Is the cat both alive and dead at the same time until we observe it?
Thought experiments have been an essential tool for many of history’s greatest minds. It is when we tackle a situation with our imagination alone.
Science, philosophy, the self and every other field of study has its own share of the most fascinating thought experiments.
It makes us think in ways that go against our intuition. Helps us analyze concepts that we usually take for granted. It wouldn’t be inaccurate to say that every great idea may have begun in someone’s mind, as a thought.
The ability to imagine realities that will probably never exist is a unique feature of the human mind. Most thought experiments have extremely unlikely set-ups. Finding loop holes in such cases is easy but it defeats the purpose. They are designed to explore deeper issues and their implications.
But it doesn’t only help answer the questions we have. It can also question the answers we give.
In the 1920’s, quantum mechanics was becoming widely accepted. It’s core concepts were rooted in uncertainty and probabilities.
The Copenhagen interpretation was a set of ideas developed by Neils Bohr and Werner Heisenberg in relation to these principles.
It stated that a particle exists in all possible states at once. It is only when we make a measurement of the particle, it collapses into the state it was observed in. So there is no meaning to its properties until measurement. The act of measurement determines its properties.
Erwin Schrodinger set up his now famous thought experiment as a reaction against what he thought was a flawed interpretation.
Imagine a cat in a box, with a vial of poison, a bit of radioactive substance and a Geiger counter to detect radiation. In the course of an hour, if one of the atoms decay, the poison will be released, killing the cat. But there is equal probability that there will be no decay.
According to the Copenhagen interpretation, due to the instability of the particle which exists in all possible states until measurement, the cat is both alive and dead at the same time. Only when we open the box and look, we determine its state.
The point of the thought experiment was to show how absurd this idea was. It questions what counts as an observation. Couldn’t the cat be an observer? The Geiger counter? It also questioned when a particle stops being in a superposition of all states and snaps into one.
Needless to say, this is an oversimplified explanation. But the objective of the thought experiment is clear enough. It poked at the idea that the state of the particle is driven by a conscious observer. Which isn’t the case. By linking a microscopic particle to a macroscopic object like a cat, he tried to show the unusual implications of the Copenhagen Interpretation.
Schrodinger’s cat remains a popular thought experiment. And quantum mechanics remains stranger than ever.
Neils Bohr put it nicely when he said, “Everything real is made up of things that cannot be considered real.”
Mary the colour blind neuroscientist
According to quantum mechanics, at the smallest scales, some facts cannot be known. But that doesn’t mean our daily lives are ruled by uncertainty. Or is it?
We know a lot about human experiences. Every sensation can be traced to neurons firing in your brain. Which is a physical property.
Does that mean consciousness is also physical in nature? Is it something we can map out neatly using our brains or is it always going to be out of reach?
Picture Mary, a brilliant neuroscientist. For some reason she is forced to live her life in a black and white room. She specialises in neurophysiology of vision. She possesses knowledge of exactly everything there is to know about colour. From its wavelengths to what happens when light enters our eye and the following activity in our brains. But she has never seen colour. When she leaves the room and sees our colourful world, does she learn anything new?
The discussion has been going on since the thought experiment was proposed in 1982. What you think happens when she sees colour for the first time tells you which side of the consciousness argument you land on.
If you feel that she does learn something new, then you’re in agreement with Frank Jackson, who came up with Mary. He argued in his paper that all knowledge is not physical in nature. That there must be something to her subjective experience that cannot be explained by anything physical.
Arguments against the thought experiment are varied. Some say that she doesn’t learn anything new. If she already had all physical facts of colour vision, she would be able to intuitively understand what different colours feel like.
Another key argument says, even the ‘new’ experience she’s having when seeing colour can be traced to physical activity in the brain. So she doesn’t gain new knowledge but a refinement of her existing knowledge.
It really comes down to this, how can we explain our experience?
A stomach ache can be perfectly described by what goes on in your body and brain. But have you ever been able to describe what that pain feels like?
This is called the explanatory gap problem. It is a limit to our ability to explain things from a physical point of view. Emotions have a physical origin in our brain but we are still unable to explain how it causes us to experience rich feelings.
Consciousness is tricky and is likely to remain unsolved for sometime. It has been discussed over the ages. Advances in neuroscience, psychology and philosophy may close the gap. Only time will tell.
But until then, you can be the authority. How you feel when you read these words, is it just a chemical reaction or is it something more than that?
The experience machine.
Before we start to understand what our conscious experience means, we could ask if any of it is even real.
There is a lot of talk of us living in a simulation. This idea isn’t new though. Rene Descartes, French mathematician and philosopher proposed a thought experiment in 1641 involving a demon tricking you into believing that your life is real when it actually isn’t.
But let’s say we aren’t in a simulation or being controlled by a demon. Assume everything is real but you were given the choice to be part of a simulation.
Robert Nozick had described the thought experiment in 1971. Imagine a machine that could simulate any kind of experience you want. You wouldn’t be able to tell the difference between reality and the machine. You could have all the happy experiences you wanted for as long as you wish.
Would you plug in? And if you didn’t, what would be your reasons not to?
The thought experiment was an argument against hedonism. A philosophy that says maximising pleasure is the primary goal for humans. Do what makes you happy.
A reason not to plug in to the machine would be that people want a real life with all its ups and downs rather than a simulated reality, even if it was only pleasure.
Most people choose real life over the simulation. The thought experiment is convincing. Maybe life really isn’t all about pleasure. But there may still be people who choose the experience machine. And they aren’t wrong. Because we have not established what right is yet.
It tries to analyse a very troubling question. What gives your life meaning? What would be a life well lived according to you? Lots of laughter, a full stomach and being remembered as a good person, or a legacy that lasts many lifetimes even if it was without any happiness.
It’s a tough question. One that will never have a definite answer. Times will change and the answers will change. But the question will stay the same.
And that is what thought experiments are for. To help you think about which side you stand on. To see the strengths and weaknesses of your argument. To confront ideas, explore our minds and understand what it’s all about.
It only takes a bit of imagination. If done right it could help lead to real breakthroughs.
So the next time you’re in a crisis, do a thought experiment and see where your imagination takes you.
All you have to do is think!