Black Hole Facts

by Roger Smith

If you are into science, astronomy or even science fiction, you probably are amazed at the phenomenon called black holes. Black holes by their very name convey mystery and intrigue and while man has theorized about the existence of black holes since the late 1700's, we are still a long way off to knowing precisely what black holes are and how they behave today.

What is a Black Hole? One of the questions most people have about black holes is exactly what they are. Black holes are theorized to be areas of space in which the gravitational field is so strong and powerful that nothing can escape and break passed its grasp. In fact, black holes show up as completely void areas of space, because not even light can escape the strong gravitational forces. It is believed that a black hole is caused by a large star imploding onto itself creating tremendous density and thus incredibly strong gravitation forces.

The Life of a Black Hole Black holes as stated above are caused by a large star- much larger than our own sun imploding. These large stars run out of fuel which is necessary for nuclear reaction. Unfortunately, as the star runs out of fuel, the effect of normally pushing energy out is outweighed by its own gravity which continues to grow exponentially until the star incredibly crushes itself. It crushes itself to such a degree that its mass becomes super dense creating incredible forces of gravity that do not let anything escape its force. It should be noted that a black hole does not last for ever, while it does not allow light to escape, x-ray radiation is emitted and eventually black holes become smaller and smaller till eventually they disappear.

Where are Black Holes Located? One of the most noticeable aspects of black holes is that they usually can be easily located due to the fact that they are completely void areas of space. Black holes have been located throughout our universe in several galaxies. It was theorized that there was even a black hole in our galaxy- the Milky Way, however for a long period of time the evidence was not complete. Recently however, a black hole was discovered in our own galaxy- actually in the center turning many astronomers' theories on their heads.

For more information regarding black holes, the Smithsonian Magazine has a fascinating article on the subject. To read it, please visit our main website.

About the Author

http://www.smithsonianmag.com Smithsonian magazine is a monthly magazine created for modern, well-rounded individuals with diverse interests. It chronicles the arts, history, sciences and popular culture of the times. Each month, expect articles from the Smithsonian Institution's award-winning, monthly general interest magazine, plus exclusive Web articles, videos, blogs, photographs and more.

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Naming Stars in Different Cultures

by Richard Pickering

While modern astronomers refer to most stars solely by catalog numbers and astronomy coordinates, many people informally name stars using name a star services. In fact, throughout history people from various cultures have used star names of their own choosing. Many civilizations explained their existence through mythological stories passed from generation to generation, and often associated these stories with the stars in the night sky. As we'll see, even a major car company is named after the stars.

To illustrate, let's start with a constellation (an area of the night sky) modern astronomers have named after a character from Greek and Roman mythology - "Orion," the Great Hunter. Orion is one of the most well known and easily-identifiable constellations, and can be seen from just about anywhere on Earth: The best time to view Orion is during the evening hours between roughly December and March. Many classical mythology stories are told about Orion and how he came to be placed in the heavens. One such story is that Orion had no fear of any animal and therefore threatened to exterminate all of the animals of the earth. When Gaia, the goddess of the earth, heard this she became enraged and sent a scorpion to kill Orion. When Orion encountered the scorpion he was unable to kill it, and the scorpion stung Orion and sent him falling to the earth, fatally wounded. In honor of this story, Orion was placed in the night sky as a constellation, as was the scorpion - known as the constellation "Scorpius."

While 21st century astronomers refer to the constellation "Orion" after a hunter from classical mythology, other cultures have had different interpretations of these same stars. One of the distinguishing features of Orion is a line of three, bright stars that form what is called "The Belt of Orion." The ancient Egyptians thought these three bright stars were the resting place of the god Osiris. The Dogon people of West Africa viewed the three stars as the stairway to heaven. These same three stars have been associated with Christmas, viewed as representing the Magi - "The Three Wise Men" (The Three Kings) from the Bible. The people of the Marshall Islands viewed Orion's stars as an octopus and a fisherman: The story told was of a fisherman who was attacked by an octopus. The fisherman defended himself by using a stone to stab the head of the octopus. Although the octopus was wounded he was able to spray his ink, behind which he hid and was able to escape. The Chimu Indians of Peru believed that the middle star of Orion's belt represented a thief or mischief maker that the Moon Goddess punished. The Moon Goddess punished the wrongdoer by sending two stars to capture him and send him to four vultures that would eat him. This mythological story served as a warning for those who would commit crimes.

Another interesting example from classical mythology is related to a beautiful group of stars in the constellation Taurus called "The Pleiades," or "The Seven Sisters." These stars are visible in the evening sky from roughly November through April, and are often confused with "The Little Dipper" (which is in another constellation) as the bright stars of the Pleiades together resemble a very small dipper, or ladle. The story from classical mythology is that Orion, the hunter, became enamored of these seven beautiful ladies, and relentlessly pursued them throughout the world. Taking pity on the young women, Zeus placed them in the heavens where Orion continues to pursue them in the night sky.

Many cultures have also associated the Pleiades with females or femininity. The Australian Aborigines saw this group of stars as a cluster of girls who were musicians. These girls play their instruments for a group of young boys who are represented by the stars seen in Orion's belt. Some Native American tribes viewed the Pleiades as seven mothers who were looking for their seven lost sons: According to the Chumash Indians of California, these seven sons had become the stars of the Big Dipper. The Kiowa Indians saw these stars as young women who were placed in the heavens by the Great Spirit so as to save them from attacking bears. In Norse mythology, they were the hens of Freya, the goddess of love, beauty and fertility. In Japan the Pleiades were known as "Subaru," after which a Japanese car company is named.

Naming stars, then, is an age-old custom that has been practiced by different civilizations around the world.

About the Author

Richard Pickering is an astronomer for Name A Star Live. While no star-naming service can change the scientific designations of stars, only Name A Star Live makes it real by providing you: Virtual Planetarium™ astronomy software; an opportunity to view your star live using an online telescope; and the launch of your star name into space!

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