Order & Disorder (2012): Season 1, Episode 2 - The Story of Information - full transcript
We are surrounded by order.
Over the last 300 years,
we've developed amazing new ways
to harness energy.
We've used this ability to
transform our environment.
But all these structures that we
see around us are just
one type of visible order that
we've created here on planet Earth.
There's another
type of invisible order,
every bit as complex that we are
only now beginning to understand.
It's something that nature has been
harnessing for billions of years.
Something we call information.
The concept of information
is a very strange one.
It's actually a very difficult idea
to get your head round.
But in the journey to try
and understand it, scientists
would discover that information is
a fundamental part of our universe.
This film is the story
of information.
And the immense power
released from manipulating it.
It's the story of how
we discovered the power of symbols.
And how writing, codes
and computers would revolutionise
our understanding of the universe.
It's the story of how, in a cosmos
collapsing into disorder,
information can be used to create
order and structure.
At first glance, information appears
to be a very straightforward idea.
It exists everywhere in our world.
Our brains are filled with it.
And we constantly exchange
it between each other.
But information has been
one of the subtlest
and most difficult concepts that
science has had to grapple with.
Understanding and harnessing it
has been an extremely long
and difficult process.
The power of information would first
be glimpsed over 5,000 years ago,
when a revolutionary
technology was developed.
One that would set the modern
world in motion.
Over the years, mankind has come up
with some pretty remarkable stuff.
But of all humanity's inventions,
there's one that really stands out.
It's the most transformative,
destructive,
creative technology ever conceived.
It is also one of the simplest.
That invention is the written word.
At its heart, writing is all about
the transmission
and storage of information.
Words allow ideas to
endure through time.
These are some of the earliest
texts in existence.
They give us an incredible insight
into the development of writing.
I've come to meet one of the few
people who can still read them -
Dr Irving Finkel.
We take writing
so much for granted these days,
it's easy to forget that it
was invented.
It certainly was.
How did it first come about?
The earliest writing that we have is
written on clay tablets
and it comes from
Iraq, Ancient Mesopotamia.
It comes from the culture
of the culture of the Sumerians.
What happened here was that they
started off with purely
pictographic signs
to express an idea.
This lasted for quite a long time,
until it occurred to somebody,
perhaps accidentally, that what you
could do is make one of these
graphic symbols on the surface
of the clay not for what it
looked like but for the sound
it represented.
So not a picture of an object,
a picture of a sound?
That's what we always called
the giant leap for mankind.
By combining different
sounding pictures,
the ancient Mesopotamians could
express any idea imaginable.
The essence of their breakthrough
was to see, for example,
that a picture of an eye
and a picture of a deer didn't have
to mean an eye and a deer.
The pictures could be used simply
for the sounds that they made.
In this case, idea.
Once this system was discovered,
it meant anything that could be
spoken, even the most strange
or abstract thoughts could be
transformed into symbols.
Information could now live
outside of the human brain.
This meant it could endure
over vast spans of time.
It was an idea that fascinated
the ancient Mesopotamians.
This lovely tablet here,
this king lived in about 2100 BC.
He buried this in the foundations
of his temple as a message
for the future.
This King Ur-Nammu, the powerful
male, King of Sumer and Akkad -
that's the south and north
part of Ancient Mesopotamia.
Her house - he built for her
and he even restored it afterwards.
This is a proud thing.
He wants everybody to know about it
and this is a real
message for the future.
What's so remarkable for me
is this is information stored
on clay for thousands of years.
Yes. Ideas that someone
had 4,000 years ago are still there.
You have ideas, you have speech,
human hopes, literature,
prayers - all these sorts
of outpourings of the human soul
fixed for ever in clay.
By turning sounds into symbols,
the Mesopotamian scribes had
discover that information could be
changed very easily from one
form to another.
From something that
existed as spoken sounds,
to something that existed
as symbols on clay tablets.
This was just the beginning.
Humans were yet to realise
the true power of symbols.
For 4,000 years, writing was pretty
much the only
information technology people used.
But in the 19th century, during
the great Industrial Revolution,
things would begin to change.
In the maelstrom of ideas
and inventions,
a series of seemingly unconnected
technologies would emerge
that all began to hint
at the immense power of information.
These technologies would all
come from very practical,
very un-theoretical origins.
They would start to reveal that
information was a much deeper
and more powerful concept
than anyone had realised.
One of the first of a new breed
of information technologies would be
developed in the French city of Lyon
at the end of the 18th century.
18th-century Lyon was home to some
of the best craftsmen in the world.
It was also a place
of great opulence,
grandeur and, above all, money.
Thanks to the rich
and fashionable aristocrats
and bankers who lived there,
it would become home to the greatest
silk-weaving industry in the world.
Almost a third of the city's
inhabitants worked in
the silk industry, and it was home
to over 14,000 looms.
This is brocade.
The material that made Lyon famous.
It's a beautiful
and intricately woven fabric that,
as you might imagine, is incredibly
labour intensive to produce.
A two-man team,
working flat out for a day,
could at best produce about an inch
of this amazing stuff.
The demand for the fine fabrics
of Lyon was immense.
But the silk weaving process
was painful slow.
But thanks to a soldier and weaver
named Joseph Marie Jaquard,
a device will be developed
to help speed up weaving.
In the process, it would reveal a
fundamental truth about information.
Building on the work of a number
of others, in 1804 Jaquard
patented his invention.
At the time, the loom was
the most complex mechanism
ever built by humankind
Jaquard's loom was
a miracle of ingenuity.
You see, he had designed a single
machine, which without any
alteration to its construction -
its hardware, to use a modem term -
could be programmed to weave any
pattern a designer could think up.
It fact, it could produce a whole
range of silk designs
with barely a pause in production.
Jaquard had found
the holy grail of weaving.
And the secret was
a simple punched card.
The punched card held within it
the essence of the designs
that the loom would weave.
When these punched cards
were fed into the loom
they would act to lower
and lift the relevant threads...
..recreating the pattern in silk.
Any design you could think of could
be broken down and translated into
a series of punch cards that could
then woven by the loom.
Information was
being translated from
picture to punch card
to the finished fabric.
It's a machine for weaving
textiles, that's its task,
but there is nothing specific
about what textile it should weave.
That is contained
in the information,
which is encoded on the cards.
So if you like, the cards, programme
it, that is to say instruct it
what to do. And this has huge
resonances for what came later.
Jaquard's Loom revolutionised
the silk industry.
But at its heart was something
deeper, something more universal
than its industrial origins
and its ability to speed up weaving.
The loom revealed the power of
abstracting information.
It showed you can take the essence
of something, extract the vital
information
and represent it in another form.
Writing had revealed you could use
a set of symbols to capture
spoken language.
Now, Jaquard had shown that with
just two symbols -
a hole or a blank space,
it was possible to capture
the information in any picture
imaginable.
This is a portrait of Jaquard that's
been woven in silk.
It's spectacularly detailed with
hundreds of thousands of stitches.
Yet all the information you need to
capture this life-like image can be
stored in a series of punched cards.
24,000 of them to be precise.
This picture is a fantastic example
of a really far-reaching idea.
That the simplest of systems -
in this case, cards with a series
of holes punched in them -
can capture the essence of something
much, much more complicated.
If 24,000 punched cards could create
an image like this...
What would happen if you had
24 million?
Or 24 trillion cards?
What new types of complex
information
might be able to be captured
and represented?
Jacquard had stumbled on an
incredibly deep
and far-reaching idea.
