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On the 14th August 1894,

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an excited crowd gathered outside
Oxford's Natural History Museum.

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This huge Gothic building
was hosting the annual meeting

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of the British Association
for the Advancement of Science.

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Over 2,000 tickets
had been sold in advance

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and the museum was already packed,

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waiting for the next talk to be
given by Professor Oliver Lodge.

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His name might not be
familiar to us now,

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but his discoveries
should have made him as famous

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as some of the other great
electrical pioneers of history.

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People like Benjamin Franklin,

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Alessandro Volta,

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or even the great Michael Faraday.

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Quite unwittingly, he would set
in motion a series of events

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that would revolutionise
the Victorian world

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of brass and telegraph wire.

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This lecture would mark the birth
of the modern electrical world,

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a world dominated by silicone
and mass wireless communication.

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In this programme,
we discover how electricity
connected the world together

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through broadcasting
and computer networks,

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and how we finally learnt to unravel
and exploit electricity

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at an atomic level.

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After centuries of man's experiments
with electricity,

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a new age of real understanding
was now dawning.

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These tubes are not
plugged in to any power source,

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but they still light up.

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It's electricity's invisible effect,

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an effect not just confined
to the wires it flows through.

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In the middle of the 19th century,

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a great theory was proposed
to explain how this could be.

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The theory says that
surrounding any electric charge -

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and there's a lot of electricity
flowing above my head -

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is a force field.

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These florescent tubes are lit
purely because they are under

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the influence of the force field
from the power cables above.

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The theory that a flow of
electricity could, in some way,

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create an invisible force field,
was originally proposed

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by Michael Faraday, but it would
take a brilliant young Scotsman

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called James Clark-Maxwell,
who would prove Faraday correct -

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and not through experimentation,
but through mathematics.

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This was all a far cry
from the typical 19th century way

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of understanding
how the world works,

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which was essentially
to see it as a physical machine.

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Before Maxwell, scientists had often
built strange machines

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or devised wondrous experiments
to create and measure electricity.

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But Maxwell was different.

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He was interested in the numbers,
and his new theory not only revealed

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electricity's invisible force field,
but how it could be manipulated.

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It would prove to be
one of the most important

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scientific discoveries of all time.

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Maxwell was a mathematician
and a great one

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and he saw electricity and magnetism
in an entirely new way.

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He expressed it all in terms of
very compact mathematical equations.

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And the most important thing
is that in Maxwell's equations

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is an understanding of electricity
and magnetism as something linked

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and as something
that can occur in waves.

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Maxwell's calculations showed how
these fields could be disturbed

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rather like touching the surface
of water with your finger.

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Changing the direction
of the electric current

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would create a ripple or wave

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through these electric
and magnetic fields.

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And constantly changing
the direction

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of the flow of the current,
forwards and backwards,

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like an alternating current, would
produce a whole series of waves,

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waves that would carry energy.

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Maxwell's maths was telling him
that changing electric currents

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would be constantly sending out
great waves of energy

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into their surroundings.

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Waves that would carry on forever
unless something absorbed them.

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Maxwell's maths
was so advanced and complicated

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that only a handful of people
understood it at the time,

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and although his work
was still only a theory,

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it inspired a young German
physicist called Heinrich Hertz.

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Hertz decided to dedicate himself
to designing an experiment

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to prove that Maxwell's waves
really existed.

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And here it is.

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This is Hertz's original apparatus

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and its beauty is in
its sheer simplicity.

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Heat generates and alternating
current that runs

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along these metal rods, with
a spark that jumps across the gap

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between these two spheres.

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Now, if Maxwell was right,

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then this alternating current
should generate an invisible

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electromagnetic wave that
spreads out into the surroundings.

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If you place a wire
in the path of that wave,

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then at the wire, there should be
a changing electromagnetic field,

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which should induce
an electric current in the wire.

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So what Hertz did was build
this ring of wire, his receiver,

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that he could carry around
in different positions in the room

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to see if he could
detect the presence of the wave.

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And the way he did that was leave
a very tiny gap in the wire,

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across which a spark would jump
if a current runs through the ring.

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Now, because the current is so weak,
that spark is very, very faint

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and Hertz spent pretty
much most of 1887

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in a darkened room staring
intensely through a lens

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to see if he could detect
the presence of this faint spark.

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But Hertz wasn't alone in trying
to create Maxwell's waves.

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Back in England, a young physics
Professor called Oliver Lodge

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had been fascinated
by the topic for years

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but hadn't had the time
to design any experiments

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to try to discover them.

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Then one day, in early 1888,
while setting up an experiment

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on lightning protection,
he noticed something unusual.

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Lodge noticed that
when he set up his equipment

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and sent an alternating
current around the wires,

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he could see glowing patches
between the wires,

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and with a bit of tweaking,

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he saw these glowing patches
formed a pattern.

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The blue glow and electrical sparks
occurred in distinct patches

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evenly spaced along the wires.

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He realised they were the peaks
and troughs of a wave,

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an invisible electromagnetic wave.

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Lodge had proved
that Maxwell was right.

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Finally, by accident,
Lodge had created

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Maxwell's electromagnetic waves
around the wires.

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The big question had been answered.

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Filled with excitement
at his discovery, Lodge prepared

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to announce it to the world, at that
summer's annual scientific meeting

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run by the British Association.

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Before it, though,
he decided to go on holiday.

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His timing couldn't have been worse,
because back in Germany,

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and at exactly the same time,

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Heinrich Hertz was also testing
Maxwell's theories.

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Eventually, Hertz found
what he was looking for...

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a minute spark.

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And as he carried his receiver
to different positions in the room,

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he was able to map out
the shape of the waves

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being produced by his apparatus.

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And he checked each of Maxwell's
calculations carefully

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and tested them experimentally.

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It was a "tour de force"
of experimental science.

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Back in Britain,

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as the crowds gathered
for the British Association meeting,

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Oliver Lodge returned from holiday
relaxed and full of anticipation.

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This, Lodge thought, would be
his moment of triumph,

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when he could announce
his discovery of Maxwell's waves.

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His great friend, the mathematician
Fitzgerald, was due to give
the opening address in the meeting.

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But in it, he proclaimed that
Heinrik Hertz had just
published astounding results.

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He had detected Maxwell's waves
travelling through space.

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"We have snatched
the thunderbolt from Jove himself

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"and enslaved the all prevailing
ether", he announced.

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Well, I can only imagine how
Lodge must have felt

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having his thunder stolen.

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Professor Oliver Lodge had
lost his moment of triumph,

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pipped at the post by
Heinrich Hertz.

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Hertz's spectacular demonstration
of electromagnetic waves,
what we now call radio waves,

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though he didn't know it at the time,
will lead to a whole revolution in
communications over the next century.

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Maxwell's theory had shown how
electric charges could create

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a force field around them.

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And that waves could spread through
these fields like ripples on a pond.

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And Hertz had built a device
that could actually create

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and detect the waves as they passed
through the air.

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But, almost immediately,

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there would be another revelation
in our understanding of electricity.

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A revelation that would once again
involve Professor Oliver Lodge.

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And, once again,
his thunder would be stolen.

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The story starts in Oxford,
in the summer of 1894.

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Hertz had died suddenly
earlier that year,

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and so Lodge prepared a memorial
lecture with a demonstration

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that would bring the idea of waves
to a wider audience.

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Lodge had worked on his lecture.

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He'd researched better ways
of detecting the waves,

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and he'd borrowed new apparatus
from friends.

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He'd made some significant
advances in the technology

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designed to detect the waves.

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This bit of apparatus generates
an alternating current

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and a spark across this gap.

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The alternating current sends out
an electromagnetic wave,

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just as Maxwell predicted, that is
picked up by the receiver.

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It sets off a very weak electric
current through these two antennae.

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Now, this is what Hertz had done.

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Lodge's improvement on this
was to set up this tube
full of iron fillings.

