Humans have always been intrigued by space. One of the curious things about space is that we haven't found other life forms yet. This is a strange fact if you take into account that the human race has been searching for extraterrestrial life since we could observe the universe. Calculation have been made that tell us there should be a large amount of extraterrestrial life, but these calculation haven't been proven true. These are based on many different factors, of which we only know a small amount. The thing is, even when we take absurdly small numbers for the unknown factors there should be many forms of extraterrestrial life in the universe. The fact that we haven't met these other life forms has been labelled "The Fermi Paradox."
The Fermi paradox explained
This article will try to explain the meaning of the Fermi paradox in a simple, easy to understand, way.
The Fermi paradox was named after Enrico Fermi, an American physicist. Enrico, who had been studying Drakes formula, found it strange that we hadn't discovered aliens yet. Following is a short history on the subject of the search for extraterrestrial life. This information is needed to fully comprehend the Fermi paradox.
A short history
Drakes equitation was invented by Dr. Frank Drake in 1961. In this equitation he tried to incorporate all factors that influence the creation of life. His efforts resulted in the following formula:
Amount of civilizations that transmit signals = stars*planets*inhabitable*creation*intelligence*technology*time
The formula explained
- stars: The speed of which stars are born. Only stars who resemble our sun are incorporated.
- Planets: The percentage of stars which have planets surrounding them.
- Inhabitable: The percentage of those planets that can harness life.
- Creation: The percentage of those planets where life arises.
- Intelligence: The percentage of those life forms that develops some sort of intelligence. (again not certain here)
- Technology: The percentage of intelligent life forms that become capable of transmitting signals into space.
- Time: This factor stands for the amount of time a life form is able to transmit signals. It takes in account the extinction of intelligent life forms or other, unknown, reasons why the transmissions cease.
Scientists are able to calculate the values for the first three factors. (stars, planets and inhabitable.) The other factors are variable. The Fermi paradox states that, even if we take extreme low values for the last four factors, there will always be a huge amount of civilizations that transmit signals.
This becomes clear by just looking at the sky by night. There is a huge number of stars out there and each one of them has a small chance of possessing a planet with a life form on it.
Possible solutions for the paradox
Humans are the only living thing in the universe
One solution could be that there is no other life form in the entire universe. This would mean that life is much rarer than scientists think. Should there be no other form of life, then it is only logical that we can't receive signals from other life forms.
There are other life forms, but we haven't made contact yet
Maybe there is an extraterrestrial race, but they haven't been found yet. It could be that the other civilization isn't able to transmit or receive signals yet, or they have transmitted signals but they are still travelling through space. the vast distances in space make for some long transmission delays. Most signals would travel with the speed of light, so it would take a year for a signal to reach a planet one light-year away.
Humans aren't able to comprehend the signal
Maybe aliens have tried to contact the earth before without scientists knowing it. This could be the case when the alien race uses signals that we don't use. This could be explained better by using an example.
Imagine someone sitting on a chair. He has been blindfolded by his friend. After some minutes his friends start flashing a light to convey Morse code in front of the blindfolded person. Although the friend did send a message to the blindfolded person, that person wouldn't even know that someone was trying to contact him. The same could apply to the signals send by another civilization.
The earth isn't interesting enough
Imagine a civilization, far beyond ours in the field of technology. Imagine that they have discovered hundreds or even thousands of civilizations. It could be that we have been discovered by such a massive, extremely intelligent, alien race that they just aren't interested in the earth.
These solutions are some of the possible explanations for the Fermi paradox. It will probably take thousands of years before the real solution is provided.
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