As long as you have enough of them,
simple symbols can be used
to describe anything
in the entire universe.
Translating information
into abstract symbols
to store and process, had proven
to be an extremely powerful idea.
But the way information was sent,
the way it was communicated, hadn't
changed for thousands of years.
The world before
telecommunications technology
was a very different place,
cos you could only send messages as
fast as you could send objects.
You'd write a message on a piece of
paper or something like that
and then you'd give it to somebody
who could run very fast,
or could go on horse
or on a ship very fast.
The point was you could only send
information as fast as
you could send matter.
But in the 19th century,
the speed at which information
could be sent would
dramatically increase,
thanks to an incredible new
information-carrying medium -
electricity.
Very soon after electricity
was discovered,
excitement grew about its potential
as a medium to transmit messages.
It seemed that if it could be
controlled and summoned at will,
electricity would be the perfect
medium for sending information.
Electricity seemed to offer
many advantages
as a way of sending messages.
It was sent down a wire which means
it could pretty much go anywhere.
It wasn't affected
by bad weather conditions
and most importantly,
it could move very quickly.
But there was one big problem facing
those in the early 19th century
who wanted to use electricity
as a means to communicate.
How could such a simple signal
be used to send complex messages?
Here in the Science Museum archive,
they have one of the most
impressive collections
of early electronic communications
technology in the world.
Here are just some
of the early devices
designed to send signals
using electricity.
This one's particularly fun.
It was developed in 1809
in Bavaria by Samuel Soemmering.
So if the sender wants
to send letter A,
he sends a current through
that corresponding wire.
At the receiver's end
is a tank full of liquid
and electric current forces
a chemical reaction
causing bubbles to appear above
the corresponding letter A.
The whole process is ingenious,
if a little laborious.
But what's really fun is that the
sender has to let the receiver know
he's about to send a signal.
He does that by sending
extra electric currents
so that more bubbles appear,
forcing an arm upwards
which releases a ball...
BELL RINGS
..and triggers a bell.
As you can imagine, this wouldn't
be the quickest of systems.
After Soemmering, all sorts
of approaches were taken
in trying to crack the problem of
sending messages using electricity.
But they all suffered from having
over-complex codes.
These devices, each cunning
and innovative in its own way,
were all destined for
the scrap heap of history.
And that's because in the 1840s,
they were superseded by a way
of sending signals that still
endures to this day.
It was developed by artist
and entrepreneur Samuel Morse,
together with his colleague
Alfred Vale.
What was so special about their
system wasn't the technology
that was used
to carry their messages,
but the incredibly simple
and effective code
they used to send them.
Just like Jacquard's punch cards,
the genius of Morse and Vale's code
lay in its simplicity.
Using a collection of short and long
pulses of electrical current,
they could spell out the letters
of the alphabet.
Vale suggested that
the most frequent letters
in the English language
get the shortest code.
So an E is sent like this.
While an X is sent like this.
This means that messages can be sent
quickly and efficiently.
Figuring out the code part of it,
the software if you like,
was as complicated as figuring out
the hardware side of things
with the batteries and the wires, and
together they made an entirely new
technology which is
the electric telegraph.
The telegraph had once again
revealed the power
of translating information
from one medium to another.
Information had at first
been fixed in human brains.
Then held in symbols in clay
and paper and punched cards.
Now, thanks to Morse, information
could reside in electricity
and this made it unimaginably
lighter and quicker
than it had every been before.
In just a few short years,
the telegraph network
would spread around
the entire globe,
laying the foundations
of the modern information age.
Between them, Jacquard and Morse had
found new novel ways to manipulate,
process and transmit information.
What had begun with the invention
of writing thousands of years ago
had culminated in the binding
of the entire planet
in a lattice of wires carrying
highly abstracted information
at incredible speeds.
For people at the end
of the 19th century
it may have seemed that humanity's
ability to manipulate
and transmit information
was at its zenith.
They couldn't have been more wrong.
Information would reveal itself
to be a more important,
more fundamental concept
than anyone could have imagined.
It would soon become apparent
that information
wasn't just about human
communication.
It was a much further-reaching
idea than that.
The true nature of information
would first be hinted at
thanks to a strange problem,
one dreamed up by a brilliant
Scottish physicist
who appeared to be thinking about
something else entirely.
James Clerk Maxwell was one of
the great minds of the 19th century.
Among his many interests,
Maxwell became fascinated
by the science of thermodynamics -
the study of heat and motion
that had sprung up
with the birth of the steam engine.
Maxwell was one of the first
to understand
that heat is really
just the motion of molecules.
The hotter something is, the faster
its molecules are moving.
This idea would lead Maxwell
to dream up a very bizarre
thought experiment in which
information played a crucial role.
Maxwell theorised that simply by
knowing what's going on
inside a box full of air, it'll be
possible to make one half hotter
and the other half colder.
Think of it like building
an oven next to a fridge
without using any energy.
It sounds crazy, but Maxwell's
argument was extremely persuasive.
It goes like this.
Imagine a small demon
perched on to of the box,
who has such excellent eye sight
that he could observe accurately
the motion of all the molecules
of air inside the box.
Now, crucially,
he's in control of a partition that
divides the box into two halves.
Every time he sees a fast-moving
molecule approaching the partition
from the right-hand side he opens it
up, allowing it through to the left.
And every time he sees a slow moving
molecule approaching the partition
from the left, he opens it up,
allowing the molecule
through to the right.
Now, you can see
what's going to happen.
Over time, all the fast-moving
hot molecules will accumulate
on the left-hand side of the box,
and all the slow-moving
cold molecules on the right.
Crucially, the demon has done
this sorting with nothing more
than information about the motion
of the molecules.
Maxwell's demon seemed to say
that just by having information
about the molecules, you could
create order from disorder.
This idea flew in the face
of 19th-century thinking.
The science of thermodynamics
had shown very clearly
that over time, the entropy
of the universe, its disorder,
would always increase.
Things were destined to fall apart.
But the demon seemed to suggest that
you could put things back together
without using any energy at all.
Just by using information,
you could create order.
It would prove to be a fiendishly
difficult problem to solve,
not least because the brilliant
Maxwell had come up with an idea
far, far ahead of its time.
It's amazing, the impact
that he had on physics,
and that he came up with
this very intricate concept
and that he already in some sense
pre-anticipated the notion
of information. It wasn't
actually there at the time,
there was no such thing.
I think this idea was astonishing.
He didn't really have a resolution,
he raised it as a concern
and he left it open.
And I think what followed
is more or less 120 years
of extremely exciting debate
and development
to try to resolve
and address this concern.
So what was going on
with Maxwell's demon?
It may sound far-fetched
and fanciful,
but imagine the possibilities
if we could build a machine
in the real world that could mimic
the actions of the Demon.
I could use it to heat a cup of
coffee, or run an engine,
or power a city all using nothing
more than pure information.
It's as though we could create
order in the universe
without expending any energy.
Scientists felt intuitively
that it had to be wrong.
The problem was it would take over
100 years to solve the problem.
While Maxwell's riddle rumbled on,
something quite unexpected
was to happen,
a new device was dreamt up that
could perform quite incredible
and complex tasks simply by
processing information.
What's more, this was a device
that could actually be built.
The machine would come to be
known as the computer, and the idea
behind it came from a quite
remarkable and visionary scientist.
Alan Turing was the first person
to conceive of the modern computer,
a machine whose sole function is to
manipulate and process information.
