Physicists and astronomers

H

Hahn, Otto 1879- 1968
German radio-chemist. Awarded the Nobel prize for Chemistry in 1944 for his discovery of nuclear fission in 1938.

Hale, George 1868- 1938
American astronomer. 200" Hale telescope on Mount Palomar named after him.

Halley, Edmund 1656-1742
Astronomer. Discovered and identified Halley's comet in 1705. Great friend of Newton.

Harrison, John 1693-1776
A British clock maker. Grid iron pendulum. Winner of competition to make a clock that could be carried across the Atlantic on board a ship and still keep good time (£20000 prize). 1764 accurate to one second per day. Four examples of these clocks in the Royal Observatory at Greenwich.

Hawking, Stephen 1942-
British theoretical Physicist, Mathematician and Astrophysicist.

Heaviside, Oliver 1850-1925
Predicted the existence of a conducting layer in the Earth's upper atmosphere. This layer reflects radio waves.

Heisenberg, Werner Karl 1901-1976
German physicist. Awarded the Nobel Prize for Physics in 1932 for the development of quantum mechanics. Proposed the Uncertainty principle (1927).

Helmholtz, Hermann Ludwig Ferdinand von 1821- 1894
German physicist. Devised Helmholtz coils to produce a nearly uniform magnetic field across a piece of apparatus. Proposed the theory of action at a distance for electric and magnetic fields. In 1847 he published a proof of the conservation of energy.

Henry, Joseph 1797-1878
American physicist. Discovered mutual inductance. Developed the electromagnet

Herschel, Caroline 1750-1848
British astronomer.

Herschel, John 1792-1871
The son of William Herschel. An astronomer who did much work on double stars. Predicted the return of Halley's comet in 1835 and travelled to South Africa to observe it.

Herschel, Sir William 1738-1822
Born in Germany and Probably the most famous astronomer of the 18th century. He discovered Uranus in 1781 and was the first to correctly suggest the shape of our galaxy. Built a large (12.2 m long) reflecting telescope.
The 4.2 m (diameter) reflecting telescope in the Canary Islands is named after him. He did much research on nebulae, publishing a catalogue of 5000 such objects in 1820. In 1857 he emigrated to England where for a time he earned his living as a musician, being the organist in the octagon chapel in Bath for sixteen years.

Hertz, Heinrich Rudolf 1857-1894
German physicist. Worked on the properties of cathode rays. Discovered the photoelectric effect in 1887. Experimental demonstration of wireless waves (1888). Professor in Bonn at the age of thirty two.

Higgs, Peter 1929-
British physicist born in Newcastle. Published details of the reaseach of the particle that was to become known as the Higgs boson, or the 'God particle', in 1964. Its discovery was announced in 2012 and finally confirmed in May 2013.

Hipparchus 190-120 BC
Greek philosopher. First accurate star catalogue and including the brightness of stars. Measured the distance of the Moon using parallax during a solar eclipse. Discovered the precession of the equinoxes. He developed the epicycle theory of Apollonius by putting the Earth off centre from the planetary orbits.

Hooke, Robert 1635-1703
British physicist. Elasticity. Hooke's law, discovered about 1600 and published in 1676. Invented the conical pendulum and the air pump.

Hubble, Edwin 1889-1953
Law of the expansion of the universe.

Huggins, Sir William 1824-1910
Work on nebulae used spectroscopic analysis. Discovered that some were composed of gas. Observed the Doppler shift in stellar spectra in 1868.

Huyghens, Christiaan 1629-1695
A Dutch physicist, mathematician and astronomer. Wave theory of light. He made his own lenses and fitted them to a twelve foot long telescope. Using this instrument he discovered the rings of Saturn. Published his mathematical work on the theory of light 'Traite de la Lumiere' in 1690. His work in mechanics included the formula for centripetal force, moment of inertia and the laws of impact and collision. In 1673 he dedicated his major work on the pendulum clock to the king.