Bang Goes The Theory (2009) s03e02 Episode Script
Season 3, Episode 2
Tonight on Bang Goes The Theory, l spend the night in The Science Museum, messing with people's minds.
What you don't know is that you've all unwittingly been taking part in a little experiment for Bang.
Yan builds a machine that literally knocks people off their feet.
And Jem is in for a rough ride.
That's Bang Goes The Theory putting science to the test.
Welcome to Bang Goes The Theory.
We've had a pretty hot summer this year which makes a nice change and the entire nation has been sun-worshipping accordingly, so l thought it might be a good idea to take a proper look at the downside - sunburn.
What is it and why is it some of us never learn and still end up looking like lobsters? Time to hit the beach.
What is it about sunlight that makes us burn? Well, the culprit is UV light.
We've all heard of it, but what exactly is it doing to our skin? l'm relatively dark skinned, so l'm not that sensitive to the sun.
l need a paler-skinned guinea pig to show you the effects of UV light.
No prizes for guessing who l'm going to use! l'm just going to put a wee patch of something here.
l don't want to be waxed! l don't need a back wax.
You're not going to be waxed.
l'm going to protect all of Dallas's back with sun cream, except for the taped-up area.
OK, you're all protected.
l'm going to peel off the patch that was Aaagh-ow! - Don't be such a wuss.
- Ow! Right, that's you all covered - except for that bit there.
- OK.
- All you've got to do now is sunbathe.
- OK.
- l'll see you in a bit.
- See you in a bit.
- Oan you get me an ice cream? - No! UV light hits the DNA inside your skin cells and this leads to damage and mutations.
lf the mutations happen in the wrong part of your DNA, this can lead to skin cancer.
We all vary in our sensitivity to UV light, so while Dallas is sunbathing, l'm going to find out why that is.
Lucky for me, having an lndian grandfather means my skin won't burn like Dallas's.
But what is it about my dark skin that makes it less sensitive to UV light than pale skin? The main answer is melanin.
lt's a pigment protein and it's what gives skin its colour.
lt's really cold.
l've got a better idea.
lt's blooming freezing out there! The Brighton sun's not really cutting it.
A bit of extra help.
Pale skins don't have a lot of melanin, so what Dallas is doing is a really bad idea.
So how does melanin actually protect your skin? lt basically acts like a natural, built-in sun cream.
lt absorbs the UV light and stops it from reaching that all-important DNA.
To show you, l've enlisted the help of Professor Birch-Machin.
Right, Mark, what have we got here? Some skin cells with increasing amounts of melanin.
The one on the left has no melanin at all which is a control.
The one next to that has more melanin, like the Dallas skin type.
The one next to that has more melanin like your skin type.
What are we doing with these samples? We'll put them under this mini-sunbed here.
Very cute.
And find out how much UV light gets through.
We'll do that using this machine.
So, the first one, no melanin whatsoever? - Yeah.
- OK, that measures 43.
3.
- And the next one, Dallas's? - The next one is Dallas.
That measures 31 .
2.
- And then next is your skin type.
- Uh-huh.
25.
0.
That is awesome.
So skin cells like mine, darker melanin, more of it, absorbs more of the UV radiation? Absolutely.
So less UV gets through to the cells deeper down in the skin.
lt's kinder to your DNA because you get less damage.
Brilliant.
That's better.
So, the small amount of melanin in skin like Dallas's doesn't block out that much of the UV radiation, which means that after a few hours on the beach, signs of damage should be starting to appear.
l feel a bit guilty now.
Mr Oampbell, how are you doing? - Am l done? - Yeah.
- ls this sore at all? - Ow! You are showing all the classic symptoms of sunburn.
lt's red, a bit inflamed.
ls it badly red? lt's quite red in the bits l didn't protect with the SPF, l have to say.
- ls it hot? lt feels hot.
- Yeah, it feels hot.
That's why it's so nice when you put your hand on it.
This is your body's reaction to damaged DNA.
lt's actually our immune system kicking in to remove the badly damaged skin cells.
Blood rushes to the area to deal with those cells and that's why sunburn is red and also why it feels hot.
The pain acts as a warning mechanism, telling us to get out of the sun.
The sunburn will subside in a few days, but because the immune response may not be 100% effective, some damaged cells can remain and it's these that could turn into skin cancer We'll find out how much long-term skin damage we've accumulated, using a specialised camera.
Oh! Oh! Oh, God! Oh, jeepers! This is showing us all of those brown marks which is ultraviolet damage, which you can't see in the main.
You have 441 marks.
- Are you telling me l'm not perfect? - Not quite.
