P2.6 Keywords

P225
  1. (5) - P2:5
  2. Gravity (2) - P2:2
    • An attraction between matter that is able to keep large masses like moons and planets in orbit.
  3. Fusion (2) - P2:2
    • Nuclear fusion involves two atomic nuclei joining to make a large nucleus. Energy is released when this happens.
  4. Galaxies (1) - P2:1
    • A galaxy can contain many millions of stars, held together by the force of gravity.
  5. Nebula (1) - P2:1
    • A nebula is an interstellar cloud of dust, hydrogen, helium and other ionized gases.
  6. Satellites (1) - P2:1
    • A satellite is an object that orbits a larger object in space.
  7. Satellite (1) - P2:1
    • A satellite is an object that orbits a larger object in space.
  8. Supernova (1) - P2:1
    • A supernova is the explosion of a star -- the largest explosion that takes place in space.
  9. Universe (1) - P2:1
    • All of space and time, energy and matter.
  10. Expanding Universe (1) - P2:1
    • Idea that Universe itself is increasing in size.
  11. Planets (1) - P2:1
    • Large object of matter that orbits a star.
  12. Receding (1) - P2:1
    • Moving further away from its original position.
  13. Dark energy (1) - P2:1
    • Process causing the Universe to speed up.
  14. Dark mass (1) - P2:1
    • Some of the observations of the universe, such as the spinning rates of galaxies, cannot easily be explained using our current theories about gravity. Scientists have suggested that the matter we can see – stars, planets and galaxies – are only part of the mass of the universe. They have suggested that most of the mass is actually matter we cannot see, called dark matter.
  15. Solar system (1) - P2:1
    • The Solar System consists of the Sun with planets in orbit around it.
  16. Sun (1) - P2:1
    • The Sun is a star. It gives out heat and light through nuclear fusion.
  17. Nuclei (1) - P2:1
    • The centre of an atom made of protons and neutrons.
  18. Life cycle (1) - P2:1
    • The different stages of the development of a star.
  19. Wavelength (1) - P2:1
    • The distance between two successive crests or troughs of a wave.
  20. Big-Bang Theory (1) - P2:1
    • Theory that states the universe as we know it started with a small singularity, that inflated over the next 13.8 billion years to the cosmos that we know today.
  21. Red-shift (1) - P2:1
    • When an object moves away from an observer, the light has its wavelength stretched, 'shifting' it to the red end of the visible spectrum.
  22. Light (1) - P2:1
    • electromagnetic waves that transfers energy, even through a vacuum.
  23. Orbit (1) - P2:1
    • the regularly repeated elliptical course of a celestial object or spacecraft about a star or planet.
  24. Velocity (1) - P2:1
    • velocity is a vector quantity; it is direction-aware.
  25. Equilibrium (1) - P2:1
    • when there is a balance of opposing forces or influences.