Space physics

• What is the first stage in the life cycle of a star?

  Protostar
• What do stars start as in their life cycle?

  Cloud of dust and gas
• What is the final stage of a star's life cycle?

  Black dwarf
• What are the stages in the life cycle of a star?

  • Protostar
  • Main sequence star
  • Red giant
  • Red super giant
  • White dwarf
  • Black dwarf
  • Supernova
  • Neutron star
  • Black hole
• How many stars does our Solar System have?

  One star — The Sun
• What force creates orbits in the Solar System?

  Gravity
• What determines the size of an orbit in the Solar System?

  The object's speed
• What is the best guess for the beginning of the universe?

  The Big Bang
• What does the universe appear to be doing?

  Expanding
• What happens to the wavelength of light from distant galaxies?

  The wavelength has increased
• What is red-shift?

  It is the shift of light wavelengths towards the red end of the spectrum
• What do measurements of red-shift indicate about distant galaxies?

  They are moving away from us
• How does the red-shift vary with distance from Earth?

  More distant galaxies have greater red-shift
• What does the red-shift indicate about the movement of galaxies?

  The light is moving away from us
• What can be inferred about the universe based on the observation of red-shift?

  The universe is expanding