Why do we get pins and needles?

Most of us have gone through the phenomenon of legs turning numb as a consequence of sitting in a particular posture for a long time. The sciatic nerve controls and provides sensation to the muscles of our buttocks, thighs, feet and legs. This nerve runs down from the hips to the legs. Anything that puts pressure on this nerve as with prolonged sitting can hinder the nerve function or sensation of the lower legs. This hindering of the nerve function due to compression leads to the numbness of the feet. When we sit sit for a prolonged period in a particular posture, it leads to the accumulation of blood in the legs and the ankle region restricting the draining away of the deoxygenated blood by the veins. The result is the gradual depletion of oxygen in the legs, which causes a dull aching pain or heavy feeling. Diseases like diabetes, lumbar spondylitis and acute weakness due to malnutrition may also cause such a problem.

Why is Barbie called by that name?

Ruth Handler had noted that her daughter Barbara liked to play with paper dolls that looked like adults rather rather than like children. When in Europe, she noticed a German doll named Lilli and bought it for Barbara. Ruth and Elliott Handler, the co-founders of Mattel, bought the rights to market Lilli: with a hair colour change from blonde to brunette, and a name change to Barbie (after Ruth's daughter Barbara). She was sold in the United States at New York's annual Toy Fair.

Why do doughnuts have holes in them?

Once , Hanson Gregory, a sea captain, was desperately hungry and he was finding it impossible to steer his vessel and eat his fried cake at the same time. Frustrated and hungry, Gregory impaled his cake over one of the spokes of the ship's wheel, creating a finger hold. This way, he managed to get a good grip on the cake. Henceforth, doughnuts have always had a hole.

Why do we yawn?

Yawning is an involuntary action that causes us to open our mouths wide 
and breathe in deeply. We yawn when oxygen levels in our lungs become low. Studies show that during normal breathing we don't use anywhere near lung capacity. The air sacs or alveoli needs fresh air or else they tend to stiffen up a bit. Therefore it is believed that the brain prompts the body to either sigh or take a yawn to get more air into the lungs.

Why is the Mars sky red?

Viking Mars landers and Pathfinder have sent back images which show a red sky seen from the surface of the Mars. This owes to the red iron rich dusts thrown up in frequent dust storms occuring on Mars. With the change in the weather conditions in Mars, the color of the Mars sky will also change. Due to the thin atmosphere of Mars, its sky will remain darker than the earth's daytime sky.

Why does the setting sun appear reddish orange?

The light of the sun on the horizon takes a longer path to reach our eyes through the atmosphere. This does not happen when the sun is directly overhead. By the time the light of the setting sun reaches our eyes, most of the blue light scatters out. The light we finally see is reddish orange. It is the color of white light minus the blue color.

Why is camel called "the ship of the desert"?

Camels are called "the ship of the desert" because of the way they move on the sand. They sway from side to side because they move both legs on one side at the same time, elevating that side. They thus have a ship-like motion which can make the rider feel sick.

Why do you cry while slicing onions?

Onion cells contain a chemical compound that contains sulfur. When we slice onions the cells rupture and react with the enzyme outside the cells. This reaction produces molecules which react with the moisture in our eyes (forming sulfuric acid ) which in turn causes an irritating sensation. This makes our eyes water.

Why does the chameleon change its color?

The popular belief is that a chameleon changes its color to camouflage itself with its surroundings and evade danger, but in reality chameleons change colour in response to changes in the light, mood or temperature.