People Power Royal Institution Christmas Lectures

HEART BEATING

We are all more powerful than you might think.

The sound you can hear now

is actually the sound of my own heartbeat.

And if you listen carefully, you can hear all of yours joining in.

So you might think that this

is just biology, but on a fundamental level,

what's happening here is a transfer of energy.

Every single one of us is a finely-tuned energy conversion machine,

honed by millions of years of evolution.

So, in this second Christmas lecture on our 80th birthday,

I am going to investigate how humans,

other animals and machines use energy.

And whether we can supercharge ourselves

to increase the performance of the human body.

So, welcome to the 80th anniversary Royal Institution Christmas lectures!

APPLAUSE

We are all walking, talking powerhouses.

I'm Saiful Islam. I'm a professor of chemistry at the University of Bath.

Like you, my body is converting energy all the time.

So let me show you, with this very sophisticated infrared camera.

So this camera, unlike a normal one,

it actually looks at heat rather than light.

So, give us a wave, this bit of the audience.

Come on. So, as you can imagine,

bright red means hot and the blues are cold.

So this side, give me a wave!

OK, let me see if I can get you into focus.

OK, so, quite a few.

And, then, over here, let me get you into focus.

Another wave.

OK, so you're all, as you can tell, giving off heat.

And, actually, wait a minute...

There's either somebody seriously ill or...

Or a bit dead.

Oh, yeah, just a mannequin.

OK, as I say, we are all giving off heat, so earlier,

we took a temperature of this lecture theatre

and it was 18.7 Celsius

and this is the reading right now.

So can you see that?

It's 20.2.

So, within an hour, it has gone up a bit.

So we are generating quite a bit of energy.

But just how much energy are we all using?

Is the human body a gas guzzler or an energy saver?

I think it was great to hear our heartbeats just now.

Every one of you is wearing a chest monitor and I've got one, too.

It's kind of strapped here.

It feels a bit uncomfortable.

And so what we're going to do,

we're going to try and find out

how much energy we all burn during this lecture.

So these are a couple of laptops and you can see it's got

lots of little squares.

It's, basically, all the different energy monitors, so if you look,

you can see, just about,

the different numbers and the different data.

And if you look at the screen, I don't know if you can see,

but right in the top right-hand corner where there is a little flame,

that's the calories burnt.

The bottom left, where there is a little heart, that's your heart rate

and the central figure is basically the energy consumption.

But there is a twist to this live experiment.

We want to split you up into two groups

to do a bit of a large-scale experiment.

So roughly from here, the central group here, to the right, OK?

So it's going to be roughly here to the right.

You're going to be in the group

what I'm going to call The Movers And Shakers.

And you're going to be moving up around all the time when you

hear this music.

MUSIC PLAYS

Come on, let's get up. Get up. Come on. Up you get!

Come on!

That's it, come on.

Come on. Come on, you can do better than that!

MUSIC STOPS Right.

Now, remember,

remember when you next hear that music,

I want you all to get up and do exactly the same thing,

strut your funky stuff, OK?

Right, the other group, you're going to do absolutely nothing.

Actually, we've got a special scientific term for you guys.

This group is going to be called The Couch Potato Group, OK?

So we're going to see the difference,

because we've got the chest monitors on.

We're going to see the difference between the groups

towards the end of the lecture.

So as part of our 80th celebrations,

we've invited Christmas lecturers past to help out.

So to help us with this demonstration,

it is a pleasure to introduce the 2007 lecturer,

Professor Hugh Montgomery.

He's up there.

Hello, Hugh. Thank you for joining us.

-It's pleasure. Thank you for having me.

-How does it feel to be back?

-Frankly terrifying, but less than it was last time, I think.

-OK.

Well, we've got Hugh to do something a bit special.

We're going to ask Hugh to do as little as possible.

He's going to, actually, just basically

lie down up there for the rest of the lecture.

-Right.

-And we've got a special term for him.

He is going to be called...

The Lazy Lecturer. So, is that OK with you, Hugh?

Absolutely fantastic. More sleep than I've had all week.

Well, hopefully, they've made things comfortable for you.

It looks lovely. I've got my coat, so it's a terrific pillow.

OK, great. So where does all this energy we are burning come from?

So, as a scientist, I love doing research

and testing ideas.

And I did an experiment on myself.

So the experiment was that I would actually take a food diary

and look at all the food I'd eaten over a whole week.

As you can see, it's a pretty mixed and dodgy diet.

So, this is the food I've taken in for a whole week,

so I actually need a volunteer to help me...

Well, actually, a couple of volunteers to help me scrape it in.

So do you want to come down, yes?

And one more? Sir, in the purple T-shirt.

Yes, if you want to come down.

-So if I take your name?

-Iggy.

Iggy?

