Original subtitles

Take three.

Hand speed.

Do you ever stop to consider just how lucky we are

to be completely surrounded

by genuine wonders of human ingenuity?

All of these super clever bits of tech

designed just to make our lives a little bit better.

The problem is,

we're now so used to these devices...

These are plug-ins?

...that we've forgotten to remember how clever they are.

I'm Professor Hannah Fry,

but you can think of me as your extremely qualified tour-guide...

Oh, my gosh!

Hey, don't mess with me.

...to the secret genius of everyday objects.

How do I get myself in these situations?

In each episode, I'll take one seemingly ordinary item...

...and I'll look at it...

Oh, yeah, there we go.

...in frankly obscene detail...

This tiny little bit is the thing that makes your microwave work.

...meet the people who helped make it...

We really like ears here, we're kind of obsessed with them.

...and follow the twisty-turny journey

through the history of its invention.

ARCHIVE: Here, carelessness could bring instant tragedy.

This time, it's the microwave oven.

There is a box in your kitchen,

that uses high-end particle physics

to beam invisible radiation around.

That sounds a little far-fetched, but it's just not something

you really think about when you're cooking your food.

So, how did World War Il radar tech...

Look how small it is!

...a 1970s rubber engineer...

Could you get that turntable?

I have a turntable.

...and a 19th-century physics experiment...

How many volts are you actually going to do?

...bring us...

CRACK! Oh!

...the microwave?

A microwave oven goes...

DING! DING! BEEP-BEEP!

...over 200 times a second, in the UK.

Even the queen of the kitchen, Nigella, has one.

I still need a bit of milk, which I've warmed in the mee-crow-wah-vey.

Excusez moi-vey?

So, what does it take to make a microwave?

I'm at Panasonic's factory in Cardiff.

They've been making them here for over 50 years.

1,000 microwaves a day roll off these production lines.

That's a lot of pings.

If you think about how common microwaves are,

this is a phenomenally successful invention,

and yet, it's an object that we pay no attention to whatsoever.

Frankly, I think we should respect our microwaves a little bit more.

I think there's a lot of technology that actually

goes on inside the oven to generate the microwaves.

A man who knows there is a lot more to microwaves

than meets the eye, is chief engineer Gareth Jones.

So, I'll take you over to the oven cavity area.

This is where sort of the microwave first begins its life.

So, it's the first sort of assembly process...

The babies... ..that we have. The babies! The baby microwave.

I'm going to take apart the microwave

and look at four key components,

from the turntable to the timer.

But I'm starting with the powerful heating source

at the core of every microwave...

...the cavity magnetron.

So, this is the cavity assembly, and they're just adding key

component inside the microwave, which is this magnetron.

That's...

This is the bit that makes the microwaves?

That's what generates the microwaves, yes.

So, without this, you've just got a box?

That's the clever bit, yeah. Yeah.

It's quite a good name, isn't it?

I work on cavity magnetrons. Yeah.

This is... It sounds quite cool, quite science fiction. Yeah.

Obviously, I now want to get my hands on that cavity magnetron,

to see what makes it tick...or zap.

So, I've set up shop in this, uh, shop.

I don't need to formally introduce you to the microwave.

You've all used one before, but what you probably haven't done

and definitely shouldn't do at home is tear one to pieces.

Well, I'm going to need to tread carefully because

this thing isn't particularly safe.

There we go. Oh, that's satisfying.

Now, let's get these screws off the back.

And that's it, the magnetron.

I think I'm going to get in a bit deeper, see what's inside.

Oh, yeah.

Oh!

Not convinced that was a good noise.

Is anyone else really hot?

Oh! Oh, yes, here we go.

I'm in.

Or so I thought.

Uh, inside the silver box,

which is inside the black box is another cylindrical box.

Nothing a quick hack with a saw can't fix,

and the magnetron is open.

We're in. OK.

This is the bit, this tiny little bit is the thing

that makes your microwave work.

To help explain how a cavity magnetron produces microwave energy,

I'm going to need to pucker up.

Now, you get a bottle of water,

and you blow over the top of it like this.

As my breath flows over the hole, the size and shape of the bottle

make it resonate at a particular frequency,

creating...

...a sound wave.

Clearly, those flute lessons were a waste of money.

The cavity magnetron has holes or cavities that work

just like the hole in the bottle.

And it's a similar thing that's happening inside here.

Except in this, it isn't a stream of air, it's a stream of electrons.

And every single one of these little cavities around here

acts like the water bottle does.

