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The universe and the Big Bang

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1.Which scientist is credited with first proposing the concept of an expanding universe through mathematical derivation in 1922?
Easy
- AEdwin Hubble
- BAlexander Friedmann
- CGeorges Lemaître
- DAlbert Einstein
2.According to the Big Bang theory, what is the estimated age of the universe?
Easy
- A4.5 billion years
- B10 billion years
- C13.787 billion years
- D20 billion years
3.The cosmic microwave background (CMB) radiation was discovered accidentally in 1964 and is considered strong evidence for the Big Bang.
Easy
True or false?
4.Place the following events in the order they occurred according to the Big Bang theory, from earliest to latest.
Medium
- Formation of atoms
- Inflationary epoch
- Formation of stars and galaxies
- Emission of cosmic microwave background
5.Which of the following is NOT considered a piece of evidence supporting the Big Bang theory?
Medium
- AAbundance of light elements
- BCosmic microwave background radiation
- CRedshift of galaxies
- DPresence of dark energy
6.Select all that apply. Which of the following are major assumptions of Big Bang cosmology?
Medium
- AUniversality of physical laws
- BThe cosmological principle
- CSteady state of the universe
- DMatter content can be modeled as a perfect fluid
7.Match each scientist to their contribution to Big Bang theory.
Hard
- Alexander Friedmann
- Edwin Hubble
- Georges Lemaître
- Proposed the 'primeval atom'
- Derived the Friedmann equations
- Observed that galaxies are moving away from Earth
8.Match each term related to the Big Bang to its correct description.
Medium
- Cosmic microwave background
- Cosmic inflation
- Dark energy
- Hubble's law
- Uniform radiation from the early universe
- Rapid early expansion solving horizon and flatness problems
- Mysterious force causing accelerating expansion
- Galaxies recede at speeds proportional to distance