APPLAUSE

INAUDIBLE

-Tally?

-Yeah.

-So we got Iggy and Tally.

So, you can see this is...some of the dodgy food I've eaten.

Some of it better than others.

So, we got a special task for you.

We're going to, actually, ask you to pass on the food to Iggy and he's going to put

it into that container there.

So what we've got are some scales, a container

and just do it as fast as you can.

And if you just pass it on to Iggy

and we just get that food into that container.

-Do I just scoop it in?

-Yeah, just scoop it in.

So we're going to just measure it later.

Just get it into that container, yeah.

So you can see... Actually, I'm quite keen on muesli.

There's quite a bit. I don't know how I ate so much soup!

So we've got there. Then, OK...

And, then...

I think I had too much bread. MUSIC PLAYS

OK, come on!

Just carry on doing it, you do that.

Come on!

OK.

OK.

MUSIC STOPS

Right. You just carry on doing that.

And if you can't reach over, there's some stuff...

There's some stuff underneath there.

So while they are doing that,

so I'd like you to welcome, to analyse the results,

last year's Christmas lecturer, Doctor Kevin Fong.

-Yes!

-Hello, how are you?

-Welcome back.

-Thank you.

How's it feel to be back in this theatre?

Do you know, I really, really wish I was giving the lectures this year.

You're welcome to take over.

Yeah, I was kidding.

You can do it. This is your weekly intake?

It is, it is.

So, we're getting them to pile it in there

and I think they are nearly done.

So I'll...

Well done! So, I'm going to make that easier for you,

why don't you get it in there? Go on!

So, what do you think of the diet?

Honestly, as a doctor, this is not good, Saiful.

There's a lot of pizza in there.

-I know.

-And chocolate.

-It's only one piece!

-Do you want a bit? I...I...I...

So there's not exactly your

-five a day in there, is there?

-I know.

-There's a lot of...

-Actually, what is lacking is the fruit content.

I don't know what happened that week.

I think I was stressed by these lectures, actually.

-Yeah.

-So, we're nearly done.

Well done, you two.

Well done. We've got one more.

This is it. Ah, thank you.

Shall we thank them? Thank you very much.

Right. We're going to try and weigh the amount of food

that's actually gone in. And it's...

What's the reading there? It says about 5.5 kilos.

So that's, roughly, what I've had over a week, so, not too bad.

Well, yeah, not too bad in terms of quantity.

Pretty poor in terms of quality, yeah.

Well, as a scientist, you'd appreciate this.

I like to do the proper science,

so not only did we look at the food going in, we also...

-Oh, no.

-We also looked at the food going out!

So, any volunteers want to help me scrape this in?

Any volunteers?

No surprises there.

Yes, this should be something I should do.

So, let me do this.

Look, I know I was famous last year for drinking my own urine,

but this is really pushing it.

I mean, really.

I'm going to use this spoon here.

So let me try and get it in there.

Oh, yes.

Oh, let's get it in!

Saiful, you've, literally, got me involved in a crap demo here.

Yes.

Oh, no.

It's chocolate! What do you think?

So, shall we take the reading?

OK. So you got about one and a half kilo, 1.6 kilos.

Yeah, and it was...

And you had just short of five kilos of food in there.

Yeah, just over five.

So why the difference?

Well, so, you've got about five...

-Let's say five kilos of food and about one and a half kilo of out...

-Yes.

-..poo there.

So, what, we've got sort of three and a half kilos difference.

And, honestly, most of that food, actually, is water.

And that's absorbed by your body.

But then, the rest of it, you use what's in the food,

the protein in particular, to build your body,

to build the organs needed to grow you.

But most of it is used in generating the energy that drives you

and everything you do. So...

So there is some point in eating that terrible diet of yours.

Well, thanks for helping out with this particular slightly unusual demo.

Thank you, Kevin Fong!

Yeah, I won't shake your hand.

Thank you.

MUSIC PLAYS

OK, up again, again!

MUSIC STOPS Right.

Thank you, Movers And Shakers.

So, exactly how much energy is in the food we eat?

Burning food is a bit of a tradition at the Christmas lectures.

If you look here, they're's Kevin again, doing some burning there.

It's a good way to find out how much energy food contains.

So we're going to do something I've called the Great Energy Bake Off.

So, food has different components and for this I need a lab coat

and sunglasses.

So, it's got fat, sugar and protein.

But I wanted to look at them separately.

So, to help them burn, we're going to soak them in liquid oxygen.

So, just to let you know, it's the food's that burning, not the oxygen, OK?

So, we'll also see...

I think we've got an infrared camera, that's it over there.

That's going to monitor the flames given off when I burn these separate

food types.

So I've...

I'm really keen on this torch.

And we've got some liquid oxygen.

