The Case of the Blind Mind's Eye

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Hello, Curios, we are back.

It is the new year.

New Year, new us.

But it might not be the new year because people listen at all sorts of different times.

Let's not get involved in the complicated nature of time so early on in the series.

So, whatever time of day or the rotation of the earth around the sun it is, we're back.

We are back.

And we've got another six delightful episodes for you.

Hopefully, we'll do more than six episodes a year this year.

Well, it really depends on what you've been all over the place.

Amen.

This is the first time I've seen you in weeks.

Possibly months, Adam.

You look much older.

Thanks.

Right.

Well, thank you for introducing what the listeners are currently doing, which is imagining my gurning old face in their mind's eye.

Because this episode...

Did I say older?

I meant more dashing.

Thank you.

This episode is all about what happens in your head when you think about someone.

Today's case takes us on a curious journey into the mind's eye.

Now, this is an interesting one.

Hannah, what do you see?

If I ask you to conjure up an image in your mind, say, of someone you love dearly, Molly the dog.

What is happening in your head when I ask you to think about Molly?

Oh, well, I mean, I can just see her.

I can see the colour of her eyes.

I can see the glistening wetness of her nose.

I can see her muddy paws as she

comes in from the garden and ruins my floor.

I mean, I can actually see her.

So it's a very clear visual image.

And that's very interesting interesting because we have had loads of messages from people saying that they can't see anything in their mind's eye at all.

So, for example, Diane Edwards wrote to us from Aberdeenshire and she discovered that she was different when on the phone to her daughter during lockdown and her daughter said, I can picture your face very clearly, which completely flummox Diane.

She could describe her daughter, brown hair, green eyes, etc., but she couldn't picture her.

And she didn't know that anyone even could do that.

So she reflected on this and how they've been on holidays together and when they describe them, she takes lots of photos because she can't recall those images.

So Diane's question to us is, how does having a blind mind's eye affect your experience of life and your ability to make memories?

Yeah, but Diane isn't the only person who's asked us this kind of question because Jude from Perth in Australia also sent us this voice message.

I've always found it really annoying that when you meditate or get hypnotised, they tell you to picture yourself somewhere, a forest by a beach.

But I've always struggled to picture myself in that place.

I don't see pictures in my head and I find it hard to understand that my friends can actually visualize a description like a purple giraffe with green spots.

I can't do that.

I don't see it.

So why is this and what part of the brain affects the ability to visualize?

Purple giraffes with green spots.

Huh.

Now, there is a vividness of visual imagery questionnaire.

It's online and there'll be a link on the programme website.

The would be something like try and visualize

your best friend and then it gives you the options.

Is the image dim and vague?

Is there no image at all?

Or is it moderately clear and lively?

Or is it perfectly lively and clear, as real as actually seeing?

Now when I did this test, it takes about 10 minutes, I came out as a hyper-visualizer.

Did you?

My official results said that I was fantastic.

So that's, well, we all know you're fantastic, but this is fantastic with a PH.

Fantastic.

Because this is to do with the name of the phenomenon that we are talking about today.

Look, two things can be true at once.

And we're going to come on to that in a moment.

But as ever, we have some real draft experts in the studio to unpick Jude's blind mind's eye.

We have Professor Julia Simner, who's a psychologist from the University of Sussex.

And neuropsychologist Professor Adam Zeman from Exeter University.

Now, their background is both in neurology and neuropsychology.

Adam, my first question to you is, well, this, you basically discovered this and actually named this particular condition.

Tell us the story.

So it's called aphantasia, the phenomenon, and it refers to the absence of the mind's eye.

There wasn't a convenient term for the absence of the mind's eye, so I chatted with a friend who was educated in the classics, and he suggested that we borrow Aristotle's term for the mind's eye, which was phantasia, and tag an A on the end to denote the absence of the mind's eye, hence aphantasia.

How long ago was this?

2015.

Oh, so very recently then.

Julia, not only are you an expert in synesthesia and aphantasia, but you are also an aphantastic.

What's the word for it?

Some people say aphant, or I would say I'm aphantasic.

So you can't visualize images in your mind?

Well, it's interesting because I'd quite like to pick up on some of the terminology.

So it is true that I cannot form a picture in my mind's eye that looks anything like the real world or anything like a photograph.

But I can do what I think of as picturing things and what I think of as visualizing things because people with aphantasia have spent their entire lives using those words.

And for people like me, that word had always just been a metaphor.

