What was the Challenger disaster?

Seven astronauts were aboard Challenger flight STS-51L when it exploded during liftoff on January 28, 1986. Christa McAuliffe was a Concord, New Hampshire, high school social studies teacher. She and the other six crew members were killed when a solid-fuel booster rocket leak led to a massive fuel tank explosion during liftoff from its launch pad.

NASA’s next flight was Discovery, which was launched on September 28, 1988. After the Challenger disaster, NASA’s three remaining shuttles— Atlantis, Discovery, and Columbia—were rebuilt, each with more than 250 modifications improving safety and performance.

Are all flowers fragrant?

Unlike the fragrant blossoms that attract bees, carrion flowers simulate the odor of a rotting animal carcass and attract carrion beetles and different types of flies, including blowflies, flesh flies, and midges. The stapelia flower, which is shaped like a starfish and grows in Africa, has fine hairs around its petals, perhaps to imitate the appearance of a small dead animal. When the bloom opens it gives off a rotting smell, imitating dead animal meat.

The smell attracts flies, which collect pollen before they fly away. Some carrion flowers, such as the European and Brazilian Dutchman’s pipe, lure insects into dark openings that lead to the foul-smelling interior where they become trapped. When the flower “releases” the insect, it is coated with fresh pollen to be taken to a different plant. The lantern stinkhorn, a fungus that releases a feces-like odor, attracts green bottle flies to spread its spores.

Why does my cat purr?

Animal specialists believe that cats purr to show contentment. Cats are born with the ability to purr; kittens make tiny rumbling sounds when they are nursing. Scientists think that purring starts out as a form of communication between a mother cat and her kittens. The purr lets the mother cat know that her babies are happy and feeding well, and she may purr back in response. Later, cats continue to purr when they are in a contented mood or as a friendly greeting. But scientists aren’t really sure how cats purr. Many think that it comes from the vibration of blood in a large vein in the cat’s chest, caused when surrounding muscles repeatedly squeeze and release the blood vessel.

Air in a cat’s lungs and windpipe increase the sound of the vibrations that can be heard (although sometimes the purring is silent and can only be felt). Other scientists think that cats purr when membranes called false vocal chords, located in a cat’s throat near the real ones, start to vibrate.

Interesting facts about Eye

1.    We should never put anything in or near our eyes, unless we have a reason to use eye drops. We would only do that if our doctor or parent told us to use them.
2.    If the lens in our eye doesn’t work quite right, we can get glasses to help us see. Glasses have lenses in them that work with our eye’s own lens to help us see better.
3.    Just behind the pupil is a lens. It is round and flat. It is thicker toward the middle.
4.    Over the front of our eye is a clear covering called the “conjunctiva.”
5.    Blinking helps to wash tears over our eyeballs. That keeps them clean and moist. Also, if something is about to hit our eye, we will blink automatically.
6.    Some people start to sneeze if they are exposed to sunlight or have a light shined into their eye.
7.    The highest recorded speed of a sneeze is 165 km per hour.
8.    Our eyes have many parts. The black part on the front of our eye is called the “pupil.” It is really a little hole that opens into the back part of our eyes.
9.    Our body has some natural protection for our eyes. Our eyelashes help to keep dirt out of our eyes. Our eyebrows are made to keep sweat from running into our eyes.
10.    The most common injury caused by cosmetics is to the eye by a mascara wand.
11.    It is impossible to sneeze with your eyes open.
12.    Around the pupil is a colored muscle called the “iris.” Our eyes may be BLUE, BROWN, GREEN, GRAY OR BLACK, because that is the color of the iris.
13.    Our eyes are very important to us, and we must protect them. We don’t want dirt, sand, splinters or even fingers to get in our eyes.
14.    The reason why your nose gets runny when you are crying is because the tears from the eyes drain into the nose.
15.    The space between your eyebrows is called the Glabella.