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The weak electric current passes
through the filings,

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forcing them to clump together.

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And, when they do,
they close a second electric circuit

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and set off the bell.

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So if I push the button
on this end...

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BELL TINKLES
..it sets off the bell
at the receiver.

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And it's doing that with
no connections between the two.

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It's like magic.

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BELL RINGING/ELECTRICAL BUZZING

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If you could imagine a packed house,

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lots of people in the audience,
and what they suddenly see is,

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as if by magic, a bell ringing.

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It's quite incredible.

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BELL RINGS

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It might not have been
the most dramatic demonstration
the audience had ever seen,

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but it certainly still created
a sensation among the crowd.

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Lodge's apparatus,
laid out like this,

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no longer looked like
a scientific experiment.

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In fact, it looked remarkably
like those telegraph machines

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that had revolutionised
communication,
but without those long cables

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stretching between
the sending and receiving stations.

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To the more worldly
and savvy members of the audience,

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this was clearly more than showing
the maestro Maxwell was right.

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This was a revolutionary
new form of communication.

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Lodge published his lecture notes
on how electromagnetic waves

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could be sent and received
using his new improvements.

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All around the world,
inventors, amateur enthusiasts

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and scientists read Lodge's
reports with excitement

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and began experimenting
with Hertzian waves.

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Two utterly different characters
were to be inspired by it.

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Both would bring improvements
to the wireless telegraph,

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and both would be remembered
for their contribution to science
far more than Oliver Lodge.

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The first was Guglielmo Marconi.

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Marconi was
a very intelligent, astute

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and a very charming individual.

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He definitely had the Italian,
Irish charm.

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He could apply this to
almost anyone from sort of young
ladies to world-renowned scientists.

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Marconi was no scientist,

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but he read all he could of
other people's work

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in order to put together
his own wireless telegraph system.

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It's possible that because he was
brought up in Bologna and it was
fairly close to the Italian coast,

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that he saw the potential of
wireless communications in relation
to maritime usage fairly early on.

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00:16:11,080 --> 00:16:15,560
Then, aged only 22,
he came to London

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with his Irish mother to market it.

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The other person inspired by
Lodge's lecture was a teacher

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at the Presidency College
in Calcutta,

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called Jagadish Chandra Bose.

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Despite degrees from
London and Cambridge,

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the appointment of an Indian
as a scientist in Calcutta had been
a battle against racial prejudice.

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Indians, it was said,
didn't have the requisite
temperament for exact science.

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Well, Bose was determined
to prove this wrong,

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and here in the archives, we can see
just how fast he set to work.

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This is a report of the 66th meeting
of the British Association

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in Liverpool, September 1896.

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And here is Bose,

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the first Indian ever to present
at the association meeting,

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talking about his work
and demonstrating his apparatus.

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He'd built and improved on
the detector that Lodge described,

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because in the hot,
sticky Indian climate,

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he'd found that the metal filings
inside the tube that Lodge
used to detect the waves

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became rusty and stuck together.

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00:17:32,520 --> 00:17:38,400
So Bose had to build
a more practical detector
using a coiled wire instead.

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His work was described
as a sensation.

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The detector was extremely reliable
and could work onboard ships,

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so had great potential for
the vast British naval fleet.

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00:17:52,120 --> 00:17:56,400
Britain was the centre of a vast
telecommunications network

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00:17:56,400 --> 00:17:58,600
which stretched
almost around the world,

240
00:17:58,600 --> 00:18:04,240
which was used to support
an equally vast maritime network of

241
00:18:04,240 --> 00:18:08,000
merchant and naval vessels,
which were used to support
the British Empire.

242
00:18:09,160 --> 00:18:16,520
But Bose, a pure scientist,
wasn't interested in the commercial
potential of wireless signals...

243
00:18:16,520 --> 00:18:18,960
unlike Marconi.

244
00:18:18,960 --> 00:18:23,560
This was sort of a new,
cutting-edge field, but Marconi

245
00:18:23,560 --> 00:18:27,240
wasn't a trained scientist, so
he came at things in a different way,

246
00:18:27,240 --> 00:18:32,040
which may have been why he progressed
so quickly in the first place.

247
00:18:32,040 --> 00:18:35,520
And he was very good at forming
connections with the people

248
00:18:35,520 --> 00:18:39,000
he needed to form connections with,
to enable his work to be done.

249
00:18:41,520 --> 00:18:45,520
Marconi used his connections to go
straight to the only place

250
00:18:45,520 --> 00:18:47,480
that had the resources to help him.

251
00:18:52,040 --> 00:18:55,720
The British Post Office was
a hugely powerful institution.

252
00:18:55,720 --> 00:18:59,960
When Marconi first
arrived in London in 1896,

253
00:18:59,960 --> 00:19:04,920
these buildings were newly completed
and already heaving with business

254
00:19:04,920 --> 00:19:08,280
from the empire's postal
and telegraphy services.

255
00:19:08,280 --> 00:19:12,880
Marconi had brought his telegraph
system with him from Italy,

256
00:19:12,880 --> 00:19:17,160
claiming it could send wireless
signals over unheard of distances.

257
00:19:17,160 --> 00:19:20,000
And the Post Office
Engineer-in-Chief,

258
00:19:20,000 --> 00:19:24,400
William Preece, immediately saw
the technology's potential.

259
00:19:26,200 --> 00:19:31,920
So, Preece offered Marconi the great
financial and engineering resources

260
00:19:31,920 --> 00:19:36,640
of the Post Office, and they
started work up on the roof.

261
00:19:38,400 --> 00:19:42,280
The old headquarters
of the Post Office were right there.

262
00:19:42,280 --> 00:19:46,760
And between this roof
and that one, Marconi
and the Post Office engineers

263
00:19:46,760 --> 00:19:51,280
would practise sending and receiving
electromagnetic waves.

264
00:19:51,280 --> 00:19:57,120
The engineers helped him
improve his apparatus,
and then Preece and Marconi together

265
00:19:57,120 --> 00:20:01,360
demonstrated it to influential
people in Government and the Navy.

266
00:20:05,440 --> 00:20:07,600
What Preece didn't realise

267
00:20:07,600 --> 00:20:13,000
was that even as he was proudly
announcing Marconi's successful
partnership with the Post Office,

268
00:20:13,000 --> 00:20:16,920
Marconi was making
plans behind the scenes.

269
00:20:18,640 --> 00:20:22,920
He'd applied for a British patent
on the whole field of
wireless telegraphy

270
00:20:22,920 --> 00:20:26,720
and was planning on setting up
his own company.

271
00:20:26,720 --> 00:20:30,720
When the patent was granted,
all hell broke loose

272
00:20:30,720 --> 00:20:33,360
in the scientific community.

273
00:20:37,160 --> 00:20:40,120
That patent was itself
revolutionary.

274
00:20:43,480 --> 00:20:46,360
You see, patents could
only be taken out on things

275
00:20:46,360 --> 00:20:48,640
that weren't public knowledge,

276
00:20:48,640 --> 00:20:53,720
but Marconi famously had hidden
his equipment in a secret box.

277
00:20:58,120 --> 00:21:00,000
And here it is.

278
00:21:00,000 --> 00:21:02,680
When his patent was finally granted,

279
00:21:02,680 --> 00:21:06,440
Marconi ceremoniously
opened the box.

280
00:21:06,440 --> 00:21:09,720
Everyone was keen to see
what inventions lay within.

281
00:21:13,880 --> 00:21:15,720
Batteries forming a circuit,

282
00:21:15,720 --> 00:21:18,240
iron filings in the tube
to complete the circuit

283
00:21:18,240 --> 00:21:20,480
to ring the bell on top.

284
00:21:20,480 --> 00:21:26,880
Nothing they hadn't seen before, and
yet, Marconi had patented the lot.

285
00:21:28,480 --> 00:21:32,160
The reason Marconi is famous
is not because of that invention.

