1.Origin of
the universe in the big bang.
2. Nuclear
Fusion And the Elements’ formation
3.The
formation of our solar system.
4.The
structure of the earth.
5.Earthquakes
and volcanoes.
6.Plate movements.
7.The rock
cycle.
8.Erosion and
the formation of soil.
Origin
of the universe in the big bang.
Here
the Big bang is listed in a story format, read further to get full details.
High energy emissions
from Crab Nebula.
3d Map of dark
matter
Life and all science
It all began with the Big bang
Ø
The Big Bang was
the very beginning of our Universe, and it probably happened about 13.73
billion years ago.
Ø
Nobody knows what
was there before the Big Bang. Time started just after the big bang.
Ø
The Universe
immediately started to get bigger and bigger and making more space (and it is still
getting bigger today).
Ø
Inside the Universe, the energy (in the form
of photons (light) and bosons)
went zipping around like crazy all over the place.
Ø
These
super-energetic photons and bosons sometimes broke up into smaller particles.
Ø
Then they would
lose energy and eventually glue themselves back together into protons and
bosons again.
Ø
But at some point,
some of the positrons and anti-protons (the anti-matter) seem to have got lost
somewhere, leaving a bunch of lonely electrons and protons with no matches.
These electrons and protons got together with each other, forming the first hydrogen atoms. Once there were clouds of these hydrogen
atoms floating around together, they formed nebulas, which soon developed into the first stars.
Nuclear
fusion and the elements’ formation
Nuclear
fusion in stars is one of the most important reasons which make life on Earth possible!
65% of your body is made up of Oxygen and 18% is Carbon.
v They are created through nuclear
fusion in stars!
v All that we are made of was cooked in the
belly of a star, millions of years ago!
v Nuclear
fusion in stars is the art of creating newer and heavier atoms by fusing
smaller nuclei together!
v Matter can be converted into energy and energy back into matter.
v Thus energy and its other form,
matter, keep molding themselves into more and more complex forms to create
beings like us.
v Stars create new elements like
Helium, Carbon, Oxygen, and Silicon and so on! We’ll see how
The
structure of the earth
The structure of the Earth
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The Earth is sphere with a diameter of about 12,700Kilometres. As we go deeper and deeper into the
earth the temperature and pressure
rises.
The core temperature is
believed to be an incredible 5000-6000°c.
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The crust
is very thin (average 20Km).
The thinnest parts are under
the oceans (OCEANIC CRUST) and
go to a depth of roughly 10 kilometers.
The thickest parts are
the continents (CONTINENTAL CRUST) which
extend down to 35 kilometers on average
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The mantle is the layer beneath the crust
which extends about half way to the centre.
It's made of solid rock and
behaves like an extremely -
viscous liquid –
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The outer core is
the layer beneath the mantle.
It is made of liquid iron and nickel.
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The inner core is the bit
in the middle!
It is made of solid iron and nickel and has massive
pressure.
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EARTH STRUCTURE
Inner
core
The inner core is
made of solid iron and nickel.
Outer
core
The
outer core is a hot, electrically conducting liquid (mainly Iron and Nickel).
This layer is not as dense as pure
molten iron
Scientists suspect that about 10% of
the layer is composed of sulphur and oxygen because these elements are abundant
in the cosmos and dissolve readily in molten iron.
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Lower mantle
The lower mantle is composed of silicon, magnesium, and oxygen.
It also contains some iron, calcium, and aluminium.
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Upper mantle
Solid
fragments of the upper mantle have been found in eroded mountain belts and
volcanic eruptions.
Olivine
(Mg,Fe)2SiO4 and
pyroxene (Mg,Fe)SiO3 have
been found.
Part
of the upper mantle called the asthenosphere might be partially molten.
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Oceanic crust
The majority of the Earth's crust was made through volcanic activity.
