How long has it been since the Big Bang and how it is measured – 06/20/2022 – Science

The world is not ashamed to reveal your age. There are many ways to let us know how much time has passed since the Big Bang to this day.

It is estimated that, since then, 13.4 billion years have passed, with a violation of 200 million years.

The chain of uncertainty that lasts for hundreds of millions of years is no small matter. However, this accuracy is reduced, thanks to the world’s accurate timepieces.

To determine the age of the universe, we take advantage of the fact that it is expanding, something we have known for almost a century.

This extension provides instances with large numbers. For example, something close to our galaxy, the black hole of Sagittarius A *, is moving at a speed of 80,000 km / s from one of its distant cousins, OJ287.

This basically happens in almost every black hole in the world. They move away from each other at the same speed as their host galaxy.

However, belief in scientific results depends on repeated experiments. And that is something that the world does not allow.

How to measure time since the Big Bang

To compensate for the impossibility of these experiments, we compared different data sources. In this way, we were able to adjust our global timepieces.

But, after all, how can we measure the past since the Big Bang?

Our core data is a Hubble feature. This is the amount of data that represents the average global percentage growth over time. Imagine that we can measure this growth on our own and also on how much it happened. By combining these two factors, we find the past tense in this evolution. In other words, we have a world clock close by.

But let’s put this information in everyday terms. The revolutionary cosmetics brand promises to make human eyelashes twice in just 60 days. Following this logic, if we use this substance and realize that our eyelashes have increased by 50%, that means that a month will have passed since the beginning of the application, right?

The answer, however, may not be so simple. If we do not keep the product daily at a faster rate, the growth rate of the eyelashes will decrease. We therefore find that the duration of the measure according to the change in size can lead to errors.

We need to know what happened every day to understand this change. This is what we call experiment control. But is this also a bad way to measure the age of the world?

When the world was smaller than the world

In 1947, physicist George Gamow used Hubble element data to estimate the age of the universe in 2.5 billion years. Shortly afterwards, geologists set the Earth’s age to 4.5 billion. How could the universe be smaller than our planet?

It is clear that the age estimate of the universe was incorrect. The problem was that they did not fully understand how to do this calculation. But it was known that expansion usually reduces congestion of elements of the universe. And, according to the nature of each of them, this process occurs at different rates.

In the early days of the world, radiation reigned. When the radiation disappears very quickly, it is replaced by a dark matter, as the density of this compound decreases more slowly.

All of this follows what is stated in Einstein’s equations. The nature of radiation and dark objects causes the universe to shrink. This means that, although in these stages there was also expansion, the speed was slowing down and slowing down.

But the theory contradicts the evidence found in other experiments. In them, the pace of world expansion was increasing.

Arrival of dark energy

There was a new feature demanding popularity in this process: dark energy.

With one of these magical events, the effects of different world stages are minimized. In other words, the initial delay of the expansion rate was reduced by the current speed. Therefore, it is wise to estimate the age of the universe directly through the Hubble element.

We emphasize that in this type of work it is important to measure the magnitude of the magnitude in anything below the universe itself. To do this, we take advantage of the fact that expansion increases the length of the electric waves that reach us from the stars.

A corresponding effect is called redshift. This is done, for example, in spectroscopy using multiple catalogs with systems of intensity and wavelengths. In this way, things that are similar to each other are identified, but different when considering the depths of the universe.

It is important to note that the farther these objects are in comparison, the more their light will be enlarged. For example, the red light that reaches us from the farthest known galaxy, GN-z11, is ultraviolet light.

The basis of cosmic timers

By calculating the red light change from the distant galaxy, we estimate the expansion that has taken place since each light was released. Then the calculation is repeated with the corresponding galaxy and the results are compared.

The next step is to average this expansion difference over time. And that time window will be different in light travel time, depending on whether it comes from one gala or another. This is similar to finding differences between galaxies.

Thus, a technique has been developed that manifests itself in power: cosmic timers. With this good idea, slowly, it is expected to be able to resolve the conflict over the values ​​of the Hubble element between the dimensions of the inner world and the deeper world.

Shortcut to know the age of each star

Since galaxies contain hundreds of billions of stars, you have to be extremely careful.

To find the age of galaxies and stars, the average population must be used. And we do it not because we want to, but because we cannot do it in any other way. It is very difficult to determine the age of each individual star.

Fortunately, the preferential trick simplifies this task. It successfully combines using a very specific signal of change in light intensity given to 4,000 angstroms. [uma unidade de medida de comprimento]. The technique is based on the presence of gases that heat galaxies and makes it possible to complete the results obtained using universal timers.

In fact, we not only estimate Hubble’s current cause in this way, but this also holds up to earlier times. By combining this knowledge with related cosmology, we improve our understanding of dark energy. And the wheel keeps turning and giving us answers about the elements of the universe.

We currently have only a small number of such timepieces in the world. However, they are very accurate. However, there are high hopes for augmenting this result in future missions.

This will allow you to create a powerful and informative catalog. The most promising experiments I refer to are EUCLID and Nancy Roman, missions launched by the European Space Agency and NASA, respectively.

Of course, they will improve the prospects for world clocks to position themselves as key units that will be able to measure not only the Hubble element, but also the evolution of the universe itself.

These developments will heighten our desire to tackle the greatest mystery: how did the universe come to be? At the moment, we do not know. But we can go back to what physicist James Clerk Maxwell said: “The ignorance of fully aware is the precursor to any real progress in knowledge.”

* This article was published in Conversation. You can read the original version here.

This text was previously published.

Ruth Lazkoz is Professor of Theoretical Physics at the Basque State University – Euskal Herriko Unibertsitete.


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