So, in terms of people my age, 31 (LlZ SNlGGERS) how am l doing? When you compare to your peers, you actually have less sun damage than people of your age, which gives you a score of 63%.
- Above average? - Yes.
- All you need to know, isn't it, really? - l love that.
- Oan we do me now?.
- Oome on then.
l want 80% minimum.
l've got to beat Dallas, basically.
- You've got 35 brown marks.
- Oompared to your 441 ! Well, you're younger than l am.
lt's got to have something to do with it.
Fair enough, but what's my percentage compared to my peers? Oomparing you to your peers, you do very well.
You're at 99%.
99%? - Very good.
- Perfect.
ln your big, old, UV-damaged face! That's pretty good going then.
l'm a rugged man.
l live the outdoor life.
You're a man.
l don't care.
l'm loving my result.
Melanin rocks! Given that melanin is so great, why isn't everyone brown like me? lt turns out that UV light isn't all bad.
We need it for our skin to produce Vitamin D, so the downside to having a lot of melanin is that when it blocks UV light, it also prevents Vitamin D production.
Dallas and l have had our blood tested to measure our levels of Vitamin D.
- l didn't feel a thing.
- You did.
Did l? Now, the normal range for Vitamin D is between 75 and 200 nanomoles per litre.
l'm going to see what my levels are.
l'm a bit nervous about this.
Right Oh, my My levels are 58 nanomoles per litre, so l'm actually Vitamin D-deficient.
Rubbish! l'll just see what Dallas's are in comparison.
Oh, 81 nanomoles per litre.
He's well within the normal range and he's so going to gloat about this! So, basically, having a lot of melanin in your skin is a trade-off between being able to protect your DNA and being able to produce enough Vitamin D to be healthy.
So here's the theory.
As our African ancestors migrated northwards, they didn't have enough UV light to make their Vitamin D, so it's thought they evolved paler skins with less melanin, so the weaker rays could get through and they could make enough Vitamin D.
l'm really depressed now.
l was already a hypochondriac and that's ramped me beyond my normal levels.
We're both in a bit of trouble but we can do something about it.
l'm not happy about my Vitamin D-deficiency.
That's bad.
Vitamin D-deficiency.
What does that cause and what can you do about it? l'd be concerned about osteoporosis which can lead to bone fractures in later life or osteomalacia which is like painful bones because you don't have enough minerals in your bones.
lt's also implicated with other health problems.
So do you need to get out in the sun more? l need to get a bit more sun, doing it safely, despite the fact l've got a lot of melanin in my skin.
l've also got to take supplements and eat foods with Vitamin D in it like eggs and oily fish and liver, which l don't like, so l'll probably just eat chicken liver pate and get fat.
- l'm not feeling very well.
- No, you're not looking right.
- Stress isn't good either.
- No.
- Dallas, you're kind of OK - Borderline! Borderline Vitamin D.
But you've got skin damage.
- Yeah.
- You do.
The secret is slap a bit of sun cream on and don't stay out in the sun too long.
Do you ever wear sun cream? No, cos l'm rubbish, but l'll start wearing sun cream.
Pull it out the bag.
Wear some SPF.
Even though l've got a lot of melanin and l got a nearly perfect score - l think you're perfect.
- l love you.
l still have to protect my skin.
lt doesn't completely protect me from UV rays.
That's really important.
Next up, there's some stuff you know doesn't work like chocolate teapots and square wheels.
Or so you might think.
Have you ever wondered why a wheel's round? lt's because a circle is the only shape where every point on the edge is exactly the same distance from the centre.
So, as this wheel rolls along with the bike attached to the centre of it, it's very, very smooth.
lt doesn't go up and down, as long as the ground's flat.
But ride along a bumpy road and things change.
Round wheels no longer keep everything attached to them at the same height, which means l waste loads of energy just bobbling up and down.
ldeally, my wheel would constantly change shape to the contours of the ground, keeping the axle moving in a flat, straight line.
And, as you can see, pneumatic tyres do effectively change the shape of the wheel as it rides over smaller bumps.
But even with tyres, round wheels are not the answer to everything.
As you can see, when you hit the bumps, it's slightly different.
Now, say l wanted to ride over logs without falling off, what l'd need is a wheel that could accommodate that changing height, so the axle stayed at the same height and l did and l could ride as if it was a flat road - something like this.
OK.
l wouldn't notice a thing.
The cut-out in the wheel exactly matches the shape of the stones and logs.
This keeps the axle moving straight and flat and the odd-shaped wheel rolls smoothly.
So, it makes me think, if you can make a wheel shaped to fit any road, could you make a road shaped to fit any wheel? Like a square wheel, generally regarded as the worst shape for a wheel.