So we're going to start off with some sugary substance and you can

see this here.

So we've got meringue on the left,

some protein powder in the middle and, lastly, for the fat,

some pork scratchings.

OK? Let's start off with the sugar, the meringue.

OK, so, off you go.

I'll get this flame, it's a lovely flame...

Yes, great.

So it had a bit of a flame.

So, let's move over to the second one, protein.

It's a protein powder.

That was pretty good, wasn't it? Yeah, that was great. So...

And, then, lastly, the pork scratchings.

This is our fat.

So this is our last one.

Come on, that deserves applause! Come on, yeah!

Yeah, so this is a replay of the infrared camera and you can see...

Look at the temperature it's got to.

That fat went up to 556 Celsius.

Pretty hot. So...

So you can tell which one won the Great Energy Bake Off.

It's clearly the fat.

But we can usually measure...

I mean, that's obviously a lovely, lovely display, but we can

measure energy from burning much more accurately than just using

the infrared camera.

So let's look at the values you would get from the different food types.

And we've got a special energy meter to display that.

But it's not any old energy meter,

it's an energy meter in units that, hopefully, you can all understand.

It's in AA batteries.

Units are usually kilocalories and kilojoules.

So for meringue, what do we get?

So, let's have a look at meringue.

About 25 AA batteries.

Protein? Wait, we've got...

Also 25.

Lastly, I think you can guess what you will see with fat?

So, lastly, fat.

What's the value for fat?

It's... Look at that.

56 AA batteries.

So it's over double the other two.

We can tell this if you look at the number of kilocalories

on the packaging of fatty foods.

They are a lot higher.

And that's because a kilocalorie is simply a measure of energy.

I mean, have a look next time you go food shopping or look at the sweets

and crisps that you eat.

So not all foods...

are this energy-rich and not all animals have evolved to eat like us.

I'd like to introduce you to two very special guests.

They are strange and exotic creatures,

but please welcome them a bit quietly, OK?

So...

Yes. Aw. SOFT APPLAUSE

Yes, a gentle clap, that's it, nice.

OK, this is Faith and this is Bonnie, the goat.

And the handlers, it's nice to meet you.

Alice and Tom.

Thank you for coming in.

I described them as exotic, perhaps they're not quite exotic,

but they are remarkable animals.

It's to do with their digestive system.

Their digestive system allows them to eat food and access energy that

we can't, all of us.

They are called ruminants.

What would be nice is a volunteer to come down and feed them.

Yes, do you want to come down?

Quiet applause. Quiet, quiet.

Right, can I take your name?

-Samuel.

-Samuel?

OK, Samuel, you've got some... I think we've got some...

-Spring greens.

-Spring greens.

-They are very partial to it.

If you take a small handful.

You carry on feeding. So they eat spring greens and they also eat hay,

as you can see there.

So how do they break drown that tough material?

They have a very special extra stomach

where bacteria ferment their food.

This breaks down tough plant cells that we can't digest.

Oh, very sweet.

They even bring up food...

..from their stomach back into their mouths,

so they can actually chew it over and over again!

I'm not sure if any of you would like to do that.

But hay has a lot less energy than pork scratchings.

Faith the sheep...

..has to eat three kilos of hay a day just to get enough energy to survive.

And in the fields, she must graze for up to seven hours a day.

That's a huge amount of time and a huge amount of hay.

So, let's all thank all of them with a quiet clap.

So thank you, Alice. Thank you, Tom.

OK, thank you very much.

GENTLE APPLAUSE

OK.

So if our diet was just hay, that hay there...

..we'd need to eat four and a half kilos a day

and mealtime would take for ever.

Can you imagine munching through all that?

AUDIENCE LAUGH

Oh, no!

That's OK.

So the high energy density of our food is one of the key factors in

how humans have time to do all the things we are really good at.

We've done the sums and I'll show you the results on our energy meter

while I jump over those.

So, for example...

..if we want to play the piano for an hour, it's...

It's going to be 91 AA batteries.

That's in an hour.

If standing up and painting takes...

..152 AA batteries.

Just walking in an hour takes... Let's have a look at walking.

..127 AA batteries.

So where does all the energy in the food that I ate earlier on,

where does it all come from?

There's a fundamental principle...

of energy.

You can't create it or destroy it.

It can only be converted from one form to another.

So the food itself must have got its energy from somewhere.

So let's follow the chain of energy and find out.

And to show you, I've got another exotic creature.

A salmon.

It's a bit of a violent salmon.

So this salmon wasn't part of my weekly diet,

where does the salmon get its energy from?

For this, I need three volunteers.

Maybe someone from this side.

Yourself, there, and one in green and one final one.

Yes, the one in the blue T-shirt. Yeah, come on down.

-So, hello there.

-Hello.

-Can I take your name?

