Reality Asylum:Are We Living In A Computer Game?

"What is "real"? How do you define "real"? If you're talking about what you can feel, what you can smell, what you can taste and see, then "real" is simply electrical signals interpreted by your brain" - Morpheus, The Matrix

Children ask some awkward questions at bedtime, don't they? Why is the sky blue? What are rainbows made of? What was that strange noise you and daddy were making last night? While these questions come out of genuine curiosity and a keenness to learn they also serve as a good ploy to stave off having to go to sleep and having to be left alone in a darkened room.

One night, Professor Catherine Heymans was putting her young son to bed when he piped up with "Mum, do you think we could be inside a computer game?". The son in question was very keen on computer games whereas Professor Heymans was no gamer and didn't know the answer. Which bugged her.

She couldn't stop thinking about it and during a trip to the Paranal Observatory in Chile's Atacama Desert she found herself with plenty of time to ponder the question in some depth. A visit to the Atacama Desert may strike you as quite extravagant so here's some context. Heymans is the 11th Astronomer Royal for Scotland and the first woman to hold that title in its two hundred year history. She's also won the William Herschel medal for outstanding merit in observational astrophysics so the Paranal Observatory in the Atacama Desert is exactly the sort of place she would visit.

It's her job and it's a job she seems to absolutely love (I'd love a job that involved visiting Chile) and it's a job that also involves providing expert commentary on all things to do with physics and outer space. So, she's a good public speaker (even if she had long covid and had to deliver the talk via a pre-recorded film) and in last night's Skeptics in the Pub - Online talk, The Universe:Reality or Simulation - hosted by Clio Bellenis of the Winchester Skeptics chapter, she came across both theatrically and enthusiastically. At times like a children's TV presenter. She also laughed ever such a lot during the Q&A. Something the long covid didn't affect thankfully.

Back in Chile, Heymans looked up at the Milky Way - our galaxy. Somewhere between one hundred billion and four hundred billion stars and most of them with at least one planet orbiting it. The Milky Way is just one galaxy and we have no idea how many galaxies there are. There are at least one hundred billion galaxies but the actual number could be in the trillions or could even be infinite.

Nobody knows. But that's a hell of a lot of stars and planets. In Heymans' mind it seems almost impossible that not a single one of them except for our humble little planet, Earth, contains life or even civilisation. But what would that life look like? What would those other civilisations look like?

They could be less advanced than us but they could be more advanced than us. Far more advanced. They may have solved the problems of violence and climate change and they may have created such realistic computer games that we would be unable to tell the difference between those games and our own lived realities.

Of course, she is not the first person to think about this. In 2003, the Swedish philosopher Nick Bostrom came up with a 'simulation hypothesis' about just this subject. He posited three theories, one of which - according to Bostrom - had to be true.

(1) Humans will become extinct before reaching a post-human (for instance, AI) stage

(2) Any post-human civilisation is unlikely to run a significant number of simulations of their evolutionary history

(3) We are almost certainly living in a computer simulacra

The brainy prof, and the brainy Swedish philosopher, lost me a bit here but I got the general gist and Heymans was quick to explain that Bostrom's hypothesis was science fiction and not science fact. That cued her up for the first, but not the last, reference to The Matrix. A film that simply cannot be ignored when tackling this subject, so powerful is its cultural currency.

Heymans asked if our reality is mathematical? Can we describe everything that happens using mathematics? If the answer to those two questions is 'yes' then it's entirely possible that simulation could happen. She then went a bit deep and started talking about algebra, 1960s mainframe computers, and free will - or the lack of it - while throwing in a frankly unnecessary Billy Connolly impression and she lost me a bit but these blogs are my report of events, not some kind of Skeptics Hansard, so if you want to know everything that Professor Catherine Heymans said last night then you should have logged on last night. It was free.

I digress. Heymans continued by talking about how the binary world of computers breaks down algebraic equations into a seriew of logical questions, creating a mathematical calculation at lightning speed by simply asking yes/no, on/off, 1/0 questions. Heymans and her colleagues created simulations to see how the planets Jupiter and Saturn were formed and then created new Saturns and Jupiters. 

Only on their computers though, not in the tangible universe. Again, the science got a bit difficult for my enthusiastic, though uneducated, brain. Quarks, neutrons, gluons, leptons, and even our old friend the Higgs boson as well as a citation for the 19c Scottish physicist James Clerk Maxwell. At one point Heymans said "don't get me started on dark energy" which seemed like a good title for a book and if she ever returns for a talk on that subject that's the blog title sorted.

In the future, Heymans opined not unreasonably, we will be able to simulate human experience but to do this we will need to fully understand the mathematics of light and how it travels through time. Heymans, thankfully for me, explained it in layman's terms. Light travels across time in the same way ripples travel through water when a stone is thrown into still water. Ripples of water, or electromagnetic force fields, radiate out from a central point.

Our biggest light is, of course, the sun. The light from that big yellow bastard is absorbed into everything it touches and, for some reason, Heymans chose an orange as an example. An orange absorbs all light except for orange light (hmmm) and that's why oranges are orange. It's also why carrots are orange though we can't be certain if it's why Donald Trump is orange. What is certain however is that his IQ is roughly the equivalent to that of an orange or a carrot or even a Wotsit. Though oranges, carrots, and Wotsits all have far more moral fibre than America's worst ever President.

Our eyes absorb light too - everything does - and then send messages to our brains for interpretation. Could signals of senses (not just vision but smell and taste) be programmed to create a simulation? It's possible but it would involve the post-humans harvesting billions of human brains in vats. Why would they bother to do that? Wouldn't they be more interested in the future than the past?

How would this simulation explain our human consciousness? If we're just programmes running on the commands of some superior intergalactic beings then why do we have feelings? Why do we love? Why do we hate? Why do we care? Why do we worry? What purpose does consciousness even serve? Philosophers will give you many different answers to that final question but there is no consensus and there is no overwhelmingly definitive answer.

Heymans lost me again on a section that involved quantum computing, trilobites, electromagnetism, crustaceans, and an AI simulated photograph of Pope Francis in a big white puffer jacket (my least favourite kind of coat, just letting you know) but she soon won me back when she started talking about how creating a simulated universe would require unfeasibly large amounts of energy.

It's not just us, humans, that would need to be simulated but everything else too. Animals, plants, landscapes, seas, buildings, aeroplanes, tables, chairs, buttons, spoons, eggcups, paperclips, sticking plasters, Frazzles, score cards for games of Yahtzee, and Anusol cream. The human brain is so complex on its own that simulating that would be a mammoth task. Simulating over eight million human brains so that each person on the planet is simulated seems like too much work even for a non-sentient post-human.

Ultimately, though, Professor Catherine Heymans was unable to find a satisfactory answer to her son's bedtime question but, more importantly, does it matter? Does it matter if we're real or we're just under the illusion that we are real? What does that change? If you feel that your life is real then it is real. Use it well.

It had been an interesting, if sometimes hard to follow, talk and it's certainly an interesting subject. A Q&A involved space travel, satnavs, the quantumverse, David Chalmers, the Fermi paradox, Arthur C. Clarke, killer asteroids, existential fear, Einstein, chatbots, the redness of cherries, and the possibility of simulations within simulations within simulations and on and on forever as well as a guest appearance from Heymans' two sleeping cats - who I think were real but may be simulations. Either way they're not losing sleep over it.

Thanks to Clio Bellenis, thanks to Skeptics in the Pub - Online, and thanks to Professor Catherine Heymans for an illuminating Thursday night in January. Keep it real.