They resonate as the stream of electrons passes over it,

translating that stream into a wave.

Except, this time, it's a microwave.

Unlike the sound wave, I can't hear a microwave,

but we might be able to see it in action.

Watch what happens with this light bulb.

Don't do this at home, by the way.

Look at that!

Even though that light bulb is not plugged in, it lights up.

This invisible energy that is manipulating atoms

and moving electrons and making stuff happen.

When the microwaves hit the light bulb,

they cause charged particles in the metal filament to move.

This creates heat, making it glow.

And it's a similar process that cooks your food really, really fast.

ARCHIVE: There is now the perfect marriage

as in this demonstration kitchen

between the freezer and the microwave and quartz ovens.

So, why are microwaves so speedy?

Well, a standard oven cooks by heating up

the air around the food, the outside of whatever you are cooking

gets hot and that heat slowly moves towards the centre.

But that's all changed now.

Microwaves don't bother messing around heating the air.

They penetrate the outside of your food, passing through,

causing water molecules on the inside to jiggle about intensely.

That friction generates heat and voila!

Hot baked beans.

All thanks to the cavity magnetron.

But how did this ingenious bit of kit come to be

invented in the first place?

It began like all the best British things,

with our fascination with the weather.

It's the early 1920s

and scientists at the UK Met Office are trying to give pilots

advanced warning of lightning storms so that they can safely avoid them.

Cue Scotsman Robert Watson-Watt.

He understood that when lightning strikes,

it generates a massive burst of invisible radio waves.

He realised they could be detected with a receiver

coupled to two antennas.

Weather will remain fine here for a time.

The sky will cloud over by about midday.

As the radio waves hit each antenna,

they do so at slightly different times.

And so, using some simple triangles, this difference was used

to give an accurate location of the dangerous weather.

His revolutionary device called the high-frequency direction finder,

or huff-duff, was so effective that it could detect thunderstorms

over Africa, 2,000 miles away.

Watt's clever invention saved many pilots from deadly storms.

But it would take war to turn the huff-duff

into the cavity magnetron.

To show you how, I'm going to recreate a World War Il

naval battle, but in miniature,

all with the help of three men in a boat

down at the Chantry radio-controlled boating club.

All right, guys? Ah, hello there.

Hi, nice afternoon down the pond? Yes.

I've brought my own boat.

Let's see how it goes. Hang on, I'm going to pop it in.

OK. Well, it floats.

Oh, look at that. wow!

Before you ask, yes, there is a point to this.

And so, back to a more serious time.

It's the late 1930s and Europe is on the brink of war.

ARCHIVE: World conquest was impossible without running smack

up against the rock called Britain.

There is a very real fear that enemy forces will begin

a campaign of destruction that could threaten our ships and aircraft.

The British Navy would have no way of knowing where they were

until it was too late.

Step back in, Robert Watson-Watt.

He realised that if he could adapt his huff-duff weather detector

into a new system that could emit radio waves as well as detect them,

it might be able to tell him where the enemy forces were...

...50 that you could attack them.

Down here, you've got these teeny-tiny little domes.

Now, in reality, these things were massive.

They were like 110 metres tall, and they were positioned along

the coastline, chucking out radio waves across

the surface of the water.

Now, as those radio waves go out, if they hit something,

like a boat, for example, they are reflected back.

And if you can detect those reflections, you know

how fast the radio waves are travelling, you can work out

how far away something is, and that essentially then gives you radar.

Radar, radar that is the master-key to everything in defence.

Radar has been fundamental to navigation and detection

since this breakthrough in 1938.

But today, we're taking it to an entirely new level.

Now, I have to tell you that no-one has done this at this

scale before, sort of pond level, duck radar, as it were.

So, have a look here, right? We've got this little radar screen.

You can see there are some dots here in the pond,

and those are the little buoys out there.

But you see this dot here that's moving across the screen?

That there, that's that boat.

You can see them perfectly.

Now, this gives you a massive advantage.

It means you know where the enemy is

without actually having to go out and spot them.

Its development was pivotal to an Allied victory,

but it wasn't infallible.

The thing is, is that the Germans were actually

one step ahead of avoiding our radar without even meaning to,

because they had an incredibly useful stealth weapon on their team.

Look at this.

One of their boats is a U-boat, a submarine,

that below the surface of the water

is completely undetected by the radar.

Do you see that? See how that dot disappears?

That is so cool.

Not during World War 11, obviously, but in our duck-radar version.

