What are comets?

Comets are solar system bodies that orbit the Sun, just as planets do, except a comet usually has a very elongated orbit. Part of its orbit is very, very far from the Sun and part is quite close to the Sun. They are sometimes nicknamed dirty “cosmic snowballs,” because they are small, irregularly shaped chunks of rock, various ices, and dust.

As the comet gets closer to the Sun, some of the ice starts to melt and boil off, along with particles of dust. These particles and gases make a cloud around the nucleus, called a coma. The coma is lit by the Sun. The sunlight also pushes this material into the brightly lit “tail” of the comet.

What has the Hubble Space Telescope discovered?

According to the National Aeronautics and Space Administration (NASA), Which is in charge of space exploration and scientific discovery for the United States, the Hubble transmits about 120 gigabytes of science data every week. That’s equal to about 3,600 feet (1,097 meters) of books on a shelf. The growing collection of pictures and data is stored on magneto-optical disks. Among its many discoveries, Hubble has revealed the age of the universe to be about 13 to 14 billion years, which is a more accurate estimate than the Big Bang range of between 10 to 20 billion years.

Hubble also played a key role in the discovery of dark energy, a mysterious force that causes the expansion of the universe to accelerate. Hubble has shown scientists galaxies in “toddler” stages of growth, helping them understand how galaxies form. It found protoplanetary disks, clumps of gas and dust around young stars that likely function as birthing grounds for new planets. It discovered that gamma-ray bursts—strange, incredibly powerful explosions of energy—occur in far-distant galaxies when massive stars collapse.

Why do we call a leg injury a “charley horse”?

The phrase charley horse has its roots in baseball. At the beginning of the twentieth century, groundskeepers often used old and lame horses to pull the equipment used to keep the playing field in top condition.

The Baltimore Orioles had a player named Charley Esper, who, after years of injuries, walked with pain. Because his limp reminded his teammates of the groundskeeper’s lame horse, they called Esper “Charley Horse.”

Interesting facts about Hair

1.    On average, a man spends about five months of his life shaving.
2.    On average, a hair strand’s life span is five and a half years.
3.    On average redheads have 90,000 hairs. People with black hair have about 110,000 hairs.
4.    Next to bone marrow, hair is the fastest growing tissue in the human body.
5.    In a lifetime, an average man will shave 20,000 times.
6.    Humans have about the same number of hair follicles as a chimpanzee has.
7.    Hair will fall out faster on a person that is on a crash diet.
8.    The longest human beard on record is 17.5 feet, held by Hans N. Langseth who was born in Norway in 1846.
9.    The average human head weighs about eight pounds.
10.    The reason why some people get a cowlick is because the growth of their hair is in a spiral pattern, which causes the hair to either stand straight up, or goes to a certain angle.
11.    The reason why hair turns gray as we age is because the pigment cells in the hair follicle start to die, which is responsible for producing “melanin” which gives the hair colour.
12.    The fastest growing tissue in the human body is hair.

13.    A lifespan of an eyelash is approximately 150 days.
14.    A survey done by Clairol 10 years ago came up with 46% of men stating that it was okay to color their hair. Now 66% of men admit to coloring their hair.
15.    The big toe is the foot reflexology pressure point for the head.
16.    The average human scalp has 100,000 hairs.
17.    The first hair dryer was a vacuum cleaner that was used for drying hair.
18.    Ancient Egyptians used to think having facial hair was an indication of personal neglect.
19.    The loss of eyelashes is referred to as madarosis.
20.    Hair and fingernails are made from the same substance, keratin.
21.    Eyebrow hair lasts between 3-5 months before it sheds.
22.    A Russian man who wore a beard during the time of Peter the Great had to pay a special tax.
23.    Everyday approximately 35 meters of hair fiber is produced on the scalp of an adult.
24.    Hair is made from the same substance as fingernails.
25.    Brylcreem, which was created in 1929, was the first man’s hair product.

Why do camels have humps?

Camels are the only animals with humps. A camel’s hump is a giant mound of fat, Which can weigh as much as 80 pounds (35 kilograms). The hump allows a camel to survive up to two weeks without food. Because camels typically live in the deserts of Africa and the Middle East, where food can be scarce for long stretches, their hump is key to their survival. When camels are born their humps are empty pockets of flexible skin. As a camel grows and begins to form its fatty tissue reserves, the humps begin to fill out and take shape.