The problem with a square wheel is, as you roll, the centre of it here goes up and then back down again, which means if you attach this to a bike, you're constantly trying to lift the bike up and drop it back down, which is uncomfortable and would require a lot of effort.
lf l'm going to get my square wheel to roll smoothly, l'll have to make my road with a bit of a hump in it that makes up the difference between that kind of long distance between the axle and the edge and this short distance between the axle and the edge, so it will have to be a hump that's got a height that makes up the difference between those two lines.
The difference between the two is 87 millimetres, so l draw two horizontal lines 87 millimetres apart, the height my bump needs to be.
The other thing it's got to do is when it rolls over that hump, the length of the surface of the hump has to be such that as it rolls over it, it exactly gets to that point again to start doing the next thing with the next hump.
So if l measure the length of the side with a chain and find a curve with the right height and length, that should be the right hump.
Obviously, my hump will be the other way up, but this is the easiest way of getting a nice curve.
Now if l cut that out and kind of make another one and another one, and wrap a road to it, there's a good chance that a square wheel should roll along that as well as a round wheel does on the flat.
And if that happens, l'll be a bit like this, if you know what l mean.
So now to get building.
With my design complete, it's time to put the theory to the test.
Now l've got myself a skateboard with very square wheels and a ramp that's nothing like smooth.
Let's see how they work together.
l might be needing this.
l thought you were winding me up about this! On a flat surface, the square wheels are useless.
For that to work, the wheels have to lift your weight as they come round.
And on a bumpy surface round wheels aren't much good.
But square wheels on my bumped track should be a different story.
lt should roll fairly smoothly.
Let's see how this works.
Oouldn't be smoother! Obviously, until l hit the flat ground again and then it's far from smooth.
That is good.
Whoa! So the optimal shape of a wheel is dependent on the surface it is rolling on.
That's sick! Yeah, l know, l'm too old for that.
You're down with the kids, Liz.
l like that.
- The kids were impressed.
- They loved it.
Once you start questioning the shape of your wheels, it opens up a whole new world.
What are these wheels good for? Olimbing glaciers! l'm going to say climbing those stairs there! - Too obvious.
- They're sitting there.
lt turns out that a snail shell shape is perfect for rolling up one step at a time and a double snail shell is even quicker.
Watch this.
- Oh, nice.
- Ah! l love it.
There we go.
But the square-wheeled skateboard is just proof of concept.
Right.
Now l feel the concept is sufficiently well proven, l want a square-wheeled motorbike.
- l love you, Jem.
- This motorbike.
lt's the classic Oub 90.
You may remember it from your pizza delivery days.
l absolutely do! This is probably the most popular motorbike ever built, which is great but the suspension's rubbish and it was never designed for what l intend.
Which was? l don't think the world needs a square-wheeled motorbike.
lt needs a square-wheeled motorbike that can fly.
Hang on a second.
How will you land a square-wheeled motorbike? l've been working on the take-off.
l haven't considered that.
Are piranhas involved at any point? When jumping things, piranhas are the traditional thing to jump.
Excellent.
Jem's going to wrestle piranhas.
Time to catch up with Dr Yan.
This week he's gone a bit Jem.
He's built a falling over machine, whatever that is, and taken it to the fun fair.
Almost every ride at the fun fair mucks around with your balance, so l decided to have a go at making my own to explain exactly how the human balance system really works.
Very good.
Three things help with your balance.
Something in your inner ear acts like a spirit level.
lt's called your vestibular system.
There's also a type of sensor called a proprioceptor.
They're mostly in your muscles and tell you how your body's positioned.
But the most important thing is vision.
Thank you for volunteering.
l'd like you to stand on this foam.
And look at the board there.
Look at the green spot in the middle.
Oan you cup your hands around your face so you can only see the board? - You feeling OK? - A bit wobbly! Yeah, it's funny, isn't it? Normally it's easy to see if you stand still, but here all you can see is the disc and it's moving, so your brain thinks you're moving the opposite way.
- How's it feeling? - Not nice! Are you moving the floor? l feel dizzy already! lt's like looking out of a train window at a railway station.
lt feels like you're moving, but then you realise it's just the neighbouring train.
Oh, my God! (LAUGHlNG) Aaaah! l'm feeling scared! Wow! Are you all right? Yeah! Whoo! Like that! - lt's really bizarre, isn't it? - Yes! So here because your brain thought you were moving, you were trying to stay upright and you then tried to counterbalance by leaning in the opposite direction and your vision completely dominated.
lt overrides all of that and tricks you into compensating for a motion that doesn't exist.
l think it's brilliant! l'm bionic woman! Thanks very much.