Just like our model, the U-boats evaded radar by submerging.

They were absolutely lethal.

However, they did have one weakness.

Periodically they had to surface,

making their small conning towers visible.

This could be exploited, but it would need an entirely new

kind of radar system that could detect the tiny towers.

In 1940, a solution was developed

from a couple of Brummie scientists

called John Randall and Henry Boot.

Don't make names like that any more.

They came up with this, which is a cavity magnetron.

The key component inside the microwave, which is this magnetron.

This new invention emitted higher frequency radio waves

called microwaves.

These were better at picking up smaller targets

and shorter micro...waves, meant the antennas could get smaller, too.

Instead of giant towers,

the whole thing could shrink down to something the size of a shoe box.

And look how small it is.

So, this thing could shoot out incredibly powerful microwaves,

but it could fit inside of the nose of an aircraft

and thus detect submarines and boats

and planes from the sky.

This powerful and mobile radar system could even spot

the tiny conning towers of a U-boat.

I mean, this is the thing that largely swung the war in our favour.

Unfortunately, not doing me much help on this pond.

Where's my boat gone?

Uh, where's my boat?

You're over there by the bridge. Oh, wow!

The development of the cavity magnetron was a pivotal moment

in World wWar II.

But how did it make it out of the military and into our kitchens?

For that, we need a story about a candy bar.

Oh, oh, that's a great picture.

I didn't even remember I had this picture.

This is...

This is my grandfather.

This is Barry Spencer.

His grandad, Percy, is known as the "father of the microwave oven”.

My grandfather was awesome.

He was incredibly curious.

I think 8th Grade is as far as he got with his formal education.

Everything else he learned on his own.

He loved to build things, to take materials and things

he learned from other machines and apply those and build new things.

That was what he liked to do.

Percy's natural talent for inventions didn't go unnoticed.

In 1940, while working at electronics company Raytheon,

his expertise won them a massive contract to work

on the newly invented cavity magnetron.

Raytheon had this amazing invention.

That's when they started thinking about,

"Well, what else can we do with this?"

Legend has it that Percy was standing next to a test magnetron

when its microwaves zapped his pocket and melted his nut cluster.

And that was when Percy had his light-bulb moment.

He was like, "Well, let me just see if it can heat food," you know,

and, "Oh, look, it heats food."

Curious, he put other objects in its path

and discovered that popcorn kernels popped,

and eggs exploded.

He invented this extremely important device,

the microwave oven.

In the early 1940s, Percy submitted dozens of patents

related to the magnetron and microwave cooking.

Even patenting today's movie night staple.

Yeah.

My grandfather invented microwave popcorn.

Put it in, popcorn gets popped, simple as can be.

In 1947, Raytheon launched the world's first commercial

microwave oven.

And in a throwback to its radar origins, called it the Radarange.

The self-taught inventor from New England had created something

that would end up in kitchens across the world.

I think of him a lot.

Yeah, sometimes I just, you know,

sitting there waiting the 30 seconds to heat something up.

And I think, "Wow, so convenient.”

And it's amazing that this was my grandfather's, you know, invention.

Percy's revolutionary idea was a defining moment

for the cavity magnetron.

In the 1950s, scientists experimented

with the cavity magnetron in various ways,

communications, traffic control and frozen hamsters.

British scientists who were trying to transform organ transplant

storage were experimenting with cryogenically frozen hamsters

when they realised that microwaves were

the perfect way to bring them back from the dead.

But microwave ovens,

the magnetron's most promising use,

weren't an immediate success.

The original Radarange cost the equivalent of £50,000

and was a mighty six feet tall.

But by the 1970s, magnetrons were cheaper and smaller

and microwave oven sales began to soar.

Eight automatic settings, work out the power and cooking time.

By the end of the 20th century,

the cavity magnetron ushered in a powerful and fast way to cook.

However, it brought a potential new danger to the kitchen.

Microwave ovens use powerful radiation to cook our food.

To be safe, it needs to be harnessed within the confines of the oven,

and that is the job

of our next component,

the Faraday cage.

The thing about microwaves is they are potentially quite dangerous.

Just popping that in there.

Yeah, that was a phone that I just put in the microwave.

Just bear with me.

Microwave ovens produce powerful waves of energy that can burn you

if you are exposed to them.

Anyway, you've got all of these microwaves bouncing around,

you don't want any of them to escape.

And so, there is something built in to one of these

to stop that from happening.

It's called a Faraday cage

and I've just put the cameraman's phone inside of one.

