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 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 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.