How old is the universe and how is its age calculated?

There is a lot of conjecture about how many years of the universe at the moment. With absolute certainty, the question of her age can not now be answered. Yes, and hardly ever find an exact answer to it. But scientists carried out a lot of research and calculations, so now this topic has more or less clear outlines.

Definition

Before you begin the story of how many years of the universe, it is worthwhile to make a reservation: its age is counted from the moment it began to expand.

To elucidate these data, an ΛCDM model was created. Scientists claim that it can predict the beginning of different epochs. But still, how many years of the universe, you can find out by finding the oldest objects, by calculating their age.

In addition, the great importance is played by periodization. In our time, three epochs are distinguished, of which certain information is known. The first is the earliest. It is called the Planck time (10 ^-43 s after the origin of the Big Bang). According to scientists, this period lasted until 10 ^-11 s. The next epoch lasted up to 10 ^-2 s. It is characterized by the appearance of quark particles - a constituent of hadrons, that is, elementary particles involved in nuclear interactions.

And the last era is modern. It started in 0.01 seconds after the Big Bang. And, as a matter of fact, the modern era continues to this day.

In general, according to modern data, the universe is now 13.75 billion years old. An amendment is allowed (± 0.11 billion).

Calculation methods with allowance for cold stars

There is another way to find out how old the universe is. And it consists in monitoring the glow of the so-called white dwarfs. They are celestial bodies of very high temperature of rather small dimensions. Approximately the size of the Earth. They represent the last stage of existence of any star. Except for those that are huge in size. In a white dwarf star turns after all of its thermonuclear fuel is burned. Before that, it still undergoes some cataclysms. For example, for some time becomes a red giant.

And how can you find out how old the universe is, with the help of white dwarfs? Do not say that it's simple, but scientists do it. Dwarfs burn their hydrogen very slowly, so that their lifespan can reach hundreds of millions of years. And all this time they shine because of the accumulated energy. And they cool down in parallel. And scientists, calculating the rate of their cooling, determine the amount of time that a star needs to reduce the temperature from that which was originally (as a rule, it is 150,000 K). To calculate how many years the universe exists, one must discover the coldest white dwarfs. At the moment, it was possible to find stars with a temperature of 4000 K. Scientists, having carefully studied all the data taking into account this information, assure that our Universe can not be older than 15 billion years.

Investigation of spherical clusters from stars

It is worth turning to this method, talking about how many years of the universe, according to scientists. These clusters are located in the peripheral zone of the Milky Way. And they revolve around his core. A definition of the date of their formation helps to determine the lower limit of the age of our universe.

The method is technically complex. However, in its essence lies the simplest idea. After all, all the clusters appear from one cloud. So they arise, it can be said, at one time. And for a certain time, hydrogen is burned in some quantities. How does it end? The appearance of a white dwarf or the formation of a neutron star.

Several years ago, studies of this kind were conducted by astronauts who used the ACS camera of a space telescope known as the "Hubble". So according to the calculations of scientists, how many years of the universe? Astronauts found out the answer, and it corresponds to official data. The age of the clusters, which they investigated, averaged 12.8 billion years. The "oldest" was 13.4 billion.

On cosmic rhythms

Here, in general, that it was possible to find out by calculations of scientists. How many years of the universe - you can not know exactly, but you can find out more approximate information by paying attention to cosmic rhythms. Their study was conducted by Explorer 80 probe about 15 years ago. Temperature fluctuations and relic radiation were taken into account . If we do not go into details, we managed to find out that our universe, most likely, is 13.5-14 billion years old.

In general, everything can be far from the way we suppose. After all, space is a surprisingly large and almost unknown space. But I am glad that his research is actively continuing.