The universe and the Big Bang

9.Arrange the following events in the order they occurred according to the Big Bang theory, from earliest to latest.

10.Select all pieces of evidence that support the Big Bang theory.

11.According to the cosmological principle, the universe is homogeneous and isotropic on large scales.

12.What percentage of the current universe's mass-energy density is made up of dark matter?

13.The fine-structure constant has been tested to show that the largest possible deviation over much of the age of the universe is of order 10^-5. This test supports which assumption of Big Bang cosmology?

14.Who first proposed the idea that the universe emerged from a 'primeval atom'?

15.What is the cosmic microwave background (CMB) radiation?

16.The Hubble constant H₀ is approximately 70 km/s/Mpc. If a galaxy is observed to have a recessional velocity of 7000 km/s, what is its approximate distance from Earth?

17.The cosmic microwave background radiation has a nearly perfect blackbody spectrum with a temperature of 2.725 K. Using Wien's displacement law (λ_max = b/T, with b = 2.898 × 10⁻³ m·K), what is the peak wavelength of the CMB?

18.Which of the following are direct consequences of the expansion of the universe predicted by the Big Bang model? (Select all that apply)

19.Observations show that the fine-structure constant has varied by less than 10⁻⁵ over much of the age of the universe. This tests which major assumption of Big Bang cosmology?

20.Which of the following is a key assumption of Big Bang cosmology that states the universe appears the same in all directions regardless of location?

21.What is the approximate percentage of the universe's mass-energy density that is made up of dark energy?

22.Which of the following are pieces of evidence that support the Big Bang theory? (Select all that apply)

23.The cosmic microwave background radiation was discovered in 1964 and has a nearly perfect blackbody spectrum with a temperature of about 2.7 K.

24.Match each scientist to their contribution to the Big Bang theory.

25.The observed uniformity of the universe leads to which two problems that are solved by cosmic inflation?

26.What is the name of the theory that describes the universe expanding from an initial state of high density and temperature?

27.The cosmological principle states that on large scales the universe is homogeneous and isotropic.

28.Which scientist first proposed that the universe emerged from a 'primeval atom'?

29.What percentage of the current universe's mass-energy density is made up of dark energy?

30.Which of the following is a key piece of evidence for the Big Bang theory that involves the relative abundances of light elements?

31.Select all that apply. Which of the following are direct consequences of the expansion of the universe predicted by the Big Bang model?

32.A student observes a distant galaxy and measures its spectrum, finding that all absorption lines are shifted to longer wavelengths compared to laboratory values. What is the most likely explanation for this observation?

33.The cosmic microwave background (CMB) radiation has a nearly perfect blackbody spectrum with a temperature of 2.725 K. If the universe were twice as old, what would be the approximate temperature of the CMB?

34.Select all that apply. Which of the following are pieces of evidence that support the Big Bang theory?

35.A student claims that the Big Bang theory predicts that the universe will eventually stop expanding and collapse in a 'Big Crunch'. Based on current observations, which of the following best evaluates this claim?

36.The cosmic microwave background (CMB) radiation was discovered accidentally in 1964. Which two scientists are credited with this discovery?

37.What does the cosmological principle state about the universe on large scales?

38.The cosmic microwave background (CMB) radiation was discovered in 1964 and has a nearly perfect blackbody spectrum with a temperature of about 2.7 K.

39.The cosmic microwave background (CMB) radiation has a nearly perfect blackbody spectrum. What does the temperature of the CMB tell us about the universe?

40.Which of the following are assumptions of Big Bang cosmology? (Select all that apply)

41.Complete the sentence about the composition of the universe.

42.The fine-structure constant has been tested to show that the largest possible deviation over much of the age of the universe is of order 10^-5. Express this as a decimal.

43.What is the name of the phase of accelerated expansion during the earliest stages of the universe that explains its observed uniformity?

44.The age of the universe is estimated to be 13.787 ± 0.02 billion years. What is the approximate age in years? Express your answer in scientific notation.

45.Complete the sentence.

46.The age of the universe is estimated to be 13.787 ± 0.02 billion years. What is the approximate age in seconds? Use 1 year = 3.156 × 10⁷ s. Give your answer in scientific notation with 4 significant figures.

47.A galaxy is observed at a distance of 200 Mpc. Using Hubble's law with H₀ = 70 km/s/Mpc, calculate its recessional velocity in km/s.

48.Using Hubble's law, if a galaxy is observed to have a recessional velocity of 1400 km/s and the Hubble constant is 70 km/s/Mpc, what is its distance in megaparsecs (Mpc)?

49.Complete the sentence about the expansion of the universe.

50.What is the name of the phase of extremely rapid expansion in the early universe that solves the horizon and flatness problems?

51.The cosmic microwave background has a temperature of 2.725 K. Using Wien's displacement law (λ_max = b/T, where b = 2.898 × 10⁻³ m·K), calculate the peak wavelength in millimetres. Give your answer to 3 significant figures.

52.What is the name of the radiation that is considered strong evidence for the Big Bang, discovered accidentally in 1964?

53.Explain how the cosmological principle simplifies the equations of general relativity in Big Bang models.

54.Describe two pieces of evidence that support the Big Bang theory.

55.Explain two problems that are solved by cosmic inflation.

56.Explain how the cosmic microwave background (CMB) radiation provides evidence for the Big Bang theory. Include at least two key properties of the CMB.

57.The fine-structure constant has been tested to show that the largest possible deviation over much of the age of the universe is of order 10^-5. Express this as a decimal.

58.The age of the universe is estimated to be 13.787 ± 0.02 billion years. What is the approximate age in years? Express your answer in scientific notation.

59.The age of the universe is estimated to be 13.787 ± 0.02 billion years. What is the approximate age in seconds? Use 1 year = 3.156 × 10⁷ s. Give your answer in scientific notation with 4 significant figures.

60.A galaxy is observed at a distance of 200 Mpc. Using Hubble's law with H₀ = 70 km/s/Mpc, calculate its recessional velocity in km/s.

61.Using Hubble's law, if a galaxy is observed to have a recessional velocity of 1400 km/s and the Hubble constant is 70 km/s/Mpc, what is its distance in megaparsecs (Mpc)?

62.The cosmic microwave background has a temperature of 2.725 K. Using Wien's displacement law (λ_max = b/T, where b = 2.898 × 10⁻³ m·K), calculate the peak wavelength in millimetres. Give your answer to 3 significant figures.