Thought Experiments

the beauty of a thought experiment. I think. So now, we've discussed individual thought experiments on the show many times before, but I think today we're gonna try to look at the idea of a thought experiment on the show. In the past, we've talked about specific thought experiments. We've talked about Stranger's Cat, We've talked about the Infinity Hotel, the Ship of Theseus. Other times it comes up kind of informally. We might say that a particular paper we're talking about

is more kin to a thought experiment. And I know that I've I've talked before about how I think of certain short stories as being more thought experiments than you know, true narratives. I think of Library of Babbel, Library of Babble other works of a lot of the short stories of Jor Haluis Borges, as well as a number of the short stories of Philip K. Dick. They're a number of those where you know, it's not really important who's

doing what exactly. You know you're not you're not really invested in a story per se, but the story is there to make you think, to turn some sort of weird idea on its head, the concept driven more than character driven exactly. Now, I have to say that one of my favorite comical treatments of thought experiments is the humorous essay Shreddnger's Cat by Steve Martin, collected in his book Pure Drivel. And there's a wonderful audio book of this as well, because Steve Martin himself is reading it.

Always great when you can get one read by the author. Yeah. Now, Martin begins this particular essay by presenting the Streusenger's Cat thought experiment just pretty much as it is, and from there he proceeds through an increasingly ridiculous mix of thought experiments that he's made up in self, such as uh vitkin Stein's banana, Elvis's charcoal briquette, Chef boy r ds bungee cord, soakagaway is rain bonnet, Apollo's non apple, non strutal,

Jim Dandy's bucket of goo, and the Finnman dilemma. Since it's one of the shorter ones, I'd like to read Steve Martin's description of the thought experiment. Elvis's charcoal briquette. A barbecue is cooking wieners in an air tight space. As the charcoal consumes the oxygen, the integrity of the briquette is weakened. An observer riding a roller coaster will become hungry for wieners, but will be thrown from the car when he stands up and cries, Elvis, get me

a hot dog. Yeah, that's got the right mouth field. I mean, it's it's absurd, it's ridiculous and uh, but it's effective as comedy because it does have that feel of a thought of experiment. And and many of them are exactly this sort of absurd little logic problem a more physical scenario, but it's utilized not for laughs but to explore some sort of generally a complex topic. I thought this was going to be the seven thought experiments You can't say on TV that it does make me

wonder what the most risk a thought experiments are. Oh, there are actually quite a few. Yeah all right, well let's we'll save that for the midnight show. So let's let's talk about thought experiments just definition wise, Like, what is the thought experiment? Well, guess, first, you could consult the idea of an experiment. An experiment is basically a test, like you have a condition and you you instantiate the

condition and you see what happens. Yeah. But on the other hand, it's worth pointing out that to merely think about an experiment is not a thought experiment. So if you if you say, for instance, think about the nine social psychology Stanford prison experiment, that's not a thought experiment. Um why not? Well, because you are You're thinking about an actual experiment that has been carried out. I mean this is kind of obvious, right, but but still it

it it's worth going through. Now if you if you think about an experiment you might conduct, say to see if movie goers who eat twizzlers are more likely to do to enjoy sci fi films and those who eat red vines. Well, that's not a thought experiment either. That's something you could conceivably do. That's like imagining an experiment you could carry out, but thinking about the experiment doesn't

really reveal anything right now. Very often the experiment in a thought experiment is exactly not the sort of thing that could be carried out in real life for a number of reasons. Maybe it's catastrophically dangerous or in or involves, you know, in encountering some feature of the universe that

is not readily it's accessible, that sort of thing. Very often thought experiments, as they apply to science, involved the the removal of things that you couldn't actually remove as variables, so like imagine a frictionless plane, or involve something that just simply does not exist, like a train go near the speed of light. We do not do not have such a thing. We're probably not gonna have such a thing anytime soon, but it's useful in the thought experiment.

And then on top of that, they frequently are narrative in nature. There's a sequence to things. In a way, they're they're almost like a joke in many senses. You know, it feels like the set up for a joke. It

feels like there's going to be a punch line. Um and I also I wondered to what extent like really successful and quote unquote successful thought experiments, like ones that really resonate culturally if if there is a sense of counterintuitive elements to the narrative, I wonder if there's something about that as well. Well. Yeah, thought experiments are an

interesting thing. So like a good thought experiment, what it should do is reveal something that is true simply by making up a story in your mind and working through the conclusions that would result from it. Now, often there are a lot of coincidental details of this story that do not matter. Uh, they don't have any effect on what this thought experiment reveals, if it reveals anything, and yet they can be enormously predictive of whether or not this is like a popular meme or not how well

it spreads. Like cats, an example, like if it were a dog, it would probably still resonate, but in a slightly different way. But if it were just a lizard or a slug, yes, people would be far less compelled by the idea of Shreddinger's bug, but they would be far more upset by the idea of Shreddinger's child or something. So like if it's a cat, that's the bull's eye,

that's right in the red zone. It's like interesting enough to be killing a cat that people are on board to to remember to pay attention, but it's not so troubling that you're turned off and you don't want to listen, right, And and then also the cat kind of makes it more palpable. Like if it was Shreddinger's um, let's say, basilisk, that would it would instantly sound a little more threatening somehow, How about Shreddinger's apparently conscious AI Yes, or uh, that's

the that's next level. Yeah, that's that's pretty good. Now. Another important aspect of thought experiments is that it's something that should generally be visualized in the mind as this, as the thought experiment has rolled out, you you're picturing it. Uh. It's in doing this it makes a concept more digestible, or it explains a you know, fundamental paradox, etcetera. And uh, and and and this again. It has a lot in common with jokes, It has a lot in common with riddles,

and they just sort of the basic structure. But it's not necessarily bringing you to uh, it's not bringing you a punch line. It's not necessarily a correct answer at the end, but there is hopefully a deeper understanding of a concept via the thought experiment. Now that being said, a thought experiment is also not a pristine, blameless thing or something set in stone. So others may take issue with the thought experiment or just completely knock it down.

They may roll out their own thought experiment that attempts to put your thought experiment to shame and uh. And there may be you know, additional interations off and we've certainly explored that on the show before with things such as the ship of Theseus. And then finally, one of the really cool things about thought experiments is that it's ideally this this chance to learn about reality, learn more

about reality by simply thinking about it. And that would, on the surface of things, seem rather odd, right, because it would be an exception to the empirical nature of how we learn about the world by seeing it, by touching it, by feeling it, by poking it, by dissecting it and running, um, you know, more or less physical experiments upon it. But to simply think about something and the idea that that will reveal something that we had not seen before or it was not clear to us beforehand. Uh.

