*This text was written by a columnist for TecMundo; learn more at the end.
You may not know it, but you are, or at least you can think of yourself, the center of the universe! That’s right, according to Teoria do Big Bangwhich is the most accepted for the beginning of time according to Physics, our universe has been expanding, in all directions, for more than 14 billion years.
This can be proved with the aid of telescopes, since, in any observed direction, galaxies are moving away from Earth, as if we were, in fact, at the center of the universe.
The curious thing is that this observation would be possible from absolutely anywhere. To understand, we can imagine a balloon that, when filled with air, takes on the shape of a sphere. If we draw several dots on the deflated balloon, when it is inflated, we will see the dots moving further and further away, without any getting closer to the others.
Balloon being filled with air as its surface increases in size.Fonte: Shutterstock
This is what happens in our universe. Just as there is no center or edge of the surface of a sphere, there is no center or edge of the universe. Another way of interpreting it is to say that the center of the universe is everywhere, therefore, you, and all things and people, may well be the center of all this immensity.
Another interesting phenomenon is that, due to the size of our universe, when we observe distant stars and galaxies, we are literally looking into the past. In our everyday experience this also happens. For it to be possible to see anything, the light emitted or reflected by that thing must travel to our eyes. This means that, at the moment this light hits our eyes and is processed, the object that emitted it is already emitting another light and what we are seeing is, if we take this to the extreme, in the past.
However, when dealing with the scale of the universe, light (which has the highest speed physically possible) coming from an object can take billions of years to reach us. Hence the concept of a light year, which is the distance that light travels in an entire year. This distance is approximately 65,000 times greater than the distance between the Sun and Earth and corresponds to more than 9 trillion kilometers.
Image of our galaxy made by the Hubble Space TelescopeFonte: Nasa
So when we use telescopes to study distant planets, stars and galaxies, we are also studying what our universe was like tens, hundreds, thousands, millions or billions of years ago, which corresponds to how long the light from these objects traveled to reach us.
The formation of galaxies, for example, like our Milky Way, was closer to being explained when, at the end of 2021, a group of scientists from different countries managed to observe the formation of what would possibly be the first galaxy in the universe, which received the called HD1 and was found 100 million light-years from Earth.
Of course, this type of observation requires several types of confirmation, which will only come with time, with more studies and a continuous observation of this distant region of the universe. A light that traveled all this time to reach us must be carefully studied and is capable of bringing valuable information so that we can understand, even better, the formation of our universe.
Rodolfo Lima Barros Souzaphysics professor and columnist at the TecMundo. He has a degree in Physics and a master’s degree in Science and Mathematics Teaching from Unicamp in the area of Public Perception of Science. He is present on social networks as @ rodolfo.sou