The ideas and
discoveries about Earth
Hipparchus
190 – 120 BC
Claudius
Ptolemy
Nicolas
Copernicus
85 – 165 AD
1473 – 1543
Tycho Brahe
1546 – 1601
Johannes
Kepler
1571 – 1630
Galileo
Galilei
1564 – 1642
Sir Isaac
Newton
Edmund
Halley
Sir William
Herschel
Caroline
Herschel
Albert
Einstein
Edwin
Hubble
1642 – 1727
1656 – 1742
1738 – 1822
1750 – 1848
1879 – 1955
1889 – 1953
Aristotle
He suggests that
the Earth is at
the centre of the
solar system.
(approx. 340 BC)
Galileo
Made major
advances in
telescope
design.
(1594 AD)
Johannes Kepler
He suggests three
laws of planetary
motion and that
orbits are ellipses
and not circles.
(1600 AD)
Edwin Hubble
Discovered
that the
universe is
expanding.
(1929 AD)
2000 AD
Ptolemy
He suggests the idea
of epicycles to
suggest how planets
move. The Earth is
still at the centre of
the Solar System.
(approx. 150 BC)
0
1000 BC
Timeline of Ideas
Aristarchus
He suggests the
idea of the Sun at
the centre of the
Solar System.
(approx. 200 BC)
Nicolas Copernicus
Isaac Newton
William
Herschel
Suggests that the
Suggested the
sun is at the centre idea of planetary Discovered
of the Solar
gravity.
Uranus
System.
(1700 AD)
(1781 AD)
Galileo Galilei
Galileo Galilei was an Italian
scientist, mathematician,
astronomer and philosopher
He 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.
Copernicus
Nicolaus 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 Newton
Sir Isaac Newton was an
English physicist,
mathematician, astronomer,
natural philosopher,
alchemist and theologian.
He had described universal
gravitation and the three laws
of motion
He 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 Hawking
Stephen 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 recordbreaking 237 weeks.
He is almost entirely paralysed and
communicates through a speech
generating device.
Professor Michael
Robinson and Dr Brian May
They 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?