Astronomers take peek at oldest event ever
WASHINGTON (AFP) — Astronomers have spied a gamma-ray burst from the universe's infancy, making it the oldest event ever witnessed and shedding light on cosmic origins, British and US scientists said Tuesday.
"This is the most remote gamma-ray burst ever detected, and also the most distant object ever discovered -- by some way," said Nial Tanvir at University of Leicester.
Gamma-ray bursts, the universe's most luminous explosion, happen when massive stars run out of nuclear fuel. Their cores collapse into a black hole or neutron star, and gas jets, in a process still not fully understood, punch out in a spectacular surge into space.
The so-called "GRB 090423" explosion, which occurred when the universe was only 640 million years old -- some five percent of its current age -- was seen by the NASA Swift satellite on April 23.
Subsequent analysis by teams of scientists, utilizing the European Southern Observatory's Very Large Telescope in Chile, showed the satellite effectively looked back in time 13 billion years.
"Swift was designed to catch these very distant bursts," said Swift lead scientist Neil Gehrels at NASA's Goddard Space Flight Center in Maryland.
"We?ve waited five years, and we finally have one."
The event's capture has the potential of illuminating astronomy in its quest to unravel the mysteries of the early universe.
"At its most basic level this discovery tells us that there were massive stars at this moment in cosmic history," said Andrew Levan at University of Warwick.
"But equally importantly we can use events like this to probe how the universe evolves when it is less than 5 percent of its current age."
Bhagavad-gita 8.17 P Attaining the Supreme
ahar yad brahmano viduh
te 'ho-ratra-vido janah
sahasra--thousand; yuga--millenniums; paryantam--including; ahah--day; yat--that; brahmanah--of Brahma; viduh--they know; ratrim--night; yuga--millenniums; sahasra-antam--similarly, at the end of one thousand; te--that; ahah-ratra--day and night; vidah--understand; janah--people.
By human calculation, a thousand ages taken together is the duration of Brahma's one day. And such also is the duration of his night.
The duration of the material universe is limited. It is manifested in cycles of kalpas. A kalpa is a day of Brahma, and one day of Brahma consists of a thousand cycles of four yugas or ages: Satya, Treta, Dvapara, and Kali. The cycle of Satya is characterized by virtue, wisdom and religion, there being practically no ignorance and vice, and the yuga lasts 1,728,000 years. In the Treta-yuga vice is introduced, and this yuga lasts 1,296,000 years. In the Dvapara-yuga there is an even greater decline in virtue and religion, vice increasing, and this yuga lasts 864,000 years. And finally in Kali-yuga (the yuga that we have now been experiencing over the past 5,000 years) there is an abundance of strife, ignorance, irreligion and vice, true virtue being practically nonexistent, and this yuga lasts 432,000 years. In Kali-yuga vice increases to such a point that at the termination of the yuga the Supreme Lord Himself appears as the Kalki avatara, vanquishes the demons, saves His devotees, and commences another Satya-yuga. Then the process is set rolling again. These four yugas, rotating a thousand times, comprise one day of Brahma, the creator god, and the same number comprise one night. Brahma lives one hundred of such "years" and then dies. These "hundred years" by earth calculations total to 311 trillion and 40 million earth years. By these calculations the life of Brahma seems fantastic and interminable, but from the viewpoint of eternity it is as brief as a lightning flash. In the Causal Ocean there are innumerable Brahmas rising and disappearing like bubbles in the Atlantic. Brahma and his creation are all part of the material universe, and therefore they are in constant flux.
In the material universe not even Brahma is free from the process of birth, old age, disease and death. Brahma, however, is directly engaged in the service of the Supreme Lord in the management of this universe--therefore he at once attains liberation. Elevated sannyasis are promoted to Brahma's particular planet, Brahmaloka, which is the highest planet in the material universe and which survives all the heavenly planets in the upper strata of the planetary system, but in due course Brahma and all the inhabitants of Brahmaloka are subject to death, according to the law of material nature.