Bang Goes The Theory (2009) s01e09 Episode Script
Episode 9
On tonight's show, Dallas explores the science of magic.
- Oonfused? A wee bit? - Just a wee bit? l experience multi-tasking with the RAF and Jem pulls silk out of a spider's rear end.
Hello and welcome to Bang Goes the Theory.
Now first up, multi-tasking isn't that right, Dallas? Oan l have two chicken tikka masala? - Put that down and watch this.
- Just wait.
Good afternoon, gents.
Today we're snapper formation.
lt costs millions to train fighter pilots like these, which is why the RAF needs to know if they have the potential to be top guns long before they ever sit in a plane.
Along with traditional training exercises, they have to pass a computer-based exam that tests their ability to multi-task even in the most extreme situations.
That is the test l am about to sit.
This is a test of your ability to do three different tasks simultaneously.
A memory test, an arithmetic task and a vigilance task.
The vigilance task requires simply zapping little diamonds in the second or two they are hidden by their own colour.
lt needs almost no concentration but once l alternate between the tasks, in this case solving arithmetic against the clock, while remembering seemingly random codes, my ability to multi-task is tested to the limit.
How well does the aptitude test that you give predict how good a pilot is going to be? We have run a study and they have proved to be very predictive tests of flying training performance all the way from the beginning, all the way to the advanced stage.
The diamonds represent the regular monitoring a pilot has to do like direction, altitude, where is my wing man? The mental arithmetic is at a slightly higher level of cognition.
Do l have enough fuel left for another bomb run, have l primed my weapon system? (lNDlSTlNOT RADlO EXOHANGE) And being able to accurately recall those lines of code tests the ability to remember important information like call signs, and co-ordinates in the split second that they're needed.
All this has to be done against the clock in an environment that offers no second chances.
To make matters worse for the pilots, some studies have shown that when we multi-task, our effective brain power drops which is a bit worrying where l am sitting.
To give you a bit of an idea, at the speed of this bad boy, we just travelled at 600 mph.
So if you want to travel from London to Holyhead, it would take five hours in a car but would take less than half an hour in this baby.
There are lots of things going through my head at the moment.
We have just pulled out on top of the cloud so that makes my life easier.
l can see what is actually happening.
l am speaking to the air traffic control centre in London.
Let them know l'm flying nice and accurately at 10,000 ft, we are about 350 mph, l have my buddy out there on my wing so he is nice and sorted.
Unbelievable.
l can keep up with one or two things but after that, l completely lose track of what is going on.
That is not really surprising because we normally think of multi-tasking as consciously doing more than one thing at the same time.
What is actually going on? The way that people understand multi-tasking is doing a lot of things at the same time.
ln fact, we can focus on one task at a time only.
We scan our environment to see what needs to be done and then we prioritise.
Then we attend to the most important task first, set it into motion and then attend to the next important task.
Really multi-tasking is not about doing lots of things exactly at the same time.
lt's about being able to switch from one to the other.
Yes, very much so.
So the idea that we can consciously do more than one thing at a time is a myth.
What we do is constantly jump from one task to another.
According to some scientists, l should have an advantage here.
MRl scans have shown that on average, women have a larger corpus callosum, the part of the brain which aids communication between its left and right sides, possibly making women better at multi-tasking.
Margaret Bailey of the RAF thinks the reason we think women have always been better than men at multi-tasking is simply down to perception.
lt starts from the stereotype image of women working at home.
Traditionally women have to look after the kids, do all the cooking, ironing, lots of tasks.
Now, men can also do the same.
There are house husbands as well.
Whatever creates the perfect fighter pilot brain, l need to know one thing, how did l do in that test? So l am ready for my test results.
- Let's have a look.
- lt's like being back as school.
How do you think you have done? l thought l did absolutely rubbish because l made some really schoolboy errors.
Let's have a look.
Here are your results.
They showed that you are around average.
l hate the word average.
Would you like to come along and apply to be a pilot? Get in.
Seriously? OK, l will take average.
l am never a fan of average but l will take it.
- So there is potential? - Yes there is.
- Really? - We just need to see your aptitudes in other areas.
Bring it! l will come back and do all the other tests.
