From NJ Nightline-A giant black hole has been caught red-handed dipping into a cosmic cookie jar of stars by NASA's Galaxy Evolution Explorer. This is the first time astronomers have seen the whole process of a black hole eating a star, from its first to nearly final bites.
"This type of event is very rare, so we are lucky to study the entire process from beginning to end," said Dr. Suvi Gezari of the California Institute of Technology, Pasadena, Calif. Gezari is lead author of a new paper appearing in the Dec. 10 issue of Astrophysical Journal Letters.
For perhaps thousands of years, the black hole rested quietly deep inside an unnamed elliptical galaxy. But then a star ventured a little too close to the sleeping black hole and was torn to shreds by the force of its gravity. Part of the shredded star swirled around the black hole, then began to plunge into it, triggering a bright ultraviolet flare that the Galaxy Evolution Explorer was able to detect.
Today, the space-based telescope continues to periodically watch this ultraviolet light fade as the black hole finishes the remaining bits of its stellar meal. The observations will ultimately provide a better understanding of how black holes evolve with their host galaxies.
"This will help us greatly in weighing black holes in the universe, and in understanding how they feed and grow in their host galaxies as the universe evolves," said Dr. Christopher Martin of Caltech, a co-author of the paper and the principal investigator for the Galaxy Evolution Explorer.
In the early 1990s, three other resting, or dormant, black holes were suspected of having eaten stars when the joint German-American-British Röntgen X-ray satellite picked up X-ray flares from their host galaxies. Astronomers had to wait until a decade later for NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton X-ray observatory to confirm those findings, showing that the black holes' X-rays had faded dramatically -- a sign that stars were swallowed.
Now, Gezari and her colleagues have, for the first time, watched a similar feeding frenzy unfold, as it happens, through the ultraviolet eyes of the Galaxy Evolution Explorer. They used the telescope's detectors to catch an ultraviolet flare from a distant galaxy, then watched the flare diminish over time, as the galaxy's central black hole consumed the star. Additional data from Chandra, the Canada France Hawaii Telescope in Hawaii and the Keck Telescope, also in Hawaii, helped the team chronicle the event in multiple wavelengths over two years.
Black holes are heaps of concentrated matter whose gravity is so strong that even light cannot escape. Supermassive black holes are believed to reside at the cores of every galaxy, though some are thought to be more active than others. Active black holes drag surrounding material into them, heating it up and causing it to glow. Dormant black holes, like the one in our Milky Way galaxy, hardly make a peep, so they are difficult to study.
That's why astronomers get excited when an unsuspecting star wanders too close to a dormant black hole, an event thought to happen about once every 10,000 years in a typical galaxy. A star will flatten and stretch apart when a nearby black hole's gravity overcomes its own self-gravity. The same phenomenon happens on Earth every day, as the moon's gravity tugs on our world, causing the oceans to rise and fall. Once a star has been disrupted, a portion of its gaseous body will then be pulled into the black hole and heated up to temperatures that emit X-rays and ultraviolet light.
"The star just couldn't hold itself together," said Gezari, adding, "Now that we know we can observe these events with ultraviolet light, we've got a new tool for finding more."
The newfound feeding black hole is thought to be tens of millions times as massive as our sun. Its host galaxy is located 4 billion light-years away in the Bootes constellation.
Note: JPL
"This type of event is very rare, so we are lucky to study the entire process from beginning to end," said Dr. Suvi Gezari of the California Institute of Technology, Pasadena, Calif. Gezari is lead author of a new paper appearing in the Dec. 10 issue of Astrophysical Journal Letters.
For perhaps thousands of years, the black hole rested quietly deep inside an unnamed elliptical galaxy. But then a star ventured a little too close to the sleeping black hole and was torn to shreds by the force of its gravity. Part of the shredded star swirled around the black hole, then began to plunge into it, triggering a bright ultraviolet flare that the Galaxy Evolution Explorer was able to detect.
Today, the space-based telescope continues to periodically watch this ultraviolet light fade as the black hole finishes the remaining bits of its stellar meal. The observations will ultimately provide a better understanding of how black holes evolve with their host galaxies.
"This will help us greatly in weighing black holes in the universe, and in understanding how they feed and grow in their host galaxies as the universe evolves," said Dr. Christopher Martin of Caltech, a co-author of the paper and the principal investigator for the Galaxy Evolution Explorer.
