Chapter 12: History of key ideas

Democritus suggests that there might be a limit to the divisibility of matter.

Aristotle suggests that the Earth is at the centre of the Universe, with the Sun, Moon, and planets on crystal spheres around.

Eratosthenes estimates the diameter of the Earth by comparing shadow angles in different places.

Hero makes a small turbine driven by jets of steam.

Ptolemy suggests that the Earth is at the centre of the Universe, and that the Sun, Moon, and planets are moving in perfect circles.

Magnetic compass used in China.

Copernicus suggests that the Sun is at the centre of the Universe, with the Earth and planets moving around it.

Gilbert suggests that the Earth acts like a giant bar magnet.

Galileo shows that all falling objects should have the same, steady acceleration.

Snell states his law of refraction.

Torricelli makes the first mercury barometer.

Guericke demonstrates atmospheric pressure.

Boyle states his law for gases.

Huygens puts forward his wave theory of light.

Hooke states his law for elastic materials.

Newton publishes his theory of gravity and laws of motion.

Fahrenheit makes the first mercury thermometer.

Franklin performs a hazardous experiment with a kite to show that lightning is electricity.

Herschel discovers the shape of our galaxy.

Volta makes the first battery.

• Dalton suggests that matter is made up of atoms.

• Young demonstrates the wave nature of light.

Faraday makes a simple form of electric motor

Ampère works out a law for the force between current-carrying conductors

• Faraday demonstrated electromagnetic induction.

• Sturgeon makes the first moving-coil meter.

First use of words 'physicist' and 'scientist.

• Fizeau measures the speed of light.

• Joule establishes the link between heat and work.

Kelvin states the law of conservation of energy

Maxwell predicts the existence of radio waves and other electromagnetic waves.

Cailletet liquefies oxygen.

Swan and Edison make the first electric light bulbs.

Hertz demonstrates the existence of radio waves.

Marconi transmits the first radio signals

Röntgen discovers X-rays.

Becquerel discovered radioactivity.

Thomson discovers the electron

M. Curie discovered radium and polonium.

Rutherford identifies alpha and beta rays.

Planck proposes the quantum theory

Einstein uses the quantum theory to explain the photoelectric effect, and publishes his special theory of relativity.

Rutherford proposes a nuclear model of the atom.

Bohr uses the quantum theory to modify Rutherford's model of the atom.

Einstein publishes his general theory of relativity.

Rutherford splits the atom and discovers the proton.

De Broglie suggests that particles can behave as waves

Schrodinger wave-mechanics model of the atom

Lemaitre suggests the possibility of the Big Bang.

Geiger and Müller invent their radiation detector

Hubble discovers that the Universe is expanding.

• Chadwick discovered the neutron.

• Cockroft and Walton produce the first nuclear change using a particle accelerator.

Hahn discovered nuclear fission.

Fermi builds the first nuclear reactor.

Bardeen, Brattain, and Shockley make the first transistor.

First artificial satellite, Sputnik I, put into orbit.

St Clair Kilby makes the first integrated circuit

Maiman builds the first laser.

First geostationary communications satellite.

First manned landing on the Moon.

Intel Corporation makes the first microprocessor

First experimental evidence of quarks.

Hubble Space Telescope launched.

Higgs particle discovered.