That that's rather curious, isn't it. Well, yeah, I mean a thought experiment is a type of logic, which means it it lacks the empirical data gathering part of learning about the world, so all it can do is draw conclusions from what is already known or assumed, though there have been plenty of cases where in fact, in the history of science, interesting stuff has come to be known without anybody going out and measuring anything new, but just by applying what was already known in a logical way

to arrive at a new conclusion. We'll talk about examples of that in a minute, all right, So I want to mention one quick example. Uh, it's not so quick in the original text, but Lucretius, who lived nine BC to b C, wrote on the Nature of Things suntura. Yeah, and uh, and he has a fun little thought experiment he rolls out. So, um, Lucretius argues that space is is infinite and what you say it isn't? Well, fine, then let's march a soldier to the edge of the

finite universe and have him throw a spear at the edge. Wait, what is the soldier's name? This is crucial? Oh, I see I skipped that part. What is the soldier's name? No, I don't know. It's not. We don't need to know his name. It's just a soldier. Yeah we could, we could call him hat I guess. But um, his original write up of it is a bit longer. This boiled down. So, yeah, march the soldier up to the edge of the universe, having throw a spear at the edge. Well, one of

two things is going to happen, he says. Well, if it flies through, then there is something beyond and your barrier is nonsense. So the universe is not actually bounded there, right, because you just threw a spear beyond the edge. Now, if the spear bounces off the barrier, well then the wall itself is proof of something beyond your your your spear just bounced off of something. What is that something? A wall is a thing? Yeah, so it In looking at this, you can see that it illustrates a conceived

version of reality and lays out an experiment. And of course it also illustrates one of the other features of thought. Experiments you can pick at them. So Lucretius may have presented this, as you know, as a real sentence stopping comment on the nature of the universe at the time.

But certainly if you if you think back of even discussions that we've had on the show about infinities and different type to the infinities, and and some of the arguments for you know, for exactly how I finite universe would work, then you can see that his argument doesn't quite hold up to modern cosmology well as you've presented it here. This is actually a great example of how thought experiments can seem brilliant but actually produce flawed conclusions

because they contain drum roll hidden assumptions. Here, I would say one fatal hidden assumption is that Lucretius takes on board without considering the geometry of a finite universe. Now again, I'm certainly not going to go and argue that space is finite. That's not my goal here, But my I would say there are ways in which space could be finite that Lucretius is overlooking with this example, because there

are different ways you could imagine a finite universe. One is a sort of closed three D space with exterior walls like the inside of a box. And this is sort of what Lucretius seems to have in mind here, and of course it does seem somewhat absurd. How could the universe be like that? It seems like it probably couldn't be. But what if the universe is simultaneously finite

and without boundaries, like the length dimension of a mobius strip? Robert, have you ever made a mobius strip, like in geometry and school? Yeah, so you just take like one length of a piece of paper and then give it a half turn and then tape its ends together, and what you have created is a piece of paper that has one continuous side. You can start drawing a line and

it goes on the entire thing. So for instance, and this this version, the soldier throws the spear and impales himself in the back exactly as long as the spear goes long enough. Yeah. So the idea, or it could be another analogy here, could be that the geometry of the three D universe is sort of like the two D geometry of the surface of a sphere. It's not infinite. The surface area of a sphere is finite. There is a limit to it, but it has no boundaries. You

never reached the edge. So yeah, that's soldier. Let's let's call him Tim tim throws the spear and it hits him in the butt. Yeah. Yeah. This also reminds, you know, the idea of saying, well, hey, my soldier throws a spear at the edge of the universe and it keeps going, then your your argument is nonsense. It also kind of sounds like, oh, we had a really cold weather today. I guess there's no global warming. I guess there's no climate change. Using a far simpler model than the than

the complexities of reality, try and make your argument. Well, yeah, but it does also. I mean, I would say that this is a good argument against a certain type of idea of the bounded universe, because if if the universe were actually finite in that it had walls on the outside of it, at any place you approached the wall,

you could test that condition, right. So I would say that highlighting absurdity is in a single test case of the idea of a universe with walls on the outside of it, that I think that's a valid way to criticize the concept. Now, I do have to say at the same time, Lucretius is a little thought experiment here, even to modern readers it it still does something when you think about it like it does force you to think about the uh these ideas of the finite and

the infinite. Uh So, just as like a simple thought experiment is kind of a logic puzzle, it still carries its own weight. Now, they're absolutely have been thought experiments that have been extremely useful and powerful in the history of the advancement of science, that have not just like made a clever seeming point, but have actually pushed science forward. And these happen a lot of time in the history of physics because physics experiments work best when you can

tightly limit the variables. But in reality, it is very hard to tightly limit the variables on pure physics experiments. Uh. There there's often just a lot of like more more friction, more resistance, more whatever than you actually want. But here's an example. Let's say you go up on top of the Washington Monument and you drop to objects side by side. They're the same shape, but one is heavier than the other.

Let's say one is a plastic DVD of Flubber and the other is the new Criterion edition of RoboCop two, which has a jewel case made out of lead. So which one hits the ground first? Well, ideally they're both going to hit the ground at the same time, right, And you know that because we live in a post

Galileo age, the post Copernican post Galileo age. But this might have been kind of a shock to you if you lived in say, ancient Rome, or in medieval Europe, where it might well have been assumed that the heavier object would hit the ground first because heavier objects fall faster. For hundreds of years, the conventional wisdom was along these lines.

It followed our intuitions, like, it makes intuitive sense that a heavier object falls faster because let's say it's harder to push a heavier object up a hill, right, So it would seem that a heavier object should fall to the ground through the air faster than a lighter object. This was the dominant strain of thinking also in in the sphere of scholars who revered the physics of Aristotle.