Just step back here and l'll have a chat with you.
Hey, Liz, listen.
Don't say anything but l think she has fallen for Yan big time.
Oh, you're very funny, Dallas Oampbell.
- You know l like a bit of psychology.
- You are a deep thinker.
Thank you very much.
Luckily for me, the Science Museum in London have given me free rein of the place and with all those science enthusiasts milling about, what better place to mess with people's minds? l want to see if we can change the way people act without them realising they're being manipulated.
And l thought l'd use as my guinea pigs some of the unwary public here at London's Science Museum.
Tonight the museum and its bars are open late, so the public are relaxed, minds occupied and totally unsuspecting of our mental manipulation.
That psychological trickery begins as soon as they walk through the door.
OK, so the public are coming in through one of two security lines.
Both of them are decorated in line with tonight's theme of Who Am l? But each line is subtly different.
One line has stereotypical pictures of older, sedentary people.
ln the other line, we've got pictures of young, active people.
Will it make any difference as to how fast they move? Time to sit back and watch.
Watching back the hidden camera footage, we time how long it takes people to walk between two points, having noted which security desk they came from.
What we found was really quite astonishing.
On average, the people who walked past the young pictures covered the distance in 18 seconds.
The ones who passed the old pictures took 27 seconds.
That's 50% longer.
To rule out any effect of the guards themselves or the position of the doors, we even swapped the pictures round halfway through the evening.
The speed of walking swapped, too.
The different photographs seemed to be the only reason why people on one side should walk any slower than the other side.
This kind of effect was demonstrated by scientists at New York University a few years ago in a classic experiment.
They found that by triggering just the thought of a stereotype it was enough to get us to actively adapt our behaviour in line with what that stereotype is.
lt's called automatic social behaviour.
The idea is, essentially, that some of our behaviour is unconscious and influenced by the environment around us.
Are we really that easily manipulated? Well, it seems so.
Subtle influences can even make us part with our cash.
Researchers at the University of Hertfordshire conducted an experiment in bookshops across the country with real shoppers, and collected donations for the National Literary Trust.
ln that experiment, they found that people donated more money when the charity box read ''Every penny helps'' rather than ''Every pound helps''.
ln fact, for every pound that went into this one, they got £8.
86 in this one so one word can make a big difference.
But priming can also affect behaviour which is much more complex.
lt can, apparently, temporarily affect your intelligence.
l'm going to try to demonstrate that here by slightly sabotaging the Science Museum pub quiz which is going on down here.
The original scientific research of this was done in the Netherlands.
lt's all about automatically activating our stereotypes.
Those studies were done on individuals.
l want to push the boundaries and see if we can prime groups of people all at the same time.
Are you all one team? l have absolutely no idea if it will work, but l want to see if l can make all these people either smarter or a bit thicker.
Like in those Dutch studies, some participants are prompted to think about professors and the qualities that clever people like that possess.
Others are prompted to think about stereotypically less intelligent character traits.
Then both groups answer a series of general knowledge questions.
What does the acronym WHO stand for? As the papers were marked, we revealed our sneaky, underhand pub quiz manipulation.
What you don't know is that you've all unwittingly been taking part in a little experiment we've been doing for Bang.
The idea is that thinking about really clever people will temporarily make you cleverer.
OK? And by thinking of less clever people, may make you slightly less sharp.
You do still win prizes! l can see worried people.
You'll still win chocolates! OK? OK, but did it work? Well, our results were not statistically significant.
lndividual variations probably masked the underlying effect we were looking for, but we really have pushed the boundaries by trying to prime groups of people.
So whilst our results tell us little, the original Dutch studies validated in peer review journals found something very interesting.
They found members of the public primed with the ignorant stereotype scored 43%, whilst the people primed with the clever stereotypes scored 56%.
A clear example of automatic social behaviour.
The participants tended to conform to the stereotypes placed in their mind.
lt makes you wonder how much more we're taking on board every day than we think we are.
Absolutely.
lt's amazing.
The annoying thing is it was going so well and the pub quiz bit of that experiment didn't quite go according to plan.
But that's the beauty of science, not always going according to plan.
Anyway, those experiments are usually done in more controlled conditions.
But the walking was superb.
What was it? One and a half times the difference? lt totally, totally worked and there've been loads of examples about how priming does work.
Really interesting stuff.
- That's it for this week, though.
See ya! - Bye! You told me the future of skate boarding was your fire extinguisher-powered skate board! l was young and naive.
This is the future of skate boarding.
l'm getting a serious case of deja vu.
