|According to the Big Bang theory, everything began from the explosion of a point of infinite density and zero volume. As time passed, space expanded and the gaps between heavenly bodies grew.
In its ten-year-long research, the Anglo-Australian Observatory in the Australian state of New South Wales determined the positions in space of 221,000 galaxies by means of a three-dimensional mapping technique. The survey, which was performed with a 3.9 metre diameter telescope at the observation post, was almost ten times larger than any previous such study (1) . Under the leadership of Dr. Matthew Colless, director of the observatory, the team of scientists first determined the position of galaxies relative to one another and the distances between them. Then they modelled the distribution of the galaxies and studied the minute variations in that model in great detail. The scientists offered their research for publication in the journal Monthly Notices of the Royal Astronomical Society.
In a similar study carried out by the Apache Point Observatory in New Mexico , USA , the positions of some 46,000 galaxies in another region of space were similarly mapped and their distribution was investigated. The study, involving the use of a 2.5 metre diameter Sloan telescope, was carried out under the leadership of Daniel Eisenstein of the University of Arizona , and is to be published in the Astrophysical Journal (2) .
The results obtained by the two groups were announced during the winter meeting of the American Astronomical Society in San Diego , California , USA on 11 January, 2005.
An Important Confirmation
The data obtained as the result of long and careful work confirmed estimates made decades ago in the field of astronomy regarding the origin of the galaxies. In the 1960s, theoreticians estimated that galaxies may have seeded in regions where matter massed in a slightly higher concentration shortly after the Big Bang. If that estimate is correct, then the seeds of the galaxies should be capable of being observed in the form of tiny fluctuations in heat levels in the remains of radiation left over from the Big Bang and known as Cosmic Background Radiation.
Cosmic Background Radiation is heat radiation that only began being emitted 350,000 years after the Big Bang. This radiation, emitted everywhere in the universe, represents a snapshot of the 350,000-year-old universe, and can be observed rather like a fossil in the present day. This radiation, first discovered in 1965, was recognised as definitive proof of the Big Bang with various studies and observations, and was investigated in great detail. Data obtained from the COBE (Cosmic Background Explorer) satellite in 1992 confirmed the estimates made in the 1960s and revealed that there were ripples in the Cosmic Background Radiation (3) . Although at that time a partial link had been determined between these and the formation of the galaxies, that link could not be definitely shown until now.
|Data obtained from the COBE satellite in 1992 revealed minute fluctuations in the emission of Cosmic.
However, that important link was constructed in the latest studies. Colless and Eisenstein's teams determined a match between the ripples seen in Cosmic Background Radiation and those in the distances between galaxies. It was thus established that the galaxies seeded in places where matter that emerged 350,000 years after the Big Bang concentrated in slightly higher densities.
At a press conference on the subject, Dr. Eisenstein said that the way galaxies are scattered across the sky now corresponds to the sound waves that gave rise to that distribution. Researchers think that gravity affected the waves and shaped the galaxies. Eisenstein made the following comment:
"We regard this as smoking-gun evidence that gravity has played the major role in growing from the initial seeds in the microwave background (left over from the Big Bang) into the galaxies and clusters of galaxies that we see around us." (4)
In a statement to the AAP news agency, Russell Cannon, from the other research team, noted that the findings were of the greatest importance, and summarised the significance of the research in these terms:
"What we've done is show the pattern of the galaxies, the distribution of the galaxies which we see here and now, is completely consistent with this other pattern that's seen in remnants of the big bang…" (5)
Findings were also obtained from the study regarding the levels of matter and energy that constitute the universe, and the universe's geometrical form. According to these, the universe consists of 4% normal matter, 25% dark matter (matter that cannot be observed but that is calculated to exist), and the rest of dark energy (mysterious energy that leads to the universe expanding faster than expected). As for the geometrical shape of the universe - it is flat.
The findings made in these studies have further strengthened the Big Bang theory. Dr. Cannon said that the research added serious weight to the Big Bang theory about the origin of the universe and emphasized that support in these words:
"We've known for a long time that the best theory for the universe is the Big Bang -- that it started in some enormous explosion in a tiny space and it expanded ever since." (6)
In a comment regarding the studies, Sir Martin Rees, the well-known Cambridge University astronomer, noted that despite using different statistical techniques and observations, the teams had arrived at the same conclusion, and that he regarded this as an indication of the results' accuracy (7) .
Physicsweb.org, one of the most important physical sciences portals on the Internet, commented that the studies "provide further evidence for the standard big bang plus inflation model of cosmology." (8)
Scientists learned that the universe had a beginning (Big Bang) and was expanding (Inflation) by reading the radiation and heavenly bodies in space thanks to the possibilities of modern science. However, these fundamental data are not at all new to mankind.
1- "Galaxy patterns reveal missing link to Big Bang," January 12, 2005, online at: http://info.anu.edu.au/mac/Media/Media_Releases/_2005/_January/_120105redshift.asp
2- "Detection of the Baryon Acoustic Peak in the Large-Scale Correlation Function of SDSS Luminous Red Galaxies", submitted to Astrophysical Journal on December 31st, 2004. See. Sloan Digital Sky Survey, "THE COSMIC YARDSTICK--Sloan Digital Sky Survey astronomers measure role of dark matter, dark energy and gravity in the distribution of galaxies," January 11, 2005, online at: http://www.sdss.org/news/releases/20050111.yardstick.html
3- "Galaxy patterns reveal missing link to Big Bang", January 12, 2005
4- Deborah Zabarenko, "'Cosmological ruler' helps measure the universe," January 11, 2005, online at: http://www.reuters.com/newsArticle.jhtml?type=scienceNews&storyID=7297222
5- "Scientists Score Galaxy Breakthrough," AAP, January 13, 2005, online at: http://www.macnewsworld.com/story/Scientists-Score-Galaxy-Breakthrough-39646.html
6- "Scientists Score Galaxy Breakthrough", AAP.
7- Maggie McKee, "Big bang sound waves explain galaxy clustering," NewScientist.com News Service, January 12, 2005, online at: http://www.newscientist.com/article.ns?id=dn6871; Mark Peplow, "Echoes of Big Bang found in galaxies," News@nature.com, January 12, 2005, online at: http://www.nature.com/news/2005/050110/full/050110-8.html
8- "Galaxy surveys put cosmology on sound footing," January 12, 2005, online at: http://physicsweb.org/articles/news/9/1/7/1