So when I picture something in my mind's eye, I think about its visual features.

There's no photograph, there's no image, but I do know what things look like.

Okay, so let's say you had a friend in who had brown hair, green eyes, you know, the similar features to our listener's daughter.

Is it that you've you've sort of committed a list of those visual characteristics to memory and you're sort of going through them?

Or I mean, just

forgive, I think it's very difficult to imagine what it's like to exist in somebody else's mind, but what does it mean that you picture them without seeing them?

Well it's just an instant sense of knowing what their what their visual features are, it's an instant sense.

And you know, in the last couple of years we've looked at whether people with aphantasia are instead just verbal thinkers.

And in fact fact, they're not.

They score low on visual imagery and they score low on verbal imagery as well.

So they don't think to themselves in words.

They don't speak to themselves out loud in words as much as other people.

Not verbal either.

Sorry, they don't speak to themselves in words.

Hang on, do you mean you don't have an internal monologue narrating everything that you're doing all the time?

Okay, this is a different type of session we've got into here.

Well, actually, they're related.

So we've found that if you are low on your visual imagery, you're more likely to be low on the other domains as well and so I have no internal voice and yeah no people with aphantasia they're less likely to think in sentences to themselves.

It must be peaceful.

It must be so peaceful.

It is so peaceful.

I have a very very peaceful inner life.

Let's just talk about how you get to,

you got to be in the position that you are because you are your researcher studies synesthesia and aphantasia.

How did you end up in this in this particular field?

So my profession is I'm kind of a professor of curious cases.

That's what my job is.

No, no, no.

You can be a research assistant for curious cases if you want.

You have to apply, though, and it's a very, very rigorous reference.

That position is taken by us.

Go on.

So, I'm a neuropsychologist, and neuropsychologists tend to work with people who have impairments, but I have always worked with people who have just sensory differences, whether they're impaired or not impaired.

And so, I work on lots of special populations.

I work on people with aphantasia, I work with people who have misophonia, which is an intense hatred of certain sounds, and I work a lot with people with synesthesia.

And this is how I found out that I have aphantasia.

So about 15 years ago, I was in Edinburgh, I just happened to be interviewing a synesthete that day, and I learned something remarkable about synesthesia.

And I was chatting to a fellow professor at the University of Edinburgh, and I said, Bob, you just won't believe this.

I've spoken to a synesthete, and when you say dog, he sees the dog as a a picture in his mind.

And Bob looked at me and said, Jules, everybody does that?

And I said, no, no, Bob, you don't understand.

If you say Bob, he sees a picture in his mind.

And that was when my colleague told me very firmly that everybody has this and that I was in the minority.

Well, let's deal with the numbers here.

I mean, this isn't a condition.

This isn't a defect at all.

But Adam, what are the sort of...

How many people can't process the image of a giraffe or a dog?

So it depends a little where you draw the line, but it's somewhere around three percent to four percent fall in the aphantasic at the aphantasic end of the spectrum, and somewhere around ten percent fall at the hyperphantasic end of the spectrum.

So the the distribution of scores seems to be skewed up towards the high end.

It's more common to be a very vivid visualizer than to lack imagery, but it's a fairly substantial proportion of the world's population who either lack imagery or have imagery which is roughly as vivid as real seeing.

Hang on.

When you sorry, I'm just sitting here in the corner as the centre of the bell curve being slightly incredulous on different people's world experiences.

Because when you say hyper-visualizer, having images in their minds that are as vivid as real life, Adam, as vivid as real life, for real.

I wanted to ask you about the test, because I did come out as a hyper-visualiser in this particular test,

but yes, I answered all of the questions with...

When you're not here, Hannah, I can see your face and I can see exactly the facial movements that you do.

Yeah, but that's because you're often stood next to the shrine of me that you've built.

This is true.

Constant presence in my life.

So what's actually happening at the top end there, Adam?

What's happening in the brain?

Well, a number of things are happening.

So visualization isn't a simple cognitive function by any means.

So if I ask you to visualise an apple, you're going to have to remember what the word apple means.

So you'll need to use...

parts of the brain that subserve language.

You're going to have to remember what an apple looks like.

So you're going to have to draw on visual memory.

You're going to have to decide that you want to comply with the task, so you're going to use parts of the brain that are involved in cognitive control, essentially deciding what we do

with our heads.

And then it seems that you use sensory regions to generate the sensory image of whatever it is that you're trying to imagine or visualise.