Here's your results.
lt is the coolest exam result l have ever gotten l have to say.
ls multi-tasking a myth? lf you're talking about really concentrating on something, it is.
Do you want me to prove it to you again? - You both can juggle right? - Badly.
Not very well.
Have a go with these oranges.
Start juggling and l am going to ask you a couple of simple science questions.
- Let's see if you can concentrate on both.
- Oan you do four? lf l concentrate.
Go.
What is Newton's third law?.
Err, um Motion? F =.
Oh! - You see.
- That is unreal.
Let's do one with you, Dallas.
l can't even single task let alone multi-task.
Go! What are the four bases in DNA? - T, O, G.
- Done.
Point taken.
Fair play, Liz, fair play.
Time to catch up with our resident brain box, Dr Yan.
When we think of freezing, we think of cold, right? Wrong.
l am going to show you that freezing is hot stuff.
We all know that ice feels cold.
So this stuff seems really strange.
Wheeeee! Oh, wow! lnstantly crystallised.
lsn't that pretty? That is really, really pretty.
lt is crystallising, the same happens when things freeze.
But it is actually getting hot.
Ow! Oome and feel it.
This is a chemical called sodium acetate, hot ice, and you can make it crystallise at room temperature.
Because it crystallises instantly, you can even do things like this with it.
How cool is that? Again, where there is crystallisation, there is heat.
Oome and feel.
lt should be quite warm.
lt was cold before.
lt's the same stuff that they use in hand warmers.
lt's the same stuff inside.
Olick the button inside and it should do the same thing as you saw.
That one is going.
lt works because, strange though it may sound, things that are crystallising and going from liquid to solid actually give out heat.
lf that sounds strange, think about it the other way round.
We are all used to the idea of heating things up to melt them, that is because you need to break up the bonds between molecules in a solid to turn it into a liquid.
That takes heat energy.
When it changes back from a liquid to a solid, the heat you put in to melt it is released again when those bonds re-form.
And back the other way.
Oan you click it? There it goes.
Hold it.
Hold it.
Does it feel hot? - Yes, it does.
- That one is really hot.
That stuff smells exactly like salt and vinegar crisps.
l don't think it would work if you put it on your chips.
lt is not quite the same thing.
lt is a beautiful thing watching those crystals grow.
Gorgeous, isn't it? Knowledge is beauty.
lt is.
A question for you guys.
What do you think is the strongest material in the whole of the natural world? Natural world? OK.
Granite? Good guess but no.
Spider silk.
lt is actually pound for pound stronger than steel.
- lnteresting stuff.
- l can believe that.
l'll happily admit, l am not the biggest fan of spiders but when it comes to their engineering skills, l really do admire them.
How do they make the toughest natural fibre on the planet? lt is all to do with what the spider silk is made of and how it is put together.
Spider silk is a biological polymer which is a chemical made up of many repeating units.
A bit like this chain of paperclips.
Their construction is so fine that it is very difficult for cracks to spread through it and, watch this, it is phenomenally strong.
Over millions of years, spiders' silk producing techniques have improved to outwit their prey.
The result, a super-thin, super-tough fibre that is practically invisible.
But what l want to know is exactly how strong is this stuff? To find out, l have come to meet expert Dr Ohris Holland from the Oxford Silk Group who has kindly offered to extract some fresh silk from the beast itself.
This is a golden orb Weaver spider, painlessly held on its back with supporting pins.
Are we trying to pull the silk out of a spider's backside? Yes, the structures at the back are spinnerets and that is where the silk leaves the body of the spider.
You should be able to see a little strand fluttering around.
l can.
lf you just grab that with the tweezers.
l have got it.
Excellent.
Excellent.
Very carefully pull that out.
Oh Wow, how does the spider make that silk? The silk isn't kept reeled up like a fire hose, it is stored in organs called silk glands.
As it is being pulled, it transforms from a liquid gel into this solid fibre that you see here.
Spider silk is extremely fine, it is 30 times thinner than a human hair.
This machine is reeling in the silk l need for my experiment and she won't miss it because just one spider can produce a whopping 30 metres a day.
That is your silk for testing.
That is astonishing.
This is the moment of truth.
l have got one tiny single strand of spider silk that is Superglued to a teeny weeny scale pan.
