# Timeline of *Systematic Data* and the Development of *Computable Knowledge*

## 20,000 BC

### 20,000 BC: Arithmetic

#### Counting abstract objects

The invention of arithmetic provides a way to abstractly compute numbers of objects.

### 15,000 BC: Cave Painting

#### Representing events by pictures

The Lascaux cave paintings record the first known narrative stories.

### 3500 BC: Written Language

#### A systematic way to record knowledge

A central event in the emergence of civilization, written language provides a systematic way to record and transmit knowledge.

### 3000 BC: Registering Land Ownership

Babylonian stone boundary markers begin to include inscriptions that record ownership of land.

## 2500 BC

### 2500 BC: Sumerian Calendar

#### Organizing time

The first known calendar system is established, rounding the lunar month to 30 days to create a 360-day year.

### 2200 BC: *I Ching*

#### Symbols for destiny

The 64 possible hexagrams of the Chinese *I Ching* are
taken to enumerate possible features of life and destiny.

### 2150 BC: Akkadian Measures

#### Making a standard for measurement

The Akkadian Empire adopts a single unified standard for measuring volume, based on the royal gur-cube.

### 1800 BC: Babylonian Census

#### Taking stock of a kingdom

The Babylonian census begins the practice of systematically counting and recording people and commodities for taxation and other purposes.

### 1790 BC: Code of Hammurabi

#### Codifying civil laws

Hammurabi writes down 281 laws prescribing civil behavior in the kingdom of Babylon.

### 1700 BC: Babylonian Mathematical Tables

Babylonians make tables of multiplication, reciprocals, squares, cubes, and square and cube roots.

### 1250 BC: Library at Thebes

#### A building to store knowledge

The Library at Thebes is the first known effort to gather and make many sources of knowledge available in one place.

### 1150 BC: Egyptian Maps

#### Recording geographic knowledge

The Turin Papyrus is the first known topographic map.

## 1000 BC

### 600 BC: Lydian Coinage

#### Coins to represent value

Lydia (in modern Turkey) introduces gold and silver coins to represent monetary value.

### 500 BC: Babylonian Astronomy

#### Using arithmetic to predict the heavens

The Babylonians introduce mathematical calculation as a way to track the behavior of planets and a few other systems in nature.

### 500 BC: Pythagoras

#### Numbers are the key to nature

The Pythagoreans promote the idea that numbers can be used to systematically understand and compute aspects of nature, music, and the world.

### 400 BC: Panini

#### Finding the rules of human language

Panini creates a grammar for Sanskrit, forming the basis for systematic linguistics.

### 387 BC: Plato's Academy

#### Teaching knowledge systematically

Plato founds his "Academy", which operates in Athens for nine centuries.

### 350 BC: Aristotle

#### Classifying the world and introducing logic

Aristotle tries to systematize knowledge, first, by classifying objects in the world, and second, by inventing the idea of logic as a way to formalize human reasoning.

### 325 BC: Library of Alexandria

#### Collecting the world's knowledge

The Library of Alexandria collects perhaps half a million scrolls with works covering all areas of knowledge.

### 300 BC: Euclid

#### Organizing mathematical truth

Euclid writes his *Elements*, systematically
presenting theorems of geometry and arithmetic.

### 250 BC: Archimedes

#### Computing as a basis for technology

Archimedes uses mathematics to create and understand technological devices and possibly builds gear-based, mechanical astronomical calculators.

### 200 BC: Eratosthenes

#### Labeling the Earth

Eratosthenes creates the system of longitude and latitude and uses it to create a scaled map of the known world.

### 100 BC: Antikythera Mechanism

#### A machine for computing

A gear-based device that survives today is created to compute calendrical computation.

### 45 BC: Julius Caesar

#### Standardizing the months

Julius Caesar institutes the Julian calendar, establishing the lengths of the twelve months.