I mean another way of thinking about it is

in terms of the idea that imagery is vision run backwards.

So normally when we're seeing information is streaming in from the world through the eyes into the brain and is being processed bottom up if you like, when you decide to visualize an apple you activate the same system but you're running it top down.

So information is flowing in the opposite direction.

In fact information is always flowing both ways in the brain but in perception it's if you like predominantly.

running bottom up and in visualization it's running predominantly top down.

If it's only 3% then most people's brains work in one particular way and we've already described a little bit of the complexities and how all of that processing is happening in many different areas of the brain.

But what is different in Jules's head compared to mine?

So we don't know much about this yet.

Studies on the neural basis of lifelong aphantasia are just beginning.

We completed one a couple of years ago with one, I think, really interesting finding, which was that in resting state brain imaging, there are stronger connections between frontal brain regions and visual brain regions in people with vivid imagery than in people with aphantasia.

So that makes a kind of intuitive sense.

It would help to explain why thought connects more readily with visual imagery, or with imagery generally, in people with hyperphantasia than it does in people with aphantasia.

In someone with aphantasia, thought is going to remain propositional.

It stays at the front of the brain, if you like, crudely.

Whereas in someone with hyperphantasia, it's going to translate very naturally into imagery.

I wonder what the effect of this is, though, when you are replaying moments back in your mind, when it comes to forming memories of holidays, for example,

do people

with this struggle to picture things in perhaps the same way as the rest of us?

So, when we look at people with aphantasia, you would expect them to be fairly impaired.

So, I once had a colleague who learned I had aphantasia, and she said, Jules, it's like you're barely sentient.

You know, how are you doing?

Jokingly, jokingly.

But she has a good point because, you know, a lot of what people do for cognition relies on vigil imagery.

One example is a direct example of what you've just talked about which is memory.

So

although you and I would both remember events reasonably well you with mental imagery and you with super mental imagery might remember just more details.

If we're drawing a picture from memory

I with aphantasia might just omit a few details.

If we're drawing a living room, maybe I would miss out a cushion.

And so there are those tiny tiny deficits but there are also things that people with aphantasia are better at.

We've found that they're better at colour memory.

So if I show you a colour swab, take it away and get you to choose it from a colour palette with 16 million colours, I will do better than you will, you know, in a group-wise level.

And how about reasoning?

So let's say that I asked you which was longer, a squirrel's tail or a rabbit's tail.

So I don't know about you, Adam, but for me, in my mind, I would be like, okay, I'm thinking of a squirrel, I'm looking at its tail, I'm sort of measuring it up against a rabbit.

The rabbit's like particularly cute.

It's got a carrot in its mouth.

Its ears are floppy.

It's got a little bit of a break.

Now I'm talking about rabbits.

But I'm sort of, I'm imagining both of them in my mind and visually comparing them.

What would it happen for you?

Well, I just instantly know.

And so this...

This kind of reminds me of an analogy that I was trying to think up earlier this week.

The analogy of learning about aphantasia is a bit like this, yeah?

So imagine everybody on the planet has a devil on one shoulder and an angel on the other shoulder and the devil gives dubious moral advice and the angel gives virtuous moral advice and that's how people navigate their moral worlds.

Without talking to their angel and their devil, they would not be able to make moral decisions.

And you're you and you don't have an angel and a devil.

And one day you wake up and you realise that this analogy that you've known your entire life is real for 97% of the population.

So I mean first of all imagine how you feel.

It kind of blows your mind.

And then you start to feel a bit sad because you haven't got an angel.

But then you start to feel really relieved that you haven't got a devil because imagery can feed into all kinds of negative things like PTSD and so on.

But overall, you come away feeling quite relieved because it feels you feel a bit sorry for people with the angel and the devil because it feels a bit clunky.

Like imagine having to talk to the angel and the devil to understand your moral world when you yourself do it instantly and automatically without that.

And it kind kind of feels a bit like that.

What are your dreams like?

My dreams are pretty sensory.

They're very sensory.

I, being a psychologist, I often wake up and think, oh, well, that had some gustatory, that had some taste in it, that dream, or, oh, I remember exactly what that smelt like in my dream.

And I do see my dreams very vividly.

With imagery.

With imagery.

And is that the same for all people with aphantasia, Adam?

This is a really fascinating dissociation, if you like.

So the majority of people with aphantasia dream visually.