That scale pan weighs just under half a gram and these these little weights weigh just about half a gram each.
l am going to see how much weight one tiny strand of spider silk can withstand.
Remember, it is already holding the half gram weight of the scale pan.
The thread is now supporting one whole gram.
l'm going to try the second weight.
The silk has no trouble holding the next weight and, amazingly, can take two more after that.
That is 2.
5 grams.
l am now going to try for three.
Right, another little coil of lead.
(HE GASPS) 3.
5 grams.
That's it.
One strand of that spider silk could take between 3 and 3.
5 grams.
l am amazed.
So, there's no denying that spider silk is strong stuff.
lt is the best the natural world has to offer.
What l want to know is, is there a man-made fibre that can beat it? There are three contenders.
Polyester, a polymer made of long flexible chains, like spider silk.
Rope made from steel with extra carbon for strength.
Finally, this PBO.
A rigid polymer which is seven times lighter than steel rope but twice as strong.
But just how strong are they? By my calculations, a minute one millimetre diameter rope made from spider silk should be able to take 100 kilos.
To get even close to beating spider silk, a 1 mm piece of man-made ropes should be enough to lift 80 kilos of me out of this very muddy pond.
Why a muddy pond? Because it seemed like a good idea at the time! Oontender number one, polyester.
The test rope is suspended here in the middle of our rig.
lts job? To lift me clean out of the water.
Whatever you can see of me is what it's lifting.
The rest of my body is totally supported by the water.
Well it took about half my weight or nearly half my weight.
But on the whole, like this pond, too weedy.
Oontender number two - steel.
lt feels stronger.
Oh Oof! That's lifted more of me than the polyester but even steel is still not as strong as spider silk.
lt's now time to test our final contender This is PBO - the latest in cutting-edge rope technology.
Let's see what it can take.
Astounding.
Just one millimetre of this has lifted me clean out of the water.
This is absolutely astonishing.
This wafer-thin strand of rope is holding my full body weight of 80 kilos.
Amazing.
l might just have found a man-made rival for spider silk.
Poly (p-phenylene 2, 6-benzobisoxazole) As hard to break as it is to spell.
Seriously what are we doing in these harnesses? l want to prove that PBO is genuinely stronger than spider silk.
- Hang on.
You proved that in your film, didn't you? - Not quite.
A one millimetre strand of PBO lifted 85 kilos of me clean of the water.
But a one millimetre strand of spider silk could lift 100 Kilos.
You two guys are 1 40 Kilos between you.
One millimetre strand of PBO.
lf you get lifted, then this is genuinely stronger than anything in the natural world.
- OK.
- OK.
l reckon we don't jerk around too much, Dallas.
- We'll just stay really Don't make me laugh.
- l'm not.
Just stay still.
OK.
lt's pretty close to its absolute limit, so still as you can.
OK.
Jamie, take it away.
Be gentle, Jamie.
That is where the pain starts.
That looks unnatural because it is unnatural.
Nothing in the natural world could do that.
That one millimetre strand of PBO has proved itself to be absolutely stronger than spider silk.
Ooming up next, it's the science of magic and misdirection which is a subject very close to my heart because l am a keen amateur magician.
When l got the chance to go up to Edinburgh to meet a man who lives and breathes magic, l leapt at the opportunity to dust off a few old tricks.
- Did you have garlic for lunch? - Sorry! l did a bit of magic in my youth.
One of the first things they teach you at magic school is the art of misdirection.
Misdirection is really about doing one thing but making people see something else.
So while l'm doing funny business with my cards, l might talk to them to distract them.
l'm going to try and give you a demonstration of how misdirection works.
Excuse me, sorry.
l couldn't show you a magic trick could l? Two red aces.
The ace of Diamonds.
.
.
diamonds.
The ace of diamonds and the ace of hearts.
That is the ace of diamonds.
Happy? Happy.
OK.
With your fingers, do that.
Your fingers like that.
Hands a little bit lower.
About there.
So now l'm gonna give you the ace of Diamonds.
Look at the card.
That is the ace of diamonds.
You have got the ace of diamonds and l have got the ace of hearts.
Watch carefully.
Diamonds, hearts.
lf l swap them Without looking, now.
l've got the diamonds, so you must have the? Hearts.
OK.