286
00:21:32,160 --> 00:21:35,720
He doesn't invent radio,
but he improves it

287
00:21:35,720 --> 00:21:37,680
and turns it into a system.

288
00:21:37,680 --> 00:21:41,680
Lodge doesn't do that.
And that's why we remember Marconi,

289
00:21:41,680 --> 00:21:44,440
and that's why
we don't remember Lodge.

290
00:21:48,640 --> 00:21:51,720
The scientific world was up in arms.

291
00:21:51,720 --> 00:21:56,600
Here was this young man
who knew very little about
the science behind his equipment

292
00:21:56,600 --> 00:22:00,520
about to make his fortune,
from their work.

293
00:22:00,520 --> 00:22:04,640
Even his great supporter Preece,
was disappointed and hurt

294
00:22:04,640 --> 00:22:09,440
when he found out Marconi
was about to go it alone
and set up his own company.

295
00:22:09,440 --> 00:22:14,160
Lodge and other scientists
began a frenzy of patenting

296
00:22:14,160 --> 00:22:18,480
every tiny detail and improvement
they made to their equipment.

297
00:22:21,760 --> 00:22:26,880
This new atmosphere shocked Bose
when he returned to Britain.

298
00:22:28,080 --> 00:22:32,960
Bose wrote home to India in
disgust at what he found in England.

299
00:22:32,960 --> 00:22:37,880
"Money, money, money all the time,
what a devouring greed!

300
00:22:37,880 --> 00:22:43,200
"I wish you could see the craze
for money of the people here."

301
00:22:43,200 --> 00:22:46,720
His disillusionment
with the changes he saw

302
00:22:46,720 --> 00:22:53,080
in the country he revered
for scientific integrity
and excellence is palpable.

303
00:22:53,080 --> 00:22:55,720
Eventually, though,
it was his friends

304
00:22:55,720 --> 00:22:59,880
who convinced Bose to take out
his one and only patent,

305
00:22:59,880 --> 00:23:04,320
on his discovery of
a new kind of detector for waves.

306
00:23:04,320 --> 00:23:10,240
It was this discovery that would
lead to perhaps an even greater
revolution for the world.

307
00:23:10,240 --> 00:23:14,480
He had discovered
the power of crystals.

308
00:23:16,080 --> 00:23:19,440
This replaces older techniques
using iron filings, which are

309
00:23:19,440 --> 00:23:21,920
messy and difficult
and don't work well.

310
00:23:21,920 --> 00:23:25,040
And here's a whole new way
of detecting radio waves,

311
00:23:25,040 --> 00:23:28,200
and it's one that's going to
be at the centre of a radio industry.

312
00:23:29,520 --> 00:23:32,160
Bose's discovery was simple,

313
00:23:32,160 --> 00:23:36,800
but it would truly shape
the modern world.

314
00:23:36,800 --> 00:23:42,320
When some crystals are
touched with metal to test
their electrical conductivity,

315
00:23:42,320 --> 00:23:46,680
they can show rather
odd and varied behaviour.

316
00:23:46,680 --> 00:23:49,000
Take this crystal, for example.

317
00:23:49,000 --> 00:23:53,880
If I can touch it
in exactly the right spot
with the tip of this metal wire,

318
00:23:53,880 --> 00:23:57,120
and then hook it up to a battery,

319
00:23:57,120 --> 00:23:59,800
it gives quite
a significant current.

320
00:24:01,920 --> 00:24:04,840
But if I switch round
my connections to the battery

321
00:24:04,840 --> 00:24:08,960
and try and pass the current
through in the opposite direction...

322
00:24:08,960 --> 00:24:10,520
it's a lot less.

323
00:24:12,880 --> 00:24:18,280
It's not a full conductor of
electricity, it's a semi-conductor.

324
00:24:18,280 --> 00:24:23,760
And it found its first use
in detecting electromagnetic waves.

325
00:24:23,760 --> 00:24:27,760
When Bose used a crystal like this
in his circuits

326
00:24:27,760 --> 00:24:30,800
instead of the tube of filings,

327
00:24:30,800 --> 00:24:36,520
he found it was a much more
efficient and effective
detector of electromagnetic waves.

328
00:24:36,520 --> 00:24:41,240
It was this strange property
of the junction between the wire,

329
00:24:41,240 --> 00:24:45,920
known as the "cat's whisker",
and the crystal,
which allowed current to pass

330
00:24:45,920 --> 00:24:49,120
much more easily on one direction
than the other,

331
00:24:49,120 --> 00:24:54,720
that meant it could be used to
extract a signal from
electromagnetic waves.

332
00:24:56,640 --> 00:25:03,040
At the time, no-one had any idea why
certain crystals acted in this way.

333
00:25:03,040 --> 00:25:07,480
But to scientists and engineers,
this strange behaviour

334
00:25:07,480 --> 00:25:11,600
had a profound and almost miraculous
practical effect.

335
00:25:12,840 --> 00:25:16,040
With crystals as detectors,

336
00:25:16,040 --> 00:25:25,000
now it was possible to broadcast
and detect the actual sound
of a human voice, or music.

337
00:25:36,240 --> 00:25:38,840
In his Oxford lecture in 1894,

338
00:25:38,840 --> 00:25:42,760
Oliver Lodge had opened
a Pandora's box.

339
00:25:42,760 --> 00:25:49,600
As an academic, he'd failed to
foresee that the scientific
discoveries he'd been such a part of

340
00:25:49,600 --> 00:25:52,440
had such commercial potential.

341
00:25:52,440 --> 00:25:54,880
The one patent
he had managed to secure,

342
00:25:54,880 --> 00:25:59,880
the crucial means of
tuning a receiver to
a particular radio signal,

343
00:25:59,880 --> 00:26:04,680
was bought off him
by Marconi's powerful company.

344
00:26:09,240 --> 00:26:12,040
Perhaps the worst indignation
for Lodge, though,

345
00:26:12,040 --> 00:26:14,480
would come in 1909,

346
00:26:14,480 --> 00:26:19,760
when Marconi was awarded
the Nobel Prize in Physics
for wireless communication.

347
00:26:21,320 --> 00:26:25,360
It's difficult to imagine a bigger
snub to the physicist

348
00:26:25,360 --> 00:26:29,520
who'd so narrowly missed out
to Hertz in the discovery
of radio waves,

349
00:26:29,520 --> 00:26:31,720
and who'd then go on
to show the world

350
00:26:31,720 --> 00:26:34,120
how they could be sent and received.

351
00:26:36,520 --> 00:26:40,080
'But despite this snub,
Lodge remained magnanimous,

352
00:26:40,080 --> 00:26:44,640
'using the new broadcasting
technology that resulted
from his work

353
00:26:44,640 --> 00:26:46,400
'to give credit to others,

354
00:26:46,400 --> 00:26:49,600
'as this rare film of him shows.'

355
00:26:49,600 --> 00:26:51,600
Hertz made a great advance.

356
00:26:53,040 --> 00:26:57,960
He discovered how to produce
and detect waves in space,

357
00:26:57,960 --> 00:27:00,720
thus bringing the ether
into practical use.

358
00:27:01,920 --> 00:27:05,880
Harnessing it, harnessing it
for the transmission of intelligence

359
00:27:05,880 --> 00:27:09,880
in a way which has subsequently been
elaborated by a number of people.

360
00:27:21,720 --> 00:27:26,040
Today, we can hardly imagine
a world without broadcasting,

361
00:27:26,040 --> 00:27:29,920
to imagine a time when radio waves
hadn't even been dreamt of.

362
00:27:31,480 --> 00:27:35,440
Engineers continued
to refine and perfect our ability

363
00:27:35,440 --> 00:27:38,880
to transmit and receive
electromagnetic waves,

364
00:27:38,880 --> 00:27:44,360
but their discovery was ultimately
a triumph of pure science,

365
00:27:44,360 --> 00:27:47,840
from Maxwell, through Hertz,
to Lodge.

