Isaac Newton. Engraving of Sir Isaac Newton (1642- 1727), English physicist, performing an optics experiment with a prism. Newton (at centre) passed a ray of light through a prism in a dark room onto a screen. The white light was refracted (bent) but different parts of it were refracted to a different extent. This meant that the screen was illuminated by bands of consecutive colours of the spectrum; these are red, orange, yellow, green, blue, indigo and violet. This experiment was performed in 1666, a productive year for Newton's research as his students at Cambridge University had been sent home due to fears of plague. He published his results in Opticks (1704).