I think this makes some people sceptical about the whole notion of aphantasia because it seems so bizarre that dream imagery could come apart from wakeful imagery, but they're very dreaming and wakefulness are very different states in terms of brain chemistry and brain activation generally.

It is a really good point you make because somebody could very easily make the argument that maybe we all have exactly the same imagery around this table and maybe we're just rating it differently.

Maybe we'll have imagery.

On a personal level, I know that I have aphantasia because I did once in my life have a mental image.

It was 1976.

I was five years old and I had been in the garden picking peas with my mum and I went to bed and I closed my eyes.

And I saw the peas behind my eyelids and it was the most bizarre thing I've ever experienced.

And I would close my eyes and look at them.

You know, I was in bed, close my eyes, look at the peas, open my eyes.

And then I just kept on doing this until I fell asleep.

And then I woke up in the morning and it was gone forever.

and I'd never before had a mental image and I've never had one since but because of that one very hyperphantasic moment I know I believe you Adam that you do have hyperphantasia because I otherwise I think I would struggle to understand what that meant.

But Jules it was just once.

Once when you were five and you and that's the only time you've had a visual image in your head and it was a peas.

Yes.

All right then let's let's think about where we are.

So we've got 3% of the population are a fantastic.

ten percent of the population are hypervisualizers like Adam that everybody else in the middle is is typical like you and me and if you are a um aphantastic I'm giving it a new word if if you have aphantasia then you can't see the images but that doesn't mean that you're not capable of spatial reasoning or of manipulating structures in your mind it just means that you're not seeing them in the same way that everybody else does.

Is that about right?

That's right.

And there are one or two associations that we haven't yet mentioned.

So a curious association with face recognition.

Many people with aphantasia describe difficulty in recognising faces and actually face people who research face recognition had noticed that some of their participants seemed to have rather weak imagery.

There was another aspect of the test which I found fascinating which when talking about describing individuals, people that you know very well,

it wasn't just what they look like, there were also questions about facial movements or tics or even their gait, you know, how they walk.

And as I was answering all of those, I was thinking, absolutely, I know exactly

how my son walks or what the face Hannah pulls when she's listening to me talking about genetics.

So, imagery is multifaceted, and that prompts me to mention another interesting dissociation between what's called object imagery and what's called spatial imagery.

So, what people with aphantasia seem to be lacking, particularly, is object imagery, so the ability to

imagine visually the visual characteristics of objects.

But

in the imagery questionnaire, which we've sent to people with aphantasia now, maybe 14,000 of them or so over the last five years, we've included a question which asks people to count the number of windows in their house or apartment mentally.

And people with aphantasia can generally do that.

And if you ask them how, they say, well, I don't see them.

I just kind of know.

I have a sense of a map, a kind of scheme of where they are.

That seems to be spatial imagery in operation, which has less conscious content but is probably nevertheless pretty important in thought, in mathematical thought, among other places.

Well, actually, so that's interesting in terms of the mathematical thought, because there was one occasion when I was put in an MRI scanner and given a series of mathematical questions.

Some of them were quite straightforward, just a bit of arithmetic, like, you know,

what's 12, take away three.

And then other were sort of high-level differential calculus, if you're interested.

What they demonstrated was that while answering these questions compared to some language questions that they also tested as a baseline, it was the visual cortex that was lighting up.

And this is not just something that appeared in me.

You know, they have tested a number of mathematicians and seen this effect that it's really in your visual cortex that that's sort of where maths happens, as it were.

So I wonder about things that are not just recalling images, but maybe about being creative, about generating new stuff.

Do we know anything about aphantasia and people's ability to achieve those kind of things?

So we do know something.

It's clear that there is a really important distinction to draw between visualization and imagination.

So it is possible to be aphantasic and highly imaginative.

And we have now many examples of...

Visually imaginative.

Even visually imaginative, in a certain way.

So as an example of imagination generically, Ed Katmull, past president of Pixar, who recently won the Turing Prize for his advances in computer imagination, is by any normal standards a highly imaginative guy, but lacks visual imagery.

Ah, now it's interesting you mentioned that, actually, because, in fact, we have a clip of Ed Catmull on BBC Radio a few years ago.

And as one of the co-founders of Pixar, you would imagine that he would need a really, really vivid visual imagination.

But here he is explaining about how he discovered that he has no mind's eye.

I have a friend who is a meditator in the Tibetan style where they use visualization.

So I asked him to teach me how to visualize.

And he gave me a simple task which was to visualize a sphere.

I went home and spent an entire week trying to visualize a sphere.