A machine that harnesses
the power of abstract symbols.
A machine that enables almost every
aspect of the modern world.
Turing's incredible idea would
first appear in a now-legendary
mathematical paper
published in 1936.
In his brief life, Alan Turing
brought fresh, groundbreaking ideas
to a whole range of topics,
from cryptography
through to biology.
The sheer breadth of his thinking
is breathtaking.
But for most scientists,
it's the concepts he outlined
in these 36 pages that
mark him out as truly special.
It's this work that makes him worthy
of the title "Genius".
Published when Turing
was just 24 years old,
On Computable Numbers
With An Application
To The Entscheidungsproblem
tackles the foundations
of mathematical logic.
What's amazing about it is that
the idea for the modern computer
emerged simply as a consequence
of Turing's brilliant reasoning.
He was thinking about something
else entirely,
he wasn't, you know,
sitting there thinking,
"I want to try and invent the modern
computer," he was thinking
about this very abstract problem
in the foundations of mathematics.
And the computer kind fell
sideways out of that research,
completely unexpectedly.
I mean, nobody could have guessed
that Turing's very abstract,
abstruse research in the foundations
of mathematics could produce
anything of any practical value
whatsoever, let alone a machine that
was going to change the lives of, you
know, nearly everyone on the planet.
Turing had set out to understand
if certain processes
in mathematics could be done
simply by following a set of rules.
And this is what would get him
thinking about computers.
In 1936, the word "computer"
had a very different meaning
to what it does today.
It meant a real person
with a pencil and paper,
engaged in arithmetical
calculations.
Banks hired many such people,
often women,
to work out interest payments.
The Inland Revenue employed them
to work out how much tax to charge.
Observatories hired them
to calculate navigational data.
Human computers were vital
to the modern world,
dealing with the huge amounts
of information produced
as science and industry
grew ever more complex.
What Turing did in his 1936 paper
was ask a simple
but profound question.
"What goes on in the mind of a
person carrying out a computation?"
To do this, he first had to discard
all the superfluous detail,
so that only the very essence of
the process of computation remained.
So, first off went the inkpot.
Then the pen, then the slide-rule.
Then the pencils
and the pads of paper.
All these things made it easier,
but none of them
were absolutely crucial to the
person carrying out the computation.
Now Turing asked, "What goes on in
the brain of a human computer?"
It's a vastly complex
biological system,
capable of consciousness, thoughts
and insights, but to Turing,
none of these was critical to
the process of computation either.
Turing realised
that to compute something,
a set of rules
had to be followed precisely.
That was all.
It takes the higher level
intelligence
that was presupposed to be
involved in calculation,
which was thinking, and says you can
have a mechanical process -
and by mechanical,
he means an unthinking process -
to perform the same act.
And therefore eliminates
the necessity of human agency,
with all its high-level functions.
And that is what is revolutionary
about what he tries to do.
Turing's brilliant mind saw that any
calculation had two aspects...
The data, and the instructions
for what to do with the data.
And this would be the key
to his insight.
Turing had to find a way of getting
machines to understand instructions
like "add," "subtract,"
"multiply," "divide"
and so on, in the same way
that humans do.
In other words, he had to find
a way of translating instructions
like these into a language that
machines could understand.
And with flawless, impeccable logic,
Turing did exactly that.
This may look like a random
series of ones and zeroes,
but to a computing machine,
it's a set of instructions
that can be read off step by step,
telling the machine to behave
in a certain way.
So, while a human computer could
look at this symbol
and understand the process
that was required,
the computing machine had to
have it explained, like this.
This paper tape that Turing
envisaged is what
we would now call
the memory of the computer.
But Turing didn't stop there.
Turing realised that feeding
a machine instructions in this way
had an amazing consequence.
It meant that just one machine is
needed to perform almost any task
you can think of.
It's a beautifully simple concept.
In order to get the machine to do
something new, all you had to do
was feed it a new set
of instructions, new information.
This idea became known
as the Universal Turing Machine.
The more you wanted your machine to
do, the longer the tape had to be.
Bigger memories could hold complex,
multilayered instructions
about how to process and order
any kind of information imaginable.
With a big enough memory,
the computer will be capable of an
almost limitless number of tasks.
This idea of Turing's,
that a multitude of different tasks
can be carried out
simply by giving a computing machine
a long sequence of instructions,
is his greatest legacy.
Since his paper,
Turing's dream has been realised.
So, calculations,
making phone calls,
recording moving images, writing
letters, listening to music -
none of these require bespoke
machines.
They can all be carried
out on a single device.
A computing machine.
This phone is a modern incarnation
of Turing's amazing idea.
Inside here are many,
many instructions.
What we call programmes,
or software, or apps,
that are nothing more than a long
sequence of numbers
telling the phone what to do.
What's amazing about Turing's idea
is its incredible scope.
The sets of instructions
that can be fed to a computer
could tell it how to mimic
telephones or typewriters.
But they could also describe
the rules of nature,
the laws of physics.
The processes of the natural world.
This is a simulation of many
millions of particles
behaving like a fluid.
To work out how it flows,
the computer simply follows a set
of instructions held in its memory.
This only begins to hint
at the power of computing machines.
This is a computer simulation
of the large-scale structure
of the entire universe.
And it reveals the true
power of Turing's idea.
Turning instructions into symbols
that a machine can understand
allows you to recreate not just
a simple picture or sound,
but a process, a system, something
that is changing and evolving.
By manipulating simple symbols,
computers are capable
of capturing the essence,
the order of
the natural world itself.
By thinking about how
the human brain processes
and computes information,
Alan Turing had had one of the most
important ideas of the 20th century.
The power of information
was revealing itself.
GARBLED VOICES
It would be very easy to think that
after Turing's ideas were made real,
the true power of information
would be unleashed.
But Turing was only half the story.
The modern information age would
require another idea,
one that would finally
pin down the nature of information,
and its relationship to the order
and disorder of the universe.
It was an idea that would be
dreamt up
by a gifted and eccentric
mathematician and engineer.
Claude Shannon was a true maverick,
and his desire to tackle
unusual problems would lead to
a revolutionary new idea.
One that would uncover the
fundamental nature of information,
and the process of communication
in all its varied forms.
This is Claude Shannon's paper,
The Mathematical Theory
Of Communication.
Now, the title may sound
a bit dry, but trust me,
it's one of the most important
scientific papers
of the 20th century.
Not only did it lay the foundations
for the modern world's
communication network,
it also gave us fresh insights
into human language,
into things we do intuitively,
like speaking and writing.
The paper was published in 1948,
while Shannon was working
at the Bell Labs in New Jersey -
the research arm of
the vast Bell Telephone Network.
It was an institution
famous for its forward-thinking,
relaxed atmosphere.
The mathematicians were free to work
on any problem that interested them.
The only thing that the laboratory
management required of them
was that they keep an open door,
and if anybody from any other
department came with a problem,
that they would at least
think about it.
Otherwise they were absolutely free,
and the atmosphere was incredible.
People were playing,
and encouraged to play.
Hello. I'm Claude Shannon,
a mathematician here at
the Bell Telephone Laboratory.
Claude Shannon in particular
was given free reign
to do pretty much
whatever he wanted.
This is Theseus.
Theseus is an electrically
controlled mouse, mouse.
Oh, they treated him
as their darling.
I never saw him juggle, but I
certainly saw him ride his unicycle.
He brought it to work one day,
and he must have cost Bell Labs
at least a hundred man-hours of time.
