"Apparently, the theoretical calculation based on the gravitational redshift of general relativity theory is well suited to astronomical observations."
“Apparently, the theoretical calculation based on the gravitational redshift of general relativity theory is well suited to astronomical observations.”
All based on astronomical observations in the light emitted from stars and galaxies. While based on the theory of general relativity, the light will be affected by gravity. At the same time, all the interpretations in astronomy based on the theory that truth is relative, but has not been possible to test Einstein theory of gravity at scales larger than the solar system. Now, the astrophysicist from the Dark Cosmology Centre at the Niels Bohr Institute have succeeded in measuring how light is affected by gravity on the way out of clusters of galaxies. These observations confirm the theoretical predictions.
The results have been published in a scientific journal, Nature.
Observations at large distances in the universe is based on redshift measurements, which is a phenomenon in which the wavelength of light from distant galaxies is shifted again and again toward the red with a greater distance. Redshift indicates how much the universe expands from the time the light remains to be measured on Earth. Furthermore, according to Einstein’s theory of general relativity, the light and the red shift is also influenced by the gravity of such a large mass of galaxy clusters and cause the light gravitational redshift. But the influence of gravity on light has never been measured on a cosmological scale.
“This is really menabjudkan. We live in an era with the technological capabilities that can actually measure such phenomena as cosmological gravitational redshift, “says astrophysicist Radek Wojtak, from the Dark Cosmology Centre at the Niels Bohr Institute at the University of Copenhagen.
Until now, the gravitational redshift is only tested with experiments and observations in relation to the distance of the earth and in relation to the solar system. With new research, this theory has been tested on a cosmological scale for the first time by analyzing the galaxies in clusters of galaxies in the distant universe. This is a very large scale, which is a factor of 1022 times larger (ten thousand billion billion times greater than the testing laboratory). Observed data confirms Einstein’s theory of general relativity. (Credit: Dark Cosmology Centre, Niels Bohr Institute)
Galaxy clusters in the beam of light
Radek Wojtak, along with colleague Steen Hansen and Jens Hjorth, has analyzed the measurements of the galaxy about 8,000 light clusters of galaxies. Galaxy clusters is the accumulation of thousands of galaxies, which gather their own due to gravity. Gravity affects the light is sent into space from these galaxies.
Researchers have studied the galaxies are located in the center of galaxy clusters and are located in the suburbs, and then measure the wavelength of light.
“We can measure the small difference in redshift galaxies and saw that the light from galaxies that are in the middle of the cluster ‘crawl’ out through the gravitational field, while the light from remote galaxies are easier to come,” said Radek Wojtak .
Then he measured the total mass of galaxy clusters, and are also affected by the gravitational potential. By using the theory of general relativity he can now calculate the gravitational redshift galaxies at these locations are different.
“Apparently, the theoretical calculation of the gravitational redshift is based on the theory of general relativity is well suited to astronomical observations. Our analysis of the observations of galaxy clusters indicate that the red shift of light is proportionally balanced in relation to the gravitational influence of the gravity of galaxy clusters. Thus, our observations confirm the theory of relativity, “said Radek Wojtak.
New light on the dark universe
This discovery has significance for the phenomenon in the universe that is trying to be revealed by the researchers, that the mysterious dark universe – dark matter and dark energy.
In addition to the celestial bodies that look like stars, planets and galaxies, the universe is also composed of a large number of materials, which according to the researchers that it exists, but that is not observable because it does not emit or reflect light. Not seen so-called dark matter. No one knew what dark matter is, but they know the mass and gravity. The latest results on the gravitational redshift does not change the model the researchers to the existence of dark matter.
The other major component in the universe is dark energy, which according to theoretical models which act like a vacuum causes the accelerated expansion of the universe. According to calculations, based on Einstein’s relativity theory, dark energy is 72 percent of the structure of the universe. Many alternative theories that try to explain the accelerated expansion without dark energy.
The theory is tested on a large scale
“Now the general theory of relativity has been tested on cosmological scales, and this confirms that the general relativity theory does indeed work. That is, there are strong indications of the existence of dark energy, “said Radek Wojtak.
The results of this new gravitational thus contributes a new insight to understand the universe is dark and gives a greater understanding of the nature of the visible universe.