The humps also come in handy for humans who have domesticated the camel. For thousands of years, people have used these strong, resilient creatures for transportation and for hauling goods. The two-hump, or Bactrian, camel was domesticated sometime before 2500 B.C.E., probably in northern Iran, northeastern Afghan – istan, and northern Pakistan. The one-hump, or Dromedary, camel was domesticated sometime between 4000 and 2000 B.C.E. in Arabia.

Why are there sixty seconds in a minute and sixty minutes in an hour?

Around 2400 BC, the ancient Sumarians, who used six as their mathematical base, divided a circle into 360 degrees, with each degree subdivided into another 60 parts, and so on. The Romans called these units minute prima, or first small part, and secunda minuta, or second small part. This system was perfect for round clock faces, and that’s why we use minutes and seconds as divisions of time.

Do all plants have leaves?

Most plants have leaves, even if they do not look like leaves. For example, blades of grass are really leaves. Mushrooms and other fungi do not have leaves, and seaweeds and lichens do not have leaves. Seaweed, a type of algae, also does not have flowers or roots. As an underwater plant, it usually clings to stones, shells, and rocks with its holdfast, a part of the plant that looks like roots. Unlike other plants that feed through their roots, seaweed takes its nutrients from the water in which it grows.

How do robots like ASIMO and Mahru work?

Robots like ASIMO and Mahru are sophisticated, expensive, highly technologically advanced machines that are built upon major components found in humans. Robot technicians use the inner workings of the human body as the model for the robots that they make. This modeling ensures that their robots are as lifelike as possible. First, the robot technician designs the five major components he or she will put into the robot: a body structure, a muscle system, a sensory environment, a power source, and a brain system.

Next, they build an intricate machine made up of electrical circuits, electrical valves, piston cylinders, electric motors, solenoids, hydraulic systems, and more—each plays a specific role in getting the robot to work. Every robot has a computer that controls everything else within its body. Many robots can talk and some can even smell, taste, and hear. To get the body of a robot moving, the computer must “tell” the specific part to move. If the technician wants the robot to do something new once it has been made, he or she writes a new computer program. In some cases, if the task is too big for the robot’s wiring system, new parts need to be installed. NUMBERS AND COUNTING

Why is nuclear power dangerous?

The good thing about fission-generated nuclear energy is that very little fuel is needed to produce huge amounts of energy. (Two pounds of nuclear fuel could produce as much energy as 6.5 million pounds of coal, for instance!) The challenging part is that the process must be very carefully controlled. (In a nuclear reactor, control rods that absorb neutrons are moved in and out of the core to control the process.) If it isn’t controlled, the result could be a build up of pressure within the reactor. If this continues, radioactive gases might be released along with steam. It was a situation like this that happened at the Chernobyl plant in the Soviet Union in 1986, resulting in radioactive pollution that still exists today. An uncontrolled nuclear reaction can cause harmful radioactive materials (such as iodine isotopes that can cause thyroid cancer) to be released into the environment. This by-product of nuclear fission is a problem connected with nuclear power. Nuclear reactors are encased in thick layers of steel and concrete to keep radiation from escaping.

And because leftover nuclear fuel is highly radioactive, it must be carefully stored far away from people for decades or even centuries before it is safe again. Transporting and disposing of dangerous waste is another challenge presented by nuclear power; at present, used fuel is sealed in safety containers and buried deep underground. The nuclear process that we get our power from is called fission, where atomic nuclei that break apart produce great energy and heat. But nuclear power can also be created by a process called fusion, where atomic nuclei join together. Scientists are still working on creating a satisfactory fusion reactor. The Sun produces its great energy and heat through the nuclear fusion of its hydrogen gases.

Why do stars twinkle?

On a clear, dark night in your backyard, you can see about 2,000 or so stars in the sky, a small fraction of the 100,000 or so stars that make up our galaxy. They seem to twinkle, or change their brightness. In reality, most of the stars are shining with a steady light. The movement of air (sometimes called turbulence) in the atmosphere of Earth causes the starlight to get slightly bent as it travels from the distant star through the atmosphere down to the ground.

This means that some of the light reaches us directly and some gets bent slightly away. To the human eye, this makes the star seem to twinkle.