I saw nothing but black.

My reaction was one of surprise because I had invented the kind of curved patches that we use to make the surfaces of all the effects you see now in movies and in animation.

So I was more puzzled than anything.

I can't see or visualize Buzz Light here.

There's something in my head about him.

It's just not an image.

And that's quite a mathematical thing.

I mean,

the surfaces, the shapes that create that Pixar character, they are quite mathematical things.

And I would say that they're visual things.

But very interestingly, picking up on the question of whether you can be visually creative and authentic, Ed Cutmull Catmull got interested in this question and he began talking to illustrators within Pixar.

And he discovered that his favourite illustrator, a guy called Glenn Keen, who led on the graphics for The Little Mermaid, is himself aphantasic and had got into big quarrels with other illustrators over the years who'd said, You can't, you must see images because otherwise, how can you work?

I think there's a lot here that's conflating the object imagery and the spatial imagery as well.

People with aphantasia are actually superior in their spatial processing in a number of tasks.

So, and me myself,

I can parallel park for Great Britain.

If there were an Olympic Games, I would be your girl, but obviously without any object imagery.

So, yeah, I think there's a lot of spatial elements in play there.

And actually, when you're doing your mathematics, although your visual cortex is firing up, your parietal cortex is really shouting out as well.

And that's an area that's very spatial, helping you with mathematics as well.

And

it may be that there are different ways of doing maths.

I mean, I think there are.

Don't be foolish.

No, there is only one right way.

So we've talked about the variation in the way people think and perceive.

But we had a question about

how this phenomenon, which has only recently been described, how this might have affected the history of thought itself.

Now, we spoke to Fiona McPherson, who's a professor of philosophy at the University of Glasgow, and she shared a surprisingly cool idea, which is that influential philosophers and psychologists throughout history have had very different ideas on the nature of thought and how much of it involves visual imagery.

And she suggests that perhaps maybe just some of them were either hyper-visualisers and some of them might have been aphantasic.

Here's Fiona McPherson.

The most famous Scottish philosopher, a philosopher who was working during the Scottish Enlightenment, was David Hume.

And his picture of thought, his theory of thought, is very visual.

He talks about thought as being the manipulation of ideas and he thinks of ideas as faint copies or impressions of perceptual experiences, at least to some degree.

So he's thinking of thought as being the manipulation of mental images.

Now there are other philosophers who've had a radically different theory of that.

So there are different kinds of people called behaviorists.

Those people tend to play down inner goings on, inner mental goings on, to a great degree.

They really want to try and explain thought just in terms of the behaviour of people.

So they're really playing down that there are things like inner images that you can consult.

Now, to date, most people have thought, well, these are just different theories, different alternatives.

We need to find evidence for which one is true.

But if you actually realise that people themselves vary on how much mental imagery they have, the thought strikes you, maybe David Hume is someone who had very vivid imagery that he used and consulted a lot.

And maybe some of the behaviorist philosophers were people who were aphantasic.

Maybe they didn't have visual imagery and didn't use it or consult it a lot.

And maybe that

inspired their different theories of the mind and explains why philosophers came up with such different accounts of what might be going on when we're thinking.

That seems like quite a big idea,

that the variation in the way that we think and the way that we imagine might have ended up having a a huge but but hidden influence on philosophy.

I don't know what your take on that is, Evan.

I think it's very plausible.

I mean each of us takes him or herself to be to be the normal, to be the standard of normality, I think.

We don't, unless we have some good reason,

naturally have a thought that what's going on in other people's heads and minds is very unlike what's going on in ours.

So it seems quite likely that philosophers would have taken it for granted that others' experience was like theirs, and those with vivid imagery would have assumed that this was the norm, and those lacking imagery would have made the same assumption.

There's interesting evidence that, hard evidence, that this

individual differences of this kind influenced psychologists' thinking about this.

So there was a big debate towards the end of the last century called the imagery debate.

Stephen Koslin was on one side of the argument, arguing that imagery does actually provide a kind of distinctive medium for thought.

A guy called Zenon Piloshin on the other side of the argument said, no, imagery is essentially just propositional,

like language.

Questionnaires were sent to psychologists who took different positions on this question, and those with less vivid imagery tended to take the Pilishin view, those with more vivid imagery tended to take the Koslin view.

You would think that we might have learned a little bit from that debate, but I think afterwards, you know, the imagery folks just continued to say that thinking was in images, and the symbolic folk just continued to say it was symbolically.

