The study of how the universe is expanding has been a central area of modern cosmology for decades. Within that, the Hubble constant, a parameter that describes the way this expansion occurs, stands as a fundamental pillar. This is a factor established by a famous astronomer Edwin Hubble In the 19th century, it referred to the apparent speed at which distant galaxies are receding. Expansion: This is a very important part to measure and measure the rate of expansion of space.
However, over the years, the precise measurement of the Hubble constant has evolved with technological advances and new observational techniques. This has allowed us to have more accurate data showing the specifics Contradiction In determining the constant according to the method used to calculate it. This contradiction “Hubble voltage” and has sparked enormous debate in the scientific community, posing major challenges to understanding the processes governing the expansion of the universe.
Edwin Hubble, father of observational cosmology
The Hubble Constant
The approach of a single constant representing the rate of expansion of the universe began to take shape in the minds of the scientific community. First decades of the 20th century. During that period, the understanding of the cosmos underwent a major change, as pioneering observations of distant galaxies showed the first signs of expansion. Changed the view of the universe Fixed.
Edwin Hubble, who in 1920 gave the starting signal for this cosmological revolution, proposed an existence. relationship The speed of motion of a galaxy – the radial velocity – and its distance, which became the conceptual basis Hubble's constant. This is a direct correlation between the redshift of a galaxy and the expansion of the universe. Also, although it was a somewhat rudimentary and imprecise calculation at first (I think it required measuring very large astronomical distances), the measurement techniques have been refined over the years.
Portrait of Edwin Hubble from 1931
Among them, method Type Ia supernova, these types of bursts use the luminosity given off by them to estimate the distance they are located. On the other hand, by measurement Cosmic background radiation – Big Bang echo – can infer the expansion rate of the expansion of the universe in its early stages.
Redshift: A Powerful Tool for Understanding the Big Bang Theory
through nearby galaxies, using those methods cepheids (variable stars) It is possible to establish reference points to calibrate these distances. Even so, they all present some constraints in terms of accuracy, due to extrapolations or the need to establish some models.
Conflict and tension
Hence, the disagreement between these estimates of the Hubble constant gave birth to the Hubble tension. Indeed, in recent years, observations and measurements have achieved great sophistication problematic It has become increasingly clear. On the one hand, observations of supernovae and cosmic background radiation indicate a low value of the constant, while measurements based directly on nearby galaxies indicate a high value.
This disagreement raises big questions Reliability in methodsas well as potential existence Physical phenomena have not yet been discovered or integrated. Is it necessary to develop new physics or is it a matter of considering systematic errors?
In this way, besides being one of the most current problems in astronomy, the Hubble tension Important To understand not only cosmic expansion, but the limits of fundamental physics and the evolution of the universe.
Resolving this paradox is expected to improve the measurement and understanding of cosmic distances Dark energy, which has not been ruled out as being involved in the problem. It is undoubtedly research that opens up new perspectives towards cosmic knowledge.
