Looking at the night sky, it seems that the stars andgalaxies are located more or less randomly. This, however, is not entirely true. Despite the randomness, the Universe is not a random confusion of objects. It may seem surprising, but the Universe has a structure consisting of massive filaments of galaxies separated by giant voids. Scientists call this structure the cosmic web. But why is she so strange? The answer probably lies in the processes that took place in the first few hundred thousand years after the Big Bang.
It looks like a space web
What are voids and galactic threads?
We are incredibly lucky. At least, that was the opinion of the outstanding theoretical physicist Stephen Hawking. According to the scientist, although we live on an ordinary planet that revolves around an unremarkable star, we have a chance to know the universe. Today, a map has been compiled not only of the exoplanets closest to Earth, but also of the entire observable Universe. And if at one glance at such a card your head starts to feel a little dizzy, then get ready for a real attraction.
Here is a map of the observable Universe. You can go crazy, right?
To try to imagine approximatescale of what is happening, let's start the countdown from the Milky Way galaxy. Our nearest galactic neighbors are the Andromeda galaxy and the Triangle galaxy. And also about 50 Local Group galaxies. The Hubble Space Telescope has repeatedly photographed these amazing inhabitants of outer space. However, do not forget that the Universe is expanding, which means that galaxies fly apart in different directions. Recently, we wrote about what is not happening in outer space, including the collision of three galaxies with each other at once.
This is how 15 thousand galaxies look in the lens of the Hubble telescope
However, in addition to galaxies in outer spacethere are nebulae, star clusters, clusters of galaxies, and even superclusters of galaxies. Some similar objects in the observable Universe were distinguished by astronomers into large-scale structures because of their incredibly large sizes. The largest of them stretch for hundreds and billions of light years. Due to their elongated shape, these objects were called galactic filaments. These threads are intertwined, fill the empty space - or voids (from the English “void”), as if forming a three-dimensional web. But this is not all - voids and galactic threads can form “great walls” - relatively flat complexes of clusters and superclusters of galaxies.
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Superclusters of galaxies and great walls
If there are more than 100 in a superclusterthousand galaxies, then such a supercluster is called Laniaica, which in translation from the Hawaiian language means "immense heaven." Nice name, right? In diameter, Laniakeia reaches 500 million light years. And so that you can better imagine its scale, we recall that the diameter of the Milky Way galaxy is about 100 thousand light-years.
The Laniakeia and the nearest supercluster of Perseus-Pis galaxies look something like this
Thus, the space network consists ofinterconnected filaments of grouped galaxies and gas, stretched across the entire universe and separated by giant voids. The largest structure discovered to date is the Great Wall of Hercules - the Northern Crown, which has a staggering 10 billion light-years in diameter and contains several billion galaxies. As for the voids, the largest is the PIC entrance, named after the astronomers Keenan, Barger and Cowie. The diameter of the pic is 2 billion light-years.
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In general, these features give the Universea bit frothy look. However, it is worth reducing the scale, as this pattern disappears, and the Universe resembles a homogeneous piece of galaxies. Astronomers have an amazing name for this sudden uniformity - End of Greatness. On a smaller scale, however, we can see the structure of the universe. But how did this structure come about?
It all started with the Big Bang
About 14 billion years ago the Big Bangspawned our universe. In the early universe, incredibly small pairs of particles and antiparticles spontaneously arose and annihilated each other. Thus, the space itself seemed to be "seething." Usually these pairs of particles destroy each other, but the rapid expansion of the early universe prevented this. As space expanded, these oscillations also increased, causing a discrepancy in the density of the universe.
Watch the video below to better understand the true dimensions of the universe.
Because matter attracts matter underby the action of gravity, these discrepancies explain why matter “sticks together” in some places and not in others. However, this does not fully explain the structure of the cosmic web. In the first 10-30 seconds after the Big Bang, the Universe was full of primary plasma, sticking together due to the aforementioned discrepancies. When this material stuck together, it created pressure that counteracted gravity, creating ripples like a sound wave. Physicists call these pulsations baryonic acoustic vibrations. Simply put, this ripple is a product of ordinary matter and dark matter. As you know, dark matter is the most mysterious structure in the Universe. In general, these and many other processes, such as the interaction of ordinary and dark matter, have created the cosmic web, which is the structure of the Universe.
Of course, there are many other processesthat influenced the cosmic web, but we'll tell you about it another time. In the end, the above may be a little dizzy. No matter how hard we try, we are not able to realize such a scale of the Universe. At the same time, understanding where we are all the same can help us look at the world a little differently.