Red Shift

• What does the observation of red shift indicate about the universe?

  The universe is expanding.
• What is the main evidence for the universe's expansion?

  The red shifting of light from galaxies.
• What is the big bang theory?

  It explains the universe's expansion from a tiny point.
• What does absorption spectra show?

  Wavelengths of light absorbed by chemicals.
• How do chemicals in the sun's atmosphere affect light?

  They absorb certain wavelengths of light.
• Why does red shift occur in light from distant galaxies?

  Light waves get stretched as galaxies move away.
• How does the balloon model represent the universe's expansion?

  Space between galaxies stretches as the balloon inflates.
• What does the balloon model illustrate about galaxy movement?

  Galaxies appear to move away due to expanding space.
• What is a limitation of the balloon model?

  Balloons can burst, unlike the universe.
• What does the expansion of the universe imply about its past?

  The universe was smaller in the past.
• What is the generally accepted idea about the universe's beginning?

  The big bang theory explains its origin.
• What does the big bang theory propose about the universe's initial state?

  It was tiny, dense, and hot.
• What happened after the initial explosion of the big bang?

  Space itself started to expand.
• What is the current status of the universe's expansion?

  It is still continuing today.
• What are the key concepts of red shift and the big bang theory?

  • Red shift indicates the universe is expanding.
  • Absorption spectra show wavelengths absorbed by chemicals.
  • Distant galaxies' light shifts towards red.
  • The big bang theory explains the universe's origin.
  • The universe was once tiny, dense, and hot.
  • Space continues to expand today.
• What are the limitations of models in understanding the universe?

  • Models simplify complex concepts.
  • Balloons can burst, unlike the universe.
  • Models may not represent all galaxies accurately.