorbs less heat rays whereas black roof absorbs more and reflects less hot rays.

>>It is hotter on a cloudy night than on a clear night because clouds prevent the heat radiated by the Earth from escaping into the sky.

>>Ice wrapped in a blanket does not melt away quickly because woolen blanket is a bad conductor of heat.

>> A rose appears red when day light falls on it because it absorbs all the constituent colors ­white light except red, which it reflects to us.