Aristotle wrote in in his work on Physics, that objects have a natural motion, They have a nature, and they have motions specific to their nature, and that part of that nature is mass. And so heavier objects fall to the ground faster than lighter objects. Now, Galileo GALILEI was reported by some biographers to have actually performed an experiment of this kind by like dropping cannonballs of different weights

from a tower. But whether or not this story is true about the physical experiment, Galileo definitely showed that you don't even need an experiment to prove that there is something wrong with the Aristotelian view of falling bodies. He could show it was wrong just by dreaming up a scenario in his head. As and as with many of the great intellectual smackdowns in history, Galileo didn't just explain

his position. He wrote a fictional Socratic style dialogue, complete with a act jawed fool to represent the opinion he was attacking. And that fool is named Simplicio. That's pretty good. Then he's also he's got a smart guy named Salviati to represent his own point of view. And this was in dialogues concerning two new sciences in sight. So first Salviati and Simplicio argue about experiments concerning cannonballs and bird

shot and stuff. And Simplicio is not moved from the Aristotelian position that objects fall through a medium with a speed proportional to their mass. And so I've tried to reconstruct the next moment in the dialogue, but sort of rewritten in more modern English and simplified to the main points. Robert, would you like to do a reading with me? Sure? What kind of accents are we going for here? Robert,

you're gonna be the smart guy. How about you give me a combination of like Gandalf wizard Saruman pronouncing from from the top of the Tower of Knowledge, combined with like Sam Elliott Wisel cowboy. All right, I'll give that a goin Now, look here, we don't even need to do any experiments to prove that Aristotle is wrong and a heavier body does not fall faster than a lighter one. Let's take Aristotle's principles as granted for a minute. What

are those principles. Well, body falling in a fixed medium like air has a fixed velocity, and that's determined by its nature. And you can increase this speed unless you add momentum. And you can't decrease this speed unless you offer some resistance to slow it down. It's all there and its nature. It's a fixed velocity. Great, So imagine two objects with different natural speeds, maybe a pebble which falls very slowly, and a great millstone which falls very fast.

Now time together, the fallen millstone will be slowed down by being tied to the pebble, which is forced by its nature to fall slower. Right right, You are, according to Aristotle, that pebble is going to slow down the bigger rock because it falls slower. Go okay, So by by tying the two stones together, the slower fall on pebble should reduce the speed at which the millstone falls, making its speed less than it would have been alone. But at the same time, when you tie them together,

their combined masses greater than the millstone alone. So shouldn't they together fall even faster than either one individually? From your principles of motion, we are forced to conclude that by tying the two stones together, the falling speed of the millstone is both increased and decreased. Well, dang it, I am stumped, all right, So that that's that's pretty fun because it basically illustrates how he's created kind of

like a little political cartoon right here, right right. And I also absolutely love that he makes the representative of Aristotle, who was during the seventeenth century widely considered like the smartest guy of all time. He names him Simplicito, which is like if somebody today wrote a dialogue trying to refute Einstein's relati civity and had the character representing Einstein's

point of view named like cletaus t dip Wad. But anyway, Karl Popper apparently wrote of this thought experiment quote one of the most important imaginary experiments in the history of natural philosophy and one of the simplest and most ingenious arguments in the history of rational thought about our universe. And as far as like imagining physical scenarios goes, I think this is the equivalent of a reductio ad absurd um argument. So reduction reductio ad absurd um is one

of the most powerful logical tools we have. It's when you combine premises that somebody holds to be true and you demonstrate that when they're taken together, they force you to conclude something absurd that cannot possibly be true, which means at least one of the premises, even though you believe them, actually cannot be right. And so here Galileo is basically using two premises. One is that the the idea that objects of different mass have different natural speeds

at which they fall. And the other is that you can add the mass of two objects together to create a greater combined mass. And so he constructs a scenario when it's actually not implausible at all to show that, when taken together, these two premises implied something absurd and self contradictory. So one of the premises has got to

be wrong. And since we accept the basic arithmetic of mass that you can add the mass of two objects together to create a greater combined mass, it showed that the idea of a fixed falling speed determined by an object's mass had to be wrong. So I would say this is absolutely a case where a thought experiment actually did reveal something useful about reality. Though of course it's it's helpful as well that you could go out and

test this with physical objects later. You you know, you do so, even if there's some hidden assumption that's guming up the conclusions you're drawing from this thought experiment, you could do physical experiments that would sort you out later. All right, Well, on that note, let's take a break, and when we come back, we'll explore some more examples of thought experiments before we discuss a little bit of a bit more about what exactly that they are and

how we might categorize them. Thank alright, we're back. So Joe is a time for Jim Dandy's bucket of goose. No, let's do Newton's bag of cheese. Sounds good? Okay? So Galileo's rocks obviously are not the only famous imaginary falling objects to provoke advances in physics. Uh The seventeenth and eighteenth century English poly math Isaac Newton was also responsible for many famous thought experiments that illustrated his revolutionary ideas.

Probably the most famous and enduring is what I'm gonna call ballistic mountain. So back in Newton's day and there was a lot of confusion about different types of motion and what explained the motion of objects in the heavens. A good example would be, let's say you drop a wool sack full of goat cheese from a tower. Which direction does it travel? Goes straight down right? You wouldn't

want to be standing under that goat cheese. And at the same time, scholars recognize that the Earth was spherical or roughly spherical, as had been proved for many hundreds of years, and it almost seemed as if objects were being pulled straight down towards the center of the Earth, and the Earth seemed to pull all objects toward it at a constant rate, as Galileo had showed, regardless of the mass of that object. And you see this all

the time, even if you throw an object horizontally. Let's say you are hurling a wool sack full of goat cheese at your enemy, the Royal astronomer John Flamsteed. If Flamsteed is too far away when you throw the sack, obviously the gravity is going to pull the sack down to the Earth before it hits him. Gravity always pulls down. But then contrast that with if you look up at the heavens at night, you will observe that the motion of the planet seems to be governed by another force entirely.

Instead of falling straight into the Sun or into the Earth, the planet seemed to travel through the heaven in smooth, roughly circular elliptical orbits, just as the Moon seems to travel in a smooth elliptical track around the Earth. So how could the motion seen in the heavens be so different from the motion scene on Earth? Like was there a divine hand guiding how the planets traveled through the void.

So Newton proposed a thought experiment in his Principia, and it went roughly like this, Robert, imagine, we're gonna get up on top of the tallest mountain on Earth, the Gigantic Monster Mountain. Maybe it's on the North Pole, all right. I guess it wouldn't because there's no land there. But maybe it could be the Mountain of Purgatory from from Dante's Divine Comedy. For all of Isaac newton sins, of which there were many, because he was a jerk, so

work off those piece. So he climbs up to the top of the Mountain of Purgatory, oh, which I guess is earthly paradise, right. But but he gets up there and he brings a cannon with him. Oh that's that's. That's already. I feel like it's probably breaking some rules, but okay, yes, and it's in a salt on the heavens already. But it's an assault on the heavens in more ways than one, more way than one, more ways

than one. I never know how to pluralize that correctly anyway, So let's say you got the cannon up at the top of the mountain. You shoot a cannon ball out parallel to the ground at a hundred kilometers per hour. What happens, Well, it travels in the familiar arc that any anybody who has used a firearm like that will recognize. So it goes horizontally at a hundred kilometers per hour while simultaneously falling towards the ground at the normal acceleration,

and eventually it hits the ground with a thud. But let's say you pack more gunpowder into the cannon and shoot the ball out of the barrel faster, say two hundred kilometers per hour. What happens, Well, it makes an arc again, but the arc is a slightly different shape. It falls to the ground at the same rate as before, but this time it travels a lot farther horizontally before

