At first glance there seems to be little connecting Brexit with the search for life on other worlds (beyond, perhaps an impact on the funding of and involvement in that search). However, given time to think on it, odd parallels between the two begin to emerge.
Over the three-and-a-bit years since the day of the June 2016 referendum, constant wall-to-wall media coverage of the UK’s plodding, tortoise-like random walk towards leaving the European Union have kept it at the forefront of our minds. In particular, the uncertainties and the associated unanswered existential questions have been driving us all to distraction. Part of what draws me to the search for life in the Universe is the mystery of unanswered questions, so in a way it is not too surprising that as time passed I began applying the same kind of thinking and reasoning to the Brexit conundrum that I would normally use for my scientific work. This does not tend to be the kind of thinking that answers questions, but, an approach that shines a light on just how many questions need to be asked in order to begin to uncover solutions.
Hence, the mystery surrounding a Brexit-induced future serves as a first tenuous link between these two very different topics. Both raise a lot of questions that we currently do not have answers for. We have ideas about what some of those answers might be: the simple overarching ones like “Does life exist on other worlds?”, or, “Will life in the UK be better or worse without the EU?” In their simplest forms these questions can have ‘yes’ or ‘no’ answers and in both cases one of those answers is considered more probable than the other. Ultimately though, the only accurate answer for both (at the time of writing) is that we do not know. Even the more nuanced questions:
The questions are very different, but attempting to answer them requires very similar approaches. Namely, envisioning how something we currently know and understand – be that life as we know it on Earth, or life as we know it in the UK today – would respond to a whole system change.
A planet with all the right ingredients for life does not have to resemble the Earth to be habitable. It can be hotter, colder, wetter and more humid, arid and drier, bombarded with more radiation, covered in a layer ice, or pretty much any combination of conditions that still allows some liquid water to exist along with something that life can use as food. To find out how we might search a multitude of habitable worlds for telltale signatures of life, we need to know how life would work on such worlds. The best way to figure this out is to take our one example of an inhabited planet – Earth – and try to work out how Earth’s biosphere (the hugely complex system comprising all life on Earth, intricately linked with the equally complex climate and geological systems) would change if we alter some of the prevailing conditions. It is a bit like predicting what would happen under various future climate change scenarios, only we get to test the system to much greater extremes, leading us to imagine possible biospheres that vary enormously from the familiar biological world around us. From this, we build up ideas about how life on other worlds would work and crucially, what clues we need to look out for to prove that life is present on another planet.
A similar approach is used to figure out how the UK will fare under a number of future scenarios that change the ‘environment’ under which the country operates, affecting society, politics, prosperity and world standing. Countries, economies, human society; all are interacting systems, equally as complex as the Earth system. Complex systems are very difficult to model, with even small perturbations sometimes causing huge system changes. Sometimes a single change to a system can result in a number of equally probable, but different, outcomes, while large alterations can result in little effective change. Or vice versa. This is why we predict such huge variations in the compositions of biospheres on other worlds. By acquiring real-world data, we can assess how likely a range of possible scenarios are within a changing system, eventually identifying the most probable course events will take – this is how decades of efforts modelling near-future climate change have led to solid, irrefutable conclusions. In astrobiology we do not (yet) have the luxury of much hard data. To an extent we can use biology’s physical limits as measured on Earth, or the statistics showing the numbers of different types of planets in the Galaxy to narrow down our predictions. Yet these are data that we are only just starting to acquire, which still leaves a lot of possibilities on the table. If and when we finally find signs of extraterrestrial life, we can really start to hone in on which of our predictions are most plausible. Until then we have to consider all possible options. The potential Brexit outcomes are equally difficult to constrain and practically impossible to experimentally test. Again, we have some ideas of more likely scenarios, but the most likely scenario of all is that, caught within the uncertain tides of a complex psychological-social-geopolitical system, events will overtake predictions long before we have things figured out.
Not knowing can be quite exciting when it comes to big unanswered questions like whether we are alone in the Universe. However, endless possibilities on an ever-approaching horizon in a world we inhabit are, for a species whose modus operandi is to predict and plan for the future, more worrying than exciting. This is perhaps where the similarities break down. As a species we base our individual and collective lives around stories. Stories of identity. Stories of purpose and meaning. Stories that satisfy our need to know why things are the way they are. Post-Brexit Britain and the search for life in the Universe are both stories with unknown endings. The difference is that, while the search for life is a story we as a species are writing for the first time, Brexit is catalysing a re-write of stories that once firmly defined who and what we are as a country. A re-write that so far only has a beginning and is far from having a satisfying conclusion.