Today we have another post which falls into the realm of Philosophy of Science. An idea which makes us question our perception of reality, of our knowledge and consciousness. This is the sceptic’s favourite – the Brain in a Vat scenario.
Let’s explain what this scenario is before we branch off into the different variations and pass any judgement. The brain in a vat scenario is the scenario when an evil scientist, machine or other more powerful being than a mere human, has removed the brain from a human’s body and suspended it in a vat full of a concoction of organ-preserving elements. The neurons in the brain are then connected by wires to a ‘supercomputer which can deliver electrical impulses to the brain, ‘identical’ to those the brain would naturally receive when existing within a body which is interacting with an independent reality. At the end of the day that’s all our perceptions of the outside world are, a result of electrical signals travelling through neurons as a by-product of our experiences. Stroke a puppy, the fur of the puppy is felt on your fingers which sends signals representing the sensation of touch to the brain. Hear the puppy bark, sound waves resonate on your eardrums, which sends signals representing the sensation of sound. The idea is the supercomputer has the ability to simulate all these sensations and thus create the experience of a perfectly normal environment. In fact if so it could have even inputted in the sensory experience of all the other supposed human beings around you. This then resonates with the philosophical view of solipsism – one can only be sure of the existence of their own mind. (Wacky)
Now because this could be possible, the philosophical sceptics (people who like to question our very basic assumptions about reality) say, it is therefore impossible to tell from the perspective of the brain whether it is in a human body or in a vat. Now you may say woah wait a minute, think of all the neural simulations the controller would have to manipulate to construct a flawless reality – but unfortunately this is not the point. The sceptic’s point is that as sensations are just a product of neural signals, if even one can be simulated, theoretically they all can (with enough time). Therefore, as we cannot say with certainty we are not simply brains in vats, it is impossible to rule out being a brain in a vat. Therefore the bottom line is we cannot know whether our beliefs about reality are at all true.
There is an argument from biology that believes a brain suspended in a vat is fundamentally different to a ‘in-body’ brain and therefore we cannot say it is even possible to replicate the experiences. The ‘in-body’ brain receives input through the senses found in the body, which in turn receive their input from the external environment. However, the BIV receives stimuli from a machine. Whether these can be completely mimicked is highly debatably. This line comes down to the neuroscientists, of which one I am certainly not. However, to the best of my knowledge, those at the leading edge of the field do believe all experience can be expressed in electrical exchanges between neurons, and if that is the case the sceptic is right andit is impossible to rule out BIV scenario. I can sense many people up to this point will not be very convinced, let me try something more familiar to persuade you, something that everyone has personally experienced. Dreams.
The dream argument is the idea on frequent basis we believe we are in reality when we are not. When we dream, unless one is skilled in the art of lucid dreaming, we believe whatever we are dreaming about is in fact real in that moment. It is only when we wake up that we realise we had been deceived. Often in dreams we can also have sensory experiences, like the dreading one of falling. How do we feel this? Well it is a product of experience, we have experienced what it feels like to fall and our neurons can replicate those signals. You may think well surely we would have woken up to the actual reality by now, humans have been around for centuries. But it’s not humans we’re talking about its the experience of the individual which is in question, for we can never be sure of the experience of others and an individual of on average 30 or so human years – a mere blip in the lifetime of the universe.
All of this is all very matrix-esque, minds inside a simulated reality. Within our collective reality (if there is such a thing and we aren’t solipsists) then we are already pursuing an endeavour like this ourselves – virtual reality. As the progress stands now we are nowhere near making our attempts at virtual reality indistinguishable from the outside reality but it a task we are pursuing. Remember reading my article on the Fermi Paradox? Given the vast number of stars in the observable universe, statistically speaking there are a vast number of Earth-like planets. Our sun is relatively young and therefore other earth-like planets may host life/civilisations much more advanced than ours, due to their planetary system have been around a lot longer. Who is to say an advanced civilisation hasn’t mastered a virtual reality indistinguishable to reality already? An uncomfortable thought.
Another argument put forward for the scenario of the existence of brains alone is the weird and wacky Boltzmann brain paradox. According to thermodynamics systems tend towards a high level of entropy (a state of chaos) see ‘A descent into chaos’. Boltzmann proposed that the probability of fluctuations away from such high-entropy states are unlikely i.e. fluctuations towards order and organization. It’s rather unlikely a swarm of bees will randomly decide to form an ordered cube. Therefore, Boltzmann believes it is far more likely for the distributed matter in the universe to come together randomly to form a brain which is alone, floating around in space with a certain neural net representing memories, than it is for the existence of brains which came about through human beings. Brains as we believe them to exist arose from evolution from ancestors which required a high level of organisation in our external environment, i.e. earth, oxygen, food. ‘In an infinite universe, the number of self-aware brains that spontaneously and randomly form out of the chaos, complete with memories of a life like ours, should vastly outnumber the brains evolved from an inconceivably rare local fluctuation the size of the observable Universe.’ In a nutshell the paradox is that it much more likely that the brains that exist are Boltzmann brains, floating around freely as opposed to evolved brains in a life-welcoming environment.
[Futurama’s episode on Boltzmann brains!]
To summarise, philosophers argue that seeing it is impossible to verify that we are not just brains in vats or brains floating alone in space we cannot be sure that this is not what we are. (Take a moment to digest that philosophical point.) And, as such we cannot be sure if our perceptions of the environment are genuine representations of reality or a trick of our senses. Whether we should be so sceptical just because we cannot rule out the scenario is another question. It is undeniable that the philosopher’s point is valid but can it be truly be taken so seriously? Does it all even matter anyway if either way we still experience the pain of having to get out of bed to go to work in the morning?! I’d been keen to know what you think… provided you aren’t just a simulation within my mind of course. Drop a comment below!