If I call Marco the cameraman's phone

while it's inside of the microwave...

The number you've called is currently unavailable.

Hmm, hasn't connected.

Let me just try again, but this time, with the door open.

MOBILE RINGS

And now, it goes straight through.

So, what's going on?

Mobile phones communicate via microwave.

I wouldn't worry.

The power of the microwaves that your phone are using

are so tiny, they're not enough to fry your brain.

When the oven door is closed, this microwave link is broken.

And that is because there is a Faraday cage

inside this that is blocking all of the microwaves.

To show you this special little cage,

I'm going to need to up my game.

I'm going to have to use one of these.

I mean, how else do you get a microwave door off?

Hoo hoo hoo!

Oh, you know what?

I've just noticed, there's actually two screws on the top.

I could have just used a screwdriver!

With the sides and the door so carefully removed,

the Faraday cage is finally revealed.

But what you are left with, the main body of your microwave,

it is just... It's just a metal cage and this is enough to stop

the microwaves bouncing through and leaking out.

But wait, isn't putting metal in the microwave a no-go?

Well, kind of.

Microwaves can induce concentrated electric fields in metal objects,

especially sharp edges or corners like forks or tinfoil.

If electric charge accumulates excessively, sparks will fly.

But on the smooth metal walls of the microwave oven,

these currents scatter harmlessly, avoiding sparks altogether.

But there is a problem.

You can't have metal all the way around because,

well, then you wouldn't be able to see what your food looked like.

And that brings me to the most interesting part of the cage,

which is this bit here.

The door.

Yeah!

There are two components to this now.

So, there is a bit of glass, which is see-through,

and there is this metal mesh.

These little holes are enough to stop microwaves from escaping.

And this is enough to stop that mobile phone from ringing.

The Faraday Cage is so crucial for preventing radiation leaks,

it's now found in every microwave oven.

But to find out where it came from,

we have to go back to the early 19th century.

The year is 1836, and a young, and, may I say,

very dapper English scientist called Michael Faraday,

has discovered that the new wonder of the age, electricity,

has a powerful but invisible property.

You don't need me to tell you how powerful electricity is,

but the thing that you do need to know is that electricity

comes with this invisible field.

Known as an electric field,

it's a space where electricity can flow even without wires.

It's really hard to show you.

Unless you've got an industrial-sized

electric field generator,

also known as a Tesla coil.

This one is housed in a special high-voltage lab in Germany.

It can produce a powerful electric field that can cross the room.

It's enough to light up fluorescent light bulbs

that aren't even plugged in.

Faraday wanted to understand how this powerful new force behaved.

He had a theory that might help contain it.

You'd have seen this in school.

You rub a balloon, you create static electricity.

This gives the balloon a charge,

which produces an electric field around it.

And you can't see it until it interacts with something.

Ah.

Faraday charged different materials and noticed some

conductors of electricity behaved in a surprising way.

This charge sits all on the outside

and none of it is on the inside.

Now, that seems like quite a simple thought,

but, actually, this is quite a revolutionary idea.

If the charge stays on the outside,

then things inside would be protected from the effects

of potentially dangerous electricity.

And not just in a balloon,

but even inside a well-known conductor like metal.

If Faraday was right, well, then, surely he should be able

to stand inside something while it was being electrocuted

from the outside.

And so, he set about building himself a tinfoil room.

He electrified the cage until it generated huge sparks,

an experiment I'm already regretting agreeing to attempt.

I'm going to use a slightly more modern version here of a cage.

And now all I need is some lightning.

That's delivered from the high voltage Tesla coil above me.

And...should be fine in here.

Now I know how those frozen hamsters felt.

Being electrocuted...in theory.

How many volts are you actually going to do?

Um, around 1.2 million volts.

How do I get myself in these situations?

What would happen if I poked my finger through?

Not advisable. As in, I'L die?

Might happen, yeah.

Oh, my goodness me, what have I done?

Charging.

OK. Achtung.

Charging.

Fire.

And fire.

ELECTRICITY CRACKS

SHE WHIMPERS

I mean, that's genuinely like being shot.

The conductive metal redirects the electric charge

of the lightning across the outside surface,

meaning there's no electric field on the inside of the cage.

So, me and the fluorescent light tube that I'm holding

remained completely protected from the 1.2 million volts.

You have to imagine, that in the 19th century,

Faraday emerges completely unharmed.

But what he'd done, he'd proven that the inside of the cage

is completely safe from the outside.

And what works for an electric charge also works for microwaves.

