It is 14 billion years ago when the universe, … … started out smaller than a grain of corn and then evolved into a sea of stars. The part of the universe visible to us today is about 90 billion light-years across.
For 99% of the human species, it is and will remain incomprehensible. Until the „Last Day“ !!!!!!!!!!!!
It is worth mentioning that it is certainly expanding. Not as fast as in the beginning but it goes on a little bit slower, new suns (stars) are shining (are created) and old ones are burning up or find their end in a supernova, that means a huge stellar explosion. One can call the whole also constant change. It was very long time usual to say, the universe has always been there and in the future it will continue to exist !
But I have already pointed out a few pages before, Hubble made a discovery. In 1929 he found out that the universe is expanding and apparently he had done this before. If one pursues this development in the time further and further back, then the universe must have developed sometime in an enormous big bang. Even though there are still open questions about the Big Bang today, at the moment it is the best model there is. Temperature: minus 270 degrees Celsius.
Evidence for the Big Bang: the background radiation
Also as already shown :
What is left of our Big Bang?
As simple as it sounds, it is the background radiation, it is the „light“ left over from the Big Bang. The origin of this light lies behind the galaxies. We astrophysicists can use it to look into the past. We know a lot of light, but the background radiation is older than any light we know.“
The satellite „Planck“, so with its help they made them visible. Thus the very early universe became representable on a quasi photo.
What do we know today? ( already…….or only……)
I remember the sun…ours, many stars, the moon and also black holes !
To the point……..
We estimate that there are about 100 billion galaxies in the universe. Again, each of them has billions of stars. Our universe, so it seems to us, is full of bright, shining objects. But research results and their calculations clearly show that galaxies and stars make up just five percent of the universe. So 95 percent is missing. Where are these, we do not know.
But what we do know is that stars and planets, they exist….
The beginning is the big bang, there were only two basic elements…. …hydrogen and helium. They were the first elements in the damn young universe. There were no other ingredients yet.
Next : A whole 200 million years after the Big Bang, the first fusion reactors of our universe were created – they were, simply stars. Their development was based on the basic cosmic elements mentioned above: the particles of hydrogen and helium agglutinated by gravity to form gas balls. Gas balls that became more and more dense and hotter – so hot that a fusion could take place, a kind of fusion. This can easily be called the birth of the first stars.
Inside them, hydrogen particles first fused into more and more helium. Helium also gave rise to elements that did not exist directly at the time of the Big Bang.
So stars contained little by little different elements and the respective star became heavier and the very heavy ones could produce more and more elements. For example also oxygen and carbon – these are the elements that became important for life on earth.
But you have to point out quite clearly that the element iron was the end. But there are even heavier elements known today, like silver or gold for example. There is another explanation for this:
So something must have happened that produced even greater energies and that was the event of a supernova.
So the event, we know today, is the death of an old star. They explode in a „supernova“ and this process produces a gigantic amount of energy.
And what do these elements have to do with our earth?…..and how did the elements come to earth?
So let?s go back in huge steps, like four and a half billion years! At this time our solar system was created. It was first a big dust cloud mixed in clouds of gas.
These were remnants of past and of course exploded suns (stars).
So a smorgasbord of dust-gas particles and also the already mentioned different elements. Gravity caused it to contract into a huge disk, already rotating.
So the attraction caused that in the center of the disk a sun ( ours ) was formed or better formed.
This „disk“ deformed in the outer areas. Dust particles agglutinated, the agglutination grew. Larger and larger bodies were formed and after a certain time they were planets.
No need to be astonished, but in this way the Earth also formed as a planet. Then, in a process lasting millions of years, life developed on Earth. All of this is virtually made of cosmic dust.
What we do not know yet: Dark matter?
There is still no proof of its existence. Of course there are already many indications: There is much more matter in our universe than we can see – it is the so-called dark matter.
At fascinating pictures of Hubble and Co, universe seems to be filled up with shining stars and galaxies. But visible matter makes up only a few percent of the universe. In fact, the universe probably consists of almost 27 percent of attractive dark matter and about 70 percent of repulsive dark energy.
