transcript
- Slide 1
- Part 1: The evolution of the solar system
- Slide 2
- Origin of the Universe Lesson 1
- Slide 3
- Introduction The universe includes all of space and all of the
known matter and energy. This includes millions of galaxies and the
stars within. Galaxies can contain up to 100000 million stars!!
Where did all this come from???
- Slide 4
- Introduction Scientist currently believe that the Universe is
expanding away from a central group of galaxies. They believe this
began 15- 20 billion years ago (BYA).
- Slide 5
- Big Bang Theory This theory states: In a huge explosion, all
matter and energy was distributed throughout the Universe. As time
passed, temperatures decreased and galaxies started forming due to
condensation (the act of reducing a gas or vapour to liquid form).
As time passes, the universe will continue to expand which means
objects in space are not in a fixed place, they are moving.
- Slide 6
- Big Bang Theory This theory is a closed model. What this means
is that all the matter currently expanding will eventually collapse
back onto itself due to gravity. (like a stretched rubber band) As
a result, there will be another huge explosion because of the
collisions of objects and the process will start again.
VideoVideo
- Slide 7
- Flat Universe Theory This theory also states that the Universe
began with a huge explosion. This theory however states that matter
will continue moving outward and not collapse back onto itself. The
universe will continue to expand.
- Slide 8
- Steady State Theory This theory is quite different from the
other two. It states that the Universe had no origin and that its
always existed. Its widely unaccepted because it states that new
matter is being created to explain the expansion of the universe.
This goes against many laws of physics.
- Slide 9
- Galaxies Galaxies are the largest structures in the Universe.
They are made from stars, gas and dust and are named according to
shape. What galaxy do we live in?
- Slide 10
- Galaxies Looking at the night sky, you can see the Milky Way.
Its the part of the sky most densely populated by bright objects.
This band of stars is the disc of our spiral galaxy.
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- Galaxies Spiral Galaxies: Spiral in shape, look like a disk if
viewed from the side. Most common galaxy in the Universe Milky Way
is a spiral galaxy
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- Galaxies Elliptical Galaxies: Very small Do not give off as
much light as spiral galaxies Have an elliptical shape
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- Galaxies Irregular Galaxies: Asymmetrical Not common
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- Galaxies Barred Spiral Galaxy: Similar to spiral Have
wings
- Slide 15
- Solar System A solar system lies within a galaxy and is
composed of planets, asteroids, comets and other objects that orbit
a star or stars.
- Slide 16
- Solar System Planet: A planet is a celestial body orbiting a
star or stellar remnant that is massive enough to be rounded by its
own gravity.
- Slide 17
- Solar System Asteroid: Relatively small objects made up of
solid fragments of matter that orbit the sun mainly in between Mars
and Jupiter.
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- Solar System Meteorite: Solid fragments of asteroids
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- Solar System Comet: A small object that orbits the sun made up
of ice and dust.
- Slide 20
- Homework Read pages 6-10 Prelim Spotlight Text Update vocab
list Complete To Think About Set 1 and 2 pg 10
- Slide 21
- Creation of our solar system Lesson 2
- Slide 22
- Solar System The creation of Earth is interlinked with the
creation of our solar system. They began forming at the same time
as a result of the same forces.
- Slide 23
- The Formation of our Solar System A large cloud of dust and gas
(nebula) began to collapse onto itself. It is believed that this
collapse may have been triggered by a shockwave from a supernova
nearby. VideoVideo Nebula Supernova
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- The Formation of our Solar System As the pressure caused by the
collapse increased, the central sphere became very hot and started
to glow forming a protostar. A wide disk formed around its
equator.
- Slide 25
- The Formation of our Solar System Next: Due to gravity the
nebula continued to collapse into a individual globular bodies and
began to rotate. The Law of Conservation of Angular Momentum helps
explain this phenomenon.
- Slide 26
- The Formation of our Solar System Debris within the disk began
to gather into large clumps by the process of accretion (The
gathering together of small bodies into larger ones by gravity).
This process is responsible for the initial formation of the
planets.
- Slide 27
- The Formation of our Solar System Depending on how close the
planetesimals were to the sun, different materials would not be
able to condense because of the heat and would be blown away by
solar radiation. This would result in the planets closest to the
sun to condense materials which have high boiling points like
metals and rocks and planetesimals on the outer edge of the solar
system would accumulate lighter materials like water, methane and
ammonia
- Slide 28
- The Formation of our Solar System This would explain the rocky
inner planets and gaseous outer planets of our solar system.
- Slide 29
- The Formation of our Solar System Accretion and collapse
accelerated until the temperatures of the protostar reached tens of
millions of degrees. The pressure and temperature reached a level
to cause hydrogen atoms to fuse and make helium. This released huge
amounts of energy as the protostar ignited as a thermonuclear
reaction. Its now a true star.
- Slide 30
- The Formation of our Solar System The ignition of the star blew
away most of the surrounding material.
- Slide 31
- Summary of The Formation of our Solar System 1. The solar
nebula began to collapse and increase its rotation 2. Centrifugal
force caused the nebula to flatten and condense at the centre 3.
Planetessimals formed from the accretion of dust and gas in the
nebula and orbit the dense, hot central core 4. Protoplanets grew
as their gravity captured more nebula material 5. The sun ignited
and a solar blast blew away the remaining unconsolidated dust and
gas leaving the planets in their orbit around the sun.
- Slide 32
- Homework Complete Dot Points 1.1-1.3 (pg3-6)