More questions

9.Arrange the following events in the order they occurred according to the Big Bang theory, from earliest to latest.
Medium
- Formation of hydrogen and helium atoms
- Recombination and emission of CMB
- Inflationary epoch
- Formation of first stars and galaxies
10.Select all pieces of evidence that support the Big Bang theory.
Medium
- ACosmic microwave background radiation
- BRedshift of distant galaxies
- CUniform temperature of the CMB
- DPresence of dark matter
- EAbundance of light elements (H, He, Li)
11.According to the cosmological principle, the universe is homogeneous and isotropic on large scales.
Easy
True or false?
12.What percentage of the current universe's mass-energy density is made up of dark matter?
Medium
- A5%
- B27%
- C68%
- D95%
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?
Hard
- ACosmological principle
- BUniversality of physical laws
- CPerfect fluid assumption
- DGeneral relativity
14.Who first proposed the idea that the universe emerged from a 'primeval atom'?
Medium
- AAlexander Friedmann
- BEdwin Hubble
- CGeorges Lemaître
- DAlbert Einstein
15.What is the cosmic microwave background (CMB) radiation?
Easy
- ARadiation from the first stars
- BHeat left over from the Big Bang
- CLight from distant galaxies
- DEnergy from dark matter
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?
Medium
- A100 Mpc
- B10 Mpc
- C700 Mpc
- D0.01 Mpc
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?
Hard
- A1.06 mm
- B0.106 mm
- C10.6 mm
- D106 mm
18.Which of the following are direct consequences of the expansion of the universe predicted by the Big Bang model? (Select all that apply)
Medium
- AGalaxies appear redshifted
- BThe cosmic microwave background has a blackbody spectrum
- CThe abundance of light elements matches predictions
- DThe universe is accelerating due to dark energy
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?
Hard
- AThe universality of physical laws
- BThe cosmological principle
- CMatter can be modeled as a perfect fluid
- DThe universe is flat
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?
Medium
- ACosmological principle
- BPerfect fluid assumption
- CUniversality of physical laws
- DHubble's law
21.What is the approximate percentage of the universe's mass-energy density that is made up of dark energy?
Medium
- A68%
- B27%
- C5%
- D95%
22.Which of the following are pieces of evidence that support the Big Bang theory? (Select all that apply)
Hard
- AAbundance of light elements (hydrogen, helium, lithium)
- BCosmic microwave background radiation
- CRedshift of galaxies (Hubble's law)
- DSteady-state model predictions
- ELarge-scale structure of the universe
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.
Easy
True or false?
24.Match each scientist to their contribution to the Big Bang theory.
Medium
- Alexander Friedmann
- Edwin Hubble
- Georges Lemaître
- Mathematical derivation of expanding universe (1922)
- Observed that galaxies are moving away proportionally to distance (1929)
- Proposed the 'primeval atom' idea (1931)
25.The observed uniformity of the universe leads to which two problems that are solved by cosmic inflation?
Hard
- AHorizon problem and flatness problem
- BDark matter problem and dark energy problem
- CBaryon asymmetry problem and structure formation problem
- DFine-tuning problem and cosmological constant problem
26.What is the name of the theory that describes the universe expanding from an initial state of high density and temperature?
Easy
- ASteady State theory
- BBig Bang theory
- COscillating Universe theory
- DInflation theory
27.The cosmological principle states that on large scales the universe is homogeneous and isotropic.
Easy
True or false?
28.Which scientist first proposed that the universe emerged from a 'primeval atom'?
Medium
- AAlexander Friedmann
- BEdwin Hubble
- CGeorges Lemaître
- DAlbert Einstein
29.What percentage of the current universe's mass-energy density is made up of dark energy?
Medium
- A5%
- B27%
- C68%
- D95%
30.Which of the following is a key piece of evidence for the Big Bang theory that involves the relative abundances of light elements?
Medium
- ACosmic microwave background radiation
- BPrimordial nucleosynthesis predictions
- CHubble's law
- DGalaxy rotation curves
31.Select all that apply. Which of the following are direct consequences of the expansion of the universe predicted by the Big Bang model?
Hard
- ARedshift of distant galaxies
- BCosmic microwave background radiation
- CNucleosynthesis of light elements
- DAccelerating expansion due to dark energy
- EFormation of black holes
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?
Medium
- AThe galaxy is moving towards Earth.
- BThe galaxy is moving away from Earth.
- CThe galaxy is stationary and the light is being absorbed by interstellar dust.
- DThe galaxy's atoms have different energy levels than those on Earth.
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?
Hard
- A1.36 K
- B2.725 K
- C5.45 K
- D0.68 K
34.Select all that apply. Which of the following are pieces of evidence that support the Big Bang theory?
Medium
- AThe cosmic microwave background radiation
- BThe abundance of light elements (hydrogen, helium, lithium)
- CThe existence of black holes
- DThe redshift of distant galaxies
- EThe observation of gravitational waves
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?
Hard
- AThe claim is correct; the universe's gravity will eventually halt expansion.
- BThe claim is incorrect; observations show the expansion is accelerating, suggesting a 'Big Rip' or indefinite expansion.
- CThe claim is partially correct; the universe will stop expanding but not collapse.
- DThe claim is untestable because we cannot observe the far future.
36.The cosmic microwave background (CMB) radiation was discovered accidentally in 1964. Which two scientists are credited with this discovery?
Medium
- AArno Penzias and Robert Wilson
- BEdwin Hubble and Georges Lemaître
- CAlexander Friedmann and Albert Einstein
- DGeorge Gamow and Ralph Alpher
37.What does the cosmological principle state about the universe on large scales?
Easy
- AIt is homogeneous and isotropic.
- BIt is expanding at an accelerating rate.
- CIt is composed mostly of dark matter.
- DIt is finite and has a center.
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.
Easy
True or false?
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?
Medium
- AIt indicates the current average temperature of stars.
- BIt is the temperature of the universe when it first became transparent to radiation, about 380,000 years after the Big Bang.
- CIt is the temperature of the initial singularity.
- DIt is the temperature of dark matter.
40.Which of the following are assumptions of Big Bang cosmology? (Select all that apply)
Hard
- AThe universe is homogeneous and isotropic on large scales.
- BPhysical laws are universal and do not change with time.
- CThe universe is infinite in size.
- DThe matter content of the universe can be modeled as a perfect fluid.
- EDark energy is the dominant component of the universe.
41.Complete the sentence about the composition of the universe.
Medium
In the current universe, luminous matter makes up less than ____% of the density, dark matter accounts for ____%, and dark energy the remaining ____%.
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.
Medium
43.What is the name of the phase of accelerated expansion during the earliest stages of the universe that explains its observed uniformity?
Medium
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.
Hard
45.Complete the sentence.
Easy
The observed recession of galaxies is described by ____ law.
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.
Medium
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.
Medium
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)?
Medium
49.Complete the sentence about the expansion of the universe.
Easy
Edwin Hubble observed that galaxies are moving away from Earth, and their recessional velocity is proportional to their ____ .
50.What is the name of the phase of extremely rapid expansion in the early universe that solves the horizon and flatness problems?
Medium
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.
Hard
52.What is the name of the radiation that is considered strong evidence for the Big Bang, discovered accidentally in 1964?
Easy
53.Explain how the cosmological principle simplifies the equations of general relativity in Big Bang models.
Hard
54.Describe two pieces of evidence that support the Big Bang theory.
Medium
55.Explain two problems that are solved by cosmic inflation.
Hard
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.
Hard
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.
Medium
- A1
- B0.00001
- C2
- D-1
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.
Hard
- A16544400000 yr
- B15165700000 yr
- C12408300000 yr
- D13787000000 yr
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.
Medium
- A522120000000000000 s
- B391590000000000000 s
- C478610000000000000 s
- D435100000000000000 s
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.
Medium
- A12600 km/s
- B15400 km/s
- C14000 km/s
- D16800 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)?
Medium
- A22 Mpc
- B24 Mpc
- C18 Mpc
- D20 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.
Hard
- A0.06 mm
- B2.06 mm
- C3.06 mm
- D1.06 mm

