Primary and Secondary Colours

COLOUR

 It is a characteristic of human visual perception that occurs when cone cells in the human eye are stimulated by light. 

Each colour is transmitted with a different wavelength.

Cones in our eyes respond to one of three ranges of wavelengths of the electromagnetic spectrum. 

Depending of the nature of colour, we can distinguish between coloured lights and colour pigments.

COLOUR PIGMENTS

All  paint colours are made from a pigment and a binder (agglutinant).

A pigment is a coloured powder. It absorbs and reflects different wavelenghts of light, depending on the colour.

Pigments come from minerals, animals, plants, and nowadays they can be synthesized in a laboratory.

A binder is a substance that makes the colour particles stick together. Depending on the type of binder used, different types of paints can be created: watercolours, crayons, gouache, pastels, oil paints, acrylics…

PRIMARY COLOURS

Magenta, cyan and yellow. They are colours that cannot be created by mixing any other colours.

SECONDARY COLOURS

They are created by mixing two primary colours.

• magenta + cyan = BLUE
• magenta + yellow = RED
• cyan + yellow = GREEN

COMPLEMENTARY COLOURS

They are pairs of colours that are on opposite sides of the color wheel.

• MAGENTA - GREEN
• CYAN - RED
• YELLOW - BLUE

         

Euclidean and Non-Euclidean Geometries.

Here you have an article that explains the difference between the euclidean and non-euclidean geometries.

The School of Athens

The School of Athens  is a fresco painted between 1510 and 1512 by renaissance artist Raphael. It covers one of the walls of the Vatican Stanzas.

Within classical architecture, it portrays many notable philosophers, mathematicians, geographers, historians and writers from Ancient Greece. Raphael depicts himself on the fresco to one side, looking directly at the spectators.

In the centre of the scene are Aristotle, pointing to the floor, and Plato (painted with the face of Raphael's contemporary artist Leonardo da Vinci), pointing to the sky.

Alexander the Great, who was Aristotle's pupil, appears on the right of the fresco. Socrates, Plato's teacher, is close to him.

Also depicted is Hypatia of Alexandria, one of the first prominent female philosophers, mathematicians and astronomers. She is on the right, looking at us the viewer.  

On the floor, and portrayed with the face of the Raphael's contemporary architect Bramante, is a figure drawing with a compass. This depicts EUCLID, who is called "the father of Geometry". (although some scholars dispute this arguing that Raphael was picturing Archimedes)

 7.  Alexander the Great.

 9.  Hypatia of Alexandria.

12. Socrates.

14. Plato.

15. Aristotle.

18. Euclid.

 R. Raphael. 

Here we start.

The Painter Francisco de Goya, by Vicente López Portaña, 1826