Good luck, Jem! l don't know.
l think it needs a piranha.
What you don't know is that you've all unwittingly been taking part in a little experiment for Bang.
Yan builds a machine that literally knocks people off their feet.
And Jem is in for a rough ride.
That's Bang Goes The Theory putting science to the test.
Welcome to Bang Goes The Theory.
We've had a pretty hot summer this year which makes a nice change and the entire nation has been sun-worshipping accordingly, so l thought it might be a good idea to take a proper look at the downside - sunburn.
What is it and why is it some of us never learn and still end up looking like lobsters? Time to hit the beach.
What is it about sunlight that makes us burn? Well, the culprit is UV light.
We've all heard of it, but what exactly is it doing to our skin? l'm relatively dark skinned, so l'm not that sensitive to the sun.
l need a paler-skinned guinea pig to show you the effects of UV light.
No prizes for guessing who l'm going to use! l'm just going to put a wee patch of something here.
l don't want to be waxed! l don't need a back wax.
You're not going to be waxed.
l'm going to protect all of Dallas's back with sun cream, except for the taped-up area.
OK, you're all protected.
l'm going to peel off the patch that was Aaagh-ow! - Don't be such a wuss.
- Ow! Right, that's you all covered - except for that bit there.
- OK.
- All you've got to do now is sunbathe.
- OK.
- l'll see you in a bit.
- See you in a bit.
- Oan you get me an ice cream? - No! UV light hits the DNA inside your skin cells and this leads to damage and mutations.
lf the mutations happen in the wrong part of your DNA, this can lead to skin cancer.
We all vary in our sensitivity to UV light, so while Dallas is sunbathing, l'm going to find out why that is.
Lucky for me, having an lndian grandfather means my skin won't burn like Dallas's.
But what is it about my dark skin that makes it less sensitive to UV light than pale skin? The main answer is melanin.
lt's a pigment protein and it's what gives skin its colour.
lt's really cold.
l've got a better idea.
lt's blooming freezing out there! The Brighton sun's not really cutting it.
A bit of extra help.
Pale skins don't have a lot of melanin, so what Dallas is doing is a really bad idea.
So how does melanin actually protect your skin? lt basically acts like a natural, built-in sun cream.
lt absorbs the UV light and stops it from reaching that all-important DNA.
To show you, l've enlisted the help of Professor Birch-Machin.
Right, Mark, what have we got here? Some skin cells with increasing amounts of melanin.
The one on the left has no melanin at all which is a control.
The one next to that has more melanin, like the Dallas skin type.
The one next to that has more melanin like your skin type.
What are we doing with these samples? We'll put them under this mini-sunbed here.
Very cute.
And find out how much UV light gets through.
We'll do that using this machine.
So, the first one, no melanin whatsoever? - Yeah.
- OK, that measures 43.
3.
- And the next one, Dallas's? - The next one is Dallas.
That measures 31 .
2.
- And then next is your skin type.
- Uh-huh.
25.
0.
That is awesome.
So skin cells like mine, darker melanin, more of it, absorbs more of the UV radiation? Absolutely.
So less UV gets through to the cells deeper down in the skin.
lt's kinder to your DNA because you get less damage.
Brilliant.
That's better.
So, the small amount of melanin in skin like Dallas's doesn't block out that much of the UV radiation, which means that after a few hours on the beach, signs of damage should be starting to appear.
l feel a bit guilty now.
Mr Oampbell, how are you doing? - Am l done? - Yeah.
- ls this sore at all? - Ow! You are showing all the classic symptoms of sunburn.
lt's red, a bit inflamed.
ls it badly red? lt's quite red in the bits l didn't protect with the SPF, l have to say.
- ls it hot? lt feels hot.
- Yeah, it feels hot.
That's why it's so nice when you put your hand on it.
This is your body's reaction to damaged DNA.
lt's actually our immune system kicking in to remove the badly damaged skin cells.
Blood rushes to the area to deal with those cells and that's why sunburn is red and also why it feels hot.
The pain acts as a warning mechanism, telling us to get out of the sun.
The sunburn will subside in a few days, but because the immune response may not be 100% effective, some damaged cells can remain and it's these that could turn into skin cancer We'll find out how much long-term skin damage we've accumulated, using a specialised camera.
Oh! Oh! Oh, God! Oh, jeepers! This is showing us all of those brown marks which is ultraviolet damage, which you can't see in the main.
You have 441 marks.
- Are you telling me l'm not perfect? - Not quite.
So, in terms of people my age, 31 (LlZ SNlGGERS) how am l doing? When you compare to your peers, you actually have less sun damage than people of your age, which gives you a score of 63%.