So hearts, diamonds.
- lf l put them both in your hand.
- Diamonds and hearts.
- Turn them both over and show the camera.
- Ah! Speechless.
Oonfused? A wee bit.
Just a wee bit? A big bit.
OK.
This is not just sleight of hand.
lt's a lot more complex than that, revealing some of the hidden workings of our brain.
l've come to Edinburgh University where researchers at Professor John Henderson's lab are looking into our visual cognition system.
They are finding out that magic actually reveals something fundamental about how our brains make sense of what we see.
We think, we feel that we look at what's in front of us.
But we don't.
We're only looking at small parts of it at any given time - here, here, here.
lf l was to bring a bright object into the scene, that would get your attention.
But the point is that whilst we're looking at one thing we're not looking at something else.
l'll pull my sleeves up so you can see.
lf l close my hand around the ball and tap the back of the hand like that, that takes your attention away from where the ball is - which is here.
Brilliant.
l've seen that trick and l can do that trick, yet l'm still fooled by it.
Presumably what is going on in my brain is very strong.
This is one reason why we have to do proper work in the lab.
Right now the theory is that if l did this and this, you will follow it.
But what if l'm wrong? What if you are looking at the watch, or the sleeve, or my hand? We need to know where you're looking.
That is where the eye-tracking equipment comes in.
lt's downstairs.
Oan we go and have a look at it? - Let's do that.
- Brilliant.
OK.
Downstairs, one of Peter's colleagues, Tim Smith, lets me loose on his eye-tracking machine.
We use an infra-red camera.
What you can see immediately is it has found these blue spots, which are your pupils.
First up, Tim shows me my normal eye movements.
This pink spot is where you're looking.
As l play it, you can see how rapidly it shifts around the scene.
That's amazing.
lt's really jumping around.
Your eyes move more frequently than you realise.
You are making these very rapid movements of your eyes - called saccadic eye movements - about three to five times a second.
So the eyes are taking little snapshots as they dance about and then stitching it together to create a whole picture.
- ls that right? - Yes.
So when a magician is doing a trick, he makes you look here, but you can't see what's there? That's true.
What Tim shows me next is really surprising.
Every time our eyes saccade, or make those little jumps, our vision actually briefly shuts down.
That means Tim could make things disappear without me noticing.
When you detect a change, l want you to press the space bar.
OK.
l'm ready to go.
Let's go.
Look all around the scene.
You can see the top of the block of flats disappear, but l can't.
Have you noticed any changes? No.
l just saw a change.
That woman was there.
Tim's computer is tracking my eye movements and it only makes a change when l'm effectively blind, because my eyes are moving from one part of the picture to another.
That's why you can see the changes, but l can't.
How many changes d'you think you saw?.
- Three.
- Let's have a look.
So this is what the scene looked like at the end.
This is what it look like at the beginning.
The tower block disappeared.
The man appeared.
The man and the little boy turned into a woman.
That was it for me.
There has now been three changes.
Did you notice the bus disappear? No.
l didn't notice the bus disappear.
- The barriers changed colour? - Not even remotely.
- Did you notice the bike disappearing? - No.
- The branch? - No.
- Or the top of this tower block? - No.
l'm rubbish.
But l have learnt why l can do magic tricks.
l'm exploiting the very way our eyes move and how they piece together what we see.
The science of magic is revealed by the magic of science.
Only recently have we had the technology to do the experiments that you are looking at today, so we can start to understand how we see the world and how we stitch it all together to give us the general experience of this constant, coherent real world.
Think of a card, any card.
- Got it? - Yes.
Seven of spades.
- Three of spades.
- Doh! And that's it for this episode of Bang Goes The Theory but we will see you very soon.
Say goodbye boys - Bye.
- Bye.
Keep going.
You should be able to feel something now Liz.
l can definitely feel something.
- Wow! That's astonishing! - Look at that.
- Oh, my life, Dallas.
- That's brilliant.
Look at that.
OK, now will you put me back together again, please? How do we put her back together? Ok, that's no even funny, what's going on? No Dallas.
How do we put her back together? - l only know the first part.
- You said you knew what you were doing! Just look at the instructions.
Dallas, these instructions are in Swedish.
