Astrophysicists have determined that a physical constant ? over the last 13 billion years, kept its value up to the fifth decimal place. Article published in the journal Science Advances.
The fine structure constant ? is a fundamental constant that characterizes the strength of electromagnetic interaction. For the first time, it took physicists at the beginning of the last century to introduce quantum corrections in the model of the atom Bohr. With its help, the researchers described the splitting of the energy levels in the atom, which gives rise to a set of closely spaced frequencies in its spectrum. Since then, scientists have taken many attempts to bring the value of the constant from theoretical considerations, however, none of these methods have not received recognition. In the standard model — the main today, the theory in particle physics — ? constant is an external parameter, i.e. its value is based on experimental data.
The constant is of great importance for theoretical physics and cosmology, as it determines the character of the most General laws that underlie the evolution of the cosmos. In particular, it is important to know whether the value of the fine structure constant in time: it depends on the behavior of electromagnetic forces in the early stages of the Universe.
Astrophysics from seven countries under the leadership of Michael Wilczynski (Michael Wilczynska) from the University of New South Wales decided to evaluate the relative change of this constant in time. To do this, the researchers used data from the VLT (Very Large Telescope) — the world’s largest optical telescopes, located in Parnasskii mountain Observatory in Chile. The researchers turned to a series of measurements of the spectrum of the quasar J1120+0641, conducted from March 2011 to April 2014. Among known quasars, this object is the second farthest from the Earth. To reach earth’s telescopes, the light from this source spends nearly 13 billion years, that allows astrophysicists to obtain information about the young Universe.
The authors identified in the direction of the quasar four typical region of space, the cosmological average age of around one billion years (for comparison, the current age of the Universe is approximately 13.8 billion). Each of the regions has its own red shift — this value characterizes the increase of the wavelength of light with distance that he walked. This effect allows us to distinguish the spectral absorption lines that arise in the interaction of light with matter at different distances from the observer. The very same interaction is electromagnetic means, the initial wavelength is determined by the value of the fine structure constant at the moment of photon absorption. Based on these facts, the researchers statistically describe the observed spectrum, choosing as a free parameter relative deviation constants ? of its current value.
As a result, scientists have estimated the most probable relative change of the constant is approximately -2×10-5, which corresponds to the fifth decimal place. However, the accuracy of determining the parameter was about 7×10-5 — statistically, it is zero. Thus astrophysicists have provided further confirmation of the hypothesis about the constancy of the fine structure constant in time, having done it for a record time-scales. Previous studies in this area treat time over two billion years from the Big Bang, whereas the authors of the current work was used to examine regions of the Universe age half your age. In addition, the researchers considered the results in conjunction with other measurements of the constants and found that the value ? with the level of statistical significance of 3.9? depends on the position of an object in space. The latter at the moment has no theoretical justification, and if the result will be able to confirm, it will give science a significant problem.
Earlier we wrote about how using VLT astrophysics were able to take a picture of the galaxy at a distance of 65 million light years and see flying past Earth double asteroid.