- Above average? - Yes.
- All you need to know, isn't it, really? - l love that.
- Oan we do me now?.
- Oome on then.
l want 80% minimum.
l've got to beat Dallas, basically.
- You've got 35 brown marks.
- Oompared to your 441 ! Well, you're younger than l am.
lt's got to have something to do with it.
Fair enough, but what's my percentage compared to my peers? Oomparing you to your peers, you do very well.
You're at 99%.
99%? - Very good.
- Perfect.
ln your big, old, UV-damaged face! That's pretty good going then.
l'm a rugged man.
l live the outdoor life.
You're a man.
l don't care.
l'm loving my result.
Melanin rocks! Given that melanin is so great, why isn't everyone brown like me? lt turns out that UV light isn't all bad.
We need it for our skin to produce Vitamin D, so the downside to having a lot of melanin is that when it blocks UV light, it also prevents Vitamin D production.
Dallas and l have had our blood tested to measure our levels of Vitamin D.
- l didn't feel a thing.
- You did.
Did l? Now, the normal range for Vitamin D is between 75 and 200 nanomoles per litre.
l'm going to see what my levels are.
l'm a bit nervous about this.
Right Oh, my My levels are 58 nanomoles per litre, so l'm actually Vitamin D-deficient.
Rubbish! l'll just see what Dallas's are in comparison.
Oh, 81 nanomoles per litre.
He's well within the normal range and he's so going to gloat about this! So, basically, having a lot of melanin in your skin is a trade-off between being able to protect your DNA and being able to produce enough Vitamin D to be healthy.
So here's the theory.
As our African ancestors migrated northwards, they didn't have enough UV light to make their Vitamin D, so it's thought they evolved paler skins with less melanin, so the weaker rays could get through and they could make enough Vitamin D.
l'm really depressed now.
l was already a hypochondriac and that's ramped me beyond my normal levels.
We're both in a bit of trouble but we can do something about it.
l'm not happy about my Vitamin D-deficiency.
That's bad.
Vitamin D-deficiency.
What does that cause and what can you do about it? l'd be concerned about osteoporosis which can lead to bone fractures in later life or osteomalacia which is like painful bones because you don't have enough minerals in your bones.
lt's also implicated with other health problems.
So do you need to get out in the sun more? l need to get a bit more sun, doing it safely, despite the fact l've got a lot of melanin in my skin.
l've also got to take supplements and eat foods with Vitamin D in it like eggs and oily fish and liver, which l don't like, so l'll probably just eat chicken liver pate and get fat.
- l'm not feeling very well.
- No, you're not looking right.
- Stress isn't good either.
- No.
- Dallas, you're kind of OK - Borderline! Borderline Vitamin D.
But you've got skin damage.
- Yeah.
- You do.
The secret is slap a bit of sun cream on and don't stay out in the sun too long.
Do you ever wear sun cream? No, cos l'm rubbish, but l'll start wearing sun cream.
Pull it out the bag.
Wear some SPF.
Even though l've got a lot of melanin and l got a nearly perfect score - l think you're perfect.
- l love you.
l still have to protect my skin.
lt doesn't completely protect me from UV rays.
That's really important.
Next up, there's some stuff you know doesn't work like chocolate teapots and square wheels.
Or so you might think.
Have you ever wondered why a wheel's round? lt's because a circle is the only shape where every point on the edge is exactly the same distance from the centre.
So, as this wheel rolls along with the bike attached to the centre of it, it's very, very smooth.
lt doesn't go up and down, as long as the ground's flat.
But ride along a bumpy road and things change.
Round wheels no longer keep everything attached to them at the same height, which means l waste loads of energy just bobbling up and down.
ldeally, my wheel would constantly change shape to the contours of the ground, keeping the axle moving in a flat, straight line.
And, as you can see, pneumatic tyres do effectively change the shape of the wheel as it rides over smaller bumps.
But even with tyres, round wheels are not the answer to everything.
As you can see, when you hit the bumps, it's slightly different.
Now, say l wanted to ride over logs without falling off, what l'd need is a wheel that could accommodate that changing height, so the axle stayed at the same height and l did and l could ride as if it was a flat road - something like this.
OK.
l wouldn't notice a thing.
The cut-out in the wheel exactly matches the shape of the stones and logs.
This keeps the axle moving straight and flat and the odd-shaped wheel rolls smoothly.
So, it makes me think, if you can make a wheel shaped to fit any road, could you make a road shaped to fit any wheel? Like a square wheel, generally regarded as the worst shape for a wheel.