-Lizzie.

Lizzie. Can I take your name?

-Isaac.

-Isaac.

-And what's your name?

-Omar.

-Omar.

OK, I'm going to put you in height order.

So if you go that side, you go on that side

and if you come across there.

So get in a straight line, OK.

We want a nice, clear picture of you.

So, I'm going to get you to hold the lovely salmon, OK?

All right, so this is a bit of a food chain,

so we want to see, really,

where these different creatures get their food from.

So I would like you to reach in there.

So, what does a salmon eat?

A salmon eats...

Put your hand in the mouth and pull out what the salmon eats.

It eats, basically, smaller fish.

And, in this case, it's just a mackerel.

But, what does mackerel get its energy from?

From its food. So why don't you stick your hand in there

and see what you can pull out. Yes.

That is phytoplankton, OK?

A good representation of phytoplankton.

So, phytoplankton is just very tiny marine plants, but like all plants,

Well, they get their energy from the sun.

So you can follow the same chain of energy for almost any food type

and any food you choose.

But it always ends up at the sun.

So every single bite of food we take is, effectively, solar powered.

Great, well, thank you, all three of you.

Thank you for coming on. So let's thank them again.

Right. But it's not just our food source that is important.

It's our size as well.

So, let me get this out.

So here we have a mouse.

Sadly, it's ex-mouse.

Well, these are the "X-MOUSE lectures".

AUDIENCE GROANS Oh...!

So, unfortunately, we wanted to use a real mouse,

but we were a bit scared that it might actually die of shock,

seeing you lot.

But it's... The reason I wanted to bring out this mouse is that it eats

about a third of its own body weight every single day, just to stay alive.

If we humans ate a third of our body weight today,

what would it look like?

It would mean eating about 150 cheeseburgers a day

if we were equivalent to that mouse.

The difference is that really small animals, like this wee mouse,

has to eat a lot more than larger mammals per unit weight.

And that's because the mouse has a relatively large surface area compared

to the volume of their body.

So this means they lose a lot more energy as heat.

So, in this case, size does matter.

OK? MUSIC PLAYS

MUSIC STOPS

You're doing really well there.

So, earlier, we saw that burning food releases its energy.

But we, obviously, don't actually burn food inside our bodies.

So how do we turn something like that salmon into energy that we can use?

So, I'm a chemist and, thankfully, a lot of this is chemistry.

So up on the screen is something I'd never thought I'd see.

This is the view of my own, I stress my own,

lower intestine from the inside.

To get this image I had to swallow a very clever device,

a very special device.

This isn't the actual one, but it looks a bit like this.

If you have a look. That is what is called a capsule endoscope.

And, essentially, it takes photos of my inside in real-time as it was

going through the body.

So I had to starve myself for two days to get a clear image.

So let's go back to the beginning of the footage

and let me talk you through what happens.

You can see these are my fingers.

I'm holding the capsule.

And I'm, actually...

There's my teeth. You can see it just passed my tongue and off it

goes down that clear channel.

And it's gone straight... Actually, the guy who was operating it at the local hospital said it went

down really quickly. I really had starved myself.

So it went down into the lower intestine and there it is.

Usually you see lots of kind of food along the way.

So what is happening within my mouth and in the stomach?

Well, it's basically some chemistry.

There are some enzymes that break down complex molecules.

And they break them down into sugar, called glucose.

And in my lower intestine that glucose goes across the intestinal walls

straight into my blood.

So the blood carries the glucose into muscles and organs

where it reacts again to give them energy.

I should say we stopped the image there.

I didn't want you to see...

..the light at the end of the tunnel, so to speak, yes.

MUSIC PLAYS Off you go. Yes, keeping them fit.

That's it. I'm going to join in this time.

Very good.

MUSIC STOPS

HUGH SNORES OK, so we've just had some really active people,

so I think it's time to catch in on Hugh.

Hugh, how are you doing?

HUGH CONTINUES TO SNORE

Right, so what does this mean for our performance?

Can we supercharge ourselves using sugar?

The answer is...sort of.

Sugar gives you that quick burst of energy, that sugar buzz.

That can be useful if you are doing a lot of exercise.

There's a reason obviously that you don't see Andy Murray snacking on

pork scratchings between games.

But, sugar, as you probably know, has its downsides, too.

Those spikes, or that rise in sugar levels in the blood,

aren't good for you long-term.

And if you take in a lot of sugar...

..it could end up being stored.

And so how does the body store some excess energy?

Well, we got a bit of a favour from a local clinic and they kindly

allowed me to borrow...

..some real human fat.

That is real. It weighs about a kilo.

It looks a bit red because of the blood in there.

But how much energy is in that kilo of human fat?

So let's go over to the energy meter to give you an indication.

So, that kilo goes up to...