But despite the frivolity,
the Bell Telephone Network
faced a huge problem.
Every day, they transmitted
vast amounts of electronic
information all across the world.
But they had no real idea of how to
measure this information properly,
or how to quantify it.
In short, their entire business
was built on something
they didn't actually understand.
Amazingly, their superstar
employee Claude Shannon
would give them
exactly what they needed.
GARBLED VOICES
In this paper, Shannon did
something absolutely incredible -
he took the vague and mysterious
concept of information
and managed to pin it down.
Now, he didn't do this using
some cleverly-worded,
philosophical definition.
He actually found a way to measure
the information
contained in a message.
GARBLED VOICES
Amazingly, Shannon realised
that the quantity of information
in a message had nothing
to do with its meaning.
Instead, he showed
it was related solely
to how unusual the message was.
Information is related
to unexpectedness.
So news is news
because it's unexpected
and the more unexpected it is,
the more newsworthy it is.
So if today's news was
the same as yesterday's news,
there would be no news at all.
And that information
content would be zero.
So suddenly you have a
relationship between...
unexpectedness and information.
GARBLED VOICES
But Shannon was to go further
and give information its
very own unit of measurement.
GARBLED VOICES
So, how did he do this?
Well, he showed that any message
you cared to send
could be translated
into binary digits -
a long sequence of ones and zeros.
So a simple greeting like "Hello"
could be written like this.
Or... like this.
Just think of this as another
way of writing the same message.
ELECTRONIC MUSIC
Shannon realised that transforming
information into binary digits
would be an immensely powerful act.
It would make information
manageable, exact,
controllable and precise.
In his paper, Shannon showed
that a single binary digit -
one of these ones or zeros - is
a fundamental unit of information.
Think of it as an atom
of information -
the smallest possible piece.
Then, having defined
this basic unit,
he even gave us a name for it,
one we're all familiar with today.
He used a shortening of
the phrase, "binary digit" -
"bit".
The humble bit turned out to be
an enormously powerful idea.
The bit is the smallest
quantity of information.
It is highly significant
because it's the fundamental atom.
It is the smallest unit
of information in which
there's sufficient discrimination
to communicate anything at all.
The power of the bit
lay in its universality.
Any system that has two states,
like a coin with heads or tails,
can carry one bit of information.
One or zero.
Punched or not punched.
On or off.
Stop or go.
All of these systems can
store one bit of information.
Thanks to Shannon,
the bit became the common
language of all information.
Anything - sounds, pictures,
text - can be turned into bits
and transmitted by any system
capable of being in just two states.
Shannon had founded
a new, far-reaching theory.
The ideas he began to explore
would form the cornerstone
of what we now call,
"information theory".
He'd taken an abstract
concept - information -
and turned it into
something tangible.
What had been just a vague notion
was now measurable - something real.
The idea of converting into bits,
into making things digital,
would fundamentally transform
many aspects of human society.
GARBLED VOICES
But information isn't
just something humans create.
We're beginning to understand
that this concept lies at the heart,
not only of 21st-century
human society,
but also at the heart
of the physical world itself.
Every "bit" of information
we've ever created, every book,
every film, the entire
contents of the internet,
amounts to pretty much nothing
when compared with
the information content of nature.
And that's because even
the most insignificant event
contains a spectacular
amount of information.
Let me show you.
Imagine how many bits of information
you would need to describe this.
The beautiful and intricate
interplay of physical laws
taking place
at scales and timeframes
that are normally
imperceptible to us.
But here you're still
only seeing a fraction
of the complexity of nature.
Imagine the interplay between the
trillions upon trillions of atoms.
The amount of bits
you would need to describe this
is almost unimaginable.
But what's amazing is that now,
thanks to the ideas of Turing and
Shannon, we're able to describe,
model and simulate nature
in ever greater detail.
But this isn't the end of the story.
Information, it seems, isn't
just a way of describing reality.
In the last few years,
we've discovered that information
is actually an inseparable
part of the physical world.
It's a really difficult idea to
get to grips with but information,
everything from a Beethoven symphony
to the contents of a dictionary,
even a fleeting thought,
all information needs to be embodied
in some form of physical system.
Amazingly, the reason
we understand the true connection
between information and reality
is because of Maxwell's demon.
Remember, it seemed like
the demon could use information
to create order in a box of air that
started out completely disordered.
Moreover, it could do this
without expending any effort.
Information seemed to be able
to break the laws of physics.
Well, that's not true - it can't.
The reason why Maxwell's demon can't
get energy for free lies here -
in his head.
What was discovered was this -
the demon really is using
nothing more than information
to create useful energy.
But this doesn't mean that he's
getting something for nothing.
Remember how the demon works?
He spots a fast-moving molecule
on one side of the box,
opens a partition and lets it
through to the other side.
But each time he does that,
he has to store information
about that molecule's
speed in his memory.
Soon his memory will fill up
and then he can only continue
if he starts deleting information.
Crucially this deletion would
require him to expend energy.
The demon needs to keep a record
of which molecules are moving where
and if the record-keeping
device is only finite size,
at some point the demon is
going to have to erase it.
That's an irreversible process
that increases
the entropy of the universe.
Its the erasure of information
that increases entropy
once and for all.
What was discovered
is that there's a certain,
specific minimum amount of energy,
known as the Landauer limit,
that's required to delete
one bit of information.
It's tiny, less than a trillion
trillionth of the amount of energy
in a gram of sugar, but it's real.
It's a part of the fundamental
fabric of the universe.
Amazingly, we can now
do real experiments
that test aspects of Maxwell's idea.
By using lasers
and tiny particles of dust,
scientists around the world
have explored the relationship
between information and energy
with incredible accuracy.
Maxwell's thought experiment,
dreamt up in the age of steam,
still remains at the cutting edge
of scientific research today.
Maxwell's demon links together
two of the most important concepts
in science - the study of energy
and the study of information
and shows that the two
are profoundly linked.
What we now know
is that information,
far from being some
abstract concept,
obeys the same laws of physics
as everything else in the universe.
Information is not
just an abstraction,
just a mathematical thing or formula
that you write on the paper.
Information is actually
carried by something.
So it is encoded onto something -
a stone, a book, a CD.
Whatever it is, there is a carrier
where the information is on.
That means that information behaves
according to those laws of physics.
So it cannot break
the laws of physics.
What humanity has learnt
over the last few millennia
is that information can never
be divorced from the physical world.
But this is not a hindrance.
What makes information so powerful
is the fact it can be stored
in any physical system we choose.
From using stone and clay
to allow information
to be preserved over eons
to using electricity and light
so it can be sent quickly,
the medium that stores information
gives it unique properties.
Today, scientists are exploring new
ways of manipulating information,
using everything from DNA
to quantum particles.
They hope that this work will
usher in a new information age,
every bit as transformative
as the last.
What we now know is that we are just
at the beginning of our journey
to unlock the power of information.
It's always been clear
that creating physical order -
the structures we see around us -
has a cost.
We need to do work
to expend energy to build them.
But in the last few years, we've
learnt that ordering information,
creating the invisible, digital
structures of the modern world,
also has an inescapable cost.
As abstract and ethereal
as information seems,
we now know it must always be
embodied in a physical system.
I find this an incredibly
exciting idea.
Think about it this way - a lump of
clay can be used to write a poem on.
Molecules of air can carry
the sound of a symphony.
And a single photon
is like a paint brush.