366
00:27:47,840 --> 00:27:53,240
But still, the very nature
of electricity itself
remained unexplained.

367
00:27:53,240 --> 00:27:58,400
What created those
electrical charges and currents
in the first place?

368
00:28:00,680 --> 00:28:04,200
Although scientists were learning
to exploit electricity,

369
00:28:04,200 --> 00:28:09,000
they still didn't know
what it actually was.

370
00:28:09,000 --> 00:28:12,160
But this question was being
answered with experiments

371
00:28:12,160 --> 00:28:16,280
looking into how electricity flowed
through different materials.

372
00:28:17,600 --> 00:28:22,280
Back in the 1850s, one of
Germany's great experimentalists

373
00:28:22,280 --> 00:28:25,640
and a talented glass blower,
Heinrich Geissler,

374
00:28:25,640 --> 00:28:28,440
created these beautiful showpieces.

375
00:28:28,440 --> 00:28:31,560
ELECTRICITY BUZZES

376
00:28:37,720 --> 00:28:42,040
Geissler pumped most of the air
out of these intricate glass tubes

377
00:28:42,040 --> 00:28:45,520
and then had small amounts
of other gases pumped in.

378
00:28:49,000 --> 00:28:52,720
He then passed an electrical
current through them.

379
00:28:52,720 --> 00:28:55,080
They glowed with stunning colours,

380
00:28:55,080 --> 00:28:59,160
and the current flowing
through the gas seemed tangible.

381
00:29:01,400 --> 00:29:04,600
Although they were designed
purely for entertainment,

382
00:29:04,600 --> 00:29:09,800
over the next 50 years, scientists
saw Giessler's tubes as a chance

383
00:29:09,800 --> 00:29:12,360
to study how electricity flowed.

384
00:29:14,240 --> 00:29:18,360
Efforts were made to pump more
and more air out of the tubes.

385
00:29:18,360 --> 00:29:22,640
Could the electric current
pass through nothingness?

386
00:29:22,640 --> 00:29:24,160
Through the vacuum?

387
00:29:28,760 --> 00:29:34,440
This is a very rare flick book film
of the British scientist

388
00:29:34,440 --> 00:29:38,560
who created a vacuum good enough
to answer that question.

389
00:29:38,560 --> 00:29:40,640
His name was William Crookes.

390
00:29:42,560 --> 00:29:45,320
Crookes create tubes like this.

391
00:29:45,320 --> 00:29:48,360
He pumped out as much
of the air as he could

392
00:29:48,360 --> 00:29:52,120
so that it was as close to a vacuum
as he could make it.

393
00:29:52,120 --> 00:29:55,840
Then, when he passed an electrical
current through the tube...

394
00:29:55,840 --> 00:29:58,840
ELECTRICAL BUZZING

395
00:29:58,840 --> 00:30:02,320
..he noticed a bright glow
on the far end.

396
00:30:02,320 --> 00:30:05,600
A beam seemed to be shining
through the tube

397
00:30:05,600 --> 00:30:08,120
and hitting the glass
at the other end.

398
00:30:08,120 --> 00:30:11,720
It seemed, at last,
we could see electricity.

399
00:30:11,720 --> 00:30:14,880
The beam became known
as a cathode ray,

400
00:30:14,880 --> 00:30:18,920
and this tube was the forerunner
of the cathode ray tube

401
00:30:18,920 --> 00:30:22,320
that was used in
television sets for decades.

402
00:30:26,840 --> 00:30:31,680
Physicist JJ Thompson
discovered that these beams

403
00:30:31,680 --> 00:30:35,320
were made up of tiny,
negatively charged particles,

404
00:30:35,320 --> 00:30:41,040
and because they were
carriers of electricity,
they became known as electrons.

405
00:30:42,320 --> 00:30:45,440
Because the electrons
only moved in one direction,

406
00:30:45,440 --> 00:30:50,080
from the heated metal plate
through the positively
charged plate at the other end,

407
00:30:50,080 --> 00:30:55,880
they behaved in exactly the same way
as Bose's semi-conductor crystals.

408
00:30:55,880 --> 00:30:59,640
But, whereas Bose's crystals were
naturally temperamental -

409
00:30:59,640 --> 00:31:02,680
you had to find the right
spot for them to work -

410
00:31:02,680 --> 00:31:05,720
these tubes could be
manufactured consistently.

411
00:31:06,760 --> 00:31:08,760
They became known as valves,

412
00:31:08,760 --> 00:31:13,080
and they soon replaced crystals
in radio sets everywhere.

413
00:31:17,320 --> 00:31:21,680
These discoveries would lead to
an explosion of new technology.

414
00:31:22,960 --> 00:31:27,600
Early 20th century electronics is all
about what you can do with valves.

415
00:31:27,600 --> 00:31:30,080
So, the radio industries
is built on valves,

416
00:31:30,080 --> 00:31:32,080
early television is built on valves,

417
00:31:32,080 --> 00:31:34,280
early computers are built
with valves.

418
00:31:34,280 --> 00:31:37,120
These are what you build
the electronic world with.

419
00:31:39,600 --> 00:31:44,680
Having discovered how to manipulate
electrons flowing through a vacuum,

420
00:31:44,680 --> 00:31:47,680
scientists were now
keen to understand

421
00:31:47,680 --> 00:31:50,520
how they could flow through
other materials.

422
00:31:51,600 --> 00:31:56,040
But that meant understanding
the things that made up materials -

423
00:31:56,040 --> 00:31:57,520
atoms.

424
00:32:07,920 --> 00:32:12,120
It was in the early years
of the 20th century that we finally

425
00:32:12,120 --> 00:32:17,000
got a handle on exactly
what atoms were made up of
and how they behaved.

426
00:32:18,320 --> 00:32:22,880
And so, what electricity actually
was on the atomic scale.

427
00:32:25,200 --> 00:32:29,000
At the University of Manchester,
Ernest Rutherford's team

428
00:32:29,000 --> 00:32:31,800
were studying the inner structure
of the atom

429
00:32:31,800 --> 00:32:36,080
and producing a picture to describe
what an atom looked like.

430
00:32:36,080 --> 00:32:43,600
This revelation would finally
help explain some of the more
puzzling features of electricity.

431
00:32:43,600 --> 00:32:47,960
By 1913, the picture of the atom
was one in which you had

432
00:32:47,960 --> 00:32:50,640
a positively charged nucleus
in the middle

433
00:32:50,640 --> 00:32:55,120
surrounded by negatively
charged orbiting electrons,

434
00:32:55,120 --> 00:32:57,360
in patterns called shells.

435
00:32:57,360 --> 00:33:02,920
Each of these shells
corresponded to an electron
with a particular energy.

436
00:33:02,920 --> 00:33:06,520
Now, given an energy boost,
an electron could jump

437
00:33:06,520 --> 00:33:09,120
from an inner shell to an outer one.

438
00:33:09,120 --> 00:33:11,760
And the energy had to be
just right -

439
00:33:11,760 --> 00:33:15,600
if it wasn't enough, the electron
wouldn't make the transition.

440
00:33:15,600 --> 00:33:18,920
And this boost was often temporary
because the electron

441
00:33:18,920 --> 00:33:22,160
would then drop back down again
to its original shell.

442
00:33:22,160 --> 00:33:25,640
As it did this, it had to
give off its excess energy

443
00:33:25,640 --> 00:33:27,760
by spitting out a photon...

444
00:33:28,800 --> 00:33:33,280
..and the energy of each photon
depended on its wavelength,

445
00:33:33,280 --> 00:33:36,000
or, as we would perceive it,
its colour.

446
00:33:39,120 --> 00:33:43,200
Understanding the structure of atoms
could now also explain

447
00:33:43,200 --> 00:33:45,840
nature's great
electrical light shows.