In the early 1990s, three other resting, or dormant, black holes were suspected of having eaten stars when the joint German-American-British Röntgen X-ray satellite picked up X-ray flares from their host galaxies. Astronomers had to wait until a decade later for NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton X-ray observatory to confirm those findings, showing that the black holes' X-rays had faded dramatically -- a sign that stars were swallowed.
Now, Gezari and her colleagues have, for the first time, watched a similar feeding frenzy unfold, as it happens, through the ultraviolet eyes of the Galaxy Evolution Explorer. They used the telescope's detectors to catch an ultraviolet flare from a distant galaxy, then watched the flare diminish over time, as the galaxy's central black hole consumed the star. Additional data from Chandra, the Canada France Hawaii Telescope in Hawaii and the Keck Telescope, also in Hawaii, helped the team chronicle the event in multiple wavelengths over two years.
Black holes are heaps of concentrated matter whose gravity is so strong that even light cannot escape. Supermassive black holes are believed to reside at the cores of every galaxy, though some are thought to be more active than others. Active black holes drag surrounding material into them, heating it up and causing it to glow. Dormant black holes, like the one in our Milky Way galaxy, hardly make a peep, so they are difficult to study.
That's why astronomers get excited when an unsuspecting star wanders too close to a dormant black hole, an event thought to happen about once every 10,000 years in a typical galaxy. A star will flatten and stretch apart when a nearby black hole's gravity overcomes its own self-gravity. The same phenomenon happens on Earth every day, as the moon's gravity tugs on our world, causing the oceans to rise and fall. Once a star has been disrupted, a portion of its gaseous body will then be pulled into the black hole and heated up to temperatures that emit X-rays and ultraviolet light.
"The star just couldn't hold itself together," said Gezari, adding, "Now that we know we can observe these events with ultraviolet light, we've got a new tool for finding more."
The newfound feeding black hole is thought to be tens of millions times as massive as our sun. Its host galaxy is located 4 billion light-years away in the Bootes constellation.
Note: JPL
AMAZING FACTS ABOUT THE UNIVERSE
Chapter 1
We are living in an age of scientific progress. In our generation we have seen man achieve some things that our forefathers considered impossible.
The pace at which science is progressing is perpetually accelerating. It has been estimated that the entire scientific knowledge that man had acquired from the time of his creation to 1750 A.D. was doubled all of a sudden within a period of 150 years by 1900 A.D. The knowledge that was man's by 1900 A.D. doubled again and this time in just 50 years - by 1950 A.D. This knowledge doubled again in just 10 years - by 1960. It has been estimated that man's scientific knowledge has been doubling thereafter every two and half years.
Take for instance the speed of travel, as one indication of scientific advance. 200 years ago man traveled on horseback just like his primitive ancestors did thousands of years earlier. But by 1900, man could travel by advanced means of locomotion at about 80 kilometres per hour and this was considered a very fast speed in those days. By 1945, jet planes had come into the air and man was traveling at 1000 kilometres per hour. Today, man travels in space at over 40,000 kilometres per hour.
We say that space has been conquered because man has reached the moon; but we must not forget that the moon is just on the fringe of space. Space itself is so vast that it staggers our imagination. Let's have a look at the universe and at space!
The average distance of the moon from the earth is about 400,000 kilometres. This is very small compared with the distance from the earth to the sun which is about 150 million kilometres. The distance of the sun looks quite considerable, but is actually quite negligible when compared with the distance of the nearest star.
When calculating distances to the stars, ordinary units of measurement will not do, for they lead us into fantastically large figures. Scientists and astronomers therefore use the "light year" as the unit of measurement - that is, the distance that light travels in one year. Remember that light travels about 300,000 kilometres (or 7 times around the earth) in one second. So the distance that it travels in one year comes to over 9000 billion kilometres.
Let us consider the distances to some of the stars. The nearest star visible to the naked eye is a star called "Alpha Centauri" - which is four and a half light years away - that is, about 250,000 times the distance to the sun. This means that if you traveled at the speed of light, even though you would reach the moon in one and a half seconds and the sun in eight and a half minutes you would have to travel for four and a half years at that speed to reach "Alpha Centauri." To get a better idea of what this means, consider a scale model of the universe where the earth is represented by a grain of sand and the sun by a marble, 3 feet away from the earth. All the planets of our solar system would then come within a radius of 100 feet from the sun. But the nearest star would be 150 miles away from the earth on that scale model of the universe.