Every aspect of
the physical universe
can be thought of as a blank canvas,
which we can use to build
beauty, structure and order.
Over the last 300 years,
we've developed amazing new ways
to harness energy.
We've used this ability to
transform our environment.
But all these structures that we
see around us are just
one type of visible order that
we've created here on planet Earth.
There's another
type of invisible order,
every bit as complex that we are
only now beginning to understand.
It's something that nature has been
harnessing for billions of years.
Something we call information.
The concept of information
is a very strange one.
It's actually a very difficult idea
to get your head round.
But in the journey to try
and understand it, scientists
would discover that information is
a fundamental part of our universe.
This film is the story
of information.
And the immense power
released from manipulating it.
It's the story of how
we discovered the power of symbols.
And how writing, codes
and computers would revolutionise
our understanding of the universe.
It's the story of how, in a cosmos
collapsing into disorder,
information can be used to create
order and structure.
At first glance, information appears
to be a very straightforward idea.
It exists everywhere in our world.
Our brains are filled with it.
And we constantly exchange
it between each other.
But information has been
one of the subtlest
and most difficult concepts that
science has had to grapple with.
Understanding and harnessing it
has been an extremely long
and difficult process.
The power of information would first
be glimpsed over 5,000 years ago,
when a revolutionary
technology was developed.
One that would set the modern
world in motion.
Over the years, mankind has come up
with some pretty remarkable stuff.
But of all humanity's inventions,
there's one that really stands out.
It's the most transformative,
destructive,
creative technology ever conceived.
It is also one of the simplest.
That invention is the written word.
At its heart, writing is all about
the transmission
and storage of information.
Words allow ideas to
endure through time.
These are some of the earliest
texts in existence.
They give us an incredible insight
into the development of writing.
I've come to meet one of the few
people who can still read them -
Dr Irving Finkel.
We take writing
so much for granted these days,
it's easy to forget that it
was invented.
It certainly was.
How did it first come about?
The earliest writing that we have is
written on clay tablets
and it comes from
Iraq, Ancient Mesopotamia.
It comes from the culture
of the culture of the Sumerians.
What happened here was that they
started off with purely
pictographic signs
to express an idea.
This lasted for quite a long time,
until it occurred to somebody,
perhaps accidentally, that what you
could do is make one of these
graphic symbols on the surface
of the clay not for what it
looked like but for the sound
it represented.
So not a picture of an object,
a picture of a sound?
That's what we always called
the giant leap for mankind.
By combining different
sounding pictures,
the ancient Mesopotamians could
express any idea imaginable.
The essence of their breakthrough
was to see, for example,
that a picture of an eye
and a picture of a deer didn't have
to mean an eye and a deer.
The pictures could be used simply
for the sounds that they made.
In this case, idea.
Once this system was discovered,
it meant anything that could be
spoken, even the most strange
or abstract thoughts could be
transformed into symbols.
Information could now live
outside of the human brain.
This meant it could endure
over vast spans of time.
It was an idea that fascinated
the ancient Mesopotamians.
This lovely tablet here,
this king lived in about 2100 BC.
He buried this in the foundations
of his temple as a message
for the future.
This King Ur-Nammu, the powerful
male, King of Sumer and Akkad -
that's the south and north
part of Ancient Mesopotamia.
Her house - he built for her
and he even restored it afterwards.
This is a proud thing.
He wants everybody to know about it
and this is a real
message for the future.
What's so remarkable for me
is this is information stored
on clay for thousands of years.
Yes. Ideas that someone
had 4,000 years ago are still there.
You have ideas, you have speech,
human hopes, literature,
prayers - all these sorts
of outpourings of the human soul
fixed for ever in clay.
By turning sounds into symbols,
the Mesopotamian scribes had
discover that information could be
changed very easily from one
form to another.
From something that
existed as spoken sounds,
to something that existed
as symbols on clay tablets.
This was just the beginning.
Humans were yet to realise
the true power of symbols.
For 4,000 years, writing was pretty
much the only
information technology people used.
But in the 19th century, during
the great Industrial Revolution,
things would begin to change.
In the maelstrom of ideas
and inventions,
a series of seemingly unconnected
technologies would emerge
that all began to hint
at the immense power of information.
These technologies would all
come from very practical,
very un-theoretical origins.
They would start to reveal that
information was a much deeper
and more powerful concept
than anyone had realised.
One of the first of a new breed
of information technologies would be
developed in the French city of Lyon
at the end of the 18th century.
18th-century Lyon was home to some
of the best craftsmen in the world.
It was also a place
of great opulence,
grandeur and, above all, money.
Thanks to the rich
and fashionable aristocrats
and bankers who lived there,
it would become home to the greatest
silk-weaving industry in the world.
Almost a third of the city's
inhabitants worked in
the silk industry, and it was home
to over 14,000 looms.
This is brocade.
The material that made Lyon famous.
It's a beautiful
and intricately woven fabric that,
as you might imagine, is incredibly
labour intensive to produce.
A two-man team,
working flat out for a day,
could at best produce about an inch
of this amazing stuff.
The demand for the fine fabrics
of Lyon was immense.
But the silk weaving process
was painful slow.
But thanks to a soldier and weaver
named Joseph Marie Jaquard,
a device will be developed
to help speed up weaving.
In the process, it would reveal a
fundamental truth about information.
Building on the work of a number
of others, in 1804 Jaquard
patented his invention.
At the time, the loom was
the most complex mechanism
ever built by humankind
Jaquard's loom was
a miracle of ingenuity.
You see, he had designed a single
machine, which without any
alteration to its construction -
its hardware, to use a modem term -
could be programmed to weave any
pattern a designer could think up.
It fact, it could produce a whole
range of silk designs
with barely a pause in production.
Jaquard had found
the holy grail of weaving.
And the secret was
a simple punched card.
The punched card held within it
the essence of the designs
that the loom would weave.
When these punched cards
were fed into the loom
they would act to lower
and lift the relevant threads...
..recreating the pattern in silk.
Any design you could think of could
be broken down and translated into
a series of punch cards that could
then woven by the loom.
Information was
being translated from
picture to punch card
to the finished fabric.
It's a machine for weaving
textiles, that's its task,
but there is nothing specific
about what textile it should weave.
That is contained
in the information,
which is encoded on the cards.
So if you like, the cards, programme
it, that is to say instruct it
what to do. And this has huge
resonances for what came later.
Jaquard's Loom revolutionised
the silk industry.
But at its heart was something
deeper, something more universal
than its industrial origins
and its ability to speed up weaving.
The loom revealed the power of
abstracting information.
It showed you can take the essence
of something, extract the vital
information
and represent it in another form.
Writing had revealed you could use
a set of symbols to capture
spoken language.
Now, Jaquard had shown that with
just two symbols -
a hole or a blank space,
it was possible to capture
the information in any picture
imaginable.
This is a portrait of Jaquard that's
been woven in silk.
It's spectacularly detailed with
hundreds of thousands of stitches.
Yet all the information you need to
capture this life-like image can be
stored in a series of punched cards.
24,000 of them to be precise.
This picture is a fantastic example
of a really far-reaching idea.
That the simplest of systems -
in this case, cards with a series
of holes punched in them -
can capture the essence of something
much, much more complicated.
If 24,000 punched cards could create
an image like this...
What would happen if you had
24 million?
Or 24 trillion cards?
What new types of complex
information
might be able to be captured
and represented?
Jacquard had stumbled on an
incredibly deep
and far-reaching idea.