- Oh, come on! - Oan we get a medic, please? 'lf you want to know what happened to Liz, log on to the website.
'
- Oonfused? A wee bit? - Just a wee bit? l experience multi-tasking with the RAF and Jem pulls silk out of a spider's rear end.
Hello and welcome to Bang Goes the Theory.
Now first up, multi-tasking isn't that right, Dallas? Oan l have two chicken tikka masala? - Put that down and watch this.
- Just wait.
Good afternoon, gents.
Today we're snapper formation.
lt costs millions to train fighter pilots like these, which is why the RAF needs to know if they have the potential to be top guns long before they ever sit in a plane.
Along with traditional training exercises, they have to pass a computer-based exam that tests their ability to multi-task even in the most extreme situations.
That is the test l am about to sit.
This is a test of your ability to do three different tasks simultaneously.
A memory test, an arithmetic task and a vigilance task.
The vigilance task requires simply zapping little diamonds in the second or two they are hidden by their own colour.
lt needs almost no concentration but once l alternate between the tasks, in this case solving arithmetic against the clock, while remembering seemingly random codes, my ability to multi-task is tested to the limit.
How well does the aptitude test that you give predict how good a pilot is going to be? We have run a study and they have proved to be very predictive tests of flying training performance all the way from the beginning, all the way to the advanced stage.
The diamonds represent the regular monitoring a pilot has to do like direction, altitude, where is my wing man? The mental arithmetic is at a slightly higher level of cognition.
Do l have enough fuel left for another bomb run, have l primed my weapon system? (lNDlSTlNOT RADlO EXOHANGE) And being able to accurately recall those lines of code tests the ability to remember important information like call signs, and co-ordinates in the split second that they're needed.
All this has to be done against the clock in an environment that offers no second chances.
To make matters worse for the pilots, some studies have shown that when we multi-task, our effective brain power drops which is a bit worrying where l am sitting.
To give you a bit of an idea, at the speed of this bad boy, we just travelled at 600 mph.
So if you want to travel from London to Holyhead, it would take five hours in a car but would take less than half an hour in this baby.
There are lots of things going through my head at the moment.
We have just pulled out on top of the cloud so that makes my life easier.
l can see what is actually happening.
l am speaking to the air traffic control centre in London.
Let them know l'm flying nice and accurately at 10,000 ft, we are about 350 mph, l have my buddy out there on my wing so he is nice and sorted.
Unbelievable.
l can keep up with one or two things but after that, l completely lose track of what is going on.
That is not really surprising because we normally think of multi-tasking as consciously doing more than one thing at the same time.
What is actually going on? The way that people understand multi-tasking is doing a lot of things at the same time.
ln fact, we can focus on one task at a time only.
We scan our environment to see what needs to be done and then we prioritise.
Then we attend to the most important task first, set it into motion and then attend to the next important task.
Really multi-tasking is not about doing lots of things exactly at the same time.
lt's about being able to switch from one to the other.
Yes, very much so.
So the idea that we can consciously do more than one thing at a time is a myth.
What we do is constantly jump from one task to another.
According to some scientists, l should have an advantage here.
MRl scans have shown that on average, women have a larger corpus callosum, the part of the brain which aids communication between its left and right sides, possibly making women better at multi-tasking.
Margaret Bailey of the RAF thinks the reason we think women have always been better than men at multi-tasking is simply down to perception.
lt starts from the stereotype image of women working at home.
Traditionally women have to look after the kids, do all the cooking, ironing, lots of tasks.
Now, men can also do the same.
There are house husbands as well.
Whatever creates the perfect fighter pilot brain, l need to know one thing, how did l do in that test? So l am ready for my test results.
- Let's have a look.
- lt's like being back as school.
How do you think you have done? l thought l did absolutely rubbish because l made some really schoolboy errors.
Let's have a look.
Here are your results.
They showed that you are around average.
l hate the word average.
Would you like to come along and apply to be a pilot? Get in.
Seriously? OK, l will take average.
l am never a fan of average but l will take it.
- So there is potential? - Yes there is.
- Really? - We just need to see your aptitudes in other areas.
Bring it! l will come back and do all the other tests.
Here's your results.
lt is the coolest exam result l have ever gotten l have to say.
ls multi-tasking a myth? lf you're talking about really concentrating on something, it is.
