The Multiverse, string theory, and how we make choices.

Originally, I thought Multiverse and string theory were the same thing, but a deeper dive shows me that the differences between the two are pretty huge. In Multiverse theory, there are unlimited dimensions in which all things happen. Under string theory there are a limited number of universes with a more limited number of outcomes dictated in a more complex pattern by the movement of energy. Although this does mean that Multiverse theory looks like the much wilder of the two, both are somewhat predictable when we break them down to the very smallest things and do a little maths. These alternate universes are not governed in the typical way we laypeople describe them – ‘somewhere in an alternate universe’, and don’t really function the way they do in art, but that doesn’t mean that we can’t take a closer look and use complicated mathematics to influence the way we live our lives.

There some amazing art about multiverses. Rick and Morty has pushed the boundary of what it means to exist in a universe where the prevailing theory is that we are not alone and Lewis Carroll’s classic exploration of a mirror world with alternate logic, Through The Looking Glass, can easily be read as a mathematic satire. Nick Payne wrote an entire play with a physicist as one of the protagonists that shows us how slight differences create multiple worlds, presenting them as layered and interchangeable. What that’s telling me is that we, the lay-public, are hungry for understanding, that not only do we turn to philosophy to know our place in the world, but that quantum mechanics might be the answer for an ordinary person looking for order in the world. Art is a way for us to make sense of complex theories through analogy, imagery and narrative, but Multiverse remains commonly the subject of jokes about how unlikely things are (‘not in this lifetime’), and string theory is considered the unintelligible domain of scientists only. If you can understand Doctor Who, though, you’ve got the gist of Multiverse theory and the building blocks for string theory. All we need to know, is: E=MC². What this famous equation tells us is that gravity and mass affect the other forces of the universe, like the speed of light, and from that we can extrapolate how we are, or would be, in these alternate universes. We don’t have to understand the nuances of how particle physics works to influence our passage through it (it has to do with dark matter and very tiny particles, and no matter how many podcasts on Paul Dirac I listen to, I can really only understand the children’s version) – for the everyday philosopher we only need to understand the conclusions. Those conclusions are to ask, what can be different? What would have had to happen differently for things to be different?

Under Multiverse theory, the existence of both entire worlds that diverge from ours and slight changes to our lives is presupposed, whereas under string theory the world cannot stray too far from ours in energy, although this does not mean that we as individuals do not exist in them – just not in our current forms. Essentially, what we can see is: in our universe, neutrons weigh more than protons, but there’s no reason that has to be the case. If protons weighed more than neutrons, and there’s no reason that shouldn’t be the case except that it is, then chemistry wouldn’t work the same way, and basically we wouldn’t be carbon-based life forms who breathe oxygen. We could be anything. Everything is the same, but our genetic makeup has evolved differently, because we breathe water or antimatter or something, because chemistry is different in that universe. It looks like the art we recognise, but its philosophical function can be different.

Initially, this is a question of identity. String theory isn’t telling us that in an alternate universe, parallel to this one, there is a version of us, and every decision you make or don’t make splits us into another world and makes a fresh path. It tells us that there are eleven possible dimensions that create universes which create many iterations of the universe, not so far removed from ours, where maths is the only constant between them. String theory tells us that the environment we take for granted – trees, carbon, mass – is essentially arbitrary, and the thing we need to interrogate is how does our passage through the world shape us? If we breathed water instead of air, would we be the same people? If we were gelatinous blobs in a gelatinous world, how could we possibly have a relationship to the ‘us’ from this world, where mass and atoms are what they are? For me, this question brings me to formless things – art, music, writing. Emotions are taken from and inspired by our relationship with the world, but they are not based on form, whether ours or that of the world around us. They do not require memory, though they sometimes come from memory, and therefore are unaffected by the idea that the passage of time as we experience it is not a constant across the universe. To take this further, I would say that therefore the essential part of humanity, that which is consistent across a multiverse where nothing dimensional can be taken for granted, is the emotions with which we go through life. The lesson here is that nothing can be understood beyond emotion, and the things which cultivate it – at least, not in a universal and unwavering sense. This is the core idea of phenomenology, but given to us from a scientific perspective.