it hits the ground. Now, imagine you just keep packing more and more power into the cannon, so that the ball goes farther every time before it hits the ground. The rate at which the cannonball falls is going to always stay the same, but the horizontal speed and the horizontal distance covered keeps increasing. And then combine this with the idea that the Earth is a sphere, which they

knew at the time of of Newton. This means that eventually you will shoot the cannonball at a speed where it travels so fast that it's falling arc is greater than the curve of the Earth. So it flies and it falls, but it never hits the ground. It travels around the Earth in a continuous circle. So the cannonball is still governed by the same two forces, gravity which wants to pull the cannonball towards the center of the Earth in inertia, which wants to keep the cannonball traveling

in a straight line. But they these forces combine to cause the ball to just keep flying around the Earth in a circle in space. And Newton had a very famous illustration of this that that sort of helped make his point, where he showed arcs of of cannon balls falling off and becoming longer and longer until they just became a circle. And now the crucial extrapolation is this is what planets due to the Sun and what the

Moon does to the Earth. So Newton had used nothing more than an imaginary scenario to demonstrate good reason for believing something shocking that the forces that govern the heavens and the forces that govern the movement of objects on the Earth like cannonballs or wool sacks full of cheese are exactly the same. This is the unification of terrestrial and celestial forces. And this this is a key principle in establishing the modern age of physics. And it's rather

brilliant too. And then he took something that was there was so so much more relatable in order to explain, you know, the movement of the spheres. Yeah, exactly. And of course this is a case where a thought experiment,

while revolutionary, was not enough to prove the case. Fortunately Newton had conducted ingenious real world experiments also, so in this case it was the use of a pendulum combined with astronomical observations to show that the Moon falls towards the Earth at about the same speed as objects dropped on Earth fall toward the ground, which is a funny thing to consider whether you're dropping a bag of cheese out of an airplane or watching the Moon fall toward

the Earth. They followed about the same rate, but the Moon's competing inertia and position of course keep it in orbit, and there are of course powerful implications that followed from Newton. These could be put to use in rocketry, like ultimately we had to figure out the delta V required to achieve lower thorbit and to escape Earth's orbit entirely if we wanted to say, send probes to other planets. Uh And and by the way, I didn't make up the

part about the sack of cheese. But Newton did actually have enemies. And just to tell one quick story, there was this astronomer named John Flamsteed. I mentioned him earlier, and Newton was pretty much a total jerk. Flamsteed was this English astronomer. He was the English Astronomer Royal during Newton's time, and he was working on catalog of objects in the heavens. And Newton wanted access to Flamsteed's catalog. Basically, he wanted data so he could use it to prove

his theories. But Flamesteed wasn't done putting it together yet, believing it wasn't ready for publication. So Newton constantly harassed and bullied him to get this information. Eventually threw his weight around with the English Royalty to get Flamsteed's catalog published early before it was ready, which Flamsteed did not

like at all. There's also a story that Newton, as the president of the Royal Society, went to the Royal Observatory to inspect Flamsteed's equipment and they got into a fight, and Flamesteed wrote that quote Newton ran himself into a great heat and very indecent passion, and he used knavish talk and called me all the ill names puppy, etcetera that he could think of. So like Newton's out there like screaming and other scientists calling them puppies, just thinking

a real real ass of himself. Yeah, anyway, shows that even some of the smartest people ever can are not above you know, puppy calling. Well, I mean it makes sense. Wasn't new In a a more of a cat person? Didn't he uh oh for cats to move in and out of the chambers of his house. I didn't look up the usage history of that word, so I don't know exactly what it meant to call somebody a puppy and whatever year this was, but profanity scholars right in might a smart Yeah what does that mean? Did he

just literally mean like a young dog? I hope. So that's the that's that's a funny interpretation. Well it sounds like Navish talk either way totally. So what are the examples do you have for us? Well, just a few quicker ones in in physics, and of course one of my favorites is that people dreamed up the concept of a black hole as a mathematical thought experiment, long before any evidence of such a thing had ever been detected, Like we talked about this in our black Holes episode.

But around seventeen eighty three and seventeen eighty four, the English natural philosophers John Michelle and Henry Cavendish dared to ask a bizarre question. So they knew that light itself had a speed, and they were armed with Newton's insights about gravity, inertia, orbits, and escape velocity, So they asked, what if there were a star so massive with with such a great gravitational attraction that escape velocity for this

star was greater than the speed of light. In other words, a star so massive that even light could not escape it. And this was perhaps the earliest formulation of the concept of a black hole, which would later be developed by so many other important astrophysicist Karl Schwartz, Shield, Chander, Shaker, Oppenheimer and others. And and if you want more on that, we have a whole episode about it from earlier this year.

Oh yeah, we did a three parter on black holes. Uh. Then, of course, the thought experiments are huge in illustrating the concepts of relativity in the speed of light, Like Einstein is famous for influential thought experiments, But we shouldn't just focus on the ones that have been very influential in physics, because, of course, thought experiments are probably even more common in

philosophy than they are in physics, even more common. And I don't want to be insulting to philosophy because I value philosophy, but I would say even more common and less often useful. Uh, they can still be illuminating, but I think we need to realize that, especially in scenarios where we can't actually test the conclusions of a thought experiment in any kind of way, we should be careful

that thought experiments don't cloud are thinking more than they reveal. Well, don't encounter thought experiments to deal with things like morality, right, and ultimately, how do you measure those things? Yes? And the I feel like those kinds of thought experiments are especially prone to be confusing because they deal with the lucretious problem. We talked about bringing in unexamined assumptions that

are influencing our thinking without us realizing it. So I think we should mention just one example of a prominent, extremely controversial thought experiment in philosophy. There's been a mountain of debate on this one, so I know we're not going to be able to do it justice in the time we have, we'll try to give it the best quickest version we can. So this is John Searle's Chinese Room thought experiment. Robert, I know you must have encountered

this one before. Yeah, So the question is, we know we can program computers to mimic the intelligent behavior of humans, but would it ever be possible for a computer to truly understand something? Or can it only simulate understanding? And this has often taken as sort of an analog of the question of can machines be conscious? Right, And no, we've we've discussed this quite a bit on the show before.