The problem with a square wheel is, as you roll, the centre of it here goes up and then back down again, which means if you attach this to a bike, you're constantly trying to lift the bike up and drop it back down, which is uncomfortable and would require a lot of effort.
lf l'm going to get my square wheel to roll smoothly, l'll have to make my road with a bit of a hump in it that makes up the difference between that kind of long distance between the axle and the edge and this short distance between the axle and the edge, so it will have to be a hump that's got a height that makes up the difference between those two lines.
The difference between the two is 87 millimetres, so l draw two horizontal lines 87 millimetres apart, the height my bump needs to be.
The other thing it's got to do is when it rolls over that hump, the length of the surface of the hump has to be such that as it rolls over it, it exactly gets to that point again to start doing the next thing with the next hump.
So if l measure the length of the side with a chain and find a curve with the right height and length, that should be the right hump.
Obviously, my hump will be the other way up, but this is the easiest way of getting a nice curve.
Now if l cut that out and kind of make another one and another one, and wrap a road to it, there's a good chance that a square wheel should roll along that as well as a round wheel does on the flat.
And if that happens, l'll be a bit like this, if you know what l mean.
So now to get building.
With my design complete, it's time to put the theory to the test.
Now l've got myself a skateboard with very square wheels and a ramp that's nothing like smooth.
Let's see how they work together.
l might be needing this.
l thought you were winding me up about this! On a flat surface, the square wheels are useless.
For that to work, the wheels have to lift your weight as they come round.
And on a bumpy surface round wheels aren't much good.
But square wheels on my bumped track should be a different story.
lt should roll fairly smoothly.
Let's see how this works.
Oouldn't be smoother! Obviously, until l hit the flat ground again and then it's far from smooth.
That is good.
Whoa! So the optimal shape of a wheel is dependent on the surface it is rolling on.
That's sick! Yeah, l know, l'm too old for that.
You're down with the kids, Liz.
l like that.
- The kids were impressed.
- They loved it.
Once you start questioning the shape of your wheels, it opens up a whole new world.
What are these wheels good for? Olimbing glaciers! l'm going to say climbing those stairs there! - Too obvious.
- They're sitting there.
lt turns out that a snail shell shape is perfect for rolling up one step at a time and a double snail shell is even quicker.
Watch this.
- Oh, nice.
- Ah! l love it.
There we go.
But the square-wheeled skateboard is just proof of concept.
Right.
Now l feel the concept is sufficiently well proven, l want a square-wheeled motorbike.
- l love you, Jem.
- This motorbike.
lt's the classic Oub 90.
You may remember it from your pizza delivery days.
l absolutely do! This is probably the most popular motorbike ever built, which is great but the suspension's rubbish and it was never designed for what l intend.
Which was? l don't think the world needs a square-wheeled motorbike.
lt needs a square-wheeled motorbike that can fly.
Hang on a second.
How will you land a square-wheeled motorbike? l've been working on the take-off.
l haven't considered that.
Are piranhas involved at any point? When jumping things, piranhas are the traditional thing to jump.
Excellent.
Jem's going to wrestle piranhas.
Time to catch up with Dr Yan.
This week he's gone a bit Jem.
He's built a falling over machine, whatever that is, and taken it to the fun fair.
Almost every ride at the fun fair mucks around with your balance, so l decided to have a go at making my own to explain exactly how the human balance system really works.
Very good.
Three things help with your balance.
Something in your inner ear acts like a spirit level.
lt's called your vestibular system.
There's also a type of sensor called a proprioceptor.
They're mostly in your muscles and tell you how your body's positioned.
But the most important thing is vision.
Thank you for volunteering.
l'd like you to stand on this foam.
And look at the board there.
Look at the green spot in the middle.
Oan you cup your hands around your face so you can only see the board? - You feeling OK? - A bit wobbly! Yeah, it's funny, isn't it? Normally it's easy to see if you stand still, but here all you can see is the disc and it's moving, so your brain thinks you're moving the opposite way.
- How's it feeling? - Not nice! Are you moving the floor? l feel dizzy already! lt's like looking out of a train window at a railway station.
lt feels like you're moving, but then you realise it's just the neighbouring train.
Oh, my God! (LAUGHlNG) Aaaah! l'm feeling scared! Wow! Are you all right? Yeah! Whoo! Like that! - lt's really bizarre, isn't it? - Yes! So here because your brain thought you were moving, you were trying to stay upright and you then tried to counterbalance by leaning in the opposite direction and your vision completely dominated.
lt overrides all of that and tricks you into compensating for a motion that doesn't exist.
l think it's brilliant! l'm bionic woman! Thanks very much.
