Many different ways from each other is used to explain how old the universe, and although various methodologies were conducted separately, but they all shows us a compability to explain the age of the universe objectively. So the following will be introduced to some of the relation of these methods.
The Age of the Universe Expands
Galaxy distances can be determined from its visible size or its brightness. Galaxies appear smaller and dimmer than the other galaxies are similar, it means a greater distance. Distance can also be determined using other distance markers, such as some types of stars. Besides distance, the rate of moving galaxy can determined by its spectrum. (The spectrum of light from the galaxy is if we break down light into its component colors like a rainbow). With knowledge of the light spectrum can provide object identity that we observed, as well as how the object was observed moving, because every spectrum of different object provides a unique pattern.
Christian Doppler in 1842 showed that when the light source moves, the movement caused a wave of change, change the colors seen in the spectrum. This effect is known as the Doppler effect. This dopler effect tells us whether a light source is close to or away from us. From here we can find out how celestial objects moving towards us as an observer on Earth, and how fast movement.
In the 1920s, Edwin Hubble discovered that galaxies moving towards us with a certain pattern. The more galaxy distant from us, the faster the movement. This pattern, known as the “expanding universe”, because this behavioral pattern seen in all directions in the sky. So could be that all the galaxies moving away from the Milky Way galaxy, but can not be said simply that the Milky Way as the center of the universe, because the same pattern could be observed by an observer who was in another galaxy. So not necessarily be inferred from Hubble’s work that we are at the center of the universe or we are in a privileged position in the universe.
Back on the measurement of light shifts observed, astronomers try to measure how long the development has occurred. If it is assumed that all galaxies depart from the same starting point, it can be deduced, how long that has been taken of a galaxy and how fast it is, then divide the distance against speed. By adding a factor – a realistic physical factors such as the influence of gravity, or the inflation of the universe, the age of the universe is obtained between 12 and 14 billion years.
Oldest Star
How can a star lights? How to determine its age? How long a star can lights? Stars (including the Sun) to shine because of thermonuclear processes in it, which serve as generators of energy, due to changes in hydrogen into helium, due to heat and pressure is very intense in the core of the star, the hydrogen nuclei fused into helium nuclei and energy is transmitted. This physical process can be used to measure the age of the star.
Nuclear physics can explain how much energy is produced from the fusion of each hydrogen atom. Known how many hot hydrogen in the star’s core, and how fast the stars use their energy to shine. Thus can be calculated how long a star shines before all the fuel runs out. If a star has exhausted the hydrogen in its core, the star turned into a ‘Red Giant’. When we find a giant star, the initial mass can be determined, initial power, and its age can be determined. Similarly, after the various old stars that have measured, obtained from this method the universe ages ranged from 10-15 billion years old.
Age of Light From the Farthest Galaxy
As it has been revealed about the distance in ‘Light Years’, observations provide information about a very distant galaxy, so that the light transmitted by these galaxies takes billions of years to reach the observer. From this, it seems we’re using a time machine, when we observe the sky, we observe the events that have occurred in the time that has elapsed. Observations from the Hubble Space Telescope provides the farthest distance to reach the observed galaxies 10 billion light years, so at least our universe has 10 billion years old.
Age of Chemical Compotition
After the initial big bang, the universe is composed of – the simplest elements, namely hydrogen and helium. A very far galaxy is proof that this is indeed so, because it has a composition of hydrogen and helium are much larger. Chemical composition is more complex than hydrogen and helium formed later due to nuclear reactions in stellar core, or when the most massive stars ended their fate in a big explosion (supernova). In the supernova that was observed, there is a chemical element that is formed after 10-20 billion years.
There are at least four independent methods each used to determine the age of the universe, although not exactly the same, but at least it shows compatibility, the age of the universe has more than 10 billion years. And all astronomers agree and believe, that the universe, all galaxies, stars really are old and have been created in a very ancient period.