The
oceanic ridge system, a 40,000 kilometre network of volcanoes, generates new
oceanic crust at the rate of 17 km3 per year, covering the ocean floor
with an igneous rock called basalt. Hawaii and Iceland are two examples of
the accumulation of basalt islands.
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Continental crust
This is the outer part of the Earth composed of crystalline rocks.
These are low-density buoyant minerals dominated
mostly by quartz (SiO2) and feldspars (metal-poor silicates).
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The rock cycle
The
rock cycle is a repeating process that causes various types of rocks to form
and decay. While the cycles for some types of rocks follow a specific path, not
all types of rocks follow the same cycle.
1.
Sedimentary Rocks
o
Sedimentary rocks are
formed from sediments such as sand, silt and clay. Evaporite deposits, such as
rock salt and rock gypsum, are types of sedimentary rocks.
Sedimentary
Processes
o
The sedimentary
process begins with igneous, sedimentary and metamorphic rocks weathering and
eroding. The loose particles then collect in a specific area. Over time, the
particles build up, forming layers and compacting the layers of particles
resting beneath them. Eventually, the sediments are cemented together by the
pressure, forming sedimentary rocks.
Igneous
Rocks
o
Igneous rocks form
from the solidification of lava or magma. If it forms intrusively, or within
the earth, the rock will have large crystals. Granite is an example of such a
coarse-grained igneous rock. If the rock forms extrusively, or on the earth's
surface, it will have fine-grained crystals. Obsidian is an example of a
fine-grained igneous rock.
Igneous
Processes
o
Igneous, sedimentary
and metamorphic rocks are subducted, or pushed down, into the earth where the
tectonic plates converge. As a result, the crust melts in the upper mantle and
becomes magma. Over time, the magma will either cool and solidify as it rises
toward the surface or be ejected from volcanic fissures in an eruption and then
cool. Igneous rocks are what is formed by that cooling.
Metamorphic
Rocks
o
Metamorphic rocks are
rocks where the crystalline structure of the rock has changed to form a new
type of rock. For example, marble is metamorphosed limestone.
Metamorphic
Processes
o
In metamorphism,
igneous, sedimentary or other metamorphic rocks are subjected to high
temperatures or pressure, which prompts them to recrystallize. The
high-pressure exposure could develop from mountain building processes in which
two tectonic plates are crashing into each other. The high-temperature exposure
could result from a partial subduction of the material that does not lead to
melting or from the rock coming in contact with super-heated material seeping
through rock fractures. In both cases, the outside forces are not enough to
fully melt the rock, but they are enough to recrystallize it.
Rock cycle simplified
diagram
Erosion and the formation of
soil
FUNCTIONS
OF SOIL
1. A habitat for several plants and
animals
2. A storage bank for water and
nutrients
3. Foundation of the world's food chain
4. Provides an anchor for plants
SOIL
FORMING FACTORS
1.
Parent
Material:
the underlying bedrock over which a soil develops.
Soils forms from a variety of parent
materials such as:
a)Till
b) Alluvial soils
c) Loess soils
2.
Climate:
Water & Temperature help break up rocks.
3.
Biological (Organisms):
The activities of bacteria, people earthworm and roots of plants.
4. Topography (relief of the land):
5. Time: (Soil takes a long time to develop
and mature)
AGENTS OF SOIL EROSION:
1. Running
Water,
2. Wind,
and
3. Glacier
(Ice)
HUMAN CAUSES OF EROSION
1. Over
cultivation by farmers,
2. Overgrazing
by herds of cattle, sheep etc,
3. Deforestation
by local groups
4. Irrigation
by farmers
5. Urbanization
EROSION CONTROL PRACTICES
1. Contour
ploughing along sloping grounds
2. Strip
Cropping across slopes
3. Terracing
along slopes
4. Damming
of Gullies
6. Removing cropland from production to allow soil
renew itself.
7. Creating
windbreaks to reduce wind speed and erosion.
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