Text search
Related images
HistoryWorld
Link
Map Click the icons to visit linked content. Hover to see the search terms. |
| |
| | | | | | |
|
| c. 13.7 billion years ago |
| | Hydrogen and helium nuclei form in the first three minutes, with perhaps another 300,000 years before they combine with electrons to form atoms | |
| |
|
| c. 13 billion years ago |
| | As gravity exerts its pressure within parts of the expanding fireball, subnuclear particles merge into more complex elements | |
| |
|
| c. 450 BC |
| | Empedocles states that all matter is made up of four elemental substances - earth, fire, air and water | |
| |
|
| c. 420 BC |
| | The Greek philosopher Democritus declares that matter is composed of indivisible and indestructible atoms | |
| |
|
| c. 380 BC |
| | A Greek text, attributed to Polybus, argues that the human body is composed of four humours | |
| |
|
| c. 300 BC |
| | Epicurus postulates a universe of indestructible atoms in which man himself is responsible for achieving a balanced life | |
| |
|
| c. 250 BC |
| | The first alchemists, working in Alexandria, are also the world's first experimental chemists | |
| |
|
| c. 1040 |
| | A Chinese manual on warfare includes the earliest known description of gunpowder | |
| |
|
| | | | |
|