As long as you have enough of them,
simple symbols can be used
to describe anything
in the entire universe.
Translating information
into abstract symbols
to store and process, had proven
to be an extremely powerful idea.
But the way information was sent,
the way it was communicated, hadn't
changed for thousands of years.
The world before
telecommunications technology
was a very different place,
cos you could only send messages as
fast as you could send objects.
You'd write a message on a piece of
paper or something like that
and then you'd give it to somebody
who could run very fast,
or could go on horse
or on a ship very fast.
The point was you could only send
information as fast as
you could send matter.
But in the 19th century,
the speed at which information
could be sent would
dramatically increase,
thanks to an incredible new
information-carrying medium -
electricity.
Very soon after electricity
was discovered,
excitement grew about its potential
as a medium to transmit messages.
It seemed that if it could be
controlled and summoned at will,
electricity would be the perfect
medium for sending information.
Electricity seemed to offer
many advantages
as a way of sending messages.
It was sent down a wire which means
it could pretty much go anywhere.
It wasn't affected
by bad weather conditions
and most importantly,
it could move very quickly.
But there was one big problem facing
those in the early 19th century
who wanted to use electricity
as a means to communicate.
How could such a simple signal
be used to send complex messages?
Here in the Science Museum archive,
they have one of the most
impressive collections
of early electronic communications
technology in the world.
Here are just some
of the early devices
designed to send signals
using electricity.
This one's particularly fun.
It was developed in 1809
in Bavaria by Samuel Soemmering.
So if the sender wants
to send letter A,
he sends a current through
that corresponding wire.
At the receiver's end
is a tank full of liquid
and electric current forces
a chemical reaction
causing bubbles to appear above
the corresponding letter A.
The whole process is ingenious,
if a little laborious.
But what's really fun is that the
sender has to let the receiver know
he's about to send a signal.
He does that by sending
extra electric currents
so that more bubbles appear,
forcing an arm upwards
which releases a ball...
BELL RINGS
..and triggers a bell.
As you can imagine, this wouldn't
be the quickest of systems.
After Soemmering, all sorts
of approaches were taken
in trying to crack the problem of
sending messages using electricity.
But they all suffered from having
over-complex codes.
These devices, each cunning
and innovative in its own way,
were all destined for
the scrap heap of history.
And that's because in the 1840s,
they were superseded by a way
of sending signals that still
endures to this day.
It was developed by artist
and entrepreneur Samuel Morse,
together with his colleague
Alfred Vale.
What was so special about their
system wasn't the technology
that was used
to carry their messages,
but the incredibly simple
and effective code
they used to send them.
Just like Jacquard's punch cards,
the genius of Morse and Vale's code
lay in its simplicity.
Using a collection of short and long
pulses of electrical current,
they could spell out the letters
of the alphabet.
Vale suggested that
the most frequent letters
in the English language
get the shortest code.
So an E is sent like this.
While an X is sent like this.
This means that messages can be sent
quickly and efficiently.
Figuring out the code part of it,
the software if you like,
was as complicated as figuring out
the hardware side of things
with the batteries and the wires, and
together they made an entirely new
technology which is
the electric telegraph.
The telegraph had once again
revealed the power
of translating information
from one medium to another.
Information had at first
been fixed in human brains.
Then held in symbols in clay
and paper and punched cards.
Now, thanks to Morse, information
could reside in electricity
and this made it unimaginably
lighter and quicker
than it had every been before.
In just a few short years,
the telegraph network
would spread around
the entire globe,
laying the foundations
of the modern information age.
Between them, Jacquard and Morse had
found new novel ways to manipulate,
process and transmit information.
What had begun with the invention
of writing thousands of years ago
had culminated in the binding
of the entire planet
in a lattice of wires carrying
highly abstracted information
at incredible speeds.
For people at the end
of the 19th century
it may have seemed that humanity's
ability to manipulate
and transmit information
was at its zenith.
They couldn't have been more wrong.
Information would reveal itself
to be a more important,
more fundamental concept
than anyone could have imagined.
It would soon become apparent
that information
wasn't just about human
communication.
It was a much further-reaching
idea than that.
The true nature of information
would first be hinted at
thanks to a strange problem,
one dreamed up by a brilliant
Scottish physicist
who appeared to be thinking about
something else entirely.
James Clerk Maxwell was one of
the great minds of the 19th century.
Among his many interests,
Maxwell became fascinated
by the science of thermodynamics -
the study of heat and motion
that had sprung up
with the birth of the steam engine.
Maxwell was one of the first
to understand
that heat is really
just the motion of molecules.
The hotter something is, the faster
its molecules are moving.
This idea would lead Maxwell
to dream up a very bizarre
thought experiment in which
information played a crucial role.
Maxwell theorised that simply by
knowing what's going on
inside a box full of air, it'll be
possible to make one half hotter
and the other half colder.
Think of it like building
an oven next to a fridge
without using any energy.
It sounds crazy, but Maxwell's
argument was extremely persuasive.
It goes like this.
Imagine a small demon
perched on to of the box,
who has such excellent eye sight
that he could observe accurately
the motion of all the molecules
of air inside the box.
Now, crucially,
he's in control of a partition that
divides the box into two halves.
Every time he sees a fast-moving
molecule approaching the partition
from the right-hand side he opens it
up, allowing it through to the left.
And every time he sees a slow moving
molecule approaching the partition
from the left, he opens it up,
allowing the molecule
through to the right.
Now, you can see
what's going to happen.
Over time, all the fast-moving
hot molecules will accumulate
on the left-hand side of the box,
and all the slow-moving
cold molecules on the right.
Crucially, the demon has done
this sorting with nothing more
than information about the motion
of the molecules.
Maxwell's demon seemed to say
that just by having information
about the molecules, you could
create order from disorder.
This idea flew in the face
of 19th-century thinking.
The science of thermodynamics
had shown very clearly
that over time, the entropy
of the universe, its disorder,
would always increase.
Things were destined to fall apart.
But the demon seemed to suggest that
you could put things back together
without using any energy at all.
Just by using information,
you could create order.
It would prove to be a fiendishly
difficult problem to solve,
not least because the brilliant
Maxwell had come up with an idea
far, far ahead of its time.
It's amazing, the impact
that he had on physics,
and that he came up with
this very intricate concept
and that he already in some sense
pre-anticipated the notion
of information. It wasn't
actually there at the time,
there was no such thing.
I think this idea was astonishing.
He didn't really have a resolution,
he raised it as a concern
and he left it open.
And I think what followed
is more or less 120 years
of extremely exciting debate
and development
to try to resolve
and address this concern.
So what was going on
with Maxwell's demon?
It may sound far-fetched
and fanciful,
but imagine the possibilities
if we could build a machine
in the real world that could mimic
the actions of the Demon.
I could use it to heat a cup of
coffee, or run an engine,
or power a city all using nothing
more than pure information.
It's as though we could create
order in the universe
without expending any energy.
Scientists felt intuitively
that it had to be wrong.
The problem was it would take over
100 years to solve the problem.
While Maxwell's riddle rumbled on,
something quite unexpected
was to happen,
a new device was dreamt up that
could perform quite incredible
and complex tasks simply by
processing information.
What's more, this was a device
that could actually be built.
The machine would come to be
known as the computer, and the idea
behind it came from a quite
remarkable and visionary scientist.
Alan Turing was the first person
to conceive of the modern computer,
a machine whose sole function is to
manipulate and process information.
A machine that harnesses
the power of abstract symbols.
