This is a submission for Kevin’s No Theme Thursday
Kevin’s artistic picture above makes me think of Alien Civilizations. Do they exist? Do they exist in our Galaxy? To quote Enrico Fermi, if they do exist “Where is Everybody?”. That is the famous Fermi Paradox.
We have found thousands of exoplanets, and it is estimated that there are 11 billion potentially habitable Earth-sized planets orbiting stars roughly the same size as the sun in the Milky Way. It is estimated that there are an additional 40 billion potentially habitable Earth-sized planets orbiting red dwarf stars in the Milky Way. Earth is an estimated 4.5 billion years old whilst our Milky Way Galaxy is an estimated to be 13.6 billion years old. Add that there are at least hundreds of billions of Galaxies like the Milky Way in the observable Universe. Yet, human astronomers have not detected any signs of alien civilizations, and there is no evidence Earth has been visited by aliens in the past.
In this context, I would like to mention the Drake equation. The Drake equation is a probabilistic equation used to estimate the number of communicative extraterrestrial civilizations in the Milky Way Galaxy. It was created in 1961 by American astrophysicist and astrobiologist Frank Drake. This is the equation N = R * Fp * Ne * Fl * Fi * Fc * L. where N is the number of civilizations in the Milky Way galaxy with which communication might be possible.
- R = the average rate of star formation in our galaxy.
- Fp = the fraction of those stars that have planets.
- Ne = the average number of planets that can potentially support life per star that has planets.
- Fl = the fraction of planets that could support life that actually develop life at some point.
- Fi = the fraction of planets with life that go on to develop intelligent life (civilizations).
- Fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space.
- L = the length of time for which such civilizations release detectable signals into space.
We have a pretty good idea of what R * Fp * Ne is but the remaining factors are unknown.
This is not really a super fact but more of a mystery. The goal of this blog is to create a list of what I call super facts. Important facts that we to be true, and yet they are disputed by many non-experts, or just highly surprising to the general public. However, I also post interesting facts and book reviews in this blog.
Is there Scientific Evidence for Alien Civilizations?
UFO sightings are not proof of alien spacecraft. The term “UFO” or “Unidentified Flying Object”, simply describes something in the sky that a person can’t recognize. Studies by NASA, Pentagon’s All-domain Anomaly Resolution Office show that the vast majority of these observations can be attributed to mundane phenomenon. Also, ask yourself, why would an alien civilization fly across interstellar space and only reveal themselves to random people with bad cameras and not to humanity as a whole. Why would they be flying around in little saucers? The typical flying saucer stories are not credible. Some UFO reports are also hoaxes or based on misidentified objects or misinterpretations of natural phenomena.
When I was in the Swedish army I was stationed near the Finnish Swedish border up north, which was close to Murmansk, a big Russian city which had the world’s largest navy base at the time. One night when I looked up in the sky I saw a shiny green elliptical shape in the night sky. It was quite big. I did not know what it was, but a lot of people called in to report it as a UFO. Were we being visited by space aliens as many believed. Some were even certain of it. No, it turned out to be Natrium cloud left behind by an intercontinental missile test launched from the Murmansk naval base.
Stories about past visitations are often guesses and conjecture mixed up with misrepresentation and fabrications. These stories are not taken seriously by scientists. SETI (Search for Extraterrestrial Intelligence) has not found any definitive evidence of alien life. SETI have not detected any signals that convincingly can be attributed to an alien intelligence. In summary, there is no scientific evidence for aliens in the declassified UFO videos, in purported alien bodies, mutilated cows or in anything else.
But why have we not found any traces of alien intelligence? Where is Everybody? That’s the Fermi Paradox.
Solutions to the Fermi Paradox
Interstellar travel and interstellar communication are incredibly difficult. Maybe we should take the fact that nothing can travel faster than the speed of light seriously. You can always speculate about warping space and wormholes but that does not mean such travel is at all physically possible. The distances in the universe are enormous and require thousands or millions of years of travel even at speeds close to the speed of light. Likewise, those distances make communication difficult. Perhaps interstellar travel and communication is too difficult to be worth it.
The so called “Great Filters” hypothesis suggests that advanced civilizations don’t last that long. Maybe they self-destruct in nuclear wars or germ warfare. Perhaps they burn fossil fuels causing severe global warming ending civilization. Maybe AI destroyed their civilization. There could also be a great filter before intelligent life occurs. What if life itself is extremely unlikely to happen.
The “Dark Forest” hypothesis suggests that advanced civilizations are hiding to avoid detection from hostile advanced civilizations. A related idea is that there is a very advanced civilization in our galaxy, which destroys all other civilizations when they become too advanced and a potential threat. If that is true, maybe we shouldn’t advertise our existence using projects like SETI.
Another suggestion is that advanced civilizations are extremely rare because they can only arise under extremely rare conditions. Not only does a planet need to be habitable, but plate tectonics, climate, the shape of continents and oceans all to be just right for intelligent life and advanced civilizations to evolve. Also, consider the fact that intelligent human life existed for hundreds of thousands of years before the rise of civilization. Perhaps we are the only civilization in our Galaxy. Perhaps we are the first civilization in our Galaxy.
Yet another suggestion is that beings that are part of advanced civilizations eventually will escape into a virtual reality world or escape into other alternative worlds.
Here is a video giving an overview of the Fermi Paradox
I would like to end with a famous quote by the famous science fiction writer Arthur C. Clark “There are two possibilities: either we are alone in the Universe, or we are not. Both are equally terrifying,”
Super Facts 