Mass Interaction 004: Is the Universe an Illusion?


We love curiosity. Curiosity makes us creative, thoughtful and progressive. So at air space, home of startups and entrepreneurs, we love to host talks that make us think a little more deeply.

On the 18th May, we were delighted to welcome science journalist Max Sanderson for the fourth instalment of Mass Interaction, a series of fascinating and accessible science discussions. This time, Max invited Professor Barry Smith and Dr Anders Sandberg to join him in considering whether or not the universe could be a simulation. We asked how real are our perceptions of the world around us, and how can we ever be certain what is real? We were joined by a lively, sold-out audience who helped us explore this complex subject.

Introducing, Max explained that his obsession with the universe being an illusion stems from watching the film The Truman Show as a child. If you’ve seen the film, you’ll know Truman’s understanding of reality isn’t entirely accurate…

Professor Smith explained this in philosophical terms, using the example of Plato’s allegory of the cave. Plato describes a group of people who have been chained up in a cave for their whole lives, facing a blank wall. They would have never seen the real world outside, and would only ever see shadows projected onto the wall from a fire behind them. They would give names to these shapes: this would become their reality. They would have no knowledge of the diverse, vivid world that lay outside the cave. They would not even be able to comprehend it. Could we be similarly deceived?

Descartes says that this is possible. Our senses deceive us. For example, when we are dreaming we have a very vivid and realistic experience which we only realise is not real once we have woken up. If we can be deceived by ourselves in this way, and if our dreams can be as vivid as real experience, how can we be certain that the experiences we take to be real are not in fact dreamlike illusions themselves? Maybe everything we experience is a type of dream.

Descartes doubted everything to figure out what could be truly known. He decided that he couldn’t doubt that he was thinking – cogito ergo sum – I think therefore I am. Other than that, he agreed that he could never know whether things really are as they appear to him. He accepted that the external world is unknowable. Professor Smith argued that contemporary neuroscience shows us that we are often even wrong about what we think!

Next, Dr Sandberg introduced the brain-in-a-vat theory. That is, a brain without a body could be connected to a supercomputer which runs a programme that makes the brain experience life as if it were a normal person. However, Dr Sandberg asked, what would this brain think when it thinks snow is white? It can’t refer to anything in the external world, as the brain does not know what snow is. There must be certain limitations on the brain’s experiences. However, perhaps it isn’t the things we are seeing that aren’t real – maybe the concepts we use to think are also not real. For example, the brain that has always been in the vat is not thinking about real snow; it is thinking about the images and sensations of snow.

This moved the conversation on to solipsism – the theory that all that exists is me and my mind. Everything else I perceive to be ‘real’ is a creation of my mind. This is a bit like the Truman Show – we are the centre of this reality. Professor Smith remarked that everybody thinks the Truman Show is happening to them – but that can’t be the case. Maybe we all need to get out a bit more!

Next we discussed the value of our senses and how reliable they are. We learned that there are odours in shampoo that make our hair feel softer – who knew?! Our sense interact more than we realise. For example, we don’t see a cup and wonder whether it is 3D or not. Our brains use touch and vision together to create an understanding of the object. The brain takes one imperfect source of knowledge and uses another to back it up and give us a concrete understanding of it.

An audience member asked if we may have more than the five senses. The speakers all agreed that definitely yes, we do! Professor Smith says that in fact, we have somewhere between 22 and 23 senses. For example, our sense of balance. It is bizarre that we so often believe Aristotle’s view that we only have the main five senses, when we clearly have a lot more. Max asked if we should say we have one sense, with many aspects, but Professor Smith disagreed: we should keep the distinction between each sense so we can better understand how they interact.

We had another great audience question: how do dogs know when their owners are coming home? Is this learned behaviour or another sense? Interestingly, this wasn’t poo-pooed! Professor Smith said that we know exactly how this works. Dogs have a sort of smell clock as part of their very sensitive sense of smell. As the smell of the owner wears off during the day, the dogs start wondering where it has gone – hence them going crazy just before they come home. We love dogs at air space, so it was brilliant learning a little bit about what makes them tick!

The interesting thing about the simulation argument is that we might not know what the world is actually like…

We began to wrap up by discussing whether there was any way we could figure out we were in a simulation, if we were. We agreed that if it was a perfect simulation then we would never know; however, it is likely that there would be errors. It would depend how those errors were fixed and covered up. Professor Smith argued that a simulated brain is not like ours, as it came about in a different way. Dr Sandberg disagreed and so Professor Smith asked him: do you not care if you are going home to the same wife every night? Even if a simulation of her looked exactly the same? Max asked how we would be able to tell the difference, but Professor Smith said that the differences matter, whether you can tell that they are there or not.

Our last audience question was a big one: is reality in its entirety reducible to computation?

Anders Sandberg said that if a computer was doing the same functions as a brain, then it is essentially the same thing. However, Barry Smith said that you can’t get smells, tastes etc. into a computer. Matter is incredibly complicated. “No computer can tell me why pain hurts so much.”

There were plenty of differing opinions over the course of the evening, with everyone being pushed to thinking outside our comfort zone! Whether you were there on the 18th or not, tweet us your thoughts with #massinteraction, and keep your eye on air space social media for details of the next one….

If you’d like to tweet any of the speakers, you can find them on Twitter:

Max Sanderson

Professor Barry Smith

Dr Anders Sandberg

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