The farthest star visible to the naked eye is in the Andromeda Galaxy, which is more than 1.5 million light years away. There are still more distant galaxies that are visible through telescopes, 6,500 million light years away.
Now look at the sizes of some of the stars. They look so small that little children say "Twinkle, twinkle little star". The earth looks pretty large! It takes us many hours to get from one place to another on this earth. But the sun is so large that 1 million spheres the size of the earth could fit into it, if it were hollow. Yet even the sun is small compared to some stars. Some stars are so large that 500 million spheres the size of the sun could fit inside each of them if they were hollow.
The star Betelgeuse, 520 light years from the earth, is one of the bright stars of the Orion belt. Its diameter is 500 million kilometres - which means that if it were hollow, the earth could comfortably revolve around the sun, INSIDE THIS STAR, in its normal orbit! (The earth's orbit around the sun being only 300 million kilometres in diameter).
Now consider the number of the stars. Our solar system is part of a galaxy called the "Milky Way". Astronomers have estimated that there are at least 100,000 million stars in this galaxy. The sun is just one such star. And the Milky way is just one galaxy among many. Astronomers tell us that there are at least 100 million galaxies in the part of space that telescopes can see. There are many more beyond.
Consider too the perfect precision with which these heavenly bodies move in their orbits. The best man-made watch is not more precise than the stars in the heavens. Surely there must be a Supreme Intelligence behind this universe, that created and planned each star and planet.
How vast is space! How small is man! One of the writers in the Bible wrote thus, "When I look up into the night skies and see the stars, I can't understand oh God why you should pay any attention to puny man". Yet, God the creator of this universe cares for each of us. This is the marvelous truth we learn in the Bible.
The value of any article is not determined by its size. A millionaire may own acres of land. But his little child is more precious to him than all those large tracts of land. So with God. Space may be vast. The stars may be huge in their size. But God loves and cherishes man more than all of His creation. Man was created to be a son of God, to have fellowship with God. It is such a fellowship with God alone that can give meaning and purpose to man's existence.
We can see the greatness of God in creation. But the Bible reveals that this God is also One who loves us and cares for us.
To read in its entirity click here
GOD, the Creator of Science
In the Beginning
"In the beginning GOD created the heavens and earth" Genesis 1:1. GOD not only created the heavens and the earth but He created the scientific basis for us to study His work. It is truly impossible for man to dispute the existence of GOD. Many have tried and failed. From the very beginning GOD provided significant evidence that our existence occurred by a greater means than a random accident in the universe.
Astronomy is a relatively new science although men have been searching the stars for thousands of years. Until the first telescope was used by Galileo in 1609, it was thought that there were only about a thousand stars in the sky. Ptolemy counted 1056, Tycho Brahe cataloged 777, and Johannes Kepler counted 1005. There are about 6000 stars which are visible to the naked eye if you count them from all locations on earth. The Word of GOD points out in Jeremiah 33:22, "As the host of heaven cannot be numbered, nor the sand of the sea measured, so will I multiply the descendants of David My servant and the Levites who minister to Me." And again in Genesis 22:17; "blessing I will bless you, and in multiplying I will multiply your descendants as the stars of the heaven and as the sand which is on the seashore; and your descendants shall possess the gate of their enemies."
When Galileo first viewed our Milky Way galaxy through his 20 power telescope, he must have realized that there were perhaps millions upon millions of stars. Actually there are 1000 to 2000 billion stars in our galaxy alone. Perhaps mankind can begin to realize the absolute accuracy of GOD's Word. I suspect that many scientific men who lived before Galileo's discovery may have totally discounted these verses as being inaccurate. The same is true today as men try to dispute the accuracy of the Bible, only to be proved incorrect later as our knowledge of the sciences increases with time.