But I think now we're at a time where we have a more open debate across people with with and without imagery enough.

We should say that a plug for Fiona McPherson's

a pretty cool online project called the Perception Census.

And if the listeners want to contribute their own visual imagination and perception questions, they can just Google the perception census online.

Yes, indeed.

But you know what?

My internal monologue now is telling us that actually we've come to the end of the show.

Actually, it's the clock.

That's not the same thing.

Are you visualising that in your mind, though?

See the numbers.

Okay, okay.

Thank you so much, Sabetiu.

Fascinating discussion.

So, Professor Fry, when it comes to being blind in your mind's eye, can we say case soul?

Yes, Dr.

Rutherford, we can.

It's called aphantasia, which is more common than you might expect.

Yeah, it affects about 3% of the population who do not visualise images in their mind's eye.

People with aphantasia are also more likely to struggle to recognise faces and probably don't have an ongoing internal monologue.

But aphantasia doesn't appear to curb creativity at all.

And for some people, their inner monologue is a key part of how they think.

Who said that?

Right, well who said that?

It was your ongoing struggles with the person that is in your head.

Do you know, really seriously, though?

Do you not have this when you're on stage?

I was in the Albert Hall the other day and I was talking to an audience of thousands of people.

And while there were words coming out of my mouth, there was a whole other person in my head just being like, well, here you are then.

That soup's a bit tight.

You really can't see anything from these days.

I mean, genuinely non-stop.

Non-stop.

And right now they know that I'm talking about them.

Oh, so there's like a meta-inner monologue.

Your inner monologue has its own inner monologue saying, they're talking about you.

You have the same thing, though, don't you?

Yeah, perhaps

not quite as explicit as that.

Yeah, of course I have it in a monologue.

It's currently telling me that I'm hungry.

Got you those dragon rails there, didn't I?

They were good.

But then immediately it's telling me there was enough.

It's because you asked for something small.

Yeah.

Yeah.

Foolish.

Yeah, well, but I'm kind of surprised in that conversation that it turns out that I'm much more of a visual thinker than I had previously thought.

And I suppose that's the point of having these sorts of conversations is that what happens in our own head is is mostly inaccessible to everyone else.

Well, yeah, I mean, I think I sort of worked on the assumption, as Adam was saying there, that your own experience of reality is the model for everybody else.

I think I sort of worked on that assumption.

But the older I get, the more I realize that it's not about the fact that there are some of us who have a typical experience and others who have an atypical experience, because

I think actually,

why on earth would any of us be the same?

I think each one of us probably has a totally unique lived experience of reality, right?

Like your internal monologue is different to mine.

Your ability to visualize is different to mine.

Tasting numbers,

you know, smelling rabbits, all of that is entirely different and unique to all of us.

Yes.

I am thinking a lot.

I've been this as a joke, but also it's true.

I'm thinking about peas.

Are you?

Yeah.

Yeah.

Jules's experience of only having had one visual image in her entire life.

One pee.

Was a

And now I'm just sort of obsessed with, as you're speaking, I've just reimagined your head as a giant P.

Would you get rid of your visual imagery if you could?

Why is this P sport you're speaking to?

No, of course not, because that's how I think.

That's, you know, even when I'm looking at data, even when I'm thinking about, you know, stuff that you find boring, like DNA and stuff, I'm thinking of it.

as what it looks like because we're a heavily visual species.

But obviously, like you say that's the typical but it's not for everyone oh you know i've got to tell you actually talking about um you talking about things that i that i find boring i um 90 of my dialogue to you i um i've got a little treat for you because remember that brilliant episode that we did about pie oh yes where i just got to run riot with my maths friends yes and i had an amazing epiphany oh yeah oh yeah you you experienced for a brief moment there my lived experience

when when I finally realised what pie was

after.

Okay, well anyway.

47 year old.

Now the thing is, is that actually we had a really intriguing response to that episode.

So Simon Lambert wrote in to us and he lets us know of a case where pie also does not equal 3.14 blah blah blah blah.

Because Simon is a chief motorsport officer.

Simon, if you ever want to invite me down to a race, you know I am actually a great big motorsport fan.

So, you know, there's a reason why you're not here of the week.

Anyway, he says,

are you just pitching for three days out?

Get back onto the script.

Ask anyone what shape a wheel/slash tyre is, and they're going to say round.

Incorrect.

What?

I.e.

a circle, right?

Because actually, in practice, it's not.

