The Milky Way galaxy where the solar system lies is home to billions of planets that has the capability to host alien life. However, until now, scientists have not succeeded to spot alien life and this conundrum is known as Fermi Paradox. Now, in a book named 'End Times', author Bryan Walsh has discussed several reasons why humans have never succeeded in discovering aliens.
In the book, Walsh put forward a theory that was initially suggested by astrophysicist Michael Hart. In a paper written in 1975, Hart argued that there had been sufficient time for alien life to get evolved in the planets that reside in the Milky Way, as this galaxy was formed approximately 13.8 billion years ago. As nobody on earth had heard anything from aliens, Hart believes that life must be confined only on the earth.
It should be also noted that a study report published in 2018 suggested that there's a roughly two-in-five chance that humans are alone in the entire cosmos.
Experts at SETI believes that aliens might be trying to reach out to humans, but they might be using an advanced method that humans are not capable enough to detect. In his book, Walsh compared this possibility by stating the example of a modern human trying to contact a caveman using a mobile phone.
In the book, Walsh also suggests that aliens might be not contacting humans on the earth just because they do not want to do so. Walsh calls this 'The Great Silence', and he suggests that aliens might not be contacting living beings on the earth just because human beings are not advanced.
As the hunt to locate aliens continue steadily, several experts believe that contacting advanced extraterrestrials is undoubtedly a bad idea. Legendary theoretical physicist Stephen Hawking had warned that earth will be doomed if aliens contact us.
"I imagine they might exist in massive ships, having used up all the resources from their home planet. Such advanced aliens would perhaps become nomads, looking to conquer and colonize whatever planets they can reach," said Stephen Hawking.