The life span of the universe is 65.438+038 billion years. How is this worked out?

No one can know how long the life of the universe will be. However, it is possible to estimate how long the universe has existed. At present, scientists have observed the microwave background radiation of the universe through satellites such as Planck, and the age of the universe is about 65.438+038 billion years through data calculation.

Because the universe is homogeneous on a large scale, that is, homogeneous and isotropic on the scale of hundreds of millions of light years, astronomers once thought that the universe was like a constant universe model, and Einstein once thought that the universe was eternal and stable, so he added constants to the general theory of relativity to get the constant universe model.

However, after 1920, people observed the universe and found that the absorption lines of most galaxies have shifted red, which means that galaxies are moving away from us. 1929, Hubble proposed that the speed of galaxy regression is proportional to the distance, which is Hubble's law. After meeting Hubble, Einstein regretted his invention of the cosmological constant, calling it his biggest mistake.

The fact that the universe is expanding is an important observational evidence of the Big Bang theory. Hubble's law shows that the duration of the distance between galaxies is the same, and the age of the universe can be calculated through Hubble time. Therefore, the key to determine the age of the universe lies in the accurate acquisition of Hubble constant.

In fact, the age of the universe is easy to understand, because the expansion of the universe has a speed, and the galaxies are also retrograde. When this speed is accurately measured, the age of the universe can be obtained through simple calculation. In the early days, due to the limitation of observation means, the age of the universe calculated by people was close to 20 billion years. Later, with the development of science and technology, scientists obtained more and more accurate Hubble constant, and now the age of the universe is 65.438+0.382 billion years.

In the future, with the further improvement of observation methods, the age of the universe will be more accurate, and in the process of understanding the universe, human beings also realize that the universe not only has a beginning, but also an end.

With the launch of survey satellites such as Wilkinson and Planck, scientists have obtained the distribution map of the oldest radiation in the universe and can accurately calculate the Hubble constant. According to the cosmological parameters obtained by Planck satellite, the age of the universe is calculated as 1388+0 billion years.