?How was the age of the universe measured
Scientists estimate the current age of the universe to be approximately 13.8 billion years.
?!But how was the age of the universe measured
The age of the universe is measured by one of two methods: the first is by measuring the rate of cosmic expansion, and the second is by measuring the cosmic microwave background radiation, known as CMB for short. Regarding the rate of cosmic expansion, cosmic expansion was proven in 1929 by the famous American astronomer Edwin Hubble when he noticed the distance of galaxies from us and from each other by studying the colors of the spectrum coming from them and their redshift (which is known as the “effect The Doppler effect, where the light of objects moving away from the observer (in this case us) is shifted to red and the light of objects approaching is shifted to blue. Edwin linked the rate of this expansion to a constant he called Hubble's constant, and thus the belief remained constant. The rate of cosmic expansion. This belief remained prevalent until 1998, when three research teams discovered that the rate of expansion of the universe is accelerating and that the “Hubble constant” is constant at the present time, but in the future the value of this constant will increase. To clarify, it is like a car traveling at high speed and “accelerating” every period of time.
Now that we have the expansion rate of the universe (measured), as well as the distances between galaxies (also measured), we can calculate the time required for the universe to be in this shape, or in other words, we can reverse the movement of the tape backwards, where the distance between galaxies was zero (the beginning of the universe).
Using this method, physicists calculated the age of the universe to be approximately 13.3 billion years.
The second method is through cosmic background radiation (CMB), which is electromagnetic waves that fill the entire universe and have an almost identical density, temperature, and frequency throughout the universe. It is considered the strongest evidence of the occurrence of the Big Bang, as it is considered one of the “resulting effects and remains.” “And since this radiation is the result of the Big Bang or the origin of the universe, by studying its distribution, density, temperature, and frequency, From its wavelength and other characteristics, we can deduce the characteristics of the early universe, including when the universe began.
In 2002, NASA launched the WMAP probe to collect information about cosmic background radiation, and when it collected information about the CMB, the age of the universe was determined to be 13.772 billion years with an error factor of 59 million years (that is, that period may be more or less 59 million years). In addition, the Planck probe of the European Space Agency (ESA) determined the age of the universe by studying cosmic background radiation to be 13.82 billion years with an error factor of 50 million years.
By combining these measurements, the age of the universe becomes 13.7 billion years, which is a logical number, as no objects in the universe (galaxies, stars, supernovas, etc.) have been observed at that age. Since time and space began with the beginning of the universe according to the Big Bang model, the age of space and time is also 13.7 billion years! Despite the high accuracy in measuring and determining these numbers, these numbers remain subject to improvement and replacement, as the measuring tools and methods for determining the age of the universe are constantly evolving, and science does not provide absolute facts, but rather its goal is to provide the best explanation that we have been able to reach to explain the physical reality of the universe.
Source: websites