T H O U G H T E X P E R I M E N T S
“Somewhere around the place I've got an unfinished short story about Schrodinger's Dog; it was mostly moaning about all the attention the cat was getting”
TERRY PRATCHETT
TERRY PRATCHETT
Both science and magic harness the limitless potential of the imagination. In science they term their breathtaking leaps of imagination 'thought experiments' - there's a list of some of the more famous examples at the foot of the page. (It's ironic that it takes scientists, not artists, to prove that imagination is not insubstantial or illusory; but physical reality in an infinitely compact, malleable and transportable format.)
Here's a challenge. Show me a thought. No, that's an event, that's the result of a thought. Show me a thought. No, notes, books, DVDs those are methods of recording a thought. Show me a thought. No, those are auditory vibrations, that's just a way of transmitting a thought. Show me a thought. No, no, those are just neurotransmitters firing off, show me a thought. And so it goes.
Thought - its safe, cost-effective, and doesn't harm the environment - I don't know why we don't use it more often.
Einstein was known for his thought experiments. His example provides a master class in the productive use of this incredible mental facility which is shared by us all. There's a tendency among the lay population to believe that modern science needs massive resources (CERN's Large Hadron Collider cost £6.19bn at last count) yet Einstein's most potent tool was imaginative visualisation - it didn't cost him a red cent to arrive at E=MC2
Of course you don't expect to come up with a Theory of Relativity every time you close your eyes and have a quick think; I am merely underscoring (for my benefit as much as anyone's - we are all sleepwalkers) that this incredible and magical resource is available to everyone. Imagination does not not have to be 'make believe' it can be very much 'make real'. My advice to would be magicians is to learn to your imagination like a scientist; don't feel inhibited if you don't have the financial resources, if the proposed experiment/rite is functionally impossible, defies known laws, or moral codes. Success, failure or confusion...it all happens in your head, so what the hey!
Possibly the most well known, and strangely glamorous, thought experiment of our times is known as 'Schrödinger's Cat'. This illustrates quantum indeterminacy through the manipulation of a perfectly sealed environment, a tiny quantity of radioactive substance and a very, very paranoid cat. The conclusions it draws and the questions it poses are pivotal to quantum mechanics (and, importantly, no cats were harmed in the making of this experiment).
But my particular favourite thought experiment is called the 'brain in a vat'. It is typical of its kind; violating, as it does, all known scientific laws and ethics. It has been profoundly influential and its concept permeates cognitive science, philosophy and popular culture.
It is also very, very spooky.
The experiment asks you to imagine a mad scientist has taken your brain from your body and placed it in a vat of some kind of life sustaining fluid. Electrodes have been connected to your brain, and these are connected to a computer that generates images and sensations. Since all your information about the world is filtered through the brain, this computer would have the ability to simulate your everyday experience. If this were indeed possible, how could you ever truly prove that the world around you was real, and not just a simulation generated by a computer?
If you’re thinking this all sounds a bit like 'The Matrix', you’re right. That film, along with several other sci-fi stories and movies, was heavily influenced by the brain in a vat thought experiment. At its heart, the exercise asks you to question the nature of experience, and to consider what it really means to be human.
The idea for the experiment, which was popularized by Hilary Putnam, dates all the way back to the 17th century philosopher Rene Descartes. In his 'Meditations on the First Philosophy', Descartes questioned whether he could ever truly prove that all his sensations were really his own, and not just an illusion caused by an 'evil daemon'. Descartes accounted for this problem with his classic maxim 'cogito ergo sum' (I think therefore I am).
Unfortunately, the brain in a vat experiment complicates this argument as a brain connected to electrodes could still think. The most important question posed, and which bridges these arguments, is what do we mean by 'am'?
The 'brain in a vat' experiment has been widely discussed among philosophers, and many objections have been raised over its premise, but there is still no good rebuttal to its central question: how do you ever truly know what is real?
Here's a challenge. Show me a thought. No, that's an event, that's the result of a thought. Show me a thought. No, notes, books, DVDs those are methods of recording a thought. Show me a thought. No, those are auditory vibrations, that's just a way of transmitting a thought. Show me a thought. No, no, those are just neurotransmitters firing off, show me a thought. And so it goes.
Thought - its safe, cost-effective, and doesn't harm the environment - I don't know why we don't use it more often.
