Why Onions Make You Cry?

Your eyes really "water" a little all the time. All of our special sense organs—the tongue, the nose, the ears and eyes are kept moist by special glands. They are exposed to the air and must be kept clean. Moisture probably makes the nerves of the sense organs more sensitive to impressions. The inside of our hands and fingers, where we feel most keenly, are moister than the backs. Now, when there is trouble in a sense organ, like too strong a taste in the mouth, or a "cold" in the nose, or a grain of dust on the eye-ball, the moistening fluid just gushes out to wash it away. Then the eyes or nose or mouth "waters" or overflows.
The eye is irritated by many things beside dust. The fumes of vinegar, pepper and onions make the eyeballs smart. Instantly the tear-glands overflow to protect the eyes. If they could not do this the eyes would become inflamed, and they might be permanently injured. Just watch now and see if onions and pepper do not make you sneeze, and make your nose "water," too, as well as your eyes. Think of lemons and feel your mouth "water."

Why Is A Cat Able To See In The Dark?

First a cat cannot see in pitch dark. It can only see in dim light than you can. You can see in very bright light, and also in dim light. If you come out of a rather dark room where you saw well enough not to bump into things, into strong sunshine, you have to shade your eyes a moment until the pupils become smaller and admit less light. Going from brightness to dimness, you can see better after the pupils of the eyes have had time to expand. It can shut out light if there is too much, or open up to admit all the possible rays if the light is too dim. The pupils of the cat's eyes are able to close like narrow slits in a shutter, to keep out the noon-glare of the sun; and to expand to a big round window that catches all the rays in semi-darkness. They sleep and rest in the daytime, and hunt their prey at night. The house cat hunts mice at night. So a cat needs eyes that are veiled from strong light by day, and that can expand to admit all the few rays of light that are abroad at night.

Why Salt Causes Thirst?

We need salt in our bodies to keep us alive.Our blood also contains salt in it. Salt melts or dissolves easily in water, and in our blood, until they become saturated. If we eat salty food the body soon gets too much salt in it. The only way to get rid of it is to dilute it with water. When the body needs water it very promptly calls for it. We say we feel thirsty.' Salt isn't the only thing that makes us thirsty. Sugar, and many strong, hot spices heat the blood and need to be diluted with water and washed out.

Why People Become Seasick?

       As human beings are land animals their bodies are fitted to live on a stationary base. The sea is always in motion. Anything floating on a big body of water is constantly lifted and let fall and tilted at many angles. This disturbs the nerves of the eyes and the balance or equilibrium of the body, producing dizziness in the head and "sickness" in the stomach. It is probable, too, that the contents of the stomach are more or less shaken by the motion.And some cannot even bear the motions of swings . But people differ very widely. Some are never made sick at sea, and others never get over the tendency, no matter how much they travel. Children rarely suffer from this malady. That is probably because they tumble about more than do grown people. It doesn't bother an active person much to have his stomach rocked, or even turned upside down.

how a duck body is dry always?

 

      Yet a duck spends most of its life swimming in ponds it is dry . The feathers do not account for this, for the duck's feathers are not different from the other birds. The secret of it is that the duck's feathers are oiled. There is an oil-making gland on the duck's back near the tail. The duck spreads a film of this oil all over the surface of its feathers. Now oil and water will not mix, so the water cannot get through this oil to wet the duck's feathers. Besides, the oil slips past the water, making swimming easier.

Why An Iron Ship Does Not Sink but a small nail sinks?

If you put a nail or a lump of iron in water it sinks at once. A piece of wood of the same size floats. Take a sheet-iron put that on the water. It floats. It weighs just as much as the lump of iron that sinks, but the weight is spread or distributed over a larger volume of water . It has been made lighter than the total amount of water it rests upon.An object sinks only when it displaces equal amount of water.The combined density of air and steel is less than that of sea water that is why the ship floats.

          A ship is just such a hollow vessel. When there is nothing in it, a ship stands high, almost on the surface of the water. As it is loaded with goods and people, it rides deeper.

          All ships have a water-line painted plainly around the hull. This is the safety loading line. No ship owners are allowed to load a vessel so heavily that that water line sinks below the surface of the water. Air spaces must be left, to keep the ship and its cargo lighter than the water that is beneath them.

INTERESTING

• Dalmatians are born without spots.
• Bats always turn left when exiting a cave.
• Men’s shirts have the buttons on the right, but women’s shirts have the buttons on the left.
• Your left lung is smaller than your right lung to make room for your heart.
• It cost 7 million dollars to build the Titanic and 200 million to make a film about it.
• The sound you hear when you crack your knuckles is actually the sound of nitrogen gas bubbles bursting.
• Human hair and fingernails continue to grow after death.
• It takes about 20 seconds for a red blood cell to circle the whole body.
• Colgate faced big obstacle marketing toothpaste in Spanish speaking countries. Colgate translates into the command “go hang yourself.”
• Chewing gum while peeling onions will keep you from crying.

Do all the planets rotate in same direction?

No ,the planet Venus rotate in a direction opposite the other planets.I have read about are that planets from dust particles and similar things hitting each other and sticking together till they get bigger and bigger. A planet like Venus probably got to be it is present size from the collision of smaller "planets". The last two small planets to collide in forming the planets we see today determine it is rotation by how they happen to hit each other. The rotation of a planet is only changed by forces that act perpendicular to the rotation axis (actually called torques) for a planet in space there are not many of these.Planets continue to rotate mostly because there are very few forces that act to slow them down.