448
00:33:45,840 --> 00:33:48,640
THUNDER

449
00:33:48,640 --> 00:33:50,440
Just like Geissler's tubes,

450
00:33:50,440 --> 00:33:54,960
the type of gas the electricity
passes through defines its colour.

451
00:33:58,080 --> 00:34:03,040
Lightning has a blue tinge because
of the nitrogen in our atmosphere.

452
00:34:04,280 --> 00:34:08,160
Higher in the atmosphere,
the gases are different

453
00:34:08,160 --> 00:34:12,320
and so is the colour
of the photons they produce,

454
00:34:12,320 --> 00:34:14,560
creating the spectacular auroras.

455
00:34:20,560 --> 00:34:24,600
Understanding atoms,
how they fit together in materials

456
00:34:24,600 --> 00:34:29,800
and how their electrons behave,
was the final key to understanding

457
00:34:29,800 --> 00:34:32,560
the fundamental nature
of electricity.

458
00:34:38,280 --> 00:34:40,480
This is a Wimshurst Machine

459
00:34:40,480 --> 00:34:43,160
and it's used to generate
electric charge.

460
00:34:45,840 --> 00:34:50,400
Electrons are rubbed off these discs
and start a flow of electricity

461
00:34:50,400 --> 00:34:53,000
through the metal arms
of the machine.

462
00:34:55,960 --> 00:34:57,880
Now, metals conduct electricity

463
00:34:57,880 --> 00:35:01,800
because the electrons are very
weakly bound inside their atoms

464
00:35:01,800 --> 00:35:06,520
and so can slosh about
and be used to flow as electricity.

465
00:35:06,520 --> 00:35:09,680
Insulators, on the other hand,
don't conduct electricity

466
00:35:09,680 --> 00:35:13,320
because the electrons are very
tightly bound inside the atoms

467
00:35:13,320 --> 00:35:15,040
and are not free to move about.

468
00:35:17,240 --> 00:35:20,040
The flow of electrons,
and hence electricity,

469
00:35:20,040 --> 00:35:22,600
through materials
was now understood.

470
00:35:22,600 --> 00:35:26,200
Conductors and insulators
could be explained.

471
00:35:26,200 --> 00:35:28,280
What was more difficult
to understand

472
00:35:28,280 --> 00:35:31,560
was the strange properties
of semi-conductors.

473
00:35:34,960 --> 00:35:39,320
Our modern electronic world
is built upon semi-conductors

474
00:35:39,320 --> 00:35:42,600
and would grind to a halt
without them.

475
00:35:42,600 --> 00:35:48,880
Jagadish Chandra Bose
may have stumbled upon their
properties back in the 1890s,

476
00:35:48,880 --> 00:35:54,120
but no-one could have foreseen
just how important
they were to become.

477
00:35:55,600 --> 00:35:58,320
But, with the outbreak
of the Second World War,

478
00:35:58,320 --> 00:36:00,040
things were about to change.

479
00:36:06,000 --> 00:36:09,960
Here in Oxford, this newly built
physics laboratory

480
00:36:09,960 --> 00:36:13,320
was immediately handed over
to the war research effort.

481
00:36:13,320 --> 00:36:17,600
The researchers here were tasked
with improving the British
radar system.

482
00:36:23,600 --> 00:36:27,480
Radar was a technology that
used electromagnetic waves

483
00:36:27,480 --> 00:36:31,600
to detect enemy bombers,
and as its accuracy improved,

484
00:36:31,600 --> 00:36:35,800
it became clear that valves
just weren't up to the job.

485
00:36:39,320 --> 00:36:42,800
So, the team had to turn
to old technology -

486
00:36:42,800 --> 00:36:47,560
instead of valves, they used
semi-conductor crystals.

487
00:36:47,560 --> 00:36:50,120
Now, they didn't use
the same sort of crystals

488
00:36:50,120 --> 00:36:53,120
that Bose had developed -
instead they used silicon.

489
00:36:56,400 --> 00:37:00,640
This device is
a silicon crystal receiver.

490
00:37:00,640 --> 00:37:03,520
There's a tiny tungsten
wire coiled down

491
00:37:03,520 --> 00:37:07,400
and touching the surface
of a little silicon crystal.

492
00:37:07,400 --> 00:37:10,960
It's incredible how important
a device it was.

493
00:37:14,520 --> 00:37:20,120
It was the first time silicon
had really been exploited
as a semi-conductor,

494
00:37:20,120 --> 00:37:24,240
but for it to work,
it needed to be very pure

495
00:37:24,240 --> 00:37:29,240
and both sides in the war put a lot
of resources into purifying it.

496
00:37:31,120 --> 00:37:34,720
In fact, the British
had better silicon devices

497
00:37:34,720 --> 00:37:39,160
so they must have had some coils
of silicon already at that time

498
00:37:39,160 --> 00:37:43,560
which we were just starting
with, you know, in Berlin.

499
00:37:45,080 --> 00:37:48,360
The British had better
silicon semi-conductors

500
00:37:48,360 --> 00:37:52,080
because they had help
from laboratories in the US,

501
00:37:52,080 --> 00:37:54,640
in particular, the famous Bell Labs.

502
00:37:54,640 --> 00:37:58,360
And it wasn't long before
physicists realised

503
00:37:58,360 --> 00:38:01,960
that if semi-conductors
could replace valves in radar,

504
00:38:01,960 --> 00:38:07,320
perhaps they could replace valves in
other devices too, like amplifiers.

505
00:38:09,920 --> 00:38:14,240
The simple vacuum tube, with its
one-way stream of electrons,

506
00:38:14,240 --> 00:38:17,560
had been modified to produce
a new device.

507
00:38:17,560 --> 00:38:21,040
By placing a metal grill
in the path of the electrons

508
00:38:21,040 --> 00:38:22,960
and applying a tiny voltage to it,

509
00:38:22,960 --> 00:38:26,760
a dramatic change in the strength
of the beam could be produced.

510
00:38:26,760 --> 00:38:29,520
These valves worked as amplifiers,

511
00:38:29,520 --> 00:38:33,760
turning a very weak electrical
signal into a much stronger one.

512
00:38:33,760 --> 00:38:37,120
An amplifier is something,
in one sense, really simple.

513
00:38:37,120 --> 00:38:41,800
You just take a small current,
you turn it into a larger current.

514
00:38:41,800 --> 00:38:44,800
But in other ways,
it changes the world,

515
00:38:44,800 --> 00:38:49,120
because when you can amplify
a signal, you can send it
anywhere in the world.

516
00:38:52,760 --> 00:38:57,160
As soon as the war was over,
German expert Herbert Matare

517
00:38:57,160 --> 00:39:00,800
and his colleague, Heinrich Welker,
started to build

518
00:39:00,800 --> 00:39:05,320
a semi-conductor device that could
be used as an electrical amplifier.

519
00:39:06,600 --> 00:39:13,280
And here is that first working model
that Matare and Welker made.

520
00:39:13,280 --> 00:39:16,520
If you look inside,
you can see the tiny crystal

521
00:39:16,520 --> 00:39:20,000
and the wires that
make contact with it.

522
00:39:20,000 --> 00:39:23,440
If you pass a small current
through one of the wires,

523
00:39:23,440 --> 00:39:27,440
this allows a much larger current
to flow through the other one,

524
00:39:27,440 --> 00:39:31,080
so it was acting
as a signal amplifier.

525
00:39:33,840 --> 00:39:38,880
These tiny devices could replace
big, expensive valves

526
00:39:38,880 --> 00:39:44,040
in long distance telephone networks,
radios and other equipment

527
00:39:44,040 --> 00:39:47,120
where a faint signal
needed boosting.

528
00:39:47,120 --> 00:39:50,600
Matare immediately realised
what he'd created,

529
00:39:50,600 --> 00:39:53,600
but his bosses were
initially not interested.