Maybe not specifically this thought experiment I don't recall off hand, but just the idea that, yeah, if a robot may know what it is to stub one's toe, but does a robot really know what it's like to stub your toe? Like? Does it? It doesn't, doesn't? Does it have that experience? Does it have that knowledge? Can it? Can it sort of whole the information in its hands and squish it around. We know it can act like it understands what it means to feel pain, But does it really understand what

it means to feel pain? Uh? So? The American philosopher John Searle proposed a thought experiment to answer this question in the early nineteen eighties. I think it was first in the year nineteen eighty, and his work asked us to imagine the following scenario. You already to go there with me, okay, So imagine you are an English speaker that does not understand a single word of written Chinese, absolutely nothing. Then you are locked in a room with a slot in the wall, a pencil and paper, and

a giant book of instructions written in English. Every now and then someone from the outside slips a piece of paper through the slot in the wall, and it has a string of Chinese characters written on it. And then you look at this piece of paper and you consult your giant instruction manual, and the manual tells you, given certain Chinese character inputs coming through the wall, which Chinese characters to write on a piece of paper and put

back out through the slot in the wall. So you write down what the instructions tell you to write based on what has come in, and then you slip the output through the slot. Now, Carl says that in this scenario, with a sufficiently powerful instruction manual, the person in the room would be able to simulate being able to understand the Chinese language despite not actually understanding a single word of it. The person is just an operator. They're just

blindly copying symbols from a rule book. They don't understand what any of the symbols mean. So in the same way, Carl says that this gets extrapolated to any computer program that would supposedly pass quote pass the Turing tests, which we've discussed the turning test on the show before. But basically it means to be able to have a text based conversation with the human such that the human would believe that the machine they were chatting with was actually

human as well. Can you can you fool a human into thing king you're a human by talking to them through text, and Searle says, it doesn't matter how convincingly the computer simulates being able to have a conversation in any language. It's still like the non Chinese speaker in the Chinese room. It can't really understand what it's doing. It's only blindly following instructions that create an illusion of

understanding where true understanding is impossible. Now, there have been tons of responses to this scenario over the years, and I think we'll come back to this towards the end of the episode. But the idea is the thought experiment of imagining the person in the Chinese room leads you to new knowledge. It should lead you to the correct conclusion that it's impossible for a machine to understand something,

or at least a machine interpreting formal instructions. Robert, I, I could almost detect by the way you're furrowing your brow that this this one's filling you with venom. Well, the Chinese room, Yeah, um no, I mean I love it. I keep I keep wanting to say something kind of snarky about like just the human experience itself being you know, like the Chinese room where there's so much that we're

doing that that we're we're not really understanding. We're just responding to stimuli and giving back what the instruction manual says we should give back. But then I do have in a way articulated one of the main types of responses to it. Yeah, but that it said yeah, but that, in my opinion, like, this is the great thing about a solid thought experiment and is in that it it provokes conversation and subsequent sort of answers and critiques of

the thought experiments. Right, So I guess in a minute we are going to end up talking about sort of formal classification systems for types of thought experiments and considering how thought experiments might or might not be useful. But uh, there, I can see that there are multiple ways that one

could be useful. Immediately, one could be useful in the way it's intended, meaning it can prove what it sets out to prove, or it could also be inadvertently is full in that even if it fails to prove what it sets out to prove, it could make common misunderstandings clear, right, does that make sense? YEA like reveal ways in which people's thinking is going wrong on a particular subject. Like it's like saying, here is a scenario that illustrates a

way of thinking about this. And then even if if what it is presenting you with is incorrect, or has some problems, or doesn't fully match up to um scientific reality, or or just preconceived notions, then at least you have you've created the model. You have you have the model on the table, and other people can come along and say, well, you know, this is interesting, but what happens when we put a hat on this guy? What happens when there are two instruction manuals, what happens when you know the

ship of theseus also has a crew, etcetera. You know, all the various complications are little tweaks that can can change the model just a little bit. I think sometimes thought experiments, even if they fail at proving what they set out to roof, can be useful in the same way that introducing terminology to a discussion can be useful, just because, like if you put an image to something or put a name to something, that makes it easier

to understand what it is you're talking about. Alright, Well, on that note, let's take one more break and when we come back, we're gonna get more into this idea of what is the thought experiment and indeed, where does the term come from? Thank? Thank alright, we're back. So in looking at the history of thought experiments, you know where you able to find the oldest one on a

like a like a cave wall. Uh No. But I mean we kind of end up getting into a similar situation when we start trying to think about this, because certainly we know that thought experiments were employed by a pre Socratic philosopher, So this has been before the life of Socrates, before four seventy BC. And and thought experiments are things that were essentially thought experience, were popular throughout the Middle Ages, and of course came into their own

in the seventeenth century. In the centuries to follow. The term itself is often attributed to one Ernst Mock who lived at eight thirty eight through nineteen sixteen. He was an Austrian physicist and philosopher. And they point this out because he used the term, let's see, if I get this right, gadoncan experimente uh. But it seems though that like it was already in use by the time he used it, and it may have derived from the Danish uh Tunka experiment. And then it turns out that GEORGA.

Lichtenberg through seventeen ninety nine he discussed quote experiments with thoughts and ideas. So funny, like all of these are coming after the advent, you know, after Galileo, like Galileo and Newton, and people had already been using these, As we said, they weren't the first to use them, but they used them in really profoundly influential ways in real science. Yeah, So it's kind of like we're looking at three phases here.

There's the phase where people are actually calling it a thought experiment, there's the phase where people are using them to great effect, and ultimately, I think if we if you go back further in time, you know, get lost in the mists of of of earlier history. I think it's fair to say that thought experiments are generally a more refined idea of something that we just do as humans, and internal simulation of of observed empirical data and processes.

Trying to run an experiment in your mind given what you know, right, and you know, I can imagine this is kind of getting into the territory of our our other show Invention, which everyone can can learn about invention pod dot com. It's a podcast about inventions and where they come from. Subscribe now, subscribe now now, Uh, seriously, stop and go and subscribe. But but you know, you

can imagine with any of these inventions. This is even some of the ancient ones that we've talked about, Like there is a thought experiment level that is that is in play. But I don't think it's a great stretch to imagine some of these ancient inventors and inventive minds

essentially engaging and thought experiments. Oh well, yeah, I mean that's an interesting way of putting it that you have to sort of before you create a tool, you have to imagine what would happen if you use something of a certain shape in a certain way without having seen

something like that done before. Right. But then again, of course we go back to what we said earlier about how just envisioning an experiment you could carry out is not in and of itself a thought experiment, but it's still kind of the roots of the thought experiment, right, Um, in terms of thinking about like, well, what are some taxonomies we can refer to for thought experiments? Uh, they're basically various ways you could categorize thought experiments, but there's

not really a fully agreed upon standards so much. Obviously you can categorize them by the discipline that they stem from. So here's a bunch of physics thought experiments. Here's some quantum physics thought experiments. Here's some some economic thought experiments, so psychological thought experiments. You know, we could also break them up based on their features, I guess, but I'm not surely really sure that does any good, because again, if it's a cat or a dog or basilisk, it