Yes, a massive amount.

That kilo has 1,869 AA batteries of energy.

That's a lot, you know, much greater than the stuff I showed you before.

It would power me for three to four days.

So, this reminds us that humans are energy storage machines as well as

energy conversion machines.

So, someone like me, you might be surprised to know,

although you saw my diet earlier,

I have about ten times this beaker of fat on my body.

It means that if I was on one of those survival programmes,

I would survive up to several weeks without eating.

But long-term, we obviously need to strike a balance

between the amount of energy we take in

and the amount of energy we use up.

Otherwise, that excess energy leads to getting us overweight.

So, does our body generate any other forms of energy from our food?

We've talked about heat, we've talked about movement,

but there is something else.

The human body is far more electric than you might think.

To show this, I need a volunteer to help me play a little game.

Yes, if you could come down, in green? Yes.

-Can I take your name?

-Isabella.

Isabella. This is Isabella.

And while Isabella's getting hooked up, I'll explain what's going on.

This kind of equipment here allows someone like Isabella to control

someone else's actions using the power of electricity.

And she's going to get wired up.

On the other end,

I haven't asked another volunteer because it can be a bit weird and

feel a bit uncomfortable but it's a great pleasure...

to introduce and invite the 2013 Christmas lecturer to help out.

Professor Alison Woollard.

Hi, there, Alison.

-Hi, good to see you.

-Nice to see you.

Thank you, Alison, for joining us and helping out.

What's it feel like, being back here in the lecture theatre again?

It feels great to be back, but not in the driving seat!

OK. So, what we're going to do, we've got a cup of water.

OK.

Why don't you just take a sip now?

-Sip, right, OK.

-Because we're going to show...

-No tricks?

-No tricks yet.

That's fine, that's nice and clear.

So, Alison, if you want to show us what they've done to you outside.

Yeah, they've put these stickers on me.

OK, and they're all fine, nothing painful?

-Yeah, no, no.

-So, what James is going to do,

he's going to hook you up.

We're not going to get started yet.

So, basically, now we're connecting Isabella to Alison.

So we're going to maybe do a bit of a test at the moment.

It's not on, I don't think it's on.

Why don't you try and clench your fist and see if it affects her.

No, nothing's going on.

So, the point is that when I switch this on, Isabella, in principle,

and hopefully in practice,

can actually stop Alison having another cup of water.

So if you pick that up.

-OK.

-Let's have a bit of a drumroll.

OK, off you go. Try drinking the water.

Oh, my goodness!

-Move it!

-Agh!

Right, you can stop now.

I'm going to turn it down.

So, Alison, looks like you've got a bit of a drinking problem!

I certainly have, yeah!

Right, so how did that feel?

Well, it felt very weird.

So I felt sort of sparks here,

like a bit of an electric shock and

then, my fingers went completely mad.

I had no control over them at all.

-Was it painful?

-No, not really.

-Just weird.

-I haven't tried this yet so I don't know what it feels like.

But I want to try it later.

Feels really weird, yeah. I'm not usually so easy to control!

So, Alison, I know you're a biologist and we have discussed this.

So, tell me, what is actually happening?

What is happening between Isabella and you?

Well, our neurons have evolved this remarkable ability to conduct electricity.

So when a neuron or a nerve is activated,

like we're doing here artificially,

it causes a difference in the voltage across the membrane.

And, so, really, our neurons are tiny, tiny little batteries.

And this difference in voltage triggers a wave of electricity that travels all

the way down the neurons until it encounters muscle and it causes

the muscle cells to contract, like the ones in my fist.

And that stimulates the movement.

So, do they know how fast that signal travels?

Well, up to about 250 mph, so about the speed of a Formula One car.

-That's pretty fast.

-Very fast.

So that's why that transfer was so speedy?

Exactly, yes.

Obviously, that was a fun demo,

but there are more quite serious applications of this kind of technology.

Amputees, people who have lost their limbs,

can, actually, control their prosthetic limbs using the power

of electricity, a bit like this.

So, we're going to do one more demo.

We don't need a drumroll this time.

So don't do it yet. And, Alison, sorry about this!

-Maximum discomfort.

-Yeah, I know! We're going to let you do it again.

So thanks for being such a sport.

So, OK. Go on, Isabella. We're going to try and stop Alison drinking again.

-Whoa...!

-Go on, you do it.

-Oh, no! All over her nice dress.

-Oh, no, no, no.

Oh, no.

I'll turn it down.

Right, I think we should give Alison a hand.

OK!

So, how much electricity do we generate?

A single nerve firing produces a very small amount of electricity.

We have well over 80 billion nerves in our brains alone.

That's eight with ten zeros after it.

This adds up to enough electricity to charge a smartphone in about 70 hours.