530
00:39:53,600 --> 00:39:56,760
Not, that is, until a paper
appeared in a journal

531
00:39:56,760 --> 00:39:59,120
announcing a Bell Labs discovery.

532
00:40:03,160 --> 00:40:07,000
A research team there
had stumbled across the same effect

533
00:40:07,000 --> 00:40:11,080
and now they were announcing
their invention to the world.

534
00:40:11,080 --> 00:40:13,280
They called it the transistor.

535
00:40:15,040 --> 00:40:20,920
They had it in December 1947,
and we had it in beginning '48.

536
00:40:20,920 --> 00:40:24,760
But just, just life, you know.

537
00:40:24,760 --> 00:40:28,600
They had it a little bit earlier,
the effect.

538
00:40:28,600 --> 00:40:33,080
But, funnily enough, their
transistors were just no good.

539
00:40:35,120 --> 00:40:38,480
Although the European device
was more reliable

540
00:40:38,480 --> 00:40:41,640
than Bell Labs' more
experimental model,

541
00:40:41,640 --> 00:40:44,800
neither quite
fulfilled their promise -

542
00:40:44,800 --> 00:40:47,880
they worked,
but were just too delicate.

543
00:40:49,240 --> 00:40:53,920
So the search was on
for a more robust way
to amplify electrical signals

544
00:40:53,920 --> 00:40:57,280
and the breakthrough
came by accident.

545
00:40:58,800 --> 00:41:02,480
In Bell Labs,
silicon crystal expert Russell Ohl

546
00:41:02,480 --> 00:41:06,880
noticed that one of his silicon
ingots had a really
bizarre property.

547
00:41:06,880 --> 00:41:10,880
It seemed to be able
to generate its own voltage

548
00:41:10,880 --> 00:41:14,720
and when he tried to measure this
by hooking it up to an Oscilloscope,

549
00:41:14,720 --> 00:41:18,200
he noticed that the voltage
changed all the time.

550
00:41:18,200 --> 00:41:21,800
The amount of voltage it generated
seemed to depend on

551
00:41:21,800 --> 00:41:24,360
how much light there was
in the room.

552
00:41:24,360 --> 00:41:28,000
So, by casting a shadow
over the crystal,

553
00:41:28,000 --> 00:41:30,120
he saw the voltage dropped.

554
00:41:30,120 --> 00:41:33,520
More light meant
the voltage went up.

555
00:41:33,520 --> 00:41:40,200
What's more, when he turned a fan on
between the lamp and the crystal

556
00:41:40,200 --> 00:41:44,440
the voltage started
to oscillate with the same frequency

557
00:41:44,440 --> 00:41:49,360
that the blades of the fan were
casting shadows over the crystal.

558
00:41:52,320 --> 00:41:56,040
One of Ohl's colleagues
immediately realised

559
00:41:56,040 --> 00:42:00,600
that the ingot had a crack in it
that formed a natural junction,

560
00:42:00,600 --> 00:42:05,040
and this tiny natural junction
in an otherwise solid block

561
00:42:05,040 --> 00:42:09,040
was acting just like
the much more delicate junction

562
00:42:09,040 --> 00:42:14,280
between the end of a wire and a
crystal that Bose had discovered.

563
00:42:14,280 --> 00:42:16,560
Except here, it was
sensitive to light.

564
00:42:18,760 --> 00:42:23,320
The ingot had cracked because
either side contained

565
00:42:23,320 --> 00:42:27,000
slightly different amounts
of impurities.

566
00:42:27,000 --> 00:42:30,880
One side had slightly more
of the element phosphorous,

567
00:42:30,880 --> 00:42:35,720
while the other had slightly more
of a different impurity - boron.

568
00:42:35,720 --> 00:42:38,320
And electrons seemed
to be able to move across

569
00:42:38,320 --> 00:42:43,240
from the phosphorous side
to the boron side,
but not vice versa.

570
00:42:43,240 --> 00:42:46,600
Photons of light
shining down onto the crystal

571
00:42:46,600 --> 00:42:49,160
were knocking electrons
out of the atoms,

572
00:42:49,160 --> 00:42:53,040
but it was the impurity atoms
that were driving this flow.

573
00:42:55,040 --> 00:42:59,400
Phosphorous has an electron
that is going spare...

574
00:42:59,400 --> 00:43:02,360
and boron is keen
to accept another,

575
00:43:02,360 --> 00:43:06,840
so electrons tended to flow
from the phosphorous side

576
00:43:06,840 --> 00:43:12,000
to the boron side and, crucially,
only flowed one way
across the junction.

577
00:43:19,160 --> 00:43:22,600
The head of the semi-conductor team,
William Shockley,

578
00:43:22,600 --> 00:43:26,840
saw the potential of this
one-way junction within a crystal,

579
00:43:26,840 --> 00:43:30,960
but how would it be possible
to create a crystal

580
00:43:30,960 --> 00:43:34,840
with two junctions in it
that could be used as an amplifier?

581
00:43:36,080 --> 00:43:39,560
Another researcher at Bell Labs
called Gordon Teal

582
00:43:39,560 --> 00:43:43,360
had been working on a technique
that would allow just that.

583
00:43:45,360 --> 00:43:49,200
He'd discovered a special way
to grow single crystals

584
00:43:49,200 --> 00:43:52,200
of the semi-conductor germanium.

585
00:43:55,240 --> 00:43:58,840
In this research institute,
they grow semi-conductor crystals

586
00:43:58,840 --> 00:44:02,920
in the same way that Teal
did back in Bell Labs -

587
00:44:02,920 --> 00:44:05,840
only here, they grow them
much, much bigger.

588
00:44:10,280 --> 00:44:15,040
At the bottom of this vat
is a container with glowing hot,

589
00:44:15,040 --> 00:44:18,880
molten germanium,
just as pure as you can get it.

590
00:44:18,880 --> 00:44:24,600
Inside it are a few atoms
of whatever impurity is required

591
00:44:24,600 --> 00:44:27,040
to alter its conductive properties.

592
00:44:27,040 --> 00:44:32,560
Now, the rotating arm above
has a seed crystal at the bottom

593
00:44:32,560 --> 00:44:37,800
that has been dipped into the liquid
and will be slowly raised up again.

594
00:44:42,120 --> 00:44:47,360
As the germanium cools and hardens,
it forms a long crystal

595
00:44:47,360 --> 00:44:49,520
like an icicle, below the seed.

596
00:44:49,520 --> 00:44:54,600
The whole length is one single,
beautiful germanium crystal.

597
00:45:02,560 --> 00:45:05,560
Teal worked out that,
as the crystal is growing,

598
00:45:05,560 --> 00:45:10,320
other impurities can be added
to the vat and mixed in.

599
00:45:10,320 --> 00:45:16,000
This gives us a single crystal with
thin layers of different impurities

600
00:45:16,000 --> 00:45:20,120
creating junctions
within the crystal.

601
00:45:27,800 --> 00:45:31,880
This crystal with two junctions
in it was Shockley's dream.

602
00:45:31,880 --> 00:45:36,320
Applying a small current through
the very thin middle section

603
00:45:36,320 --> 00:45:41,360
allows a much larger current to flow
through the whole triple sandwich.

604
00:45:44,960 --> 00:45:47,680
From a single crystal like this,

605
00:45:47,680 --> 00:45:51,200
hundreds of tiny solid blocks
could be cut,

606
00:45:51,200 --> 00:45:56,840
each containing the two junctions
that would allow the movement
of electrons through them

607
00:45:56,840 --> 00:45:58,960
to be precisely controlled.

608
00:46:01,360 --> 00:46:04,960
These tiny and reliable devices

609
00:46:04,960 --> 00:46:08,800
could be used in all sorts
of electrical equipment.

610
00:46:08,800 --> 00:46:13,080
You cannot have the electronic
equipment that we have
without tiny components.