Do you want me to prove it to you again? - You both can juggle right? - Badly.
Not very well.
Have a go with these oranges.
Start juggling and l am going to ask you a couple of simple science questions.
- Let's see if you can concentrate on both.
- Oan you do four? lf l concentrate.
Go.
What is Newton's third law?.
Err, um Motion? F =.
Oh! - You see.
- That is unreal.
Let's do one with you, Dallas.
l can't even single task let alone multi-task.
Go! What are the four bases in DNA? - T, O, G.
- Done.
Point taken.
Fair play, Liz, fair play.
Time to catch up with our resident brain box, Dr Yan.
When we think of freezing, we think of cold, right? Wrong.
l am going to show you that freezing is hot stuff.
We all know that ice feels cold.
So this stuff seems really strange.
Wheeeee! Oh, wow! lnstantly crystallised.
lsn't that pretty? That is really, really pretty.
lt is crystallising, the same happens when things freeze.
But it is actually getting hot.
Ow! Oome and feel it.
This is a chemical called sodium acetate, hot ice, and you can make it crystallise at room temperature.
Because it crystallises instantly, you can even do things like this with it.
How cool is that? Again, where there is crystallisation, there is heat.
Oome and feel.
lt should be quite warm.
lt was cold before.
lt's the same stuff that they use in hand warmers.
lt's the same stuff inside.
Olick the button inside and it should do the same thing as you saw.
That one is going.
lt works because, strange though it may sound, things that are crystallising and going from liquid to solid actually give out heat.
lf that sounds strange, think about it the other way round.
We are all used to the idea of heating things up to melt them, that is because you need to break up the bonds between molecules in a solid to turn it into a liquid.
That takes heat energy.
When it changes back from a liquid to a solid, the heat you put in to melt it is released again when those bonds re-form.
And back the other way.
Oan you click it? There it goes.
Hold it.
Hold it.
Does it feel hot? - Yes, it does.
- That one is really hot.
That stuff smells exactly like salt and vinegar crisps.
l don't think it would work if you put it on your chips.
lt is not quite the same thing.
lt is a beautiful thing watching those crystals grow.
Gorgeous, isn't it? Knowledge is beauty.
lt is.
A question for you guys.
What do you think is the strongest material in the whole of the natural world? Natural world? OK.
Granite? Good guess but no.
Spider silk.
lt is actually pound for pound stronger than steel.
- lnteresting stuff.
- l can believe that.
l'll happily admit, l am not the biggest fan of spiders but when it comes to their engineering skills, l really do admire them.
How do they make the toughest natural fibre on the planet? lt is all to do with what the spider silk is made of and how it is put together.
Spider silk is a biological polymer which is a chemical made up of many repeating units.
A bit like this chain of paperclips.
Their construction is so fine that it is very difficult for cracks to spread through it and, watch this, it is phenomenally strong.
Over millions of years, spiders' silk producing techniques have improved to outwit their prey.
The result, a super-thin, super-tough fibre that is practically invisible.
But what l want to know is exactly how strong is this stuff? To find out, l have come to meet expert Dr Ohris Holland from the Oxford Silk Group who has kindly offered to extract some fresh silk from the beast itself.
This is a golden orb Weaver spider, painlessly held on its back with supporting pins.
Are we trying to pull the silk out of a spider's backside? Yes, the structures at the back are spinnerets and that is where the silk leaves the body of the spider.
You should be able to see a little strand fluttering around.
l can.
lf you just grab that with the tweezers.
l have got it.
Excellent.
Excellent.
Very carefully pull that out.
Oh Wow, how does the spider make that silk? The silk isn't kept reeled up like a fire hose, it is stored in organs called silk glands.
As it is being pulled, it transforms from a liquid gel into this solid fibre that you see here.
Spider silk is extremely fine, it is 30 times thinner than a human hair.
This machine is reeling in the silk l need for my experiment and she won't miss it because just one spider can produce a whopping 30 metres a day.
That is your silk for testing.
That is astonishing.
This is the moment of truth.
l have got one tiny single strand of spider silk that is Superglued to a teeny weeny scale pan.
That scale pan weighs just under half a gram and these these little weights weigh just about half a gram each.
l am going to see how much weight one tiny strand of spider silk can withstand.
