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Origins of the Elements - Coggle Diagram

- - - - Current accepted theory of the beginning of the universe
      - Definition
        
        Everything in the universe was created out of a single point through a big bang, or explosion and it has expanded to the form that we see today
      - The start point of space and time and is where all the energy in the universe was created
  - - - The phase when the universe rapidly expands
  - - - The process of particles collided and turned themselves back into energy
  - - - Fuses together to create the basis of every atom
        
        Mainly created mostly:
        
        Hydrogen
        
        Helium
  - - - Forming Stars
    - - This created the larger elements we see today
      - Exploding stars create Supernovas
    - - Creating the universe
- - - - Definition
        
        Denotes the distance between the sun and the earth
      - Basically the Earth's orbital radius
    - - Definition
        
        Distance that light will travel over the space of a year
  - - - Mass of our sun
      - 1 solar mass
- - - - Distance separating us and a star, if the star's parallax angle is one arcsecond
      - Useful for distances in space, as they are usually enormous
    - - Distance from one star to the sun is one parsec
        
        Parallax angle is 1 arcsecond
        
        Earth's orbital radius is 1 AU
    - - One million parsexs
        
        Useful for describing even larger distances between galaxies
    - - SE
        
        Distance from Earth to Sun
      - arcseconds
        
        Covert to degrees by multiplying 1/3600
      - SD
        
        Distance from Sun to Distant Star
  - - - A special unit of measurement for very small angles in space
      - 1/3600 of a degree
  - - - The apparent change in position of an object when you observe it from two different points
    - - This movement is observed through parallax
    - - We can use trigonometry to calculate the distance from the faraway star and the earth
      - Calculated in arcseconds
- - - - Static
        
        Definition
        
        The size of the universe is not changing and is static
        
        Einstein tried to make an equation to have this work
        
        Alexander Friedmann
        
        Found mathematical proof that the universe is expanding
    - - Flat
        
        Definition
        
        Expansion may slow and eventually stop in the future
      - Closed
        
        Definition
        
        Universe will stop expanding and start contracting
        
        Lead to the big crunch
        
        When everything collapses in on itself
      - Open
        
        Definition
        
        Universe is expanding at an accelerating rate, so it'll only continue to expand faster
        
        Will continue to expand for ever
  - - - Creator of the Hubble telescope
      - What did he do
        
        He looked at spectra from stars in distant galaxies and comparing it to the sun
        
        Noticed that the pattern of lines were the same but shifted to the red end of spectrum
        
        Red Shift
        
        Interpreted to mean that galaxies were receding away from us at very high velocities
        
        Physical expansion of space was causing this recession
        
        Using the size we can work out how far away they were
  - - - Is measured in megaparsec
        
        Linear relationship between velocity and the distance
    - - Velocity of recession
        
        Km/s
        
        Hubble's constant
        
        co
        
        convert to ms
        
        Distance away from us
        
        Mpc
        
        Megaparsec
        
        Convert to Mpc
    - - Used to find out how fast a galaxy is moving away from us
        
        Given the distance of how far away we are
      - States that recessional velocity is directly proportional to its distance from earth
- - - - An object that when in thermal equilibrium with its surroundings, absorbs all electromagnetic radiation incident upon it, and emits all EM radiation in a spectrum entirely based on its temperature
    - - If they are at the same temperature as their surroundings blackbodies absorb all of the light and they don't reflect anything
        
        Absorbs all EM radiation
        
        Does not reflect any radiation
      - Absorbs all EM radiation and will emit different amounts of frequency of light, depending on the temperature
    - - Thermal energy converts to EM radiation and emits light
      - Amount of radiation
        
        dependant on the temperature
    - - Emits infrared light
    - - However models some behaviours accurately
        
        Allows us to:
        
        Estimate temperature if we assume it is a black body
        
        Most commonly modelled object as a black body
        
        star
        
        Absorbs all the light that hits the,
        
        Emission of light is dependant on its temperature
  - - - Wavelength
        
        Smaller Wavelength
        
        Higher Frequency
        
        Higher Energy
        
        More Radiation Emitted
        
        Spectral Radiance
        
        Measure of how much energy comes out of the blackbody at a specific wavelength
      - Location of Maximum
        
        Wavelength at which maximum occurs is unique to a particular temperature
      - Increase of Temperature
        