611
00:46:13,080 --> 00:46:16,920
And you get a weird effect -
the smaller they get,
the more reliable they get,

612
00:46:16,920 --> 00:46:18,480
it's a win-win situation.

613
00:46:18,480 --> 00:46:19,760
APPLAUSE

614
00:46:20,880 --> 00:46:26,560
The Bell Labs team
were awarded the Nobel Prize
for their world changing invention,

615
00:46:26,560 --> 00:46:30,400
while the European team
were forgotten.

616
00:46:34,520 --> 00:46:36,760
William Shockley left Bell Labs,

617
00:46:36,760 --> 00:46:42,560
and in 1955 set up
his own semi-conductor Laboratory
in rural California,

618
00:46:42,560 --> 00:46:47,160
recruiting the country's
best physics graduates.

619
00:46:47,160 --> 00:46:49,680
But the celebratory mood
didn't last long,

620
00:46:49,680 --> 00:46:54,200
because Shockley was almost
impossible to work for.

621
00:46:54,200 --> 00:46:59,760
People left his company
because they just disliked
the way he treated them.

622
00:46:59,760 --> 00:47:04,240
So, the fact that Shockley
was actually such a git

623
00:47:04,240 --> 00:47:07,040
is why you have Silicon Valley.

624
00:47:07,040 --> 00:47:12,440
It starts that whole process
of spin-off and growth
and new companies,

625
00:47:12,440 --> 00:47:17,280
and it all starts off with Shockley
being such a shocking human being.

626
00:47:28,040 --> 00:47:30,800
The new companies were
in competition with each other

627
00:47:30,800 --> 00:47:34,240
to come up with the latest
semi-conductor devices.

628
00:47:34,240 --> 00:47:36,960
They made transistors so small

629
00:47:36,960 --> 00:47:41,440
that huge numbers of them
could be incorporated
into an electrical circuit

630
00:47:41,440 --> 00:47:45,120
printed on a single slice
of semi-conductor crystal.

631
00:47:49,440 --> 00:47:55,280
These tiny and reliable chips
could be used in
all sorts of electrical equipment...

632
00:47:55,280 --> 00:47:58,480
most famously in computers.

633
00:47:58,480 --> 00:48:01,000
A new age had dawned.

634
00:48:11,000 --> 00:48:14,640
Today, microchips are everywhere.

635
00:48:14,640 --> 00:48:18,520
They've transformed almost
every aspect of modern life,

636
00:48:18,520 --> 00:48:22,280
from communication to transport
and entertainment.

637
00:48:23,560 --> 00:48:25,960
But, perhaps, just as importantly,

638
00:48:25,960 --> 00:48:28,720
our computers have become
so powerful

639
00:48:28,720 --> 00:48:33,400
they're helping us to understand
the universe in all its complexity.

640
00:48:36,800 --> 00:48:40,240
A single microchip
like this one today

641
00:48:40,240 --> 00:48:45,000
can contain around
four billion transistors.

642
00:48:45,000 --> 00:48:49,720
It's incredible how far technology
has come in 60 years.

643
00:48:53,000 --> 00:48:56,120
It's easy to think that with
the great leaps we've made

644
00:48:56,120 --> 00:48:58,840
in understanding
and exploiting electricity,

645
00:48:58,840 --> 00:49:02,640
there's little left
to learn about it.

646
00:49:02,640 --> 00:49:04,760
But we'd be wrong.

647
00:49:06,360 --> 00:49:10,960
For instance, making
the circuits smaller and smaller

648
00:49:10,960 --> 00:49:16,440
meant that a particular feature
of electricity that had been
known about for over a century

649
00:49:16,440 --> 00:49:19,080
was becoming
more and more problematic.

650
00:49:19,080 --> 00:49:20,560
Resistance.

651
00:49:23,840 --> 00:49:27,360
A computer chip has to be
continuously cooled.

652
00:49:27,360 --> 00:49:29,880
If you take away the fan,
this is what happens.

653
00:49:33,120 --> 00:49:34,560
Wow! That's shooting up!

654
00:49:34,560 --> 00:49:37,680
100, 120, 130 degrees...

655
00:49:42,560 --> 00:49:46,480
..200 degrees, and it cut out.

656
00:49:46,480 --> 00:49:50,240
That just took a few seconds and
the chip is well and truly cooked.

657
00:49:50,240 --> 00:49:54,120
You see, as the electrons
flow through the chip,

658
00:49:54,120 --> 00:49:56,760
they're not just travelling around
unimpeded.

659
00:49:56,760 --> 00:49:59,160
They're bumping into
the atoms of silicone,

660
00:49:59,160 --> 00:50:04,120
and the energy being lost by
these electrons is producing heat.

661
00:50:05,120 --> 00:50:07,560
Now, sometimes this was useful.

662
00:50:07,560 --> 00:50:11,080
Inventors made electric heaters
and ovens,

663
00:50:11,080 --> 00:50:13,680
and whenever they
got something to glow white-hot,

664
00:50:13,680 --> 00:50:15,680
well, that's a light bulb.

665
00:50:15,680 --> 00:50:18,680
But resistance
in electronic apparatus,

666
00:50:18,680 --> 00:50:20,200
and in power lines,

667
00:50:20,200 --> 00:50:21,880
is the major waste of energy

668
00:50:21,880 --> 00:50:24,560
and a huge problem.

669
00:50:29,200 --> 00:50:35,640
It's thought that resistance
wastes up to 20%
of all the electricity we generate.

670
00:50:35,640 --> 00:50:40,200
It's one of the greatest problems
of modern times.

671
00:50:40,200 --> 00:50:45,240
And the search is on for a way
to solve the problem of resistance.

672
00:50:50,680 --> 00:50:52,640
What we think of as temperature

673
00:50:52,640 --> 00:50:58,720
is really a measure of how much the
atoms in a material are vibrating.

674
00:50:58,720 --> 00:51:00,600
And if the atoms are vibrating,

675
00:51:00,600 --> 00:51:02,880
then electrons flowing through

676
00:51:02,880 --> 00:51:05,320
are more likely to bump into them.

677
00:51:05,320 --> 00:51:07,600
So, in general,
the hotter the material,

678
00:51:07,600 --> 00:51:10,000
the higher its
electrical resistance,

679
00:51:10,000 --> 00:51:11,440
and the cooler it is,

680
00:51:11,440 --> 00:51:13,280
the lower the resistance.

681
00:51:13,280 --> 00:51:15,960
But what happens
if you cool something right down,

682
00:51:15,960 --> 00:51:18,600
close to absolute zero,

683
00:51:18,600 --> 00:51:22,640
-273 degrees Celsius?

684
00:51:22,640 --> 00:51:24,600
Well, at absolute zero,

685
00:51:24,600 --> 00:51:26,400
there's no heat at all,

686
00:51:26,400 --> 00:51:29,320
and so the atoms
aren't moving at all.

687
00:51:29,320 --> 00:51:32,280
What happens then
to the flow of electricity?

688
00:51:32,280 --> 00:51:34,680
The flow of electrons?

689
00:51:37,680 --> 00:51:42,160
Using a special device
called a cryostat,

690
00:51:42,160 --> 00:51:45,920
that can keep things close
to absolute zero, we can find out.

691
00:51:45,920 --> 00:51:49,080
Inside this cryostat,

692
00:51:49,080 --> 00:51:50,600
in this coil, is mercury,

693
00:51:50,600 --> 00:51:52,120
the famous liquid metal.

694
00:51:52,120 --> 00:51:55,160
And it forms
part of an electric circuit.

695
00:51:55,160 --> 00:51:59,520
Now, this equipment here measures
the resistance in the mercury,

696
00:51:59,520 --> 00:52:02,800
but look what happens
as I lower the mercury

697
00:52:02,800 --> 00:52:06,640
into the coldest part
of the cryostat.

698
00:52:09,160 --> 00:52:11,000
There it is.