BERMUDA TRIANGLE

The Bermuda Triangle, also known as the Devil's Triangle, is a region of the northwestern Atlantic Ocean in which a number of aircraft and surface vessels have disappeared in circumstances that fall beyond the boundaries of human error or acts of nature.The more familiar, triangular region formed by points on the Atlantic coast of Florida; San Juan, Puerto Rico; and the mid-Atlantic island of Bermuda, with most of the accidents concentrated along the southern boundary around the Bahamas and the Florida Straits.

There are various reasons stated for the accidents in this mysterious triangular region.
1)extraterrestrial beings
2)Human error
3)Freak waves
4)Gulf Stream--The Gulf Stream is an ocean current that originates in the Gulf of Mexico, and then through the Straits of Florida, into the North Atlantic. In essence, it is a river within an ocean, and like a river, it can and does carry floating objects
5)Hurricanes--Hurricanes are extremely powerful storms which are spawned in the Atlantic near the equator.
6)Compass variations--Compass problems are one of the cited phrases in many Triangle incidents. The North Magnetic Pole is not the North Pole; rather it is the north end of the earth's magnetic field. The North Magnetic Pole does wander, but so slowly that the wandering would not be noticeable on time scale of a sea or air voyage. In general, the compass does not point exactly the direction of the North Magnetic Pole, but rather the compass needle aligns itself to the local geomagnetic field, which can vary in a complex manner over the Earth's surface, as well as over time
7)Methane hydrates--An explanation for some of the disappearances has focused on the presence of vast fields of methane hydrates on the continental shelves. Laboratory experiments carried out in Australia have proven that bubbles can, indeed, sink a scale model ship by decreasing the density of the water, any wreckage consequently rising to the surface would be rapidly dispersed by the Gulf Stream.

RINGS

what are the concentric ring s visible on the wood of a cut tree trunk?

Concentric rings visible on the wood of a cut tree trunk or other woody stem are the annual rings . Each ring represents a period of growth when new xylem is laid down to replace tissue being converted into wood . The wood formed from xylem produced in the spring and early summer has larger and more numerous vessels than the wood formed from xylem produced in autumn when growth is slowing down. The result is a clear boundary between the pale spring wood and the denser, darker autumn wood. Annual rings may be used to estimate the age of the plant, although occasionally more than one growth ring is produced in a given year.we can also estimate the amount of rainfall with the help of gap between the rings.



Why do some planets have rings around them and the rest do not?

If an orbiting object approaches a planet then it may be torn apart by the
tidal force of the planet. The exact distance at which this happens depends
on the composition of the orbiting object. This object could be a moon or a
passing comet or asteroid. A ring is formed by the debris of such objects.
So the planet has to be lucky enough to get an object within the correct
range and at not too oblique an incidence.

FEVER&EARTH

Why body temperature raises when we have fever?
Fever ,also known as pyrexia, or a febrile response from the Latin word febris meaning fever, is a frequent medical symptom that describes an increase in internal body temperature to levels that are above normal (37°C, 98.6°F). Fever is most accurately characterized as a temporary elevation in the body's thermoregulatory set-point, usually by about 1-2°C.The elevation in thermoregulatory set-point means that the previous "normal body temperature" is considered hypothermic, and effector mechanisms kick in.The rise in temperature is to kill the micro organisms. The person who is developing the fever has a cold sensation, and an increase in heart rate, muscle tone and shivering attempt to counteract the perceived hypothermia, thereby reaching the new thermoregulatory set-point.

Let's say that it were possible to bore a tunnel from one side of the Earth, through the center of the Earth and out the other side. I know the core of the Earth is molten iron, but assume that it wasn't and you could actually drill this tunnel. If I were to jump into the tunnel on one side of the Earth, what would happen?

Although it would be impossible to do this on earth, as the core is hot and earth also have oceans and groundwater to mess things up. In addition due to the atmosphere there would be aerodynamic drag ,a nice vacuum in it that eliminates it.
So, imagine that the tunnel is 20 feet (7 meters) in diameter. you would find is that your weight decreases as you move towards the centre. As you descend into the tunnel, more and more of the earth's mass is above you, so it attracts you upward. Once you climbed down to the center of the earth you would be weightless. The mass of the earth is all around you and attracting you equally, so it all cancels out and you would feel weightless.
If you were to actually leap into the tunnel and allow yourself to fall, you would accelerate toward the center to a very high speed. Then you would zoom through the center and start decelerating. You would eventually stop when you reached the tunnel's lip on the other side of the earth, and then you would start falling back down the tunnel in the other direction. You would oscillate back and forth like this forever.

why concrete is watered every day?

Although the terms cement and concrete often are used interchangeably, cement is actually an ingredient of concrete. Concrete is basically a mixture of aggregates and paste. The aggregates are sand and gravel or crushed stone; the paste is water and cement. Concrete gets stronger as it gets older. Curing is one of the most important steps in concrete construction, because proper curing greatly increases concrete strength and durability. Concrete hardens as a result of hydration: the chemical reaction between cement and water. However, hydration occurs only if water is available and if the concrete's temperature stays within a suitable range. During the curing period-from five to seven days after placement for conventional concrete-the concrete surface needs to be kept moist to permit the hydration process. new concrete can be wet with soaking hoses, sprinklers or covered with wet burlap, or can be coated with commercially available curing compounds, which seal in moisture