Bigger than Big Revision

Outcome One: Features of the Universe

• Features of the Universe:

  • Galaxy
  • Collection of gas, dust, and billions of stars and their solar systems
  • Held together by gravity
  • E.g. Milky Way
  • Galaxies are formed when gases and dust in a nebula combine to form a star, remaining materials form a Solar System around the star, and those stars group together to form galaxies
  • Solar System
  • A Solar System is a gravitationally bound system of a star and objects that orbit the star
  • Stars
  • Stars are spherical masses of hydrogen undergoing a fusion reaction to produce helium and huge amounts of light and heat energy
  • Nebula
  • An interstellar cloud of dust and gas where stars can form
  • Smaller than galaxies, but can still be 30 light years in diameter
  • Black Holes
  • A place in space where gravity pulls so much that even light cannot get out
  • Formed with supernova

• Stars

  • Life Cycle of Stars

  1. Nebula: A cloud of gas and dust in space.

  2. Protostar: The nebula begins to collapse due to gravity, forming a protostar.

  3. Main Sequence: The protostar becomes a main sequence star, where it fuses hydrogen into helium in its core.

  4. Super Giants: Stars greater than 8x the mass of our Sun swells into super giants which blow up into a supernova

     1. Neutron Stars: Regular supernovas are really dense and gravity acts on the matter to form a solid core
     2. Black Holes: If the remains of the supernova have more mass than 3x of our sun, the force of gravity is strong enough to suck everything (even light) into it

  5. Red Giant: When the star runs out of hydrogen, it expands and becomes a red giant.

  6. Planetary Nebula: The outer layers of the red giant are expelled, forming a planetary nebula.

  7. White Dwarf: The core of the red giant collapses to form a white dwarf.

  • Classification of Stars
  • Stars are classified based on their spectral characteristics, which are determined by their temperature:
    • O: Hottest stars, blue-white in colour.
    • B: Blue-white stars.
    • A: White stars.
    • F: Yellow-white stars.
    • G: Yellow stars, like our sun.
    • K: Orange stars.
    • M: Coolest stars, red in colour.

Outcome Two: Measurement of objects in the universe

• The most common method for measuring distance in space is to measure how far light travels in one year
  • This is known as a light year, which we say is around 9.6 billion km
• Parallax!!
  • Parallax is an apparent shift or change in the position of an object when viewed from different angles. This is often used as a way to measure distance, as the amount of parallax observed can indicate how far away the object is. It can be easily observed by holding a finger up and looking at it with one eye, then switching to the other eye and noticing how the finger appears to move relative to the background.
  • A Parallax error is when the measurement of an object's length is more or less than the true length because your eye is positioned at an angle, you can prevent this by taking the angle of your view into consideration when measuring the distance.

Outcome Three: Technology & the Universe

• Technological developments have played a crucial role in advancing scientific understanding of the universe. For instance, the Hubble Space Telescope has provided astronomers with unprecedented views of the cosmos, allowing them to study distant galaxies and stars in detail.
• Another example is the Large Hadron Collider, which has enabled scientists to study the fundamental particles that make up the universe and test theories such as the Higgs boson.
• Additionally, the development of computer simulations has allowed scientists to model complex phenomena such as the formation of galaxies and the evolution of the universe.

Outcome Four: Scientific thinking: Origin of the universe

• Scientific thinking about the origin of the universe is refined over time through a process of review by the scientific community. This process involves the formulation of hypotheses, testing of these hypotheses through experiments and observations, and the peer review of results by other scientists. As new evidence is gathered, theories are modified or discarded, and new theories are proposed. This iterative process of refinement leads to a better understanding of the universe and its origins.
• Our current understanding of the universe is that it is infinite, and ever-expanding

Outcome Five: The Big Bang Theory

• The Big Bang theory proposes that the universe began as a singularity, a point of infinite density and temperature.
• About 13.8 billion years ago, this singularity rapidly expanded, creating space, time, and matter. This expansion is still ongoing today.
• The theory is supported by various lines of evidence, including cosmic microwave background radiation, the abundance of light elements, and the large-scale structure of the universe.
• By studying these phenomena, scientists have estimated the age of the universe to be around 13.8 billion years old.

Outcome Six: Gravity

• Gravity is the force by which a planet or other body draws objects toward its center
• Objects with more mass have more gravity. Gravity also gets weaker with distance. So, the closer objects are to each other, the stronger their gravitational pull is. Earth's gravity comes from all its mass.
• good luck with this one lol i’m sick idk what i’m doing

Outcome Seven: Scientific Evidence & Human Impact

• One current issue affecting society that is the result of human activity on global systems is climate change. Climate change is the long-term alteration of temperature and typical weather patterns in a place. It is caused by the release of greenhouse gases, such as carbon dioxide, methane, and nitrous oxide, into the atmosphere. These gases trap heat from the sun, causing temperatures to rise and leading to a range of negative effects, including sea-level rise, stronger storms, and more frequent and severe heatwaves, droughts, and wildfires.

  There is a wealth of scientific evidence supporting the existence and magnitude of climate change, including:

  1. Temperature records: Instrumental temperature records dating back to the mid-19th century show that the Earth's surface has warmed by about 1°C since then, with most of the warming occurring in the past few decades.
  2. Carbon dioxide concentrations: The concentration of carbon dioxide in the Earth's atmosphere has increased by more than 40% since the pre-industrial era, mainly due to human activities such as burning fossil fuels and deforestation.
  3. Sea-level rise: Sea levels have risen by about 20cm since the start of the 20th century, with about two-thirds of that rise occurring in the past few decades. This is due to the melting of glaciers and ice sheets, as well as the thermal expansion of warmer ocean waters.
  4. Extreme weather events: There has been an increase in the frequency and intensity of extreme weather events, such as heatwaves, droughts, and hurricanes, in many parts of the world. Climate change is expected to continue to exacerbate these events in the coming decades.

  Another current issue affecting society that is the result of human activity on global systems is biodiversity loss. Biodiversity is the variety of life on Earth, including the different species, genetic diversity, and ecosystems that make up the planet's natural heritage. Human activities, such as habitat destruction, overfishing, pollution, and the introduction of invasive species, are causing a rapid decline in biodiversity.

  The scientific evidence supporting the existence and magnitude of biodiversity loss includes:

  1. Extinction rates: The current rate of species extinction is estimated to be 100 to 1,000 times higher than the natural rate. This means that up to one million species could be lost in the coming decades.
  2. Habitat destruction: Human activities, such as deforestation, land-use change, and urbanization, are the main drivers of habitat loss, which is the leading cause of species extinction.
  3. Overfishing: Many fish populations have been depleted by overfishing, which is the main driver of declines in marine biodiversity.
  4. Pollution: Pollution, such as from chemicals, plastic waste, and oil spills, can harm wildlife and their habitats, leading to declines in biodiversity.

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