        Peak moves further left
        
        Wavelengths get shorter
        
        more radiation emitted
- - - - Blue
      - Red
      - Yellow
      - Orange
      - White
  - - - 52000K
      - 2000K
    - - Higher Frequency
        
        will be more blue hence, hotter
  - - - Allows us to map how far away these stars are
  - - - Measure of how much energy it gives off
      - Intrinsic brightneess
  - - - Mnemonics
        
        Only
        Boring
        Astronomers
        Find
        Gratitude
        Knowing
        Mnemonics
      - O - Blue
        
        28 000 - 50 000
      - B - Blue-white
        
        10 000 - 28 000
      - A - White
        
        7 500 - 10 000
      - F - Yellow-White
        
        6 000 - 7 500
      - G - Yellow
        
        4 900 - 6 000
      - K - Orange
        
        3 500 - 4 900
      - M - Red
        
        2 000 - 3 500
    - - A class is assigned a letter and an associated temperature range
    - - Different elements in stars produce absorption spectra with lines missing
      - They are also at different levels of ionisation
        
        As they get hotter electrons can make bigger jumps allowing them absorb higher energy photons
- - - - Classifies stars according to their luminosity, spectral class, colour, temperature, and evolutionary stage
    - - Luminosity relative to Sun
        
        Mass increases as luminosity
        
        Temperature (K)
      - x-axis is decreasing
      - Axis increments are not constant
  - - - Giants
        
        High luminosity
        
        Cold but bright
        
        Stars migrate off main sequence and reach later stages of life
      - Main Sequence
        
        Goes from hot and bright to
        
        Cold and Dim
        
        Definition
        
        All stars begin their lives and live out most of their days on the main sequence
      - White Dwarves
        
        Very hot but dim and have very long lifetimes
        
        Move to the right of the diagram as they age
        
        Temperature drops
- - - - Created from basic elements in free space
        
        Begin as a cloud of helium dust
        
        held together by gravity
      - Definition
        
        Cloud of hydrogen gas and stellar dust in space held togethr by gravity
      - Begin to collapse in on itself due to gravitational force
        
        Generates heat as pressure increases
        
        Hot enough to ignite hydrogen in middle of star and begin nuclear fusion
      - sit on main sequence
        
        depending on how massive it is
        
        the large it is the further up and left it'll be on the HR diagram
    - - Definition
        
        Characterised by the nuclear fusion of hydrogen into helium
        
        Nuclear Fusion
        
        How a star generates energy
      - Helium has slightly less mass than hydrogen
        
        mass difference converted to energy
        
        using einstein's mass-energy equivalence
        
        Created energy provides a outwards force of pressure which balances the inwards force from gravity
    - - Initiated by large gravitational forces
  - - - Energy produced from hydrogen fusion stabilises the star
      - When the star runs out of hydrogen fuel
        
        Core contracts
        
        Shell expands
      - Temperature drops and luminosity increases as star becomes giant
    - - Proton-Proton Chain
        
        Dominant fusion process for smaller main sequence stars
        
        Converts 4 hydrogen nuclei to 1 helium nucleus
        
        6 hydrogen nuclei to 1 helium nucleus + 2 spare hydrogen nuclei
        
        Energy released expressed as:
      - CNO Cycle
        
        Dominant fusion process for larger main sequence stars
        
        4 hydrogen nuclei to 1 helium nucleus
        
        Uses a carbon atom to catalyse the reaction
        
        carbon converted back n forth between:
        
        Carbon
        
        Nitrogen
        
        Oxygen
  - - - Formed when hydrogen runs out and helium is used as fuel instead
    - - Helium requires much higher temperature to initiate fusion
      - Star's overall temperature is :decreasing
        Core temperature is increasing
    - - Triple Alpha Process
        
        3 helium nuclei to carbon
      - < 8 solar masses
        
        Smaller stars stop fusion after helium
        
        leave core filled with
        
        carbon
        
        oxygen
      - 8 solar masses
        
        Larger stars continue fusion
        
        leave core filled with iron
- - - - < 8 solar masses
  - - - 8 - 20 solar masses
    - - continues all the way up to iron
        
        helium runs out and explodes
        
        Supernova
        
        Explosion that sends elements from the star's outer layer flying out across the universe
        
        compresses star's core
    - - Small and dense core
      - About 20 km in diameter but much heavier than our sun
  - - - 20 solar masses
    - - the remnants of their supernova collapse and form a black hole
      - Black Hole
        
        Infinitely small and dense
        
        Gravitational force is so strong it prevents light from escaping