doesn't matter. That's just some some flavoring that's added to the little story of the thought experiment. Well, I'm already seeing in the examples we've discussed so far, one clear distinction that emerges, which is the thought experiment that shows the absurdity or contradictions inherent in some pre existing idea, versus the thought experiment that demonstrates a new conclusion or

show reveals new knowledge based on premises you already accept. Right, And that's that's where we come back to Karl Popper, who we talked about briefly earlier. Karl Popper was an Austrian British philosopher and professor who lived nineteen o two through and he this is this is basically how he divided up thought experiments. He said, they're basically three types heuristic, in other words, to illustrate a theory. Okay, so this would be the kind that just helps clarify what you're

talking about, gives people something to picture. And you would argue that maybe I don't know what, I'm not quite sure how Newton's canon would fit in there. Was that just to illustrate or did he actually prove something using the image of the canon? Well, you could also argue that it falls into the next category, right critical against the theory, because he's kind of playing with the preconceived notions about how these things would work. Right Well, I

guess yeah. It does challenge the idea that they're different mechanics at operation in the heavens than there are on the earth. And now the Carl Popper's third category then

is apologetic in favor of a theory. Okay, so you've got the kind that illustrates, the kind that challenges, and the kind that argues in favor of Now, on a similar note, you have Canadian philosopher of science James Robert Brown still still alive and kicking as of this recording, and he's divided thought experiments into two major categories similar along similar lines, constructive and destructive. Okay, there's of the broad categories, okay, and then there are some some subtypes

to the destructive category. So there's contradictive, this is a thought experiment that points out a contradiction to a given idea. Then there's paradoxical, so you have a thought experimentment here that shows how a given idea is conflicting with a commonly held belief. Then you have the undermine, or a thought experiment that actively undermines an idea. And then there's the counter thought experiment, a thought experiment that serves as

a rebuttal to another thought experiment. You know, I think I generally would find that thought experiments are more often sound when deployed as destructive or critical tools than as constructive or apologetic tools. And I think this is because, of course, as we know, thought experiments do not provide

new data or new evidence of anything. They only illustrate logical relationships between things that we already know or already believe, So they can take existing knowledge and use that to extract late to new knowledge, but it's much easier to use them in a way that's reasonable to demonstrate a contradiction between existing pieces of knowledge or principles that the

extended version of the reductive ad absurdom. These are I think some of the most powerful uses of thought experiments when they when they have the power to clearly show that things that you already believe or accept or are you know, bound to accept, are in fact self contradictory. All right, so let's let's get down to one of the questions that has often discussed your regarding thought experiments. Uh, people say, well, do they really tell us anything? Oh yeah,

some people hate thought experiments. I think it really just just riled up because it's like, oh, you know, it seems like this navel gazing kind of thing, Like, if you're not going to go out and do physical experiments in the physical world, what are you even talking about? Why you know, why are you wasting your time? Armchair science is is one of the criticisms is often thrown

out regarding thought experiments. But of course thought experi erments have been really useful in the history of science, as we've talked about before, a lot of important advances in the history of science have been before they were confirmed in fact by physical experiments, were predicted by thought experiments. That this is a very common feature, especially in physics. I mean you could even say in fact that there there are whole realms of physics today. It's probably what

you would call theoretical physics. You often hear this division of theoretical physics, physics and experimental physics. Uh, there, there's all this stuff in theoretical physics right now that we don't have a way of testing with physical experiments yet. And you can, you can kind of try to make your arguments one way or another stronger about string theory or something like that, but it just we we don't have a test for it yet. So you could say that all of that is in a way a type

of mathematically elegant thought experiment. But but if you go back and look at you know, Newton and Galileo and all this, and certainly Einstein, there's no denying that thought ex periments have been extremely useful and productive in the history of physics. But thought experiments can sometimes also, as we've acknowledged, be confusing and misleading, even though there are other times illuminating. A favorite of ours on here is,

of course Daniel Dennett. You know, he likes to highlight that the different kinds of thought experiments that try to leverage our intuitions into new discoveries simply by tightly controlling the variables of an imagined scenario. And some of the most famous thought experiments in history, actually, I think maybe

confuse more than they illuminate. I don't want to put words in his mouth, but I think Dinnett would say this about Donald Davidson's swamp Man, which we discussed in our ship Thesist episode, or Searle's Chinese Room, which maybe

we should come back to now. So we explain searles Chinese Room earlier, with the person exchanging the symbols in the room, and the question of does the person in the room who doesn't speak Chinese but can simulate perfect conversational output in Chinese by following this instruction manual, does

that person really understand Chinese? And a lot of people have thought, yeah, this is a powerful disproof of the notion that computers could ever think, understand, or be conscious, and a lot of other thinkers have been incredibly critical of this. An example of a reply to the Chinese room that makes sense to me is what if what's true of the part might not be true of the system as a whole. So imagine again this person in

the room. The person in the room doesn't understand Chinese, and thus the responses they produce are not meaningful to them. But you could argue that the room itself, the set of instructions, combined with the memories and sensory experiences and logic that went into the creation of the instructions, and the human operator and the pencil and paper taken together perhaps do understand Chinese. And Crle rejects this line of thinking.

One of the reasons is he says, you know, this is a kind of illicit externalizing of thoughts, saying like paper could think, or a book of instructions could think, but but like I think, like he's the person who put this system together. You know, you are the one who put a human inside a room as the metaphor for a computer. Computers do not actually have a tiny human inside them that's performing operations with opportunities to understand

or not understand. Likewise, there is not actually a little human sitting inside your brain with the job of understanding or not understanding inputs and outputs. Your brain is a system in many ways. You might say that system of your brain that produces your mind is more comparable to the entire system of the person in the room, the room, the instructions and all that, than it is just the person inside. I think the evidence is pretty clear that the mind is not one thing, and there's no evidence

of an observer within the observer. The mind is that, at the very least a system of information processing but also story inputs and outputs all working together. There's not there's no evidence of a pilot inside who does all of the final understanding. Right. That's rights as simple as it would be to imagine that, you know, because it would reduce whatever we're trying to figure out, would reduce it to a person would get back into that that

that kind of you know, neolithic mindset. And so I think this now, I certainly don't want to say that that I'm not like casting expersions on John Searle. I'm sure he is a very brilliant man, much smarter than me. And there's been a lot more you know, complex back

and forth on this. But just to somebody who's right about this a good bit, it seems to me like this is one of those thought experiments that needlessly turns up confusion just by bringing in a lot of unnecessary assumptions and the connotations of the imagery you use in the thing, like we've got a person inside a room that that's making you think of analogies to a person sitting inside the computer or an observer inside the observer in the brain right now. I I do take the

