The ideas and discoveries about

Earth

Hipparchus 190 – 120 BC

Claudius Ptolemy 85 – 165 AD

Nicolas Copernicus 1473 – 1543

Tycho Brahe 1546 – 1601

Sir Isaac Newton1642 – 1727

Edmund Halley 1656 – 1742

Caroline Herschel 1750 – 1848

Albert Einstein 1879 – 1955

Johannes Kepler 1571 – 1630

Galileo Galilei 1564 – 1642

Edwin Hubble 1889 – 1953

Sir William Herschel 1738 – 1822

Timeline of Ideas10

00 B

C

2000

AD

0

Nicolas CopernicusSuggests that the sun is at the centre of the

Solar System.(1543 AD)

AristotleHe suggests that the Earth is at the centre of the solar

system.(approx. 340 BC)

PtolemyHe suggests the idea of

epicycles to suggest how planets move.

The Earth is still at the centre of the Solar

System.(approx. 150 BC)

AristarchusHe suggests the

idea of the Sun at the centre of the

Solar System.(approx. 200 BC)

Johannes KeplerHe suggests three laws of planetary motion and that

orbits are ellipses and not circles.

(1600 AD)

GalileoMade major advances in telescope design.

(1594 AD)

Isaac NewtonSuggested the idea

of planetary gravity.

(1700 AD)

William Herschel

Discovered Uranus

(1781 AD)

Edwin HubbleDiscovered that the universe is

expanding.(1929 AD)

Galileo Galilei Galileo Galilei was an Italian scientist, mathematician, astronomer and philosopherHe improved the telescope and consequent astronomical observations.He was named the ‘father of modern observational astronomy’, ‘father of physics’, ‘father of science’ and ‘father of modern science’.

Galileo Galilei (cont.)

Galileo was able to use this telescope to prove the truth of the Copernican system of heliocentrism. He published his observations which went against the teaching of the Church. He was brought to trial and was imprisoned for life. Other scientists seized its importance and could learn more the world.He was the first person to identify Sunspots and to see the 4 brightest moons of Jupiter. He also noticed that our view of Venus changes in the same way as that of our Moon.

CopernicusNicolaus Copernicus was a Renaissance mathematician and astronomer.

He came up with the heliocentric system where the Sun was at the center in 1508.

Earlier starwatchers had believed the same, but he brought it to the world of and used his own observations to back up his idea.

His ideas, including the revelation that the Earth rotates on its axis, were too different for most of the scholars of his time to accept.

In 1512, he recorded a basic sketch of his system in a manuscript called Commentariolus

Isaac NewtonSir Isaac Newton was an English physicist, mathematician, astronomer, natural philosopher, alchemist and theologian.He had described universal gravitation and the three laws of motionHe built the first practical reflecting telescope

Henrietta Swan Leavitt

Henrietta Swan Leavitt was an American astronomer. Leavitt discovered the relation between the luminosity and the period of Cepheid variable stars. Her discovery allowed astronomers to measure the distance between the Earth and faraway galaxies. Edwin Hubble used the luminosity-period relation for Cepheids to determine that the Universe is expanding.

Subrahmanyan Chandrasekhar

Subrahmanyan Chandrasekhar, was an Indian-American astrophysicist.He won the 1983 Nobel Prize for Physics for key discoveries that led to the currently accepted theory on the later evolutionary stages of massive stars.Chandrasekhar worked in various areas including stellar structure, theory of white dwarfs, stellar dynamics, theory of radiative transfer, quantum theory of the negative ion of Hydrogen, hydrodynamic and hydromagnetic stability, equilibrium and the stability of ellipsoidal figures of equilibrium, general relativity, mathematical theory of black holes and theory of colliding gravitational waves.

Stephen HawkingStephen William Hawking, is a theoretical physicist, cosmologist, and author. His significant scientific works are gravitational singularities theorems and the theoretical prediction that black holes emit radiation, often called Hawking radiation. He thinks that we may be able to leave earth, aliens exist and that time travel is possible.

Hawking has achieved success with works of popular science in which he discusses his own theories and cosmology in general; his A Brief History of Time stayed on the British Sunday Times best-sellers list for a record-breaking 237 weeks.

He is almost entirely paralysed and communicates through a speech generating device.

Professor Michael Robinson and Dr

Brian MayThey modelled the space dust in the solar system.It explains the infrared radiation from zodiacal dust seen

Quiz!Who was Galilio Galilei?What is Nicolas Copernicus famous for? What did Isaac Newton invent?Edwin Hubble used the theory of which scientist to determine that the Universe is expanding?Who was Subrahmanyan Chandrasekhar?What did Stephen Hawking predict?What did Professor Michael Robinson and Dr Brian May do?