Microwaves also cannot penetrate the cage.

And because they're generated inside the oven, when the microwave energy

hits the Faraday cage, it bounces around inside, but can't escape.

Do you remember this little guy here?

The front door of microwave is completing a Faraday cage

inside of your machine.

And this is what stops the microwaves

that are generated on the inside from escaping.

Faraday died before microwaves were discovered.

So, he never knew that his cage would change the world

one ready meal at a time.

The first Faraday cages were scientific instruments

used in experiments to push the boundaries of our knowledge

of physics and electricity.

But in the 1940s, with a development of microwave ovens,

they moved into being everyday objects.

Those first test models used a galvanised rubbish bin and lid

to contain the microwaves.

And it did the job, although it wasn't much good for seeing

if your lasagne was ready.

And then in 1955,

domestic microwaves with a custom-built metal cage came along.

Cut to today and the bonkers thing is that their design

has hardly changed at all.

But we have now found more uses for Faraday cages.

They keep radio waves from interfering with

MRI scanners in hospitals.

Every plane is basically a giant Faraday cage that protects us

from lightning strikes.

And for the more paranoid among us, Faraday bags are a way to ensure

no-one is snooping on your phone or laptop.

Back at the Panasonic factory, they build their Faraday cages

with safety in mind from the very beginning.

We need to ensure there's no leaking basically.

The microwaves are not escaping.

Meet the Faraday cage guru,

or as he prefers to be called,

mechanical engineer Thomasz Moishko.

I mean, this is the Faraday cage being formed, then? Yes.

The birth of the beast. Yes.

It began life as individual sheets of metal.

And so, you are glueing them together

to make sure that the microwaves can't escape?

Uh, so they're crimped.

So, we ensure the whole back of the appliance is fully sealed.

I see.

With the Faraday cage complete,

each microwave is then scanned by a radiation-detecting robot.

What's the robot doing? Smashing...

Selecting the power. ..smashing the buttons. Yeah?

And then selecting the time, then start.

Oh, what's inside it?

Um, so that's, we call it a pizza.

The pizza, sadly, is just a powered LED mat

that shows the oven is working.

I mean, just add pineapple to really top the disappointment, lads.

How often do you get them breaching, breaching the door?

It's happened sometimes, you know, it's... Nothing's perfect.

But we normally find them, and everything will need adjusting,

come back for the same tests and we're checking again.

But, generally, you are quite good at making microwave cages? Yes.

There's one last process before the microwaves are boxed up

and shipped out.

So, we're taking a picture of every single oven,

so we know what is the cosmetic condition of each appliance

before it leaves leave the factory.

Yeah, the picture is taken there.

And there.

The next component appears to be a simple rotating dish,

but without it, you'd have unevenly cooked food.

It's the microwave's spinning soul, the turntable.

There is one slight problem with microwaves.

Let me show you what I'm talking about here.

OK, so let me just get rid of this turntable for a second.

And, uh, let's have a sweet treat, shall we?

Microwave some marshmallows.

So, inside this, you've got your magnetron.

It's firing out microwaves.

And so, if you try and heat up your food without using the turntable,

there'll be some sections which are, like, volcano hot

and other sections that are totally untouched and stone-cold

as when they went in.

You can see this really clearly on a thermal camera.

You have got this white-hot ring around the outside

where things are completely melted,

and then a central ring where the marshmallows are still really cold.

What's happening is that as microwaves enter the oven,

they reflect off the walls and combine with each other.

In some places, the waves cancel each other

out along the middle line, resulting in low-energy cold spots.

And in others, they amplify each other at the peaks

and troughs, creating hot spots.

The result is known as a standing wave,

and it gets stuck in this pattern.

That shape of that wave,

the hot bits and the cold bits inside your microwave,

they're not going to change.

And so, if the wave won't change,

you have to move the food to make sure that it gets all cooked.

And that is why microwaves need a turntable,

to move food through the hot spots of the standing wave

so it cooks evenly.

Um, there you go.

They're all gone squishy.

It's just a plate of molten gooey mess.

Molten, gooey, delicious mess, that is.

This is my job, by the way.

This is what I do for a living.

The turntable hasn't always been a feature in microwave cooking.

The first microwave ovens of the 1950s had no turntable.

To avoid cold spots, you had to periodically turn the food by hand.

For decades, they tried and failed

to come up with a satisfactory solution.

A paddle, or stirrer, helps to distribute the microwaves

evenly inside the cooker.

