Sci-fi films and TV shows have routinely depicted a brutal race of aliens visiting Earth in their spaceships and enslaving unfortunate Earthlings.
But according to one expert, extraterrestrial life may actually be too scared of ‘dangerous’ and ‘violent’ humans to want to come here.
Dr Gordon Gallup, a biopsychologist at the University of Albany, argues that humans are ‘dangerous, violent and ceaselessly engage in endless bloody conflicts and war’.
As an example, Dr Gallup cites ‘the total destruction of the highly advanced Aztec and Inca civilizations’ and the subsequent genocide of the native people, their temples and buildings destroyed and their wealth and natural resources stolen.
‘If the humans of Earth became aware of advanced civilizations and desirable resources on other worlds, might these native extraterrestrial populations eventually suffer the same fate as befell the natives of Mexico and Peru?,’ he writes.
‘If there is intelligent life elsewhere, they may view humans as extremely dangerous. Maybe this is why there is no proof or compelling evidence of extraterrestrial intelligence: we pose too great a risk, and they do not want to be discovered.’
During his lifetime, the famous British astrophysicist Professor Stephen Hawking raised concerns about the dangers posed by intelligent and hostile extraterrestrials, Dr Gallup points out.
These aliens might arrive to conquer, enslave, destroy, and colonise humans to exploit the resources of our planet having exhausted those of their own.
This has long been perpetuated by TV and film – for example, ‘Battlefield Earth’, a 2000 film based on a novel written by Scientology founder L. Ron Hubbard, depicts a brutal race of giant aliens called ‘The Psychlos’ subjecting humans to slave labour.
According to Professor Hawking, the outcome might be analogous to when Columbus came to America, which did not turn out well for Native Americans, Dr Gallup says.
But the truth could be completely the opposite – it might also be possible that aliens live in fear of being found.
Overall, humans are unique because ‘they have developed the technological capability to cause their own extinction’.
‘Humans appear to be poised at the brink of reaching the tipping point when it comes to our dependence on fossil fuels and the resulting effects on climate change,’ Dr Gallup says.
‘The trajectory suggests that for the ﬁrst time in the history of Earth, we are headed for a mass extinction that is occurring as a result of the actions of a single species; i.e., human.’
The paper draws on the Fermi paradox, which is the apparent contradiction between the lack of evidence for extraterrestrial civilizations and various high estimates for their probability.
In other words, if there is extraterrestrial life, why have we not found any evidence for it?
According to estimates from Erik Zackrisson, an astrophysicist at Uppsala University in Sweden, there are 70 quintillion planets in the universe – that’s 7 followed by 20 zeroes.
In the Milky Way galaxy alone, there many as many as six billion Earth-like planets, according to a 2020 study by University of British Columbia astronomers.
According to NASA, some 4.933 exoplanets – planets outside our own solar system – have been confirmed in 3,704 systems.
The majority of these exoplanets are gaseous, like Jupiter or Neptune, rather than terrestrial, according to NASA’s online database.
As for whether intelligent life exists other than on Earth, Dr Gallup says: ‘The history of biology on Earth makes it clear that intelligent, technologically sophisticated life is the exception rather than the rule.
‘Despite billions of different lifeforms, the track record of intelligent life with complex tool-making capabilities and the cognitive ability to achieve self-consciousness, indicate that it has only appeared once, which makes the prospect of ﬁnding technologically sophisticated intelligent life elsewhere exponentially remote.’
WHAT IS THE FERMI PARADOX?
The Fermi Paradox questions why, given the estimated 200bn-400bn stars and at least 100bn planets in our galaxy, there have been no signs of alien life.
The contradiction is named after its creator, Italian physicist Enrico Fermi.
He first posed the question back in 1950.
Fermi believed it was too extraordinary that a single extraterrestrial signal or engineering project has yet to be detected in the universe — despite its immense vastness.
Fermi concluded there must a barrier that limits the rise of intelligent, self-aware, technologically advanced space-colonising civilisations.
This barrier is sometimes referred to as the ‘Great Filter’.
If the main obstacle preventing the colonisation of other planets is not in our past, then the barrier that will stop humanity’s prospects of reaching other worlds must lie in our future, scientists have theorised.
Professor Brian Cox believes the advances in science and engineering required by a civilisation to start conquering the stars ultimately lead to its destruction.
He said: ‘One solution to the Fermi paradox is that it is not possible to run a world that has the power to destroy itself and that needs global collaborative solutions to prevent that.
‘It may be that the growth of science and engineering inevitably outstrips the development of political expertise, leading to disaster.’
Other possible explanations for the Fermi Paradox include that no other intelligent species have arisen in the universe, intelligent alien species are out there — but lack the necessary technology to communicate with Earth.
Some believe that the distances between intelligent civilsations are too great to allow any kind of two-way communication.
If two worlds are separated by several thousand light-years, it’s possible that one or both civilisation will be extinct before a dialogue can be established.
The so-called Zoo hypothesis claims intelligent alien life is out there, but deliberately avoids any contact with life on Earth to allow its natural evolution.
DOES ALIEN LIFE EXIST?
No life beyond Earth has ever been found; there is no evidence that alien life has ever visited our planet.
However, this does not mean that the universe is lifeless other than on Earth, according to NASA.
The space agency says: ‘While no clear signs of life have ever been detected, the possibility of extraterrestrial biology – the scientific logic that supports it – has grown increasingly plausible.’
One popular school of thought is that our own existence is evidence that there is certainly life on other planets, as the likelihood of Earth being a ‘one-off’ is almost zero.
However, one argument against this is – if there is extraterrestrial life, why have we not found any evidence for it?