Einstein was known for his thought experiments. His example provides a master class in the productive use of this incredible mental facility which is shared by us all. There's a tendency among the lay population to believe that modern science needs massive resources (CERN's Large Hadron Collider cost £6.19bn at last count) yet Einstein's most potent tool was imaginative visualisation - it didn't cost him a red cent to arrive at E=MC2
Of course you don't expect to come up with a Theory of Relativity every time you close your eyes and have a quick think; I am merely underscoring (for my benefit as much as anyone's - we are all sleepwalkers) that this incredible and magical resource is available to everyone. Imagination does not not have to be 'make believe' it can be very much 'make real'. My advice to would be magicians is to learn to your imagination like a scientist; don't feel inhibited if you don't have the financial resources, if the proposed experiment/rite is functionally impossible, defies known laws, or moral codes. Success, failure or confusion...it all happens in your head, so what the hey!
Possibly the most well known, and strangely glamorous, thought experiment of our times is known as 'Schrödinger's Cat'. This illustrates quantum indeterminacy through the manipulation of a perfectly sealed environment, a tiny quantity of radioactive substance and a very, very paranoid cat. The conclusions it draws and the questions it poses are pivotal to quantum mechanics (and, importantly, no cats were harmed in the making of this experiment).
But my particular favourite thought experiment is called the 'brain in a vat'. It is typical of its kind; violating, as it does, all known scientific laws and ethics. It has been profoundly influential and its concept permeates cognitive science, philosophy and popular culture.
It is also very, very spooky.
The experiment asks you to imagine a mad scientist has taken your brain from your body and placed it in a vat of some kind of life sustaining fluid. Electrodes have been connected to your brain, and these are connected to a computer that generates images and sensations. Since all your information about the world is filtered through the brain, this computer would have the ability to simulate your everyday experience. If this were indeed possible, how could you ever truly prove that the world around you was real, and not just a simulation generated by a computer?
If you’re thinking this all sounds a bit like 'The Matrix', you’re right. That film, along with several other sci-fi stories and movies, was heavily influenced by the brain in a vat thought experiment. At its heart, the exercise asks you to question the nature of experience, and to consider what it really means to be human.
The idea for the experiment, which was popularized by Hilary Putnam, dates all the way back to the 17th century philosopher Rene Descartes. In his 'Meditations on the First Philosophy', Descartes questioned whether he could ever truly prove that all his sensations were really his own, and not just an illusion caused by an 'evil daemon'. Descartes accounted for this problem with his classic maxim 'cogito ergo sum' (I think therefore I am).
Unfortunately, the brain in a vat experiment complicates this argument as a brain connected to electrodes could still think. The most important question posed, and which bridges these arguments, is what do we mean by 'am'?
The 'brain in a vat' experiment has been widely discussed among philosophers, and many objections have been raised over its premise, but there is still no good rebuttal to its central question: how do you ever truly know what is real?
O T H E R W E L L K N O W N T H O U G H T E X P E R I M E N T S
- Bell's spaceship paradox (special relativity)
- Brownian ratchet (Richard Feynman's "perpetual motion" machine that does not violate the second law and does no work at thermal equilibrium)
- Bucket argument – argues that space is absolute, not relational
- Double-slit experiment (quantum mechanics)
- Elitzur–Vaidman bomb-tester (quantum mechanics)
- Einstein's box
- EPR paradox (quantum mechanics) (forms of this have actually been performed)
- Feynman sprinkler (classical mechanics)
- Galileo's ship (classical relativity principle) 1632
- Galileo's Leaning Tower of Pisa experiment (rebuttal of Aristotelian Gravity)
- GHZ experiment (quantum mechanics)
- Heisenberg's microscope (quantum mechanics)
- Kepler's Dream (change of point of view as support for the Copernican hypothesis)
- Ladder paradox (special relativity)
- Laplace's demon
- Maxwell's demon (thermodynamics) 1871
- Monkey and the Hunter, The (gravitation)
- Moving magnet and conductor problem
- Newton's cannonball (Newton's laws of motion)
- Popper's experiment (quantum mechanics)
- Quantum pseudo telepathy (quantum mechanics)
- Quantum suicide (quantum mechanics)
- Schrödinger's cat (quantum mechanics)
- Sticky bead argument (general relativity)
- Renninger negative-result experiment (quantum mechanics)
- Twin paradox (special relativity)
- Wheeler's delayed choice experiment (quantum mechanics)
- Wigner's friend (quantum mechanics)