A machine that enables almost every
aspect of the modern world.
Turing's incredible idea would
first appear in a now-legendary
mathematical paper
published in 1936.
In his brief life, Alan Turing
brought fresh, groundbreaking ideas
to a whole range of topics,
from cryptography
through to biology.
The sheer breadth of his thinking
is breathtaking.
But for most scientists,
it's the concepts he outlined
in these 36 pages that
mark him out as truly special.
It's this work that makes him worthy
of the title "Genius".
Published when Turing
was just 24 years old,
On Computable Numbers
With An Application
To The Entscheidungsproblem
tackles the foundations
of mathematical logic.
What's amazing about it is that
the idea for the modern computer
emerged simply as a consequence
of Turing's brilliant reasoning.
He was thinking about something
else entirely,
he wasn't, you know,
sitting there thinking,
"I want to try and invent the modern
computer," he was thinking
about this very abstract problem
in the foundations of mathematics.
And the computer kind fell
sideways out of that research,
completely unexpectedly.
I mean, nobody could have guessed
that Turing's very abstract,
abstruse research in the foundations
of mathematics could produce
anything of any practical value
whatsoever, let alone a machine that
was going to change the lives of, you
know, nearly everyone on the planet.
Turing had set out to understand
if certain processes
in mathematics could be done
simply by following a set of rules.
And this is what would get him
thinking about computers.
In 1936, the word "computer"
had a very different meaning
to what it does today.
It meant a real person
with a pencil and paper,
engaged in arithmetical
calculations.
Banks hired many such people,
often women,
to work out interest payments.
The Inland Revenue employed them
to work out how much tax to charge.
Observatories hired them
to calculate navigational data.
Human computers were vital
to the modern world,
dealing with the huge amounts
of information produced
as science and industry
grew ever more complex.
What Turing did in his 1936 paper
was ask a simple
but profound question.
"What goes on in the mind of a
person carrying out a computation?"
To do this, he first had to discard
all the superfluous detail,
so that only the very essence of
the process of computation remained.
So, first off went the inkpot.
Then the pen, then the slide-rule.
Then the pencils
and the pads of paper.
All these things made it easier,
but none of them
were absolutely crucial to the
person carrying out the computation.
Now Turing asked, "What goes on in
the brain of a human computer?"
It's a vastly complex
biological system,
capable of consciousness, thoughts
and insights, but to Turing,
none of these was critical to
the process of computation either.
Turing realised
that to compute something,
a set of rules
had to be followed precisely.
That was all.
It takes the higher level
intelligence
that was presupposed to be
involved in calculation,
which was thinking, and says you can
have a mechanical process -
and by mechanical,
he means an unthinking process -
to perform the same act.
And therefore eliminates
the necessity of human agency,
with all its high-level functions.
And that is what is revolutionary
about what he tries to do.
Turing's brilliant mind saw that any
calculation had two aspects...
The data, and the instructions
for what to do with the data.
And this would be the key
to his insight.
Turing had to find a way of getting
machines to understand instructions
like "add," "subtract,"
"multiply," "divide"
and so on, in the same way
that humans do.
In other words, he had to find
a way of translating instructions
like these into a language that
machines could understand.
And with flawless, impeccable logic,
Turing did exactly that.
This may look like a random
series of ones and zeroes,
but to a computing machine,
it's a set of instructions
that can be read off step by step,
telling the machine to behave
in a certain way.
So, while a human computer could
look at this symbol
and understand the process
that was required,
the computing machine had to
have it explained, like this.
This paper tape that Turing
envisaged is what
we would now call
the memory of the computer.
But Turing didn't stop there.
Turing realised that feeding
a machine instructions in this way
had an amazing consequence.
It meant that just one machine is
needed to perform almost any task
you can think of.
It's a beautifully simple concept.
In order to get the machine to do
something new, all you had to do
was feed it a new set
of instructions, new information.
This idea became known
as the Universal Turing Machine.
The more you wanted your machine to
do, the longer the tape had to be.
Bigger memories could hold complex,
multilayered instructions
about how to process and order
any kind of information imaginable.
With a big enough memory,
the computer will be capable of an
almost limitless number of tasks.
This idea of Turing's,
that a multitude of different tasks
can be carried out
simply by giving a computing machine
a long sequence of instructions,
is his greatest legacy.
Since his paper,
Turing's dream has been realised.
So, calculations,
making phone calls,
recording moving images, writing
letters, listening to music -
none of these require bespoke
machines.
They can all be carried
out on a single device.
A computing machine.
This phone is a modern incarnation
of Turing's amazing idea.
Inside here are many,
many instructions.
What we call programmes,
or software, or apps,
that are nothing more than a long
sequence of numbers
telling the phone what to do.
What's amazing about Turing's idea
is its incredible scope.
The sets of instructions
that can be fed to a computer
could tell it how to mimic
telephones or typewriters.
But they could also describe
the rules of nature,
the laws of physics.
The processes of the natural world.
This is a simulation of many
millions of particles
behaving like a fluid.
To work out how it flows,
the computer simply follows a set
of instructions held in its memory.
This only begins to hint
at the power of computing machines.
This is a computer simulation
of the large-scale structure
of the entire universe.
And it reveals the true
power of Turing's idea.
Turning instructions into symbols
that a machine can understand
allows you to recreate not just
a simple picture or sound,
but a process, a system, something
that is changing and evolving.
By manipulating simple symbols,
computers are capable
of capturing the essence,
the order of
the natural world itself.
By thinking about how
the human brain processes
and computes information,
Alan Turing had had one of the most
important ideas of the 20th century.
The power of information
was revealing itself.
GARBLED VOICES
It would be very easy to think that
after Turing's ideas were made real,
the true power of information
would be unleashed.
But Turing was only half the story.
The modern information age would
require another idea,
one that would finally
pin down the nature of information,
and its relationship to the order
and disorder of the universe.
It was an idea that would be
dreamt up
by a gifted and eccentric
mathematician and engineer.
Claude Shannon was a true maverick,
and his desire to tackle
unusual problems would lead to
a revolutionary new idea.
One that would uncover the
fundamental nature of information,
and the process of communication
in all its varied forms.
This is Claude Shannon's paper,
The Mathematical Theory
Of Communication.
Now, the title may sound
a bit dry, but trust me,
it's one of the most important
scientific papers
of the 20th century.
Not only did it lay the foundations
for the modern world's
communication network,
it also gave us fresh insights
into human language,
into things we do intuitively,
like speaking and writing.
The paper was published in 1948,
while Shannon was working
at the Bell Labs in New Jersey -
the research arm of
the vast Bell Telephone Network.
It was an institution
famous for its forward-thinking,
relaxed atmosphere.
The mathematicians were free to work
on any problem that interested them.
The only thing that the laboratory
management required of them
was that they keep an open door,
and if anybody from any other
department came with a problem,
that they would at least
think about it.
Otherwise they were absolutely free,
and the atmosphere was incredible.
People were playing,
and encouraged to play.
Hello. I'm Claude Shannon,
a mathematician here at
the Bell Telephone Laboratory.
Claude Shannon in particular
was given free reign
to do pretty much
whatever he wanted.
This is Theseus.
Theseus is an electrically
controlled mouse, mouse.
Oh, they treated him
as their darling.
I never saw him juggle, but I
certainly saw him ride his unicycle.
He brought it to work one day,
and he must have cost Bell Labs
at least a hundred man-hours of time.
But despite the frivolity,
the Bell Telephone Network
faced a huge problem.