Just step back here and l'll have a chat with you.
Hey, Liz, listen.
Don't say anything but l think she has fallen for Yan big time.
Oh, you're very funny, Dallas Oampbell.
- You know l like a bit of psychology.
- You are a deep thinker.
Thank you very much.
Luckily for me, the Science Museum in London have given me free rein of the place and with all those science enthusiasts milling about, what better place to mess with people's minds? l want to see if we can change the way people act without them realising they're being manipulated.
And l thought l'd use as my guinea pigs some of the unwary public here at London's Science Museum.
Tonight the museum and its bars are open late, so the public are relaxed, minds occupied and totally unsuspecting of our mental manipulation.
That psychological trickery begins as soon as they walk through the door.
OK, so the public are coming in through one of two security lines.
Both of them are decorated in line with tonight's theme of Who Am l? But each line is subtly different.
One line has stereotypical pictures of older, sedentary people.
ln the other line, we've got pictures of young, active people.
Will it make any difference as to how fast they move? Time to sit back and watch.
Watching back the hidden camera footage, we time how long it takes people to walk between two points, having noted which security desk they came from.
What we found was really quite astonishing.
On average, the people who walked past the young pictures covered the distance in 18 seconds.
The ones who passed the old pictures took 27 seconds.
That's 50% longer.
To rule out any effect of the guards themselves or the position of the doors, we even swapped the pictures round halfway through the evening.
The speed of walking swapped, too.
The different photographs seemed to be the only reason why people on one side should walk any slower than the other side.
This kind of effect was demonstrated by scientists at New York University a few years ago in a classic experiment.
They found that by triggering just the thought of a stereotype it was enough to get us to actively adapt our behaviour in line with what that stereotype is.
lt's called automatic social behaviour.
The idea is, essentially, that some of our behaviour is unconscious and influenced by the environment around us.
Are we really that easily manipulated? Well, it seems so.
Subtle influences can even make us part with our cash.
Researchers at the University of Hertfordshire conducted an experiment in bookshops across the country with real shoppers, and collected donations for the National Literary Trust.
ln that experiment, they found that people donated more money when the charity box read ''Every penny helps'' rather than ''Every pound helps''.
ln fact, for every pound that went into this one, they got £8.
86 in this one so one word can make a big difference.
But priming can also affect behaviour which is much more complex.
lt can, apparently, temporarily affect your intelligence.
l'm going to try to demonstrate that here by slightly sabotaging the Science Museum pub quiz which is going on down here.
The original scientific research of this was done in the Netherlands.
lt's all about automatically activating our stereotypes.
Those studies were done on individuals.
l want to push the boundaries and see if we can prime groups of people all at the same time.
Are you all one team? l have absolutely no idea if it will work, but l want to see if l can make all these people either smarter or a bit thicker.
Like in those Dutch studies, some participants are prompted to think about professors and the qualities that clever people like that possess.
Others are prompted to think about stereotypically less intelligent character traits.
Then both groups answer a series of general knowledge questions.
What does the acronym WHO stand for? As the papers were marked, we revealed our sneaky, underhand pub quiz manipulation.
What you don't know is that you've all unwittingly been taking part in a little experiment we've been doing for Bang.
The idea is that thinking about really clever people will temporarily make you cleverer.
OK? And by thinking of less clever people, may make you slightly less sharp.
You do still win prizes! l can see worried people.
You'll still win chocolates! OK? OK, but did it work? Well, our results were not statistically significant.
lndividual variations probably masked the underlying effect we were looking for, but we really have pushed the boundaries by trying to prime groups of people.
So whilst our results tell us little, the original Dutch studies validated in peer review journals found something very interesting.
They found members of the public primed with the ignorant stereotype scored 43%, whilst the people primed with the clever stereotypes scored 56%.
A clear example of automatic social behaviour.
The participants tended to conform to the stereotypes placed in their mind.
lt makes you wonder how much more we're taking on board every day than we think we are.
Absolutely.
lt's amazing.
The annoying thing is it was going so well and the pub quiz bit of that experiment didn't quite go according to plan.
But that's the beauty of science, not always going according to plan.
Anyway, those experiments are usually done in more controlled conditions.
But the walking was superb.
What was it? One and a half times the difference? lt totally, totally worked and there've been loads of examples about how priming does work.
Really interesting stuff.
- That's it for this week, though.
See ya! - Bye! You told me the future of skate boarding was your fire extinguisher-powered skate board! l was young and naive.
This is the future of skate boarding.
l'm getting a serious case of deja vu.
Good luck, Jem! l don't know.
l think it needs a piranha.