The problem of uneven cooking was impacting on microwave sales.

A spinning solution that could be added to your microwave to even

things out would come from a man trying to solve a rubber problem.

Half of your meal is burned,

and half of your meal is ice cold

because of this problem with microwave.

That is Gary Mandle.

In the early 1970s, he was working with microwave technology,

but not in domestic ovens.

So, I had a winter job after high school with this company

called Gerling Moore, which made industrial microwave ovens.

Kind of, custom things.

And my job was as an assistant to the chief engineer Peter Jorgensen.

He took me under his wing,

and they had this contract with Goodyear Tire to vulcanise rubber.

Vulcanised rubber is the tough stuff that wellies and tyres are made of.

It's produced by heating natural rubber with chemicals,

but it's a tricky business.

And so, Goodyear hoped that this new microwave tech would make it easier.

The vulcaniser was a large microwave oven, about six feet squared,

and it had a Pyrex tube about eight, ten inches in diameter.

And hard rubber would come in one end of the tube

and as the tube rotated, it would roll down into the tube

through the microwave cavity

and the microwaves would vulcanise the rubber.

Only, it wasn't quite going to plan.

So, as the rubber went down the tube,

you would have these standing waves.

Ah, yes, the cause of the dreaded hot and cold spots.

And it would melt the rubber and eventually it catches fire.

This happened over and over again until one night, they'd had enough.

At that point, we've put out another fire on the vulcaniser

and it's late at night

and Peter and I are exhausted working this.

They began chatting about the problem.

So, what we had to do, was find a way to rotate the object inside

so that it would pass through where these standing waves were.

And that's kind of what took us down the road to the turntable.

It was a eureka moment, though, sadly, not for Goodyear.

There's no way we can do a turntable in here.

We can't have the tube of Pyrex spinning around the room.

But in smaller cavities like a home oven,

we could have something in the bottom of the oven

that spun and passed the food through these waves.

They were convinced that a turntable that could be added into any

microwave would sort out the hot and cold spots.

What was unique about our idea was,

one, the turntable itself.

Something that was portable that you could put in your oven

that would rotate the food and cook it evenly.

And at the end of the day, we both decided,

we're going to quit and we're going to pursue this.

He quit, I quit, and then, we started working on it.

It took seven years to complete the design,

but finally in 1980, they received a patent

and the microwave industry immediately saw the potential.

The patent was published.

And it couldn't have been two days later,

we got a letter from Nordic Ware,

"We need to talk to you."

They came up with an offer almost right away.

Nordic Ware took exclusive rights to the patent

and started producing turntables.

The reaction was huge.

It wasn't 150,000 units a year.

It was millions of units a year and...

...could you get the turntable?

Ah, there's a turntable?

I have a turntable.

Wow!

$5 rebate!

5% rebate.

Betty Crocker approved!

This simple turntable that you added to your microwave

solved a problem that had been plaguing the industry for decades,

and it changed Gary's life.

It turned my family from starving...

...to...we actually were able to,

you know, really start getting our lives together.

When I go in the store, you'll see a microwave and it's very nice

to go and point at that and say,

"I had something to do with that."

And I'm very proud of that.

It wasn't until the mid-1980s that turntables were fitted

as standard in microwaves.

Japanese manufacturers Sharp, were the first to sell them

with built-in spinning plates and other brands soon followed.

However, to make sure your food is cooked perfectly,

the microwave needs one last, but fundamental part.

Without our final component,

your food is either overdone or undercooked.

The crucial key to making sure everything is cooked just right.

It's the timer.

As anyone who's ever exploded their dinner in the microwave

will tell you, when it comes to microwave cooking,

timing is everything.

So, you can tell even before I open the door,

you can tell that that's going to be overcooked?

I know that they're not happy in there, the beans.

Yeah, so...

That's Victoria Simone, Panasonic's head home economist

and titan of timing.

She knows that every second counts.

The only other thing that I use my microwave for,

occasionally, is to cook a baked potato.

Victoria spends her life working out how long different foods take

to microwave, to provide timing guides.

So, she's slightly horrified by my approach.

So, chuck it in, nine minutes or so.

That's what I would do.

Just kind of guessing at the time.

It's almost ready now.

All | know is, this is going to be a delicious evening meal for me.

I mean, look.

Delicious.

Enjoy. You smell the burning?

Does smell a little bit in there!

It'll be delicious!

What are you trying to say? What are you trying to say?

Look that's... Oh, that's beautiful.

Does this not bring you back to school dinners?

