The first galaxies begin to form, as self-contained gravitational systems with gases gradually coalescing into stars

A new galaxy, the Milky Way, forms - and one of its stars is our sun

The new star settles down, while nuclear dust in the vicinity coalesces into planets and asteroids orbiting the sun

The Greeks are intrigued by the iron-attracting property of a mineral which they find in the district of Magnesia

The Greeks observe the strange effect of electricity, seen when amber (known to them as electron) is rubbed

Archimedes (it is said) leaps out of his bath shouting eureka ('I have found it') when he perceives how to test for relative density

Iste quibusdam in au

William Gilbert, physician to Queen Elizabeth, concludes that the earth is a magnet and coins the term 'magnetic pole'

Electricity is given its name (in the Latin phrase vis electrica) by the English physician, William Gilbert

Galileo's Discorsi, published in Leiden, lays the groundwork for mathematical physics

With the help of his more robust brother-in-law, Blaise Pascal provides physical proof that atmospheric pressure varies with altitude

Otto von Guericke uses sixteen horses to demonstrate in Regensburg the power of a vacuum

Isaac Newton spends a creative period in Lincolnshire, at home in Woolsthorpe Manor, apples or no apples

Isaac Newton's experiments with the prism demonstrate the link between wavelength and colour in light

Ole Roemer, a Danish astronomer working with Cassini in Paris, calculates the speed of light with an error of only 25%

Christiaan Huygens expounds the theory that light consists of a vibration forming a ripple of waves

Newton publishes Principia Mathematica, proving gravity to be a constant in all physical systems

Fahrenheit perfects the mercury thermometer and decides on a 180-degree interval between the freezing and boiling points of water

Swedish astronomer Anders Celsius proposes 100 degrees between the freezing and boiling points of water

The principle of the Leyden jar is discovered by an amateur German physicist, Ewald Georg von Kleist, dean of the cathedral in Kamin

Benjamin Franklin flies a kite into a thunder cloud to demonstrate the nature of electricity

Scottish chemist and physicist Joseph Black observes the latent heat in melting ice

French physicist Charles Augustin de Coulomb begins publishing his discoveries in the field of electricity and magnetism

Italian physicist Alessandro Volta describes to the Royal Society in London how his 'pile' of discs can produce electric current

English chemist John Dalton reads a paper describing his Law of Partial Pressure in gases (discovered in 1801)