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Wednesday, April 29, 2009

Stellar explosion reveals most distant known object in universe

Scientists say a faint burst of radiation discovered last week is the remnant of a massive stellar explosion that took place more than 13 billion years ago, or only about 630 million years after the big bang.

The gamma-ray burst, dubbed GRB 090423, points to what astronomers are calling the most distant object in the universe.

The fading infrared afterglow of GRB 090423 appears in the centre of this false-colour image taken with the Gemini North Telescope in Hawaii. The burst is the farthest cosmic explosion yet seen, with a distance of over 13 billion light years.
(Sources:Gemini Observatory/NSF/AURA, D. Fox and A. Cucchiara (Penn State) and E. Berger (Harvard)

Gamma rays are the highest-energy wavelength of light produced when high-energy particles collide. The large-scale gamma-ray bursts are believed to be produced when massive stars collapse into black holes, releasing jets of gas that react and heat up the gas surrounding the dying star.

Astronomers on Tuesday said they believe the gamma-ray burst discovered is the result of such a stellar explosion.

NASA's Swift satellite first spotted the 10-second-long burst on April 23, but could not see any corresponding visible light to match it. This suggested the burst occurred in an early time of the universe some 13 billion years ago, when dense clouds of hydrogen gas completely absorbed visible light, obscuring our view of a time when scientists believe the first stars and galaxies were born.

Subsequent examinations of the gamma-ray burst were taken from two ground-based telescopes located on Mauna Kea, Hawaii: the United Kingdom Infrared Telescope and the Gemini North telescope.

Astronomers using these telescopes were able to look at the burst's infrared light afterglow to determine the distance of the explosion based on its redshift, or how much the light's wavelength had stretched towards the red end of the spectrum in response to the expansion of the universe.

Just as the sound of a radio from a car moving away from us sounds stretched out, so too does light shift to a longer wavelength as its source moves farther away. Since the universe is expanding, faraway objects are moving away at a faster rate than those closer to us, and so their redshift is correspondingly higher.

The examination of the afterglow confirmed the burst's redshift of 8.2, the highest ever recorded. This corresponds to a distance of 13.035 billion light-years.


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Thoughts worth thinking about

"Our subconscious minds have no sense of humor, play no jokes and cannot tell the difference between reality and an imagined thought or image. What we continually think about eventually will manifest in our lives."-Sidney Madwed

Laws alone can not secure freedom of expression; in order that every woman and man present their views without penalty, there must be spirit of tolerance in the entire population.- Albert Einstein Too often we underestimate the power of a touch, a smile, a kind word, a listening ear, an honest compliment, or the smallest act of caring, all of which have the potential to turn a life around. - Leo Buscaglia

A person's true wealth is the good he or she does in the world. - Mohammed

Our task must be to free ourselves... by widening our circle of compassion to embrace all living creatures and the whole of nature and its beauty. -Albert Einstein

The best way to find yourself, is to lose yourself in the service of others. - Ghandi

The unselfish effort to bring cheer to others will be the beginning of a happier life for ourselves. - Helen Keller

Aim for success, not perfection. Never give up your right to be wrong, because then you will lose the ability to learn new things and move forward with your life. Remember that fear always lurks behind perfectionism. Confronting your fears and allowing yourself the right to be human can, paradoxically, make yourself a happier and more productive person. - Dr. David M. Burns

Life is as dear to a mute creature as it is to man. Just as one wants happiness and fears pain, just as one wants to live and not die, so do other creatures. -His Holiness The Dalai Lama

Mankind's true moral test, its fundamental test (which lies deeply buried from view), consists of its attitude towards those who are at its mercy: animals. And in this respect mankind has suffered a fundamental debacle, a debacle so fundamental that all others stem from it. -

Milan Kundera, The Unbearable Lightness of Being

The worst sin towards our fellow creatures is not to hate them, but to be indifferent to them. That's the essence of inhumanity. -George Bernard Shaw

Ego's trick is to make us lose sight of our interdependence. That kind of ego-thought gives us a perfect justification to look out only for ourselves. But that is far from the truth. In reality we all depend on each other and we have to help each other. The husband has to help his wife, the wife has to help the husband, the mother has to help her children, and the children are supposed to help the parents too, whether they want to or not.-Gehlek Rinpoche Source: "The Best Buddhist Writing 2005 pg. 165

The hostile attitude of conquering nature ignores the basic interdependence of all things and events---that the world beyond the skin is actually an extension of our own bodies---and will end in destroying the very environment from which we emerge and upon which our whole life depends.