“I shall then suppose, not that God who is supremely good and the fountain of truth, but some evil genius not less powerful than deceitful, has employed his whole energies in deceiving me; I shall consider that the heavens, the earth, colours, figures, sound, and all other external things are nought but the illusions and dreams of which this genius has availed himself in order to lay traps for my credulity; I shall consider myself as having no hands, no eyes, no flesh, no blood, nor any senses, yet falsely believing myself to possess all these things; I shall remain obstinately attached to this idea, and if by this means it is not in my power to arrive at the knowledge of any truth, I may at least do what is in my power [i.e. suspend my judgment], and with firm purpose avoid giving credence to any false thing, or being imposed upon by this arch deceiver, however powerful and deceptive he may be.” Meditations on First Philosophy , Meditation 1, Rene Descartes Last year, two groups of US neuroscientists independently published two stunning papers that led to sensational news headlines like “Frankenswine” and “Aporkalypse”. One team at the Yale School of Medicine in New Haven, Connecticut, assembled fresh brain cells or neurons taken from pigs that had just been killed , and thought they detected coordinated waves of electrical activity that might possibly indicate consciousness. The researchers were so shocked they anaesthetised the brain cells as a precaution and reported the experiments to US authorities. An outside neurologist was brought in, who thought they had misread their electroencephalogram (EEG) used to detect electrical activities in neurons. Still all parties involved thought the EEG activity was possible in principle and that the Yale team was right to shut down the experiment. Instead of pig neurons, another group, based at the University of California, San Diego, was experimenting with hundreds of miniature human brains, called brain organoids, that were grown from human stem cells. Floating in Petri dishes, the tiny brains that were the size of sesame seeds really did produce coordinated waves of electrical activity that mimic those recorded in premature babies. The team found that the waves continued for months before the experiments were shut down. This type of brain-wide, coordinated electrical activity is one of the properties of a conscious brain. The San Diego team has experimented connecting the brain organoids to control walking robots and to develop more humanlike artificial intelligence systems. Are we butterflies or computer games? Creating a conscious brain in a jar, once a philosophical thought experiment inspired by Descartes and the sci-fi plot of a famous episode in the 1960s Star Trek TV series, may well become a reality one day. Star Trek , by the way, has had an uncanny record in predicting future inventions, such as mobile phones that could be used everywhere on a planet. Meanwhile, some computer scientists and physicists have been conceptualising experiments that may prove or disprove whether we are all nothing more than a computer simulation. They are responding to Oxford philosopher Nick Bostrom’s argument, first published in 2003, that logically and statistically, we are far more likely to be simulated than real. The experimental design ideas, though still not carried out, point out that there are usually glitches in any computer program. It may be possible to look at, say, telltale signs of glitches in simulated cosmic rays, or slight anomalies that depart from the fixed values of some universal constants in physical laws. Such ideas have been alarming to some people. Last year, The New York Times ran an opinion piece, a cri de coeur asking scientists not to carry out such physical experiments. What would happen if we find out we really are just computer simulations? Wouldn’t societies and humanity itself lose all sense of purpose and collapse? Wouldn’t the experimenters – our God or gods – just pull the plug and wipe us out since they might decide there was no point to continue with the simulation experiment? I find the egoism of thinking that if there were simulators out there, they came up with us Lisa Randall Many scientists and philosophers think such concerns are overblown. Just because some experiments may reproduce EEG responses doesn’t mean the clumps of brain cells could be conscious. And how would scientists, or anyone else, know if they were? In an interview with Nature , the premier research publication journal, Anil Seth, a prominent cognitive neuroscientist at the University of Sussex, says scientists and philosophers don’t even have an agreed upon theory or definition of consciousness, so it’s misleading to talk about assembled brain cells becoming “conscious”. “Confidence largely depends on what theory we believe in,” he said. “It’s a circularity.” The late Hilary Putnam, one of the great contemporary philosophers, once advanced an elegant argument stating we can’t be “brains in a vat” because if we were, we would not know what being “a brain in a vat” means in our language. It must be noted that unlike the simulation hypothesis, brain organoids have many practical uses, such as testing drugs for neurodegenerative diseases. Lisa Randall, a theoretical physicist at Harvard University, has said it’s puzzling so many serious scholars are taking up the simulation hypothesis, whether for or against. “I find the egoism of thinking that if there were simulators out there, they came up with us,” she said. “The self-centredness to this whole thing is kind of hilarious.” Randall might be on to something. For thousands of years, people have believed that of all the things that Allah, Yahweh, Elohim or whatever you want to call the great creator, could have created, he/she/it/they chose to create us. That’s kind of ridiculous. Many of us can no longer believe in the Bible or the Koran. But our religious impulse is still there. An all-powerful simulator is just another word for creator. The most speculative areas of contemporary science, empirically untested or untestable, are a back door for religious urges, disguised as hypotheses, to slip in.