16.    The white part of our eye is called the “sclera.” At the front, the sclera becomes clear and is called the “cornea.”
17.    We don’t want our eyes to get scratched or poked. That could damage our sight!
18.    Babies’ eyes do not produce tears until the baby is approximately six to eight weeks old.
19.    Inside our eye, at the back, is a part called the “retina.” On the retina are cells called “rods” and “cones.” These rods and cones help us to see colors and light.
20.    Your eyes blinks over 10,000,000 times a year!
21.    The study of the iris of the eye is called iridology.
22.    The shark cornea has been used in eye surgery, since its cornea is similar to a human cornea.
23.    The number one cause of blindness in adults in the United States is diabetes.
24.    The eyeball of a human weighs approximately 28 grams.
25.    The eye of a human can distinguish 500 shades of the gray.
26.    The cornea is the only living tissue in the human body that does not contain any blood vessels.
27.    The conjunctiva is a membrane that covers the human eye.
28.    Sailors once thought that wearing a gold earring would improve their eyesight.
29.    Research has indicated that a tie that is on too tight cam increase the risk of glaucoma in men.
30.    People generally read 25% slower from a computer screen compared to paper.
31.    Men are able to read fine print better than women can.
32.    In the United States, approximately 25,000 eye injuries occur that result in the person becoming totally blind.
33.    All babies are colour blind when they are born.
34.    A human eyeball weighs an ounce.

Why do baby boys wear blue and girls wear pink?

The custom of dressing baby boys in blue clothes began around 1400. Blue was the colour of the sky and therefore Heaven, so it was believed that the colour warded off evil spirits. Male children were considered a greater blessing than females, so it was assumed that demons had no interest in girls.

It was another hundred years before girls were given red as a colour, which was later softened to pink.

Why do we call the perfect world “Utopia”?

The word Utopia was created by the English philosopher Sir Thomas More in 1516 and was the title of his book that compared the state of life in Europe at the time with an imaginary ideal society. Utopia is from Greek meaning nowhere.

The thrust of More’s message was that an ideal world, or Utopia, will never exist, and that our only choice is to improve the standards of our existing society.

Is it true that parts of Earth are always covered in ice?

About one-tenth of Earth’s surface is always under the cover of ice. And almost 90 percent of that ice is found in the continent of Antarctica. The remaining 10 percent is found on the mountains in the form of glaciers.

The ice sheet that covers Antarctica is almost one-and-a-half times the size of the United States.

What do potato chips have to do with the heart?

Potato chips often contain saturated fats, which over time can clog the arteries that carry blood to the heart. The oils used to cook the chips are made up of saturated fats, which increases cholesterol production in the body, a known risk factor for heart disease.

Heart disease results from a condition known as atherosclerosis, which happens when a waxy substance forms inside the arteries that supply blood to your heart.

How does the metal switch in a toaster bend?

It bends because it is made of two metals that are joined together, something called a bimetal switch. One metal (usually brass) expands quickly when heated, while the other expands much more slowly. This difference causes the switch to bend toward the low-expansion metal.

Bimetal switches are used in other appliances that switch electricity on and off to keep their temperatures even, like irons and refrigerators. The thermostat that regulates the temperature of your home by turning your furnace and air conditioner on and off also uses a bimetal switch.

Can farm animals be cloned?

Yes. In 1997 a team of scientists at the Roslin Institute in Edinburgh, Scotland, announced the birth of Dolly the sheep, the first clone (identical copy) of an adult mammal. The process used to create Dolly, called somatic cell nuclear transfer, began with an egg cell from one sheep. The scientists destroyed that egg cell’s nucleus and then injected the nucleus from the cell of another sheep into the egg cell. With a little encouragement from electronic stimulation, the donated nucleus fused with the egg cell, and the new cell began to divide.

The cluster of cells was then implanted into the uterus of the sheep that had provided the egg cell, and five months later Dolly was born—an exact replica not of the sheep that had carried her in the womb but of the sheep that had supplied the nucleus. While cloning mammals is very controversial, some scientists argue that cloning farm animals has advantages to livestock farmers, who could use the technology to breed only highquality animals that produce the most milk or the finest wool.