Why have we not found intelligent civilizations in our universe yet?

One theory is that those intelligent civilizations are just too far away. Even if there could be over 30 intelligent civilizations in our galaxy. They can simply be too far away from us. Milky Way is a huge place. When we are thinking about the size of the Milky Way the diameter of the main gas disk is 200 000 light years. 

And there are stars outside the main gas disk. But the thing that limits the forming of lifeforms in the galaxies is that there must be elements that are required for life. And of course, there must be planets that are suitable for lifeforms. 

We know that all stars don't have planets orbiting them. There are billions of blue giants in the universe. Those stars are formed in the gas clouds that are forming mainly of hydrogen. Those blue giants and supergiants are common in the open star clusters. So the open star clusters are full of young stars. 

And they can turn into galaxies. Milky Way has been open star cluster once until there was formed black hole. And an elliptic protogalaxy formed because a black hole pulled the gas cloud into it and forms a quasar. Then formed the whirl and the material disk started to form. So there is a possibility that there are planets in the elliptic galaxies. 

There is also the possibility that larger galaxies are "hovering" gas out from the open star clusters and they cannot form planets. Another case that the galaxy cannot form is that the cosmic eruption destroys that gas cloud. But if the open star cluster is forming those blue giants would turn into black holes when they used their fuel. 

And then those black holes are starting to impact forming the quasar. In some other visions, the gas cloud collapses into a supermassive black hole. And then that black hole starts to form quasar around it. So quasars are protogalaxies. And once Sagittarius A was one of those quasars. 

Planets in young galaxies would be gas giants because there are no heavy elements yet. All elements form in the fusion reactions inside stars. And there must be enough heavy and solid elements that can form planets in the nebula that rocky planets can form. 

When the Milky Way started to form around the supermassive black hole called Sagittarius A, there were no heavy elements in the young milky way. There must be stars that can form elements like silicone and metals that form rocky planets. Many stars have exoplanets. But those exoplanets are so-called hot or cold Jupiters or other types of gas giants. 

The gas giants can, of course, have primitive lifeforms in their clouds. But that requires that the planet's temperature is low enough that there are water clouds. Water is urgent for the lifeforms as we know them. 

The water itself cannot form life. And even if there are lifeforms on some exoplanets there is a possibility that those lifeforms cannot rise to drylands because the radiation that comes from the neutron stars and black holes sterilizes the dry lands. 

The water layer also protects lifeforms against cosmic radiation. And especially gamma- and X-ray radiation that comes from the black holes and neutron stars. The high-energy electrons and other particles send high-power X- and gamma-ray bursts when they hit the planet's atmosphere. 

If the planet is too close to neutron stars or black holes those objects send the high-energy particles to the planet's atmosphere. And those particles cause very powerful X- and gamma-ray bursts that can cause a situation where the planet's dry areas are under the high-power X- and gamma-ray radiation. 

We are the luckiest species in the world. We are far away from the center of the Milky Way. Many people think that we should search for intelligent lifeforms from the center of our galaxy because there are more stars. The fact is that there are also more comets, asteroids, and more radiation. So there is a bigger possibility that the cosmic impacts destroy those planets. 

And if those planets are too close to Sagittarius A or some other black hole burns those lifeforms away. Or those planets vaporize into interplanetary nebulas that fall into black holes. 

But then we must realize that if there is some kind of civilization on another side of the center of the Milky Way we would not hear that civilization. The radiation that comes from Sagittarius A would cover all signals that come behind it. 

See also:

Black holes

Galaxies (Elliptic, and spiral galaxies)

Open star clusters

Sagittarius A

Quasars

https://astronomyandtechnology.blogspot.com/

The problems of SETI-program

Kimmo Huosionmaa

SETI (Search for Extraterrestrial Intelligence) program is one of the most dangerous programs in our planet. Even if we haven't get contact or signal from extraterrestrial intelligence, the telescopes might get it in next night. Or they can get contact beyond 1000 years. Some people think that waiting for a contact is like waiting for a train or something like that. SETI program is not so simple because we can't know when the first message is coming.

Or does it come in our lifetime? When we are talking about that project. If we will get the signal from other civilization, but we might ever take contact to those civilizations. They might be so far there, that we ever can't message together because the civilization might be in Andromeda galaxy. That proves the existence of alien civilization, but that doesn't mean that this civilization has ever meanings for us. That civilization would be so far, that even if they jump in their UFO:s right now, our sun would be turned a red giant before they arrive.

Problems of SETI program is that if we will get contact to other civilization, we might get under attack. But if we use the right technology we can hide our existence from aliens. We can cover our entire planet holograms, what makes humanoids to believe that our civilization does not exist. And of course, radio telescopes might use as a gigantic ECM-system, what makes our planet seem like there will not find any interesting. The system will be sent back waves to humanoids transmission, that they can’t see our planet's surface with radar and they can’t get repulses in their telescopes.  

That radiation makes the radio waves or their echoes weak, that they can’t go back to the transmitter. Or otherwise the signals what will be sent back to humanoids would be so powerful that they would think that this will be gigantic super earth, there will be no life forms exist. But this scenario is pure fiction if published information is true.

But everybody knows that federal authorities are not talking true all the time. SETI is one of the most complicated missions on Earth science community. If you want to investigate extraterrestrial civilizations you have nothing where to start. There is not even one single message what is proven that is coming from another star. If somebody believes extraterrestrial intelligence, that does not mean that he or she believes little green men, or why that person wouldn't believe that some people might have green skin. There is one great “if" in those scenarios.

If somebody has put the genetic what causes photosynthesis in the flora to human DNA, that will make the human skin transformation to green. But what kind of technology that speculative humanoid civilization might have. They might have the technology to create “wormholes", but the problem with wormhole travel is that that kind of stuff will need two black holes, what will put resonate to same frequency, and after that those black holes must be separated and another will pull to the place, where that civilization wants to travel. That will take very long time for that civilization, and success of that project can see until the trip is done. That’s why aliens must be sure that there is something interesting.

Otherwise, the trip is made for nothing. And it can take even thousands of years. But there is always artist’s freedom to use imagination about other civilizations. They might have gigantic Dyson spheres, where could be floating “island” in the middle of that colossal ship, what might be the size of a planet. That island would be in the area, where is not gravitation field, and that area might use for production, what needs absolute zero-gravity condition. There might be nano-technological and biotechnological research areas, where they create nano-robots and other that kind of stuff.

https://crisisofdemocracticstates.blogspot.fi/