So, of course,

we won't be plugging phones into our brains any time soon.

So we can use technology to generate electricity from our bodies,

but what about our bodies themselves?

How good are they at converting and generating energy?

How powerful are we and how do we compare to something like a machine?

There's only one way to find out.

Let's pit them against each other, let's have a fight!

OK, so we need a professional for this.

So, please welcome Britain's human-powered land speed record holder,

Ken Buckley!

-Hi.

-Hi, there.

So, Ken, you've got this record. Tell us more about this record,

what does the record mean?

So, it's the British land speed record for human-powered vehicles.

So, basically, as fast as you can get a human-powered bicycle to go.

OK, so how fast did you get?

So we did a top speed of 76.6 miles an hour.

So tell me about the training you need to get to that kind of speed,

what kind of training do you need to do?

So, I do about 15-20 hours a week, mostly on the bike,

some in the gym and a lot of stretching and yoga and other stuff as well.

OK. So, what we got here,

we got your bike and we've hooked it up to an electrical generator.

An electrical generator with a difference.

We've got it connected up to some devices, so we've got some lights,

we've got a blender and we've got a kettle here.

And we're going to see if the human machine can help to power some real machines. OK?

So we're going to get our top athlete. So...

I think we need a bit of a drumroll for this, don't we?

So let's have a little drumroll, and off you go.

So, you can see the lights coming on, so that's straightforward.

So lights don't need that much energy.

So let's see if we've got the blender.

Blender, no problem.

For the kettle, it's very difficult to monitor the kettle,

so we've got an infrared camera.

OK?

So we got the kettle coming on, and that's the tough one.

So this is the temperature of the kettle,

21.6 degrees, so it's cold water

or warm water.

So let's see if it goes up.

No.

Can you get to 100 degrees?

THEY LAUGH

OK, thanks, Ken, let's stop there.

Let's give him applause.

So, as you can see,

it was easy to get to the lights and the blender

but that boiling a kettle needed a lot of energy.

And...I think you're hotter than the kettle!

Yeah, that's about right, yeah.

Actually, let's put the thermal camera on Ken.

Let's see how he's looking. Look at that.

Let's compare it to me, and I haven't been doing anything!

That looked like tough work.

-Yeah, that was hard.

-Yes.

-OK, thank you.

-Thanks very much.

At their absolute peak,

a highly trained professional can't even boil a kettle.

So, compared to some common machines, we're not very powerful.

So, can we improve our performance for the same amount of energy?

Can we supercharge ourselves?

To find out, I'd like you to welcome the 2010 Christmas lecturer,

Professor Mark Miodownik.

-Great.

-Thank you.

OK, Mark, can you come down here?

So, Mark, what's it like to be back in the lecture theatre?

I can honestly say I would not rather be anywhere else.

Absolutely. I don't blame you.

And if you've just watched our cycling generator,

how do you think you'd fare?

Do you exercise much?

It's mostly brainpower, I have to admit.

Yep. I sit.

-You sit.

-I sit. I look.

-Do you do sports at all?

I cycle to work.

-Cycle to work? All right. OK.

-I was looking at the cycling there thinking, "I could do that."

Oh, right. Well, what if we use these running machines to pit you against Ken,

our cycling land speed record holder?

Let's bring him on. Ken, are you there?

-Hi there, Ken, again.

-Hi, there.

-Hello.

-This is Mark.

-Hi, Mark.

-How's it going?

So, we're going to do an experiment.

We just want to see how much energy you're going to use,

so we're going to start getting you kitted out.

So, if you could both get on to the treadmills...

What we have here is obviously a couple of treadmills,

but they are connected up to some monitors.

And they are going to be putting on some masks.

These masks all connect to a Vox machine.

What it does is it measures...

And you can see on the screens there,

it measures the amount of oxygen that you take in and the amount

of oxygen is given out.

And why that's useful is that you can actually relate it directly

to the amount of energy used.

The energy expenditure, and that's the two Es you see on

those two monitors.

And we're just going to compare the two...

..so before they get going, a simple question.

Who thinks that Mark will be using more energy than Ken?

Hands up. OK.

So, who thinks that Ken will be using the more energy?

Interesting. Right. So let's get the treadmills started.

OK. Off they go.

OK. So let's see how they're doing.

There is a difference already between the two,

quite a significant difference.

So let's let it run for a bit,

see if we can tire out Mark just from walking.

If I knew you were going to do this to me

I wouldn't have worn a three-piece suit, you know.

OK. So let's begin to wind down.

Shall we stop now? OK. Let's stop them both.

So you can see, if you look at the numbers...

..Ken is actually using more energy than Mark...

..which is interesting.

I have to say,

Ken has more muscle than you, Mark and that is the main reason.

Ken being more muscular...

he needs more energy to move.