problem of consciousness seriously. I'm not one of those people who you know, would hand awave and say, oh, yeah, consciousness is easy to explain, it's just a you know, systems theory or whatever. But I don't think the Chinese room proves machines can't think or understand, or have intentional or meaningful internal representations or be conscious. I think that's

still an open question into my mind. The Chinese room experiment is one of these thought experiments that creates a lot of confusion by the hidden assumptions it imports with its central imagery. I don't know, am I being unfair? No? I think you're being being very fair. I mean again, I come back to um to certainly like political cartoons as as a reference, you know, not that not to reduce the Chinese Room to something so you know, ultimately kind of base. But there is a boiling down of

of a process. There's a boiling down of a of a problem that takes place in a thought experiment like this, and then you do have to ask, well, in reducing it to this model, what of the necessary complexity is lost that is necessary to understanding what's going on. Yeah, I think that's exactly right, and I would say for me, crucially it's the image of the person in the room that's the especially confusing thing in this thing here, Like

what if there wasn't a person there. What if you just instead said the room is a machine that takes in that takes in symbols and puts out symbols, then you're basically not really changing much. You're just saying, well, it's a computer, and then that's what we're talking about originally. But anyway, so we mentioned Daniel Dennet. He's written extensive

criticism of the Chinese Room. I think this was even the context of his coinage of the term intuition pump, which is the title of one of his books, Intuition Pumps, Uh, dinn It writes, quote, Intuition pumps are cunningly designed to focus the reader's attention on the important features and to deflect the reader from bogging down in hard to follow details. There's nothing wrong with this in principle. Indeed, one of philosophy's highest callings is finding ways of helping people see

the forest and not just the trees. But intuition pumps are often abused, though seldom deliberately. Of course, dann It himself has has played with thought experiments before. Absolutely, I'm instantly reminded of the it was almost kind of a little short story he wrote about those A robot with a human brain. Wonderful. Yes, the where am I? I

think it was called? So dan It is as he says, they're certainly not opposed to thought experiments, but he uh, he points out, I think quite correctly that sometimes they actually confuse more than they illuminate. Whether that's true of the ones he himself is put together, it's it's hard

to say. I mean a lot of times. The benefits of these physics thought experiments, as we've been saying, is you can eventually go out and test and see whether they were on the right track or whether they were confused by some you know, hidden assumption taken on board. It's harder to do with a lot of these thought experiments about say the physical location of consciousness or something

like that. Uh So, one example from Dennett's book Intuition Pumps that we talked about in our Ship of Theseus episode. You remember the Swampman because it's essentially swamp thing from the comic book, right, Yeah, So this was an example of you know, Dinnett explaining how intuition pumps can go wrong. And again, intuition pumps are just thought experiments that that rely on our intuitions that don't like take specific data on board. Really, I'll try to do very very quick.

The example was this guy named Donald Davidson. He was a philosopher. So he said, assume lightning strikes me while I'm out walking in the swamp, and it evaporates my body and I'm just gone. And then meanwhile, it also strikes a tree next door, and it rearranges that tree into an exact adom for Adam copy of me with all my memories, and he calls this creature swamp Man. And so he asks, is that copy really me? Davidson says, you know, is it really friends with my friends even

though it has never met them before? Does it really know what a banana tastes like even though it has never tasted or even touched one? This was offered, I think, to interrogate the question of how the history of an object is related to the identity of that object. Is a thing that is an exact copy of you, that behaves exactly like you, but hasn't been where you've been and done what you've done in what ways? Is that

actually different from you? But didn't responds to this story by saying, you know, this thought experiment might not actually reveal all that much. And as a point of analogy, he asks us to consider the cow shark. So the cow shark again, is it's created when a normal cow gives birth to an animal that is adam, For Adam exactly like a shark that you would find swimming in the ocean. And he asks, now, is this newborn animal

a cow or a shark? Oh, but also take on board that it has cow DNA in all of its cells. Now a question like this, it might do something useful, like it might help us identify what features we think are important when we use words like cow and shark, But it really doesn't reveal anything about biology or about the world. You know, you're not going to get new

information about reality from it. I think the best it could hope to do is help us figure out what we mean by words, and not to say there isn't value in that. But yeah, that seems to be about all that it does. Yes, so then it actually arrives at a claim. He says, quote, the utility of a thought experiment is inversely proportional to the size of its

departures from reality. That's why he's saying. You know, Swampman just doesn't seem to be all that useful and understanding what it what it means to be a physical object like a person, because something like that is never going to happen in reality. I also, and I felt this way before too. I also feel like swamp Man is just a little too complicated, Like just use Star Trek.

Just say Cat to Picard teleports down to Planet X and then back up to the Enterprise, Like is then what happens when he hangs out with his friends, what happens when he plays the flute, etcetera. Well, I guess it's the same problem either way. But to answer that question, you're using your intuitions, which are trained on a world where that never happens. So your intuitions just don't do much. They're there, They are not honed to solving this kind

of problem. Your intuitions are much more useful in say, like combining premises about how things fall and stuff like that, right, because actually you're quite experienced with falling, and you can combine that with observations about gravity and stuff. Now, I

don't I don't think uh. Dennett's little proclamation there about the size of its departures from reality is then again like a solvent that will that will fix all the problems, because it can be very hard to measure the size of a departure from reality in the consistent way, Like does the Chinese room experiment depart more or less from reality than Einstein imagining a train traveling near the speed of light? Right? Because the Chinese room you could do that,

I mean, maybe somebody has done that. I mean, all you need is just a person in a room and an individual on the outside writing Chinese characters down right, I mean you know, and also speaking and being able to being able to speak and write Chinese. Obviously you can't have just nonsense going in, but that are the only two components, and we could we could pull this

off today if we needed to. Though, I would say that the problem with the Chinese room actually is not its departures from reality, as in, like, it's not plausible that you could make a room like this and put somebody in it because you have a determined if it's illustrating anything about how a proposed machine is thinking or not thinking, right, the lack of its use, I think is it's in its departures from the thing it's supposed

to represent. It's supposed to be an analogy for a computer, but it's actually not a good analogy for a computer, because it's a room and a person and some pencil and paper that just like they're not the same thing. But with Swampman, Yeah, they're all these fantastic ideas in

it that don't match up with reality. Whereas the ship of theseus is a is A is so brilliant and and as and as to the test of time, because everybody can can associate with that, like the upkeep of physical structures and devices, the constant replacement of those things, the constant change to things that we think have autonomy,

