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 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 is blue for boys and pink for girls?
In ancient times, it was believed that certain colors could combat the   evil spirits that lingered over nurseries. Because blue was associated   with the heavenly spirits, boys were clothed in that color, boys then   being considered the most valuable resource to parents. Although baby   girls did not have a color 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, Baldr, 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 colored 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 Anglicized, 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 who in 1596 invented an indoor water closet  for  Queen Elizabeth I.
 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 colors, 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 color   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.
 Why do you get hiccups?
Hiccups happen when the diaphragm, the muscle that controls our   breathing, becomes irritated and start to spasm and contract   uncontrollably. With each contraction, air is pulled into the lungs very   quickly, passes through the voice box, and then the epiglottis closes   behind the rush of air, shaking the vocal chords, causing the “hic”   sound. The irritation can be caused by rapid eating, emotional stress   and even some diseases. The best cure? Breathing into a paper bag. This   calms the diaphragm by increasing the amount of carbon dioxide in your   bloodstream.
 Why are camels called “ships of the desert?”
Camels are called “ships of the desert” because of the way they move,   not because of their transport capabilities. Camels sway from side to   side because they move both legs on one side at the same time, elevating   that side. This is called pacing, a ship-like motion which can make  the  rider feel sick.