Remember, it is already holding the half gram weight of the scale pan.
The thread is now supporting one whole gram.
l'm going to try the second weight.
The silk has no trouble holding the next weight and, amazingly, can take two more after that.
That is 2.
5 grams.
l am now going to try for three.
Right, another little coil of lead.
(HE GASPS) 3.
5 grams.
That's it.
One strand of that spider silk could take between 3 and 3.
5 grams.
l am amazed.
So, there's no denying that spider silk is strong stuff.
lt is the best the natural world has to offer.
What l want to know is, is there a man-made fibre that can beat it? There are three contenders.
Polyester, a polymer made of long flexible chains, like spider silk.
Rope made from steel with extra carbon for strength.
Finally, this PBO.
A rigid polymer which is seven times lighter than steel rope but twice as strong.
But just how strong are they? By my calculations, a minute one millimetre diameter rope made from spider silk should be able to take 100 kilos.
To get even close to beating spider silk, a 1 mm piece of man-made ropes should be enough to lift 80 kilos of me out of this very muddy pond.
Why a muddy pond? Because it seemed like a good idea at the time! Oontender number one, polyester.
The test rope is suspended here in the middle of our rig.
lts job? To lift me clean out of the water.
Whatever you can see of me is what it's lifting.
The rest of my body is totally supported by the water.
Well it took about half my weight or nearly half my weight.
But on the whole, like this pond, too weedy.
Oontender number two - steel.
lt feels stronger.
Oh Oof! That's lifted more of me than the polyester but even steel is still not as strong as spider silk.
lt's now time to test our final contender This is PBO - the latest in cutting-edge rope technology.
Let's see what it can take.
Astounding.
Just one millimetre of this has lifted me clean out of the water.
This is absolutely astonishing.
This wafer-thin strand of rope is holding my full body weight of 80 kilos.
Amazing.
l might just have found a man-made rival for spider silk.
Poly (p-phenylene 2, 6-benzobisoxazole) As hard to break as it is to spell.
Seriously what are we doing in these harnesses? l want to prove that PBO is genuinely stronger than spider silk.
- Hang on.
You proved that in your film, didn't you? - Not quite.
A one millimetre strand of PBO lifted 85 kilos of me clean of the water.
But a one millimetre strand of spider silk could lift 100 Kilos.
You two guys are 1 40 Kilos between you.
One millimetre strand of PBO.
lf you get lifted, then this is genuinely stronger than anything in the natural world.
- OK.
- OK.
l reckon we don't jerk around too much, Dallas.
- We'll just stay really Don't make me laugh.
- l'm not.
Just stay still.
OK.
lt's pretty close to its absolute limit, so still as you can.
OK.
Jamie, take it away.
Be gentle, Jamie.
That is where the pain starts.
That looks unnatural because it is unnatural.
Nothing in the natural world could do that.
That one millimetre strand of PBO has proved itself to be absolutely stronger than spider silk.
Ooming up next, it's the science of magic and misdirection which is a subject very close to my heart because l am a keen amateur magician.
When l got the chance to go up to Edinburgh to meet a man who lives and breathes magic, l leapt at the opportunity to dust off a few old tricks.
- Did you have garlic for lunch? - Sorry! l did a bit of magic in my youth.
One of the first things they teach you at magic school is the art of misdirection.
Misdirection is really about doing one thing but making people see something else.
So while l'm doing funny business with my cards, l might talk to them to distract them.
l'm going to try and give you a demonstration of how misdirection works.
Excuse me, sorry.
l couldn't show you a magic trick could l? Two red aces.
The ace of Diamonds.
.
.
diamonds.
The ace of diamonds and the ace of hearts.
That is the ace of diamonds.
Happy? Happy.
OK.
With your fingers, do that.
Your fingers like that.
Hands a little bit lower.
About there.
So now l'm gonna give you the ace of Diamonds.
Look at the card.
That is the ace of diamonds.
You have got the ace of diamonds and l have got the ace of hearts.
Watch carefully.
Diamonds, hearts.
lf l swap them Without looking, now.
l've got the diamonds, so you must have the? Hearts.
OK.
So hearts, diamonds.
- lf l put them both in your hand.
