What If Earth Has an Identical Twin?

VOICE OVER: Noah Baum WRITTEN BY: Alex Slade
For scientists and astronomers scanning the skies for signs of alien life, it's the holy grail of all discoveries - a duplicate Earth. A planet capable of harbouring life, evolution and a potential destination for the future of humankind. But how would such a discovery change our own lives? What would happen if Earth had an identical twin?

What if Earth Has an Identical Twin?

We may not immediately see it when we look up at the stars, but – according to some theories – somewhere out there is another world not unlike our own. In fact, it could be identical, with the same look, feel, history, atmosphere and general properties. Further still, given the infinite possibilities of an apparently endless universe, some theorists have speculated that there could be an identical version of human life, too. So, there’s another you, going about their daily lives elsewhere… perhaps they even take time to scan their skies and wonder what you – as in, the real you – are doing, or if you even exist. No matter how far you subscribe to the idea of a mirror image world though, the concept does throw up plenty of questions – not least, how would we react upon its discovery?

One of the first things we’d have to get our heads around are the odds of an identical planet actually happening – which are almost impossibly long. The chances of us being on this little blue planet, perfectly positioned and developed for life to exist, feel fairly long in the first place. So, the existence of Earth’s ‘identical twin’ would shake our fundamental beliefs and our understanding of life. While most scientists agree that some form of alien life should almost definitely exist, replicant humans on a duplicate planet are not what we’re expecting – unless you’re a supporter of the ‘Many Worlds Hypothesis’, in which case it’s exactly what you’re expecting! For some, such a discovery would prove the existence of God. For others, it’d confirm an alternative higher power, or the existence of the multiverse. For a select few, it’d verify that life really is just a super-complicated computer game – with the identical planet perhaps serving as our own narrative, but at a slightly different save point.

Of course, in recent years our search for Earth-like planets – or so-called ‘Earth 2.0s’ – has intensified, thanks largely to NASA’s Kepler project. While these studies are yet to throw up an identical twin – with the same land masses, same weather patterns, same neighboring planets, same everything – they have homed in on some similar concepts. For one, if we did discover an even partly comparable world hosting human life – at equally impossible odds – we’d want to know how the heck humankind had got there. The go-to answer for lots of us? Aliens.

Suddenly, with proof of humans elsewhere in the universe, we’d feel sure that a higher species or creature had facilitated our spreading out. But their purpose – and therefore ours – would likely still feel a mystery. However, we wouldn’t be alone in our existential confusion, because our identical inhabitants on Earth’s identical twin would naturally feel identically bewildered – assuming that they’re aware that we’ve discovered them… which they surely would be, because in their identical histories they’d be discovering us at the same time.

Either way, for hundreds, thousands, perhaps even millions of years, all either planet would really be able to do is speculate – because the tech to visit one another just doesn’t exist. The identical Earth would have to be multiple lightyears away from our own – presumably in a copy of our Solar System. But, for generations we’d strive to develop methods of communicating and monitoring ‘Earth 2’, always safe in the knowledge that we’re not alone in the universe.

On a personal level, paranoia could set in. Let’s say a future version of ourselves develops tech capable of observing the identical Earth – so our like-for-like doppelgangers can be seen through mega-telescopes. You could start to believe that the ‘other you’ looks stronger, fitter or healthier than you actually are – which could cause confidence issues. Alternatively, the other you could appear haggard, frail or out of shape – leading you to believe that this is your fate. Or encouraging you to just quit your diet, anyway.

Going further still, and if we (and they) develop a means of communicating with each other, some people might worry that their far-flung clone is smarter, friendlier or funnier than they are. Their very existence would give us the opportunity to experience ourselves from an outside perspective – but what if we don’t like what we see? Alternatively, what if we love it? The ego can only over-inflate so much!

We can study how humans behave in unfamiliar scenarios as much as we like, but nothing could prepare us for this. The psychological toll would be unprecedented, with irrationality and hysteria taking over. In terms of ‘important dates in human history’ – this would be right at the top.

But, over time, the positives could well outweigh the negatives. We know that humanity is a curious species, always looking for knowledge and answers to great mysteries – and this would be the greatest of all. In the same way as it would provide us with an alternative perspective on ourselves, we’d also experience an outside viewpoint on our planet – allowing us to assess the things they (and therefore we) are doing well, and badly. For topics ranging from ‘the effects of global warming’ to ‘the threat of plastic pollution’, we’d suddenly have an ultra-specific case study to learn from.

Finally, should we ever develop a way of actually visiting our identical twin, both worlds would truly change forever. An optimistic view says that we’d co-operate with each other, perhaps pool our resources, and share our experiences. The pessimist predicts war, invasion and an aggressive attempt by both planets to establish rule over the other. In the first case, life could conceivably be double as good. In the second, Armageddon would be twice as destructive.

Whichever way the scenario was to pan out, the presence of an Identical Earth would shift everything we thought we knew. We’d first lose any sense we might’ve had that we are unique. Next, we’d have to navigate through various levels of existential crisis. Then, our theories on life, science, humanity and faith would be reshaped to fit our new reality. Is the universe what we think it is? Is the multiverse real? And if there’s already one identical Earth out there, could there be even more of them?