Because as soon as you put a bit of weight on that tire,

like a car, for example, then the bottom of the tire is going to flatten.

Agreed.

And so it's therefore not circular anymore.

And so Simon needs to be able to calculate the speed of the car given the rotation of the drivetrain, right?

Need to know like when the number of revolutions you're doing and how fast the car is going to go, which means that you can't use pi because it's not circular.

So instead, they use pi to be 3.05.

What?

That can't be right.

Deal with it.

But wait a minute.

Wait a minute.

Yeah.

I'm sure he does do that and I'm sure they win a lot of races.

Well, we don't know what team he works for.

But if he's true.

That's true.

Good point.

Actually, only contact me if you work with one with good ones.

Wow.

It's just, it's ruthless.

Anyway, what I was going to say was, if you're calculating the circumference of a circle

and you use pi as actually as it is as an irrational number, surely if you dent it, it's not going to make any difference to that number.

What, Adam?

Well, it's not going to stretch it.

Adam.

Physically.

Oh, God, am I doing a bad math?

What...

Do you remember what pi is for?

What does pi give you the ratio between the radius and the circumference.

And then if you squash the outside of the tire, what are you effectively squashing?

The circumference.

No, the radius.

What?

One of the two.

But basically, it's a piece of material.

No, no, no, no, no.

Yeah, but

it's a deformable piece of material.

You're a deformable piece of material.

Your radius is fixed, right?

But you're taking, if you're like going around the outside of the circumference, right?

You're taking a shortcut because you're saying, okay, there's like, I'll go all the way around the outside of the radius, right?

And then I'll get to that that bit, and the arm's going to

skip off a bit because it's flattened.

All right.

So you're shortening them, you're shortening the circumference, but you're fixing the radius remains fixed.

But that's because the material itself is elastic.

Exactly.

If it was an inelastic material, then you'd have a rubbish

car, but pie would still be 3.14.

Yes.

Okay, all right.

That is what they did in Chariots of Fire.

And look what happened there.

I accept.

What?

That is not.

When was there a racing?

They had rigid wheels.

Chariots of Fire, they were running races.

No, what's the one with the chariots?

Okay, you beat me on maths.

I will deal with 80s film trivia.

Come on, what's the one with the chariots?

Thank you, Ben-Hur.

Bob Nettles in the studio said, Ben-Hur.

It's chariots of fire, not about chariots.

No, it's about

running races.

It's about Roger Bannister doing the four-minute mile.

I was reading math textbooks when you were watching films.

Actually, that was 1981.

I didn't think you were born.

Easy mistake to make.

Shall we move on?

I think that now you've secured your invitation to

Simon's track day and that we've worked out what Pi is actually for, I think we should move on to Curio of the Week.

Well, actually, before we get to the real Curio of the Week, we've got a bit of...

We haven't done this before, but we're going to do a bit of retro Curio of the weeking featuring two previous Curios of the Week.

Okay.

And these are juicy because the first one, it was one of your absolute favourites, which was Gareth,

the Driftwood Seven specialist.

Oh, yeah, the Seven Hole Donut.

It's up in my house.

Is it actually?

No, it's in storage.

But...

That's because you're making it.

It will be up in my house.

Right.

So he sent us this amazing video of him

making this beautiful seven-hole donut, which is on our episode about topology, right?

Anyway, Gareth made this amazing video and sent you the seven-hole donut.

And we just had a lovely message from him saying that that video, since we posted it, which you should go and look at on YouTube,

got a massive boost.

It did.

It went from 20 views to 5,000 views.

That is a boost.

And the really nice thing about it is that...

When you go on to the YouTube page, all the comments are just these really lovely, lovely things of loads of curios talking to each other.

Which is really rare because on YouTube, most of the comments are it's generally a sewer of awfulness, but these were just charming.

Some of the comments are really nice, as well.

Because of course it's a seven-hole donut that he's made.

Someone says, yes, it looks just like me.

Great likeness.

Wow.

Because a human is seven.

Yeah, yeah, yeah.

But look, there's another reason why we're talking about this because one of the comments came from one Tony Waghorn and it said, from one curio of the week to another.

And we quickly, it didn't take long for us to remember what it was that Tony got his cure at the week batch for because it was Tony and Sam who did the remix of the Neanderthal reenactment of the voice.

So, just for some context,

remember what this was.

Oh, of course, I remember what this was.