699
00:52:11,000 --> 00:52:13,680
The resistance has dropped
to absolutely nothing.

700
00:52:13,680 --> 00:52:16,960
Mercury, like many substances
we now know,

701
00:52:16,960 --> 00:52:18,640
have this property.

702
00:52:18,640 --> 00:52:20,880
It's called
"becoming super conducting",

703
00:52:20,880 --> 00:52:25,240
which means they have no resistance
at all to the flow of electricity.

704
00:52:26,400 --> 00:52:29,080
But these materials only work

705
00:52:29,080 --> 00:52:32,040
when they're very, very cold.

706
00:52:32,040 --> 00:52:37,360
If we could use a superconducting
material in our power cables,

707
00:52:37,360 --> 00:52:39,320
and in our electronic apparatus,

708
00:52:39,320 --> 00:52:44,720
we'd avoid losing so much
of our precious electrical energy
through resistance.

709
00:52:47,840 --> 00:52:51,120
The problem, of course, is that
superconductors had to be kept

710
00:52:51,120 --> 00:52:54,080
at extremely low temperatures.

711
00:52:54,080 --> 00:52:57,240
Then, in 1986,

712
00:52:57,240 --> 00:52:58,840
a breakthrough was made.

713
00:53:01,760 --> 00:53:04,920
In a small laboratory
near Zurich, Switzerland,

714
00:53:04,920 --> 00:53:09,520
IBM physicists recently discovered
superconductivity
in a new class of materials

715
00:53:09,520 --> 00:53:13,880
that is being called one of the most
important scientific breakthroughs
in many decades.

716
00:53:15,840 --> 00:53:21,040
This is a block of the same material
made by the researchers
in Switzerland.

717
00:53:21,040 --> 00:53:23,160
It doesn't look very remarkable,

718
00:53:23,160 --> 00:53:25,680
but if you cool it down
with liquid nitrogen,

719
00:53:25,680 --> 00:53:28,280
something special happens.

720
00:53:28,280 --> 00:53:31,080
It becomes a superconductor,

721
00:53:31,080 --> 00:53:35,440
and because electricity
and magnetism are so tightly linked,

722
00:53:35,440 --> 00:53:38,600
that gives it equally
extraordinary magnetic properties.

723
00:53:40,040 --> 00:53:42,360
This magnet is suspended,

724
00:53:42,360 --> 00:53:45,280
levitating above the superconductor.

725
00:53:47,680 --> 00:53:51,640
The exciting thing is,
that although cold,

726
00:53:51,640 --> 00:53:55,600
this material
is way above absolute zero.

727
00:54:05,400 --> 00:54:08,440
These magnetic fields are so strong

728
00:54:08,440 --> 00:54:12,120
that not only can they support
the weight of this magnet,

729
00:54:12,120 --> 00:54:14,640
but they should also support
MY weight.

730
00:54:14,640 --> 00:54:17,080
I'm about to be levitated.

731
00:54:19,240 --> 00:54:22,400
Oh, it's a very,
very strange sensation.

732
00:54:26,040 --> 00:54:29,720
When this material
was first discovered in 1986,

733
00:54:29,720 --> 00:54:31,640
it created a revolution.

734
00:54:31,640 --> 00:54:35,880
Not only had no-one considered
that it might be superconducting,

735
00:54:35,880 --> 00:54:41,360
but it was doing so
at a temperature much warmer
than anyone had thought possible.

736
00:54:41,360 --> 00:54:45,400
We are tantalisingly close
to getting room temperature
superconductors.

737
00:54:45,400 --> 00:54:46,800
We're not there yet,

738
00:54:46,800 --> 00:54:49,360
but one day,
a new material will be found.

739
00:54:49,360 --> 00:54:52,320
And when we put that into
our electronics equipment,

740
00:54:52,320 --> 00:54:56,120
we could build a cheaper, better,
more sustainable world.

741
00:54:58,120 --> 00:55:02,640
Today, materials have been produced
that exhibit this phenomenon

742
00:55:02,640 --> 00:55:06,320
at the sort of temperatures
you get in your freezer.

743
00:55:06,320 --> 00:55:11,480
But these new superconductors
can't be fully explained
by the theoreticians.

744
00:55:11,480 --> 00:55:13,960
So without a complete understanding,

745
00:55:13,960 --> 00:55:17,440
experimentalists
are often guided as much by luck

746
00:55:17,440 --> 00:55:20,240
as they are by a proper
scientific understanding.

747
00:55:22,200 --> 00:55:25,800
Recently, a laboratory in Japan
held a party

748
00:55:25,800 --> 00:55:28,600
in which they ended up
dosing their superconductors

749
00:55:28,600 --> 00:55:30,600
with a range of alcoholic beverages.

750
00:55:31,760 --> 00:55:34,760
Unexpectedly,
they found that red wine

751
00:55:34,760 --> 00:55:38,240
improves the performance
of the superconductors.

752
00:55:40,480 --> 00:55:42,400
Electrical research

753
00:55:42,400 --> 00:55:45,160
now has the potential, once again,

754
00:55:45,160 --> 00:55:47,640
to revolutionise our world,

755
00:55:47,640 --> 00:55:51,880
IF room temperature superconductors
can be found.

756
00:56:02,120 --> 00:56:06,400
Our addiction to electricity's power
is only increasing.

757
00:56:06,400 --> 00:56:11,120
And when we fully understand how to
exploit superconductors,

758
00:56:11,120 --> 00:56:14,720
a new electrical world
will be upon us.

759
00:56:14,720 --> 00:56:20,560
It's going to lead to
one of the most exciting periods
of human discovery and invention,

760
00:56:20,560 --> 00:56:24,880
a brand-new set of tools,
techniques and technologies

761
00:56:24,880 --> 00:56:27,640
to once again transform the world.

762
00:56:35,160 --> 00:56:38,400
Electricity has changed our world.

763
00:56:38,400 --> 00:56:43,880
Only a few hundred years ago,
it was seen as a mysterious
and magical wonder.

764
00:56:44,920 --> 00:56:51,920
Then, it leapt out of the laboratory
with a series of strange
and wondrous experiments,

765
00:56:51,920 --> 00:56:54,760
eventually being captured
and put to use.

766
00:56:56,640 --> 00:56:58,720
It revolutionised communication,

767
00:56:58,720 --> 00:57:00,040
first through cables,

768
00:57:00,040 --> 00:57:04,400
and then as waves through
electricity's far-reaching fields.

769
00:57:06,200 --> 00:57:09,640
It powers and lights
the modern world.

770
00:57:09,640 --> 00:57:13,360
Today, we can hardly imagine life
without electricity.

771
00:57:13,360 --> 00:57:15,560
It defines our era,

772
00:57:15,560 --> 00:57:18,480
and we'd be utterly lost without it.

773
00:57:21,000 --> 00:57:23,800
And yet, it still offers us more.

774
00:57:23,800 --> 00:57:28,440
We stand, once again, at the
beginning of a new age of discovery,

775
00:57:28,440 --> 00:57:29,960
a new revolution.

776
00:57:36,960 --> 00:57:38,920
But above all else,

777
00:57:38,920 --> 00:57:43,920
there's one thing that all those
who deal in the science
of electricity know -

778
00:57:43,920 --> 00:57:46,920
its story is not over yet.

779
00:58:05,560 --> 00:58:08,720
To find out more about
the story of electricity,

780
00:58:08,720 --> 00:58:11,360
and to put your power knowledge
to the test,

781
00:58:11,360 --> 00:58:15,560
try the Open University's
interactive energy game.

782
00:58:15,560 --> 00:58:20,200
Go to:

783
00:58:20,200 --> 00:58:22,640
..and follow links
to the Open University.

784
00:58:44,600 --> 00:58:47,760
Subtitles by Red Bee Media Ltd

785
00:58:47,760 --> 00:58:51,120
E-mail subtitling@bbc.co.uk