PPT: Origin of the Earth | Geography Class 11 - Humanities/Arts PDF Download

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Origin of the Earth
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Origin of the Earth
Early Theories
A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of the 
earth.
One of the earlier and popular arguments was by German philosopher Immanuel Kant. Mathematician Laplace 
revised it in 1796. It is known as Nebular Hypothesis.
The hypothesis considered that the planets were formed out of a cloud of material associated with a youthful sun, 
which was slowly rotating.
Page 3


Origin of the Earth
Early Theories
A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of the 
earth.
One of the earlier and popular arguments was by German philosopher Immanuel Kant. Mathematician Laplace 
revised it in 1796. It is known as Nebular Hypothesis.
The hypothesis considered that the planets were formed out of a cloud of material associated with a youthful sun, 
which was slowly rotating.
Nebular Hypothesis
Proposed by Immanuel Kant and revised by Laplace in 1796
Planets formed from a cloud of material around a young, slowly rotating sun
Revised Theories (1950)
Otto Schmidt in Russia and Carl Weizascar in Germany revised the 'nebular hypothesis'
They proposed that the sun was surrounded by solar nebula containing mostly hydrogen 
and helium along with dust
The friction and collision of particles led to formation of a disk-shaped cloud
The planets were formed through the process of accretion
Page 4


Origin of the Earth
Early Theories
A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of the 
earth.
One of the earlier and popular arguments was by German philosopher Immanuel Kant. Mathematician Laplace 
revised it in 1796. It is known as Nebular Hypothesis.
The hypothesis considered that the planets were formed out of a cloud of material associated with a youthful sun, 
which was slowly rotating.
Nebular Hypothesis
Proposed by Immanuel Kant and revised by Laplace in 1796
Planets formed from a cloud of material around a young, slowly rotating sun
Revised Theories (1950)
Otto Schmidt in Russia and Carl Weizascar in Germany revised the 'nebular hypothesis'
They proposed that the sun was surrounded by solar nebula containing mostly hydrogen 
and helium along with dust
The friction and collision of particles led to formation of a disk-shaped cloud
The planets were formed through the process of accretion
Modern Theories
The Big Bang Theory was introduced by Edwin Hubble in 
1920
It offers a contemporary explanation for Earth's origin
Also known as the Expanding Universe Hypothesis
States that the universe continuously expands
Suggests all universal matter was initially concentrated at 
its center in an extremely hot, dense point
Around 13.7 billion years ago, a massive explosion occurred
This explosion triggered atom formation
Eventually energy was converted into matter
Page 5


Origin of the Earth
Early Theories
A large number of hypotheses were put forth by different philosophers and scientists regarding the origin of the 
earth.
One of the earlier and popular arguments was by German philosopher Immanuel Kant. Mathematician Laplace 
revised it in 1796. It is known as Nebular Hypothesis.
The hypothesis considered that the planets were formed out of a cloud of material associated with a youthful sun, 
which was slowly rotating.
Nebular Hypothesis
Proposed by Immanuel Kant and revised by Laplace in 1796
Planets formed from a cloud of material around a young, slowly rotating sun
Revised Theories (1950)
Otto Schmidt in Russia and Carl Weizascar in Germany revised the 'nebular hypothesis'
They proposed that the sun was surrounded by solar nebula containing mostly hydrogen 
and helium along with dust
The friction and collision of particles led to formation of a disk-shaped cloud
The planets were formed through the process of accretion
Modern Theories
The Big Bang Theory was introduced by Edwin Hubble in 
1920
It offers a contemporary explanation for Earth's origin
Also known as the Expanding Universe Hypothesis
States that the universe continuously expands
Suggests all universal matter was initially concentrated at 
its center in an extremely hot, dense point
Around 13.7 billion years ago, a massive explosion occurred
This explosion triggered atom formation
Eventually energy was converted into matter
Stages of the Big Bang Theory
Singularity
All matter and energy existed in a "tiny ball" (singular atom) with infinite temperature and density.
Big Bang Explosion
The "tiny ball" exploded violently 13.7 billion years ago, leading to rapid expansion. Some energy 
converted into matter. Rapid expansion within fractions of a second; first atoms formed within three 
minutes.
Cooling and Atomic Matter Formation
300,000 years after the Big Bang, temperature dropped to 4,500K. Atomic matter formed, and the 
universe became transparent.