- Diamonds and hearts.
- Turn them both over and show the camera.
- Ah! Speechless.
Oonfused? A wee bit.
Just a wee bit? A big bit.
OK.
This is not just sleight of hand.
lt's a lot more complex than that, revealing some of the hidden workings of our brain.
l've come to Edinburgh University where researchers at Professor John Henderson's lab are looking into our visual cognition system.
They are finding out that magic actually reveals something fundamental about how our brains make sense of what we see.
We think, we feel that we look at what's in front of us.
But we don't.
We're only looking at small parts of it at any given time - here, here, here.
lf l was to bring a bright object into the scene, that would get your attention.
But the point is that whilst we're looking at one thing we're not looking at something else.
l'll pull my sleeves up so you can see.
lf l close my hand around the ball and tap the back of the hand like that, that takes your attention away from where the ball is - which is here.
Brilliant.
l've seen that trick and l can do that trick, yet l'm still fooled by it.
Presumably what is going on in my brain is very strong.
This is one reason why we have to do proper work in the lab.
Right now the theory is that if l did this and this, you will follow it.
But what if l'm wrong? What if you are looking at the watch, or the sleeve, or my hand? We need to know where you're looking.
That is where the eye-tracking equipment comes in.
lt's downstairs.
Oan we go and have a look at it? - Let's do that.
- Brilliant.
OK.
Downstairs, one of Peter's colleagues, Tim Smith, lets me loose on his eye-tracking machine.
We use an infra-red camera.
What you can see immediately is it has found these blue spots, which are your pupils.
First up, Tim shows me my normal eye movements.
This pink spot is where you're looking.
As l play it, you can see how rapidly it shifts around the scene.
That's amazing.
lt's really jumping around.
Your eyes move more frequently than you realise.
You are making these very rapid movements of your eyes - called saccadic eye movements - about three to five times a second.
So the eyes are taking little snapshots as they dance about and then stitching it together to create a whole picture.
- ls that right? - Yes.
So when a magician is doing a trick, he makes you look here, but you can't see what's there? That's true.
What Tim shows me next is really surprising.
Every time our eyes saccade, or make those little jumps, our vision actually briefly shuts down.
That means Tim could make things disappear without me noticing.
When you detect a change, l want you to press the space bar.
OK.
l'm ready to go.
Let's go.
Look all around the scene.
You can see the top of the block of flats disappear, but l can't.
Have you noticed any changes? No.
l just saw a change.
That woman was there.
Tim's computer is tracking my eye movements and it only makes a change when l'm effectively blind, because my eyes are moving from one part of the picture to another.
That's why you can see the changes, but l can't.
How many changes d'you think you saw?.
- Three.
- Let's have a look.
So this is what the scene looked like at the end.
This is what it look like at the beginning.
The tower block disappeared.
The man appeared.
The man and the little boy turned into a woman.
That was it for me.
There has now been three changes.
Did you notice the bus disappear? No.
l didn't notice the bus disappear.
- The barriers changed colour? - Not even remotely.
- Did you notice the bike disappearing? - No.
- The branch? - No.
- Or the top of this tower block? - No.
l'm rubbish.
But l have learnt why l can do magic tricks.
l'm exploiting the very way our eyes move and how they piece together what we see.
The science of magic is revealed by the magic of science.
Only recently have we had the technology to do the experiments that you are looking at today, so we can start to understand how we see the world and how we stitch it all together to give us the general experience of this constant, coherent real world.
Think of a card, any card.
- Got it? - Yes.
Seven of spades.
- Three of spades.
- Doh! And that's it for this episode of Bang Goes The Theory but we will see you very soon.
Say goodbye boys - Bye.
- Bye.
Keep going.
You should be able to feel something now Liz.
l can definitely feel something.
- Wow! That's astonishing! - Look at that.
- Oh, my life, Dallas.
- That's brilliant.
Look at that.
OK, now will you put me back together again, please? How do we put her back together? Ok, that's no even funny, what's going on? No Dallas.
How do we put her back together? - l only know the first part.
- You said you knew what you were doing! Just look at the instructions.
Dallas, these instructions are in Swedish.
- Oh, come on! - Oan we get a medic, please? 'lf you want to know what happened to Liz, log on to the website.
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