9.3 Cosmology

• What is the age of the universe according to the Big Bang theory?

  13.8 billion years
• The recombination era occurred approximately 380,000 years after the Big Bang, making the universe transparent.

  True
• Match the evidence supporting the Big Bang with its significance:

  Cosmic Microwave Background (CMB) ↔️ Uniform background radiation from the early universe

  Redshift of distant galaxies ↔️ Indicates the universe is expanding

  Abundance of light elements ↔️ Consistent with theoretical calculations
• What law describes the relationship between a galaxy's recessional velocity and its distance?

  Hubble's Law
• The redshift of distant galaxies confirms the expansion of the universe.


  True
• The observed ratios of hydrogen, helium, and lithium support nucleosynthesis in the early universe
• What does the Hubble constant measure?

  Current rate of expansion
• Compare the expansion of the universe to the Big Bang theory by matching their key concepts.

  1️⃣ Expansion of the Universe: Galaxies are moving away from each other

  2️⃣ Big Bang Theory: Universe originated from a hot, dense state

  3️⃣ Expansion of the Universe: Expansion rate described by Hubble's Law

  4️⃣ Big Bang Theory: Expansion and cooling allowed formation of particles, atoms, stars, and galaxies
• Hubble's Law predicts that galaxies farther away have a higher recessional velocity.


  True
• What type of event occurred at t=0 according to the Big Bang theory?

  Initial expansion
• Arrange the key events in the Big Bang's timeline based on their approximate time after the Big Bang.

  1️⃣ Big Bang: t=0

  2️⃣ Inflation: 10^-36 s

  3️⃣ Nucleosynthesis: t < 20 minutes

  4️⃣ Recombination: ~380,000 years

  5️⃣ Galaxy Formation: Billions of years
• When did the Big Bang theory propose the universe originated?

  13.8 billion years ago
• The Cosmic Microwave Background (CMB) is uniform background radiation from the early universe.


  True
• During the nucleosynthesis phase, light atomic nuclei such as hydrogen, helium, and lithium were formed
• Arrange the key events in the universe's evolution according to their chronological order.

  1️⃣ Big Bang

  2️⃣ Inflation

  3️⃣ Nucleosynthesis

  4️⃣ Recombination

  5️⃣ Galaxy Formation
• Dark matter and dark energy are not fully understood and cannot be directly observed
• Match the evidence with its supporting aspect of the Big Bang theory:

  Cosmic Microwave Background (CMB) ↔️ Big Bang model's temperature and spectrum predictions

  Redshift of distant galaxies ↔️ Expansion of the universe

  Abundance of light elements ↔️ Nucleosynthesis in the early universe
• The Hubble constant is a fixed value that has not changed over time.

  False
• The expansion of the universe is evidence for the Big Bang theory
• What evidence supports the Big Bang's claim that galaxies are moving away from each other?

  Redshift of light
• Match the expansion of the universe with its implications for the Big Bang theory:

  Galaxies are moving away from each other ↔️ Universe originated from a hot, dense state

  Expansion rate described by Hubble's Law ↔️ Allows for the formation of particles, atoms, stars, and galaxies

  Redshift of distant galaxies is observed ↔️ Consistent with evidence like CMB and light element abundances
• The inflation phase in the early universe caused a rapid acceleration
• Evidence supporting the Big Bang includes the Cosmic Microwave Background (CMB).

  True
• The Big Bang theory suggests the universe originated from an extremely hot and dense state.
• Match the event in the universe's evolution with its description:

  Big Bang ↔️ Initial expansion from a hot, dense state

  Inflation ↔️ Rapid acceleration of the universe

  Nucleosynthesis ↔️ Formation of light atomic nuclei
• During recombination, electrons combined with nuclei, making the universe transparent.
• Arrange the key events in the universe's evolution in chronological order:

  1️⃣ Big Bang

  2️⃣ Inflation

  3️⃣ Nucleosynthesis

  4️⃣ Recombination

  5️⃣ Galaxy Formation
• The expansion rate of the universe aligns with Hubble's Law.

  True
• The redshift of distant galaxies provides evidence for the expansion of the universe.
• Galaxies are moving away from each other, which is consistent with the Big Bang theory.

  True
• What are two unexplained components of the Big Bang theory?

  Dark matter and dark energy
• Galaxies are moving away from each other, indicating that the universe is expanding
• Match the concept with its limitation or alternative model:

  Big Bang Theory ↔️ Cannot fully explain dark matter

  Cyclic Models ↔️ Suggest cycles of expansion and contraction
• Dark energy is a mysterious force driving the accelerating expansion
• The Cosmic Microwave Background (CMB) is uniform background radiation from the early universe
• The abundance of light elements matches theoretical calculations from the Big Bang theory.


  True
• What theory do the pieces of evidence in this material support?

  Big Bang theory
• Redshift of distant galaxies confirms the expansion of the universe


  True
• Match the term with its definition:

  Hubble's Law ↔️ Relationship between recessional velocity and distance

  Recessional Velocity ↔️ Speed at which a galaxy moves away

  Hubble Constant ↔️ Current rate of expansion
• What are galaxies doing according to the expansion of the universe?

  Moving away from each other