That's because his body has adapted to both consuming and generating more energy.

As with everything to do with energy, you don't get a free lunch,

so, this, here...

Ooh! Nearly came off.

This is...

When Ken's training, this is his daily diet.

So Ken, being an athlete, is definitely supercharged.

Ken can do more work than most of us.

So let's thank Mark and Ken for doing this demonstration.

Thank you.

Thank you. Mark, thank you. Thanks for coming on.

MUSIC PLAYS

MUSIC STOPS

Yes. Well done.

Some good moves there, actually.

So let's catch in on Hugh.

How're you doing, Hugh?

HUGH SNORES

He looks very comfortable.

We'll come back to him.

So, there are ways to supercharge our bodies and improve our performance.

It's called training.

What about increasing performance without training?

Is that possible?

There's a drug that many athletes take to increase their performance.

It gives them better reaction times and helps them with their fatigue.

It used to be banned...

..but use was so widespread it's now become legal and I'm going to take

some right now, live on this stage tonight.

The drug is caffeine.

And, actually, I need some.

That's nice and hot.

So I was thinking about how to show you the effects

of caffeine on reaction times.

So please welcome my warm-up man, Matt.

-Good to see you.

-Good to see you.

So, Matt, I understand we got you to do something that was a bit difficult.

We asked you to give up caffeine.

-Yes.

-For how long?

Well, even though I do love my coffee,

somehow you convinced me to go for two weeks completely decaffeinated.

-So, no coffee?

-No coffee, no chocolates, no tea, it's been a nightmare.

So you are completely decaffeinated.

I'm absolutely decaffeinated, my goodness.

With that decaffeinated state, what did we do to you?

We thought we'd test your reaction times.

-Yes.

-So you can tell us more about this.

This is a BATAK machine, I believe.

-Yes.

-What did we get you to do?

This tests your reaction times by lighting up these different letters

and numbers, and you've got to hit the one that's lit up as fast as you can

and then that repeats, as some form of unusual psychological torture, for about 30 seconds.

So I think we might have some footage.

Do we have some footage of you doing something earlier?

-Yes.

-So talk us through it.

-So there you are.

-So there I am,

this is me without caffeine at all for two weeks

and I'm doing, can't even find it, there it is,

I'm doing my best to hit the lights as fast as I can and I'm doing poorly.

I think we've given you some coffee since then.

Have we? We've given you some coffee?

Yes, so since that was recorded,

I was allowed coffee for the first time in two weeks.

I've had three coffees since that happened

and my brain suddenly feels alive again.

So what was the results from that...?

-29 buzzers hit in 30 seconds.

-29?

Fewer than one a second.

That's me enjoying my coffee,

when we were getting ready for the recording.

-I love it.

-Really enjoying it.

-Yeah, I know. Really enjoying it.

So we're going to, actually, test Matt again, after that,

after he's had the coffee.

So why don't you get into position, but don't start yet.

Get into position. I think you know how to start it off, do you?

Yeah, I hit E and it all breaks off.

So I think this really does deserve a super-duper drumroll from

everybody, so come on.

And go.

-MACHINE:

-'Time up.'

Yes. Yeah!

I have to congratulate you, what an improvement.

What an improvement. So that caffeine really had an effect there.

-I feel alive.

-You feel alive.

So how did it feel that time?

Amazing. Like everything narrowed in and I was just seeing the machine,

seeing the lights and I was almost moving before I was thinking.

OK, well, let's thank Matt once more.

Thank you. Thanks a lot.

Obviously, that was just a demonstration, it was a sample of one,

but there are proper scientific studies with larger sample sizes that have

shown that caffeine does have a very strong effect on performance.

It increases activity in the brain

and tricks the body into releasing adrenaline.

It can improve your reaction times by up to 10% and even reduces

your feeling of fatigue.

But caffeine is no wonder drug.

The increase in performance is tiny...

..but those tiny margins can make a big difference for professional athletes.

But, obviously, it's not going to make me Mo Farah.

So, so far, we've looked mostly at improving the way our bodies use energy...

..but can we look at food itself?

Earlier, we worked out how much energy was in each food type...

..but that didn't include how much energy it took to produce that food

in the first place.

So can we produce food more efficiently?

So here's...

..another cheeseburger, here.

We can do the calculations.

Did you know that each burger takes the equivalent of ten burgers' worth

of energy...

..to produce?

So all this to produce that.

That's a lot.

So why is it so much?

Well, wheat to produce bread needs irrigation and takes electricity,

but it's the meat...

..that takes the most energy to produce.

So better take this away before our next beautiful guests come on...

..so this is, definitely, a very quiet welcome.

In fact, it probably doesn't need any applause.

So...

This...

this...

this is Inky Minx here on your left,

and her baby is with her, and she's called Jet, and the handlers.