There is an actor who is being trained to speak as a Neanderthal supposedly would do, according to something, something, something, pretended science, but actually really it's absolute nonsense.

He speaks in a very high-pitched and urgent tone.

Yes.

And that is what Tony and Sam remixed for us.

One, two, three, one, two, three.

One, two, three.

One, two, three.

One, two, three.

And again.

One, two, three.

And again.

One, two, three.

One, two, three.

And again.

And again.

And again.

Amazing.

I mean, any opportunity to play that over and over again, that is the second time we've heard that.

So, well done, Tony and Gareth for being cure of the week.

Well, effectively, default default twice.

Let's go to the new curio of the week though.

Ilan.

Oh, Ilan's going to come in.

Ilan, our producer, is going to come into the studio because he's got something and we do not know what this is.

Fast and curious, occasionally spurious, totally geek chic.

Rutherford and Fries, Curio of the Week.

Okay, here we go.

So we have got a little white box.

It's addressed to Professor Ryan Dr.

Rutherford at BBC.

Accurate.

It costs £4.45 on postage.

Let's hope it was worth it.

Okay, here we go.

Oh!

Oh, this is Hannah's...

This is a nice thing.

Oh, my goodness me.

What is it?

It's absolutely amazing.

Okay, wait.

I'm just going to...

Okay, I'm going to read you the thing first.

It's really good.

Dear Professor Hannah Vryan, Dr.

Either Rutherford, I'm a regular listener to your podcast and a huge fan of you both.

I'm also an avid crochet designer.

So I made these little models of you and made them prior to this latest series, Hence the Moustaches.

I hope that you love the best from Lucy.

Oh my goodness.

Isn't that extraordinary?

Okay, this is so good.

I cannot even...

Look, I'm sorry, if you're a fantastic, then you're just going to be lost.

This description.

Who's this from Lucy?

Lucy.

I don't know herself.

You're going to sell him?

No.

But, and here's me.

Here's my little me.

Amazing hair.

Amazing.

You know what, though?

The detail on this is extraordinary because

the faces are, they're not just these round blobs, right?

She's crocheted noses on.

There's tiny little eyes with stitching on them.

She's got the correct colour eyes for me.

Little ears are, you know,

I look like a ginger Einstein.

It's the moustaches are there.

Even in the photograph which Adam and I had taken, this is, oh my lord, I was wearing a flowery top and actually she has replicated the floral pattern on the top.

Oh, wow.

Not just at the front, all the way around the back, look.

That is amazing.

Your hair looks a little bit like one of those troll dolls.

That is extraordinary.

Well, look, look at me.

Apart from my head looking quite a lot like Freddie Mercury

at his peak, she's got me all in black, which is, I mean, I actually think I'm wearing the clothes right now that she's put me in.

A little black cardigan because I'm a, you know, sort of mid-tier academic.

Okay.

That's astonishing.

That's sensational.

Little belt with an actual gold loop.

Yeah.

This might be curio.

I mean, this is going to be curio of the series.

You know what?

You've set the bar, Lucy.

Yeah, you really have set the bar.

Well done to you, Lucy.

Okay, all that remains is to remind you that you can send in your questions to curiouscases at BBC.com.uk.

Adam and I don't read any of them, but Ilan reads all of them.

So

I've actually forgotten my BBC email password

three years ago.

I never had one.

They never gave me one.

I got invited to a party I found out after the party.

Was it a good party?

I didn't go, didn't open your email.

Anyway, our team does read every single message that comes through.

So yeah, please do send in your questions and other comments that you have and entries for Curie of the Week.

But until next time...

Nature Bang.

Hello.

Hello.

And welcome to Nature Bang.

I'm Becky Ripley.

I'm Emily Knight.

And in this series from BBC Radio 4, we look to the natural world to answer some of life's big questions.

Like, how can a brainless slime mold help us solve complex mapping problems?

And what can an octopus teach us about the relationship between mind and body?

It really stretches your understanding of consciousness.

With the help of evolutionary biologists...

I'm actually always very comfortable comparing us to other species.

Philosophers.

You never really know what it could be like to be another creature.

And spongologists.

Is that your job title?

Are you a spongologist?

Well, I am in certain spheres.

It's science meets storytelling with a philosophical twist.

It really gets to the heart of free will and what it means to be you.

So, if you want to find out more about yourself via cockatoos that dance, frogs that freeze, and single-cell amoebas that design border policies, subscribe to Nature Bang from BBC Radio 4, available on BBC Sounds.

Bye.

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