The knowledge that the earth is round is also a relatively new discovery of science and human exploration in the history of mankind. During the time of Christopher Columbus, the common held belief was that the earth was flat and that a sailor, if venturing to far out to sea would fall of the edge of the earth. The knowledge that the earth is round was clearly proclaimed in GOD's Word in several Old Testament verses, which were written approximately 700 years before Christ was born. The prophet Isaiah in 40:22 wrote: "It is He who sits above the circle of the earth, and its inhabitants are like grasshoppers, who stretches out the heavens like a curtain, and spreads them out like a tent to dwell in." Again in Proverbs 8:27 GOD clearly explains the physical nature of our earth. "When He prepared the heavens, I was there, when He drew a circle on the face of the deep." In Job 26:10 the prophet wrote: "He drew a circular horizon on the face of the waters, at the boundary of light and darkness." These three prophets, writing hundreds of years apart, are 100% accurate and in agreement.
The science of Geophysics is a relatively new field of study for mankind. Our GOD, however, existed before the universe was formed. In the book of Job 26:7 the prophet wrote: "He stretches out the north over empty space; he hangs the earth on nothing." This verse must have certainly puzzled the wise men 700 years before Christ was born, as well as men of science right up until Newton proposed his theory for the law of gravity. Even today scientists cannot do much more than measure the strength of gravity. It is invisible. Gravity exists, but there is little known about it other than that gravity holds the planets of our solar system in place millions of miles from the sun. Perhaps gravity can simply be described by the following verse in Hebrews 1:3. "Who being the brightness of His glory and the express image of His person, and upholding all things by the Word of His power.."
Meteorology is the science of weather. Since weather is important to the existence of all life on earth, you might expect GOD to mention something about it in his Word. GOD wrote in Ecclesiastes 1 :6-7, "The wind goes toward the south, and turns around to the north; the wind whirls about continually, and comes again on its circuit. All the rivers run into the sea, yet the sea is not full; to the place from which the rivers come, there they return again." Again in Job 36:27-29, "For He draws up drops of water, which distill as rain from the mist, which the clouds drop down and pour abundantly on man. Indeed, can anyone understand the spreading of clouds, the thunder from His canopy?" Here GOD, through the prophets, explains weather patterns that have only become known scientifically by mankind in perhaps the last hundred years.
Mankind is also one of GOD's miraculous creations. Since GOD is our creator, you would expect him to have a complete understanding of our physical nature, including how best to care for us. The science of biology was clearly evident in the Old Testament. A profound understanding of the infectious nature of disease is evident in Leviticus 13:45-46. [Note: 'Leprosy' has a broader meaning in the Bible than it does today.] "Now the leper on whom the sore is, his clothes shall be torn and his head bare; and he shall cover his mustache, and cry, "'Unclean! Unclean!" He shall be unclean. All the days he has the sore he shall be unclean. He is unclean, and he shall dwell alone; his dwelling shall be outside the camp." The fact that disease can even be spread by contact with infected clothing is explained in Leviticus 13:50-52. "The priest shall examine the plague and isolate that which has the plague seven days. And he shall examine the plague on the seventh day. If the plague has spread in the garment, either in the warp or in the weave, in the leather or in anything made of leather, the plague is an active leprosy. It is unclean. He shall therefore burn that garment in which is the plague, whether warp or weave, in wool or in linen, or anything of leather, for it is an active leprosy; the garment shall be burned in the fire."
The importance GOD places on life and our dependence on blood is clearly expressed in Leviticus 17:10-11. "And whatever man of the house of Israel, or of the strangers who dwell among you, who eats any blood, I will set my face against that person who eats blood, and will cut him off from among his people. For the life of the flesh is in the blood, and I have given it to you upon the altar to make atonement for your souls; for it is the blood that makes atonement for the soul." The importance of blood in the physical world is but a mirror image of the priceless eternal life-giving blood of GOD's Son Jesus who died on the cross for mankind's sin, as our Eternal Father reminds us in Revelation 1:5 - "and from Jesus Christ, the faithful witness, the firstborn from the dead, and the ruler over the kings of the earth. To Him who loved us and washed us from our sins in His own blood. "
It should be pointed out that the few verses that are included in this brochure are not sufficient by themselves to teach GOD's plan of salvation. Only a thorough study of the New Testament of Jesus Christ and obedience to the Gospel can accomplish this. The short study of theses verses, however, can help build your faith in the total accuracy and validity of the Word of GOD.
May GOD bless you through the knowledge of His Son Jesus.
Joe Andrasik
Christians of the churches of Christ may reproduce this tract in any reprinted format as long as it is given away freely.
All references are from the New King James version of the Bible.
Published in The Old Paths Archive (http://www.oldpaths.com)
This article can be found HERE.
No comments:
Post a Comment