Alongside the strings, though, we have multiverse theory. In this theory there are an unlimited number of worlds, perhaps compacted or at different times, and because of this we think that there is the probability that within these universes are a number of worlds which diverge from ours only slightly. It does create the idea of some kind of ‘butterfly effect’, the idea that every choice you make or don’t make creates a you who is living your life, but better or worse, which can be overwhelming. This conception of multiverse theory makes us anticipate that both outcomes of a problem are inevitable, and makes our life paths feel like a hierarchy. Do you want to live in the universe with the less desirable inevitable outcome? Perhaps it makes you resigned to the outcome, as if you are not really making choices? But this is to misunderstand the multiverse, or perhaps our place in it. To say that they diverge from ours only slightly means in the laws of physics. Even in this insane theory which seems to say that, essentially, anything that is possible exists simultaneously, there are limitations. The vibrations which make up the energy which travels between the dimensions requires a connection between the dimensions, and is affected by the way the connections move – geometry, mathematics, chemical makeup all affect the connections between the universes, and thus, although theoretically infinite, will be a number. Just a very high, potentially incalculable number. The idea that there is a ‘you’ in these universes is similar to that thought experiment about locking monkeys in a room with typewriters until they write Hamlet – it’s inevitability, odds, really high numbers, rather than fate or predestination.

Is it possible that there’s a you in these universes, living your exact life? Sure, but we’re talking chances of billions to the power of billions. If that many universes exist, maybe you’re in there twice, but in those universes that version of you doesn’t automatically make a different choice to the one you make, in this world. It would be possible for you to both make the same choice, and result in the same or different outcomes dependent on how that world formed. Although it is theoretically possible that there is a carbon-copy of you living a perfect life, your desired outcome is not necessarily happening. Multiverse theory simply uses quantum physics and to explain how it can be possible that things we expect to be mathematically true are. Its effect on us is to create a sense of unique experience, to emphasise our free will – because if there were another you, they could make the same or different choices as you, and neither of you will be impacted by the others’ decision. We can take this idea into our relationships in the concrete world: our decisions are our own. Inevitably there will be an effect on others, but only we can understand the myriad of tiny things over hundreds of years that go into any decision. In some ways, each decision is the only decision you can make, and if the alternate-universe you chose something different, it would be because of some intangible difference between your experiences. Although another ‘you’ might exist through circumstance, only you can exist and perceive in the dimensional space that you exist in.

What these theories have in common is a use case – although physicists are using string theory and multiverse theory to explore the potential differences in atomical makeup between universes, the idea of different universes in which forces act slightly differently to ours gives us, the layperson observing particle physics, a guide to relate to the universe as we pass through it. I find this a good lens through which to examine life: change the variables, and work out if you would still feel the same. For a particle physicist the variable they change might be what the sun is made of or the speed of light; for you, it might be money, or having more time, or if the weather will be good enough to grill outdoors. These unmovable variables potentially being different show us how we might move through the world if things were different, and allow us to understand how things are. They show us that, were things different, everything would be different, and the effect might be nothing or everything. Multiverse theories show us that we can only make the choices we do make, which might be freeing or cloying depending on who you are.

The other major philosophical tenet we can take away from particle physics is, sometimes things just are. Quantum physicists are looking for reasons within the structures that most of us take for granted, and whilst the reason might be god or mathematics, it’s entirely possible that Douglas Adams was right all along and somehow it’s merely a miracle of probability that we exist.

Science and philosophy are two sides of the same coin. Big, scary scientific theories have big implications for what it means to be a human, living life, if we choose to read them in that way; philosophy is the middleman for interpreting these big ‘ole truths. The implications of both Multiverse and string theory for how we live our lives are going unexplored because we think it’s not our place to engage with these incomprehensible and lofty theories, but they actually can be interpreted in a way that speaks to normal people and affects our decision-making process. We can use these complex theoretical models of understanding the universe to our advantage and create a framework for going about our life that will make us happier, and more attuned to our decisions.

Perhaps you are also interested in my previous work using mathematic philosophy as a way of negating anxiety. I think too much but maybe it can help.

Please can somebody recommend me some populist / accessible maths or physics to read? I find this shit super interesting but have not done anything resembling a science since I was 15.