Every day, they transmitted
vast amounts of electronic
information all across the world.
But they had no real idea of how to
measure this information properly,
or how to quantify it.
In short, their entire business
was built on something
they didn't actually understand.
Amazingly, their superstar
employee Claude Shannon
would give them
exactly what they needed.
GARBLED VOICES
In this paper, Shannon did
something absolutely incredible -
he took the vague and mysterious
concept of information
and managed to pin it down.
Now, he didn't do this using
some cleverly-worded,
philosophical definition.
He actually found a way to measure
the information
contained in a message.
GARBLED VOICES
Amazingly, Shannon realised
that the quantity of information
in a message had nothing
to do with its meaning.
Instead, he showed
it was related solely
to how unusual the message was.
Information is related
to unexpectedness.
So news is news
because it's unexpected
and the more unexpected it is,
the more newsworthy it is.
So if today's news was
the same as yesterday's news,
there would be no news at all.
And that information
content would be zero.
So suddenly you have a
relationship between...
unexpectedness and information.
GARBLED VOICES
But Shannon was to go further
and give information its
very own unit of measurement.
GARBLED VOICES
So, how did he do this?
Well, he showed that any message
you cared to send
could be translated
into binary digits -
a long sequence of ones and zeros.
So a simple greeting like "Hello"
could be written like this.
Or... like this.
Just think of this as another
way of writing the same message.
ELECTRONIC MUSIC
Shannon realised that transforming
information into binary digits
would be an immensely powerful act.
It would make information
manageable, exact,
controllable and precise.
In his paper, Shannon showed
that a single binary digit -
one of these ones or zeros - is
a fundamental unit of information.
Think of it as an atom
of information -
the smallest possible piece.
Then, having defined
this basic unit,
he even gave us a name for it,
one we're all familiar with today.
He used a shortening of
the phrase, "binary digit" -
"bit".
The humble bit turned out to be
an enormously powerful idea.
The bit is the smallest
quantity of information.
It is highly significant
because it's the fundamental atom.
It is the smallest unit
of information in which
there's sufficient discrimination
to communicate anything at all.
The power of the bit
lay in its universality.
Any system that has two states,
like a coin with heads or tails,
can carry one bit of information.
One or zero.
Punched or not punched.
On or off.
Stop or go.
All of these systems can
store one bit of information.
Thanks to Shannon,
the bit became the common
language of all information.
Anything - sounds, pictures,
text - can be turned into bits
and transmitted by any system
capable of being in just two states.
Shannon had founded
a new, far-reaching theory.
The ideas he began to explore
would form the cornerstone
of what we now call,
"information theory".
He'd taken an abstract
concept - information -
and turned it into
something tangible.
What had been just a vague notion
was now measurable - something real.
The idea of converting into bits,
into making things digital,
would fundamentally transform
many aspects of human society.
GARBLED VOICES
But information isn't
just something humans create.
We're beginning to understand
that this concept lies at the heart,
not only of 21st-century
human society,
but also at the heart
of the physical world itself.
Every "bit" of information
we've ever created, every book,
every film, the entire
contents of the internet,
amounts to pretty much nothing
when compared with
the information content of nature.
And that's because even
the most insignificant event
contains a spectacular
amount of information.
Let me show you.
Imagine how many bits of information
you would need to describe this.
The beautiful and intricate
interplay of physical laws
taking place
at scales and timeframes
that are normally
imperceptible to us.
But here you're still
only seeing a fraction
of the complexity of nature.
Imagine the interplay between the
trillions upon trillions of atoms.
The amount of bits
you would need to describe this
is almost unimaginable.
But what's amazing is that now,
thanks to the ideas of Turing and
Shannon, we're able to describe,
model and simulate nature
in ever greater detail.
But this isn't the end of the story.
Information, it seems, isn't
just a way of describing reality.
In the last few years,
we've discovered that information
is actually an inseparable
part of the physical world.
It's a really difficult idea to
get to grips with but information,
everything from a Beethoven symphony
to the contents of a dictionary,
even a fleeting thought,
all information needs to be embodied
in some form of physical system.
Amazingly, the reason
we understand the true connection
between information and reality
is because of Maxwell's demon.
Remember, it seemed like
the demon could use information
to create order in a box of air that
started out completely disordered.
Moreover, it could do this
without expending any effort.
Information seemed to be able
to break the laws of physics.
Well, that's not true - it can't.
The reason why Maxwell's demon can't
get energy for free lies here -
in his head.
What was discovered was this -
the demon really is using
nothing more than information
to create useful energy.
But this doesn't mean that he's
getting something for nothing.
Remember how the demon works?
He spots a fast-moving molecule
on one side of the box,
opens a partition and lets it
through to the other side.
But each time he does that,
he has to store information
about that molecule's
speed in his memory.
Soon his memory will fill up
and then he can only continue
if he starts deleting information.
Crucially this deletion would
require him to expend energy.
The demon needs to keep a record
of which molecules are moving where
and if the record-keeping
device is only finite size,
at some point the demon is
going to have to erase it.
That's an irreversible process
that increases
the entropy of the universe.
Its the erasure of information
that increases entropy
once and for all.
What was discovered
is that there's a certain,
specific minimum amount of energy,
known as the Landauer limit,
that's required to delete
one bit of information.
It's tiny, less than a trillion
trillionth of the amount of energy
in a gram of sugar, but it's real.
It's a part of the fundamental
fabric of the universe.
Amazingly, we can now
do real experiments
that test aspects of Maxwell's idea.
By using lasers
and tiny particles of dust,
scientists around the world
have explored the relationship
between information and energy
with incredible accuracy.
Maxwell's thought experiment,
dreamt up in the age of steam,
still remains at the cutting edge
of scientific research today.
Maxwell's demon links together
two of the most important concepts
in science - the study of energy
and the study of information
and shows that the two
are profoundly linked.
What we now know
is that information,
far from being some
abstract concept,
obeys the same laws of physics
as everything else in the universe.
Information is not
just an abstraction,
just a mathematical thing or formula
that you write on the paper.
Information is actually
carried by something.
So it is encoded onto something -
a stone, a book, a CD.
Whatever it is, there is a carrier
where the information is on.
That means that information behaves
according to those laws of physics.
So it cannot break
the laws of physics.
What humanity has learnt
over the last few millennia
is that information can never
be divorced from the physical world.
But this is not a hindrance.
What makes information so powerful
is the fact it can be stored
in any physical system we choose.
From using stone and clay
to allow information
to be preserved over eons
to using electricity and light
so it can be sent quickly,
the medium that stores information
gives it unique properties.
Today, scientists are exploring new
ways of manipulating information,
using everything from DNA
to quantum particles.
They hope that this work will
usher in a new information age,
every bit as transformative
as the last.
What we now know is that we are just
at the beginning of our journey
to unlock the power of information.
It's always been clear
that creating physical order -
the structures we see around us -
has a cost.
We need to do work
to expend energy to build them.
But in the last few years, we've
learnt that ordering information,
creating the invisible, digital
structures of the modern world,
also has an inescapable cost.
As abstract and ethereal
as information seems,
we now know it must always be
embodied in a physical system.
I find this an incredibly
exciting idea.
Think about it this way - a lump of
clay can be used to write a poem on.
Molecules of air can carry
the sound of a symphony.
And a single photon
is like a paint brush.
Every aspect of
the physical universe
can be thought of as a blank canvas,
which we can use to build
beauty, structure and order.