I mean, that's really quite cooked, isn't it?

I thought I was doing all right there.

Can you imagine how happy my kids are to have me as their mum?

Luckily, thanks to experts like Victoria, most foods come

with precise instructions to set on the microwave's handy timer,

avoiding incinerated spuds altogether.

But how did we get the timer of today?

Humans have been obsessed with measuring time since, well,

the beginning of time, but we only started measuring our cooking time

properly once we got accurate ovens in the 20th century.

Early kitchen timers were hourglasses,

followed by mechanical, wind-up timers -

chicken-shape optional.

But when microwaves came along in the 1940s,

they were the first ovens that had to include an integrated timer

as standard.

To find out why, we have to go back to Percy Spencer,

and the very first prototype microwave oven.

There is one story, possibly apocryphal,

that one day, Percy was trying to demonstrate

the effect of the microwave by trying to cook a raw egg.

He cut a hole in the side of a kettle, placed an egqg in it,

and then directed microwaves towards it.

This whole circle of engineers, including one who is

extremely eager, he's peering over at this sort of vibrating egg

in the middle and then ends up getting splattered in the face

with the egg.

Which is unfortunate, but the egg was cooked.

Higher, higher!

To avoid egg on your face, timing is everything with microwave ovens.

After Percy's incident, the guy who founded Raytheon,

a guy called Laurence Marshall,

he becomes totally obsessed with the microwave oven

and he's hoping that this might be the thing that can save

the company from all of its financial troubles.

But Laurence knows the commercial success of this crazy new oven

will be jeopardised if customers face exploding eggs

or overcooked food.

So, every free moment, he'd come out of the boardroom

to get stuck in on experimenting with timing.

He realises that there is a really delicate balance to be struck,

not just about the amount of energy that's going into the food,

but also with the time that you are cooking it for.

So, he gets his engineers to make him a sort of home-made microwave,

he uses a trash can, gets a magnetron and shoves it in the side.

He starts using it to heat up cups of water.

“Not good enough!" cries Marshall, we have to use real food.

He nips down to the grocery store,

and he gets himself an absolute shed load of a new product

that they have just released, which is pre-packaged gingerbread mix.

I mean, who doesn't love a bit of ginger?

Night after night, he tried cooking gingerbread with different amounts

of microwave energy and time.

He knows if you put the power on too low

and for too short a time, you're going to end up with something

that is just a bit of a squidgy mess.

However, too much energy for too long and you get...

I mean, that's quite the...

That's quite the aroma.

Oh, my gosh!

Can you see the smoke? This is not going to...

This is... Whoa!

SHE CHUCKLES

This is not going to be the thing that really sells the microwave

as an effective cooking tool.

BLEEP!

Ah, so, Laurence Marshall, how's your microwave experiment going?

OK, delicious.

I mean, I think that's probably the wrong combination

of energy and time.

Shall we try again?

But after a lot, a lot, a lot of gingerbread,

a lot of smoke, and a lot of squidgy dough,

he realises that there is this sweet spot in the middle.

Oh, look at that!

It's cooked.

It's cooked!

Laurence's obsession with timing meant that when the first

Radarange microwave was launched, it came with a built-in timer.

This allowed for incredibly precise speed cooking.

Take, for example, the Speedy Weeny,

Raytheon's microwave hot-dog vending machine.

Installed in Grand Central Station in 1947,

its on board timer meant that it produced the perfect hot dog

every time in just 20 seconds.

History doesn't record if it also served condiments.

Timer precision improved throughout the '50s and '60s

as more complex mechanical versions came on the scene.

The new Norelco has three simple dials that lets you cook

everything the others cook, only easier.

Digital timer displays made their first appearance in the 1970s.

Another feature to consider is an easy-to-read digital timer,

which lets you set up to 60 minutes of continuous cooking

or defrosting time.

By the 2000s, our timers were getting cleverer than ever.

Our microwaves are great at reheating and some cooking,

but they have their limits.

What if, one day, microwave ovens could cook a whole Sunday roast?

Sound too good to be true?

It could be the future.

A new oven promises a glimpse into what the next generation

of microwave cooking might look like.

I know you're a proper posh chef, but today,

I mean, you basically brought out an ice cube.

That's chef Cesar Fernandez.

And, yes, he's putting a massive ice cube into a microwave.

You're going to microwave an ice cube?

What do you think is going to happen?

I mean, it's going to melt, obviously.

Maybe that's what will happen. Maybe not. OK.

But, yeah, let me just get my block of ice inside the oven.

