Red Shift (T)

• What is redshift?

  Redshift is the phenomenon where light from distant galaxies has an increased wavelength compared to light from closer galaxies.
• How does redshift provide evidence for the Big Bang theory?

  It shows that galaxies are moving away from each other, indicating an expanding universe consistent with the Big Bang theory.
• What happens to the light spectrum of distant galaxies compared to nearby galaxies?

  • Light from distant galaxies shows a larger redshift
  • Wavelengths are increased
  • Indicates that distant galaxies are moving away faster
• What do scientists call the phenomenon where galaxies are moving away from each other?

  Scientists call this phenomenon redshift.
• What does the observation that distant galaxies have a larger redshift than nearby galaxies imply about the universe?

  It implies that the universe is expanding.
• What was the initial assumption about the expansion of the universe before 1998?

  That the expansion would gradually slow down due to gravity.
• What did astronomers observe about the rate of expansion of the universe in 1998?

  They observed that the rate of expansion is increasing.
• What are dark matter and dark energy, and why are they significant in the context of the universe's expansion?

  • Dark matter and dark energy are forms of matter and energy that cannot be detected
  • They may explain the accelerating expansion of the universe