stored or transmitted -- using some medium.

When you paint, you are representing your message

using a continuous pattern,

with seemingly endless numbers of possible forms.

You are free to express yourself.

When humans began developing writing systems,

we naturally had to divide our world into a finite

number of atomic units -- which we express using 'symbols.'

Now any written language can be thought of in this way.

Messages are formed by arranging

symbols in specific patterns.

Let's return to 3,000 BC,

and explore two ancient writing systems.

First, in ancient Egypt we had 'hieroglyphics' --

a priestly form of communication, reserved for

governmental, fiscal, magical and religious purposes.

It was practiced by a select few writers, known as 'scribes.'

And writing was generally unintelligible

to the common people.

The symbols, themselves, broadly fall into two categories:

'word signs' -- which are symbols that represent

a single meaningful concept --

back -- apple

-- and 'sound signs.'

These symbols represent chunks of sound.

[PEOPLE PRONOUNCING SINGLE-SYLLABLE SOUNDS]

Now the total number of different symbols

in common use was over 1,500.

And if you divide all of these symbols

into word signs versus sound signs,

we find a much smaller portion of sound signs.

There were around 140 sound signs --

-- and of these, only 33 represented distinct consonants --

a tiny fraction of all of the symbols in use.

At the time, the medium used

to store the symbols was primarily rock.

And this was ideal for durable inscriptions

allowing messages to travel into the future.

Mobility was not a main concern

when communicating messages in this way.

However, a new physical medium

for storing symbols was emerging at the time.

Along the Nile, silt deposits, left from flooding,

made the surrounding land extremely fertile.

And one of the many crops they grew was 'papyrus.'

It could be sliced into strips,

and these strips were then soaked --

and [woven] together, and finally, pressed --

allowing the natural sugars to act as glue.

After several days, it dried and formed

an almost weightless tablet.

This medium was ideal for sending messages

across greater spaces -- [compared to inscriptions on] more

durable [surfaces] -- focused on time.

Now this shift towards cheap,

portable mediums for storing symbols

coincided with the spread of writing

into the hands of more people, for new purposes.

Gradually, as people began to write more on papyrus,

the symbols evolved to suit more rapid writing.

This led to a cursive script known as 'hieratic.'

For example, here is the world's

oldest surviving surgical document.

It's written in hieratic script, dated to around 1,600 BC.

Now these symbols were based on hieroglyphics,

however, the pictures were simplified to match

the swiftness of writing -- an ancient shorthand.

Also, the number of common symbols

in use began to shrink -- down to around 700.

By escaping from the heavy medium of stone,

thought gained lightness.

A marked increase in writing by hand

was accompanied by the secularization

of writing, thought, and activity.

This led to a new writing system called 'demotic' --

around 650 BC -- which was devised specifically

to facilitate the ease of rapid writing.

For example, this text is known as a marriage contract,

and is one of the earliest known examples of demotic script.

It's interesting to notice that there was

a dramatic reduction, again, in the total number

of symbols with this new system --

roughly 10% of the total number

of symbols used before.

This was due to a shift towards

the use of 'phonetic' symbols -- or sound signs --

[PEOPLE PRONOUNCING SOUND SIGNS]

-- over word symbols -- or meaning signs.

And the new simplicity meant that

children could be taught to write at a young age.

We see this same pattern in other cultures.

Let's return back to 3,000 BC and visit Mesopotamia

where 'cuneiform' was the writing system --

originally used for fiscal purposes,

as it was a powerful method

of tracking debt and surplus commodities --

before the invention of coins.

For example, here is a document recording

someone's stock of animal hides.

And this type of writing evolved to suit other needs.

For example, this tablet contains a recipe

for bread and beer.

And here's another tablet

which contains a legal document.

Now originally, the writing system

was used by the Sumerians --

and there were over 2,000 different symbols in use --

which could also be divided into

word signs and sound signs.

Akkadian gradually replaced Sumerian

as the spoken language.

And here is the earliest known dictionary -- from 2,300 BC.

It contains word lists in Sumerian and Akkadian.

And this was discovered in modern Syria.

When it was adapted by the Akkadians,

and fitted to their language,

they reduced the number of symbols to around 600.

And they did this again

by moving towards sound signs.

Again, we see both hieroglyphics and cuneiform

using several hundred sound symbols

in their more evolved forms.

And as writing systems escaped their formal usage,

and spread to more and more people,

the soil was ripe for the invention of

a brand new writing system for the people.

One of the great discoveries in the history of writing,

is dated to around 1,700 BC.

The Sinai Inscriptions were found in the Sinai Peninsula --

and they were about 20 feet apart.

This was important, because each picture

denotes a consonant sound --

and no word signs are used.

When sounded out correctly,

the letters would produce words in ancient Semitic.

Although not fully deciphered, this message appears

to be of the form 'name, rank, and prayer.'

The two words deciphered are 'chief' and 'god.'

This innocent example was part of a writing revolution --

creating meaning by merging sound signs only.

[GIRL PRONOUNCING ONE- AND TWO-SYLLABLE WORDS]

By 1,000 BC, we arrive at the Phoenician alphabet,

which emerges along the Mediterranean,

used by the Phoenicians,

who are a maritime trading culture.

The Phoenician writing system was based on

the principle that one sign represents one consonant.

And it was used to write a northern Semitic language

containing only 22 symbols total.

The symbols chosen to represent these sounds

were often borrowed from hieroglyphic pictures --

so that the letter's name began with the letter's sound.

For example, 'mem' -- which stood for 'water' --

became what we know of as the letter 'M.'

'Alph' which stood for ox,

became what we know of as the letter 'A.'

But the secret power of this alphabet --

unknown to its inventors --

was that it did not need Semitic speech

in order to work.

[PEOPLE PRONOUNCING SINGLE-SYLLABLE SOUNDS]

With modest adjustments, these miraculous letters

would be fitted to diverse tongues of

Europe, India, and southeast Asia --

carrying literacy around the globe.

This was the source of the Greek -- and later Roman --

alphabet forms we know today.

The idea of an alphabet is a powerful method

for transmitting and storing information.

Realize, it doesn't really matter

what the symbols are, or how you choose them --

or even what language [they're] in.

Information is just a selection

from a collection of possible symbols.

And over time, we have always looked for

faster, more efficient ways of transporting

information across greater and greater spaces.

And when we tred doing this using new mediums

which travel faster than any human or animal,

an engineering problem presents itself.

Hello? Hello!