like like ourselves or or sports teams, clubs, buildings, etcetera. Well, a kind of chilling takeaway from from that distinction you make between the ship of theseus and the ship of theseus version as instantiated in Swampman, is that maybe it makes more sense to have to answer questions about the meaning of identity as it refers to things than as it does refer to people. Yeah, in many ways, it is easier to think of people as things if you're

just doing these kind of computations. I also want to clarify that if you're more interested in the Chinese Room, they're like a billion other classes of responses to it you can go look up. Like one is that you know, you should really maybe think about putting that computer inside a robot and then that would be more consistent with

the type of experience that a human has. And so like what if you put the Chinese room in a thing that could go around and look with cameras outside and you know all that kind of So there are just tons of different responses. While I don't find it convincing on on what it tries to prove. I do think it's one of these things that is at least inadvertently useful for clarifying what people mean when they're talking about this subject, because usually if you start asking something

like can a machine be conscious? You just don't even have a foothold to start reasoning. Just where do you go? It's just I don't know, yeah, because on one hand, it's hard enough to know what consciousness is for us and then to extrapolate what that would mean to a machine. You there's just no like, how do you feel in the values on that equation? So I give it credit

for that. It it I don't think it's all us the question, but it does give you a first place to start climbing where you can even contemplate what it would mean to solve this question. Now, to return back just the idea of what is the thought experiment? What is an a thought experiment? I do want to refer to just a few ideas that have been pointed out

by Dan Falk and his Ian article Armchair science. Thought experiment played a crucial role in the history of science, But do they tell us anything about the real world? He points out that John Norton, a philosopher at the University of Pittsburgh, has argued that we shouldn't elevate thought experiments too highly. They are essentially quote elegantly crafted arguments

that bring vivid pictures to the mind's eye. So the argument here is that the thought experiments, as we've been discussing, don't produce any new knowledge themselves, but rather constituted deduction of existing knowledge. And he maintains that all thought experiments are are simply restate, can simply be restated. His arguments, like his challenge, his sort of rough challenges, you can bring me a thought experiment, I'll just restate it as argument,

and that's all there is to it. Well, I think he's essentially correct that any good thought experiment can be restated as a deductive argument, you know, with the kind of the boring you know, logic class style logical premises. Right, But thought experiments are useful because they're easier to remember, they're easier to understand, and they give you pictures that you can wrap your mind around, right exactly. They change the way you think about something, and and that's ultimately

I believe the point. The counterpoint that is made by James Robert Brown, a philoso for the University of Toronto, who points out that like, Okay, yeah, Norton, you may be right, and he even says, I think Norton probably could restate all thought experiments as arguments, but we don't really work them out in our heads as arguments. We work them out in the form of these thought experiments. The cognitive process here because is much is much more

intuitive and less analytical thought experiments. Therefore, they transformed the ad the analytical into the intuitive. What did we evolve thinking for? What was it use full four? I mean, can't be sure, but it really seems like what's likely is not that, say, our boreal primates were trying to work out analytical premises of an argument and say, you know, premise one is no. I mean, they were imagining scenarios, like thinking is useful for saying, Okay, if I went

down on the ground right now, what would happen? Oh, yeah, that's right. There was a leopard down there. So if leopard and me on the ground, that that's not good. Imagining scenarios is so much more natural and intuitive to us than than formal syllogistic arguments. Now, Falk also points out that there's a third possibility here. The third argument presented by cognitive scientists Nancy Nurcessian of the Georgian Institute of Technology, as she argues that thought experiments are simply

middle mental modeling. If Falk provides a quote for her from her in his article, quote, a mental model is basically a representation of the structure, function, or behavior of some system. You're interested in, some real world system that retains its sensory and motor properties that you get from perception. When we manipulate a mental model, she argues, we use quote some of the same kind of processing that you

would use to manipulate things in the real world. So, yeah, the idea here, it's it's the example that has often put forth is if someone says, hey, how many windows are there in your house? And then how unless you just carry around that raw data in your head, the way you solve that is probably to form a mental image of your house or room by room, form the

mental images and then count the windows. But you had to have looked at your house already, right, Yeah, you can't just have just you know, uh, you know, experimental knowledge like you have to have some real knowledge you have walked through your house, you've seen your house, and then and that's what you're using to reconstruct this this model.

On the other hand, it's worth pointing out that just counting the windows in your house is probably a quicker way essentially falling back on the sign on sign of an invest investigation is going to be the clearcut method of solving that particular question. Yes, especially if you care

about getting the right answer right. Yes, Uh, those sometimes, I mean, I thought experiments can be very useful, especially in scenarios where you're not super concerned with precision, but you're more concerned with like the directionality of an answer. Like a thought experiment can be quite useful in uh, just getting a guess about whether a quantity in reality is going to increase or decrease without knowing exactly how much it's going to increase or decrease, you know what

I mean. Yeah, And then of course it to go back to black holes for instance. Like that's an example of counting windows in a house you haven't been to yet, by by your by your understanding of everything surrounding whatever that house should be, so that there there are cases where that is the best method for trying to count the windows in a given house. Well, it's almost like knowing, like what is the what is the tension and support strength of glass? Now trying to imagine how big of

a glass house could exist before it falls over. You know, you don't have to build that house. If you already know some things about glass, you can run that experiment on paper or in your head. But anyway, what I think this all means is that we should build two glass towers, one bigger than the other, and drop them both but tie them together, and then shoot a cannon off of them, and then drop a bag of cheese from them. And basically you're you're arguing for a shared

cinematic universe of thought experiments. I mean, I think most of them are in the public domain, So this would be a great This would be a great franchise for somebody to to pick up and run with. You know, at this point, I think a good number of the most famous thought experiments have at some point had like an indie movie made out of them. You know, there's got to be I would be shocked if there is not a Chinese room movie. Well, I'm sure we'll we'll

hear about it from listeners if there is one. Uh. So there you have it. Thought experiments. Uh, hopefully a nice overview of what they are, what they are not, some different ways of classifying them, some different examples both from past episodes and some that we haven't really picked up and looked at here on the show. But hopefully this will this will be useful moving forward as we inevitably encounter other thought experiments in our consideration of various topics.

What I hope this allows us to do is to be more confident in dismissing the ones they're not useful. Yes, you have to realize that they are not. You know, they're not holy scripture set in stone, that that that they can be flawed. There in many cases they are flawed. And uh, but then that's also part of their usefulness is that the flawed model can be presented and someone can say, well, let's look at this, look at let's

change something in this model and see what happens. All right. Well, hey, if you you want to check out more episodes of stuff to blow your mind, you want to check out, say, for instance, the episodes we did on black Holes, the Ship of THESEUS uh any of these These various topics were heard too in this episode, Well, you can find them all. It's stuff to blow your Mind dot com.

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