Why (Feb 2006)

Why does wet fabric appear darker?
When fabric gets wet, light coming towards it refracts within the water, dispersing the light. In addition, the surface of the water causes incoherent light scattering. The combination of these two effects causes less light to reflect to your eyes and makes the wet fabric appear darker.

Why does water not calm the tongue after eating hot spicy food?
The spices in most of the hot foods that we eat are oily, and, like your elementary school science teacher taught you, oil and water don't mix. In this case, the water just rolls over the oily spices.
What can you do to calm your aching tongue? Eat bread. The bread will absorb the oily spices. A second solution is to drink milk. Milk contains a substance called "casein" which will bind to the spices and carry them away. Alcohol also dissolves oily spices.

Why is blue for boys and pink for girls?
In ancient times, it was believed that certain colours could combat the evil spirits that lingered over nurseries. Because blue was associated with the heavenly spirits, boys were clothed in that colour, boys then being considered the most valuable resource to parents. Although baby girls did not have a colour associated with them, they were mostly clothed in black. It was only in the Middle Ages when pink became associated with baby girls.

Why do people kiss under the mistletoe at Christmas?
In ancient myth, when the son of the Norse goddess Frigga was killed by an arrow made of mistletoe and then brought back to life, she blessed the mistletoe and bestowed a kiss on all who passed beneath it. In the 18th century, the legend was adopted as a promise to marry. At Christmas a lady standing under a mistletoe may not refuse a kiss. If she does, she cannot expect to marry the following year. So it is told.

Why are there bunnies and eggs at Easter?
The ancient Anglo-Saxons celebrated the return of spring with a carnival commemorating their goddess of offspring and of springtime, Eostre. The word carnival possibly originated from the Latin ‘carne vale' meaning "flesh, farewell" or "meat, farewell." The offerings were rabbits and coloured eggs, bidding an end to winter.
As it happened, the pagan festival of Eostre occurred at the same time of year as the Christian observance of the Resurrection of Christ and it didn't take the Christian missionaries long to convert the Anglo-Saxons when they encountered them in the second century. The offering of rabbits and eggs eventually became the Easter bunny and Easter eggs.

If blood is red, why are veins blue?
Blood is bright red in its oxygenated form and a dark red in deoxygenated form. In simpler terms, it is bright red when it leaves the lungs full of oxygen and dark red when it returns to the lungs for a refill. Veins appear blue because light penetrating the skin is absorbed and reflected in high energy wavelengths back to the eye. Higher energy wavelengths are blue.

Why did Columbus and others try to sail around the world?
You probably know that people native to the Americas are called "Indians" because early explorers like Christopher Columbus thought they had come across the Indian spice islands. Traders were forced to sail westward after the spice route to the East by land was blocked for Europeans by Muslim uprisings.

Why is it called a "loo?"
The British word for toilet, "loo", derives from the French "garde a l'eau!" In medieval Europe people had little conception of hygiene and threw the contents of their chamber pots out the window into the street below. In France the practice was preceded by "garde a l'eau!" ("watch out for the water!"). In England, this phrase was Anglicised, first to "gardy-loo!", then just "loo", and eventually came to mean the toilet/lavatory itself. The American word for toilet, "john", is called after the John Harington mentioned above.

Why is the sky blue?
When sunlight travels through the atmosphere, it collides with gas molecules. These molecules scatter the light. The shorter the wavelength of light, the more it is scattered by the atmosphere. Because it has a shorter wavelength than the other colours, blue light is scattered more, ten times more than red light, for instance. That is why the sky is blue.
Why does the setting sun look reddish orange? When the sun is on the horizon, its light takes a longer path through the atmosphere to reach your eyes than when the sun is directly overhead. By the time the light of the setting sun reaches your eyes, most of the blue light has been scattered out. The light you finally see is reddish orange, the colour of white light minus blue.

Why do onions make you cry?
Onions, like other plants, are made of cells. The cells are divided into two sections separated by a membrane. One side of the membrane contains an enzyme which helps chemical processes occur in your body. The other side of the membrane contains molecules that contain sulfur. When you cut an onion, the contents on each side of the membrane mix and cause a chemical reaction. This reaction produces molecules such as ethylsufine which make your eyes water.
To prevent crying when you cut an onion, cut it under a running tap of cold water. The sulfur compounds dissolve in water and are rinsed down the sink before they reach your eyes. You can also put the onion in the freezer for ten minutes before you cut it. Cold temperatures slow down the reaction between the enzyme and the sulfur compounds so fewer of the burning molecules will reach your eyes.