All right, so let's see what happens.

After seven minutes, how has the ice fared?

I'm expecting a miniature tidal wave

to greet me as I open the door. Go on.

Oh, OK, literally nothing has happened.

The ice remains entirely intact.

The ice didn't cook, but something else has.

Let's just reveal what's inside the ice block.

Oh!

So, as you can see in here,

we've got a perfectly cooked piece of fish.

Gosh, look at that! Oh, my gosh, it's falling apart.

Can I try some?

It's perfectly cooked. It is.

It's perfectly cooked.

Cesar's ice stunt shows that this is no ordinary oven.

Instead of a cavity magnetron,

it uses a silicon chip that converts electrical energy into microwaves.

And crucially, this means it can generate different frequencies

of microwave, depending on the foods you want to cook.

Hold on a minute.

Inside the ice,

it's still very, like, frosty.

Like, there's actual frost on the inside.

And then it's hot.

It's hot.

It's properly hot.

The technology was originally developed for reheating

transplant organs.

A job of ultimate precision.

So, let's give it a bit more of a challenge.

Right, I'm hosting a dinner party. That is a good trick.

But, ultimately, you want something a bit more substantial to feed them.

Something else that you can do with the Dialog Oven is actually

doing multi-component dishes.

Also known as meat and two veg.

So, as you can see in here, in this tray, I've got a fillet

of pork wrapped in a bit of Parma ham with some really nice seasoning.

And then, I've got a nice selection of vegetables,

specially picked for you.

You are going to separate this out though, right,

presumably when you cook it?

After all, each of the ingredients have a very different cooking time.

No.

So, literally everything is going to go in together at the same time

and after 15 to 20 minutes, every single component will be perfect.

I'm sceptical, but I want to see it in action.

Place it in the oven.

15 minutes might sound like a lot for a microwave,

but actually, it's cooking an entire meal in less than

half the time it would take in a conventional oven.

And it smells really good and then, just come over here.

Close this little guy.

Oh, look at this!

I love a bit of courgette. Oh, crunch.

Crunch. But cooked. Yeah.

Shove it all in at once and see, see if you can distinguish!

Here we go.

Oh, my gosh!

That's genuinely amazing.

That's genuinely amazing. Thank you.

You still got, like, a bite in the courgette.

The meat is really soft.

And then there's like just a tiny bit of kind of crispiness

on the mushrooms.

Eat your heart out, Nigella.

But how does this mee-crow-wah-vey perform such magic?

The way the oven works and the technology,

that we call the Dialog,

means that the oven can actually create a dialogue

between the oven and the food.

Clever sensors inside the oven monitor how much energy

or microwave radiation the food is absorbing.

An algorithm then adjusts the strength

and frequency of the microwaves to ensure all parts of the meal

are perfectly cooked when the timer goes off.

We can send enough kilojoules

or enough energy into each component,

so everything is going to be perfectly ready at the end.

Like, genuinely, I'm properly blown away.

Thank you, thank you.

There's just one tiny thing about this microwave.

It costs nearly ten grand.

So I think it's probably going to stay

a product of the future for some time yet.

The microwave oven has been a staple in our kitchens for almost 70 years.

A culinary marvel that uses a World War Il surveillance device...

Do you see that? See how that dot disappears?

That's so cool!

...and 19th-century discoveries about electricity...

How many volts are you actually going to do?

Um, around 1.2 million volts.

Oh!

...to cook our meals super quick.

It's almost ready now.

All | know is, this is going to be a delicious evening meal.

They may have started as futuristic miracles,

but, today, we kind of just take them for granted.

I mean, if anything,

they're a bit of an eyesore on your kitchen counter.

When you actually think about what they are doing,

they are playing around with very technical,

high-end particle physics here.

They're like using electromagnetic radiation to manipulate

water molecules at the atomic level.

It's like, there is something kind of magical

about how far humans have come

at manipulating the laws of nature

that we could find microwaves boring,

that we could possibly find them mundane.

Next time,

it's headphones.

What?

It's the story of an electrocuted 19th-century opera singer...

Where is it? Ow!

Yeah, I felt that.

...chopper pilots in the Korean War...

It's incredible how much difference it makes.

...and a 1950s jazz trumpeter.

This is what started it all.

SHE STRUMS

What do I think about how we could design mobile phones

to be more sustainable?

Well...

If you want to find out how I answer or to learn more

about how technology and product design can be more sustainable,

go to...

...and follow the links to the Open University.