Dark matter could consist of previously unknown elementary particles, which however do not emit any radiation and would therefore be invisible to telescopes. Astrophysicists in general suspect that it is only revealed by its gravity: it conglomerates in dense clouds around galaxies and from there it changes the way stars move through space…………..I see it a little bit different and will comment on it separately !
With more and more sophisticated detectors scientists are looking for traces of the mysterious form of matter. Whether it really exists, is still unclear: Up to now none of the measuring instruments has picked up a clear signal.
Almost at the same time Fritz Zwicky made an interesting if not disturbing discovery ? Although he was not as prominent among astronomers as E. Hubble, his research results caused a sensation.
He came up with a very good idea with ulterior motives, one did not know. He’s going after the coma cluster. There he was studying the motion of the galaxies. He then came to the following conclusion, namely, the mutual attraction of the galaxies there by their gravity is too small to keep the galaxy cluster together. And he came to the following conclusion: ……There must be a very large amount of invisible matter in the cluster – dark matter!
His idea was not taken seriously by his colleagues at that time and as it happens, the dark matter was put aside for a short time. It even fell into oblivion.
But the saying: Out of sight, out of mind ! should not be applied here. Then, at the beginning of the 70’s (of course in 1970) dark matter came back into the focus of science. It was a young astronomer, with the name Vera Rubin, she started to observe stars while rotating in galaxies.
She actually expected to find the same thing as the motion of the planets in our home solar system.
Now let’s get closer to the motion of stars.
A common assumption is that if the stars are further away from the center of gravity, the slower they should move. But Vera Rubin was completely surprised to discover something else: The stars in the outer regions of known galaxies were almost as fast as those in the center. With this assumption, the galaxies would fly apart and the outer stars would be hurled away. None of this happened, the galaxies remained stable. However this discovery of ruby raised serious questions and already Zwicky’s result or better thesis reawakened: So there must be much more mass than the mass of the shining stars. The remark or fixation on dark matter was no longer a mystery – it seemed to really exist!
……..and if it already exists, ……….how much Dark Matter is there?
Now began the great search or scientific hunt worldwide by many astronomers. Where can we find the missing mass in the universe.
There were known or, so far, common astronomical objects. But they are just bad to observe, like planets, cold suns, dark gas clouds. Some of you will know the English expression for these previously mentioned objects: MACHOs (Massive Compact Halo Objects). Black holes were also included in a kind of preliminary calculation, although they were only indirectly observed at the time.
But all the macho’s included in the calculation did not yield enough „dark matter“ at the end of the day.
In the end, dark matter could not be explained, what kind of substance („something“) was hidden there ?
The nature of Dark Matter remained unexplored, but astronomers are succeeding in estimating its quantity with increasing accuracy.
What is the reason for this ? …..the telescopes became technically better and better from year to year.
The detection of so-called gravitational lenses is easier with it. Also the large mass accumulations – such as „clusters of galaxies – which bend space and deform the light from objects behind them.
Remember, the more mass a lens has, the more light is deflected. Again and again, we come across repeated and clear results: it is fixed in galaxy clusters is significantly more dark than luminous matter.
It is technically possible to make an interesting calculation if we consider the distribution of dark matter.
For a small section of the sky, astronomers can even calculate the distribution of dark matter in this way. The result: There is probably five times more Dark Matter than visible.
Now there is definitely a specific question. It’s all about Dark Matter, so tell me, where does it come from?
It is relatively clear, who searches for a long time, will find something…….Again it is the cosmologists, they research or better try to explain the nature of Dark Matter. Quite fast in thought they get help from an unexpected direction. The particle physicists, they have been taking something for granted since the 1970s, and they have also claimed it. There is still a whole range of as yet undiscovered elementary particles. (could give better)
As always, what you are looking for got a name and it is true :The name is WIMPs (Weakly Interacting Massive Particles) and of course something was demanded of them. They are particles that do not interact with electromagnetic radiation – i.e. light, X-rays, radio waves – and that means nothing else than that they are, or have to be, invisible to telescopes.
Part 3 will follow soon