Host
Corey Hopkins
Podcast Content
There have been numerous attempts to explain the Fermi paradox, mostly suggesting that intelligent extraterrestrials are extremely rare, that such civilizations are brief-lived, or that they do exist, but humans see no evidence of them for a variety of reasons. Other explanations of The Fermi paradox include that extraterrestrials are spying on Earth, that they are completely ignorant of Earth, that they visited before the rise of civilization, or that they visited in ways we cannot detect.
One of the most common explanations for the Fermi paradox is that simply, any signals decipherable would require an enormous amount of time to travel through the Universe. It also takes time for any species to evolve sufficiently to communicate between stars, to travel through intergalactic space, and possibly colonize. There is also more than enough time within our galaxies 1-3.8 billion-year lifespan to allow civilizations to travel across the entire galaxy, even at the slower speeds that we humans are currently traveling.
If we are not alone, the remaining probability is that life exists on other planets, and has had some reasons for not colonizing the Milky Way. All this combined means that there must also be plenty of Earth-size planets within the habitable zones of the galaxy which can support life. If we are going to presume -- through the Copernican principle -- that the Sun is not especially special, intelligent life must exist in even a small fraction of some of those stars. The odds appear to be impossibly long that other intelligent life exists there, given there are more than 200 billion stars in our galaxy alone, and each has on average at least one planet.
Given the vastness of the universe, and the amount of galaxies, stars, and planets throughout it, surely other sentient life exists there. All these mind-bending hypotheses aside, perhaps we should entertain the possibility that sentient beings such as ourselves are just a rarity in the universe. Either way, the search for life is an important area of study in contemporary astronomy; some even believe we could soon receive results telling us we are not alone in our galaxy.
We might also one day know somewhat better just how widespread biolife is in our corner of the galaxy, which is crucial information when considering the Fermi paradox. Assuming this will throw out Solution One to the Fermi paradox - that, indeed, we are woefully lonely, in our own galaxy. Only then -- after we are full-fledged adult members of the galactic society -- could we actually come up with answers to the Fermi paradox, and be the Star Trek-style interstellar civilization we dreamed our sci-fi dreams into reality. For those of the group I thought, the only hope we had, were not the great filter thrown our way, was that conditions in the universe had only recently, for the first time since the Big Bang, reached the point where intelligent life could evolve.
The question now becomes, not about where, but why we do not feel even the smallest signals of intelligent civilizations outside of the Earth. This question, which was raised 70 years ago by Fermi, remains unanswered, even though our sophisticated Earth-based and space-based instruments are combing the night skies looking for any signs of intelligent life beyond Earth.
Given the fact that our stars and Earth are part of a young planetary system relative to the rest of the Universe - and that interstellar travel may well be quite simple to accomplish - the Fermi paradox says Earth must have been visited by extraterrestrials before. What Enrico Fermi recognized right away was that the aliens had more than enough time to pepper the galaxy with their presence.
The words came as Enrico Fermi was discussing the plausible likelihood of a multitude of complex societies inhabiting the galaxy with his dinner companion. Edward Teller wrote, The effect of his question was widespread laughter, for it was the odd thing that, in spite of the fact that Fermis question came out of a transparent blue, everyone at the table seemed at once to realize that Italian-American physicist Enrico Fermi was talking about alien life. Both Herbert Yorke and Edward Teller seemed to assume that the physicist Enrico Fermi was doubting the viability of interstellar travel--nobody thought that he was doubting the possibility of an extraterrestrial civilization. As for continuing this conversation, Herbert York wrote in 1984: Italian-American physicist Enrico Fermi followed this with a number of calculations about the likelihood of Earth-like planets, the likelihood of life giving an Earth, the likelihood of humans giving life, the probable growth and durability of higher technologies, etc.
The physicist Enrico Fermis so-called Fermi paradox may more properly be called the Hart-Tipler argument against the existence of technological extraterrestrials, which does not sound as authoritative as the older title, but seems to everyone. The other is the so-called Fermi paradox, which says we would have to see intelligent extraterrestrials here, if they existed anywhere, since they would have inevitably colonized the galaxy through stellar migration - and because we see no visible signs of extraterrestrials here, looking for signs of them is a futile effort.
In other words, much of the materials that are suitable to make habitable planets are still out there -- giving extra time for an alien civilization to form.