Thank you very much, Felicity, and thanks for coming along.

Oh, aren't they lovely?

Obviously, to get to this size, Inky would have had to have eaten

about 2,025 kilos of grain.

We've got the real stuff now.

So, in general...

Actually, I think Inky has to...

close her ears, doesn't she?

In general, to produce just one kilo of beef takes seven kilos of grain,

and growing grain requires fertiliser, irrigation and transport.

So, in pure energy terms, this isn't a very good trade.

I have to thank the handlers and Inky Minx and their beautiful little...

..calf to come in.

So thank you very much for coming in.

Thank you.

Cows also produce something else from their food.

Let's see that with a simple demonstration.

So this is a bag or a balloon

that contains the same amount of methane gas

that Inky produces every single minute.

Actually, about the time she was in the lecture theatre.

So did you know most of this comes from burps, or up-windies,

as my children call them.

This balloon contains a lot of energy that normally goes into

the atmosphere.

Shall we take it away...

..or set it alight? AUDIENCE: Set it alight!

Thank you. I've got a pyrotechnic expert to do this for us.

I think another drumroll is worthy here.

Another drumroll, come on.

POP Yes!

Come on, a bit of applause.

What a great flame. That's fantastic.

So as we've seen, in terms of using energy,

producing meat isn't particularly efficient, so are there...

alternatives?

Interestingly, there is a source of protein just as energy-dense as beef,

but it takes...

less than half the amount of energy to produce, and luckily for you...

we've got some with us in the lecture theatre today.

And these are...

..insects, crickets and mealworms.

Would anybody like to try one?

So let's have a look, the camera there, look.

Look at that.

AUDIENCE CHATTER LOUDLY

They're perfectly safe to eat, so if you want to try them out, just...

I think they're going to go round. I'm going to try one of the crickets.

AUDIENCE GROAN Mm.

They're great.

No?

Try them out. There's some over there.

Who's tried some?

They're nice.

So what do you think? Have you tried them?

OK?

OK, I...

OK, I've...

I've tried them and I think they are, actually...

I think, actually, they're quite tasty.

So that stuff, that really is the fuel of the future,

and it's time to get the results from our big energy experiment.

MUSIC STARTS

MUSIC STOPS OK.

HUGH SNORES So we're going from the active group to the back,

to The Lazy Lecturer.

So, Hugh, how are you doing, Lazy Lecturer?

I've done very well, thank you very much.

I've had a lovely sleep this evening, thank you.

Oh, good, I'm glad you had a nice comfortable time.

Great, I'll come back to you in a second.

Backstage, we've added up the numbers and the results are in.

We've taken a sample of you lot and we've got the final figures,

which have been fed to me.

Did you know that in terms of AA batteries, The Couch Potatoes,

the amount of energy used is 4,498.

In terms of AA batteries

for The Movers And Shakers, it's 4,942.

So, really, the half of the lecture theatre that was moving about all

that time, The Movers And Shakers,

used just a bit more energy than the team who were just sitting,

so, again, the overall difference...

..is pretty small overall, for all of us.

So let's go to our Lazy Lecturer once more, Hugh,

who's been lying down doing nothing for the whole lecture.

Well, actually, you've burned energy doing absolutely nothing.

Life is expensive.

So, even at rest, my heart would be working between one and two watts.

When the explosions went off and I got a bit more excited,

probably running up to four or five watts.

Brain alert is running around 20 watts,

but maybe a little less when I was sleeping.

So there's constant activity going on,

even the work of breathing will be consuming around 4-5% of your total

oxygen consumption, so even sleeping takes quite a lot of energy.

Well, thank you, Hugh, for snoring through my lectures.

And thank you for coming along to my lecture today.

-Thank you, Hugh.

-Thank you for having me.

-Shall we applaud him?

So why didn't The Movers And Shakers use loads more energy than The Couch Potatoes?

Well, just keeping our bodies warm and alive takes a surprising amount of energy.

Keeping our heart pumping uses 5% of our daily energy.

Our brains, 20%.

Our liver, well over 20%.

In fact, about 70% of our energy goes on simply keeping alive,

so what's the total amount of energy we use over a whole day?

If we scale up the results from the audience it comes to approximately 900 AA batteries.

If we divide the amount of energy we use over a whole day by the number of seconds,

we get a power rating.

This figure tells us how much energy it takes for all human activity.

Our movements, our thoughts, our dreams.

The answer may surprise you.

It surprised me.

Each person has the same power rating as...

..100 watts light bulb.

That is clearly a light bulb moment.

And, next time, in our 80th anniversary Christmas lectures,

we're going to try and make a mobile phone last a whole year without

plugging into the mains, and also break a world record.

Thank you and goodnight.