Believing in Aliens

Has physics let the fight against conspiracy theories obscure true progress?

On February 4 this year, Avi Loeb's Extraterrestrial: The First Sign of Intelligent Life Beyond Earth hit the (virtual) shelves in bookstores around the world. Loeb boasts an impressive array of credentials, including a decade as chair of Harvard's astronomy department, as well as experience leading or driving a remarkable list of research projects and collaborations. But his book, and particularly his work in the years leading up to it, has turned him into one of the single most controversial figures in cosmology today.

The debate began in 2017 with the discovery of a strangely-shaped object leaving the solar system, now referred to as ‘Oumuamua’, from the Hawaiian for ‘a messenger from afar’. The Hawaiian telescope which initially reported the observation revealed several distinctive and unexpected properties about it, including its cigar-like shape, remarkable brightness and highly irregular path. As academics rushed to pinpoint an explanation of its origin and appearance, observatories catching their last glimpse of the object sent in further data — but ‘Oumuamua’ continued to confound.

Loeb, however, had an answer, one which seemed to him to be the obvious conclusion to draw, however much it shocked and outraged his colleagues. There was no natural explanation for ‘Oumuamua’s existence: it must be the product of an extraterrestrial civilisation. As someone with extensive research experience into light sails, which use the power of the Sun to propel them through space, Loeb suggested (as one of many possibilities) that Oumuamua’s brightness could be explained by its origin as a space probe designed with a similar mechanism by its theorised alien creators.

In fact, the established scientific literature far from precludes the possibility of intelligent life elsewhere in the universe. The legendary physicist Enrico Fermi once posed a well-known question that spawned a paradox investigated by a multitude of scientists down the line: where is everybody? In other words, if there are so many viable candidates for locations for life to develop, why haven’t we heard from them, or been able to detect them? But given the stigma attached to the idea of aliens in physics arising from bad science and conspiracy theories peddled by those seeking to spread misinformation, the aversion to a non-natural explanation of Oumuamua is understandable. Loeb argues we should not let that become a barrier to genuine progress and discovery. To him, scientists have a duty to explore the possibility — especially since we are empowered with the technology needed to do so. He also believes the public’s huge interest in the issue is another vital factor in the need to extend research.

There are some valid reservations held about his ideas. Some experts have argued that it is narrow-minded to assume that the behaviour we display in bodies within and near to the Solar System is common to all regions of the universe; Oumuamua’s ‘other-ness’ doesn’t in itself indicate an artificial origin. Furthermore, it is easy to explain anything in terms of the productive capabilities of a vague extra-terrestrial civilisation with unknown technological advancement levels. Is it good science to default to this ‘easy’ option out, instead of seeking to use the opportunity to push the boundaries of our knowledge of the universe?

Either way, whether or not it is ultimately confirmed or disproven, the possibility that Oumuamua is an alien creation should not be rejected from the outset; doing so would be a disservice to scientific discovery. It makes sense to scrutinise it and to thoroughly explore other possibilities, but the stigma surrounding interstellar life must be carefully dismantled.

Francesca VII