Flashcards

What is the Big Bang theory?

The Big Bang theory describes how the universe expanded from an initial state of high density and temperature about 13.787 billion years ago.

What is the age of the universe according to the Big Bang model?

The universe is estimated to be 13.787 ± 0.02 billion years old.

What are the major components of the universe?

Stars, galaxies, and other celestial objects; also dark matter and dark energy.

What is an astronomical unit (AU)?

An astronomical unit is the average distance from Earth to the Sun, about 150 million kilometers.

What is a light-year?

A light-year is the distance light travels in one year, about 9.46 trillion kilometers.

What is scientific notation and why is it used in astronomy?

Scientific notation expresses very large or small numbers as a product of a number between 1 and 10 and a power of 10. It simplifies writing distances like light-years.

What is Hubble's law?

Hubble's law states that galaxies are moving away from Earth at a speed proportional to their distance, indicating the universe is expanding.

What is the cosmic microwave background (CMB) radiation?

CMB is the leftover radiation from the Big Bang, discovered in 1964, providing strong evidence for the theory.

How does the abundance of light elements support the Big Bang?

The Big Bang model predicts the primordial formation of mostly hydrogen, with some helium and lithium, matching observed abundances.

What is cosmic inflation?

Cosmic inflation is a phase of extremely rapid expansion in the earliest moments of the universe, explaining its uniformity and flatness.

What is the cosmological principle?

It states that on large scales the universe is homogeneous and isotropic—the same in all directions regardless of location.

What is dark matter?

Dark matter is a form of matter that does not emit light but exerts gravitational effects; it accounts for about 27% of the universe's mass-energy density.

What is dark energy?

Dark energy is a mysterious force causing the accelerated expansion of the universe; it makes up about 68% of the universe's mass-energy density.

What is redshift and how does it relate to the Big Bang?

Redshift is the stretching of light to longer wavelengths as galaxies move away; it shows the universe is expanding, supporting the Big Bang.

Who proposed the concept of an expanding universe mathematically?

Alexander Friedmann derived the Friedmann equations in 1922, describing the expansion of the universe.

Who first proposed the 'primeval atom' idea that became the Big Bang?

Georges Lemaître proposed in 1931 that the universe emerged from a 'primeval atom'.

What is the Friedmann–Lemaître–Robertson–Walker (FLRW) metric?

It is a solution to Einstein's equations that describes a homogeneous, isotropic expanding universe.

What is a particle horizon?

A particle horizon is the maximum distance from which light has had time to reach us since the Big Bang, limiting the observable universe.

What is baryon asymmetry?

Baryon asymmetry is the observed imbalance between matter and antimatter in the universe, not yet fully explained by the Big Bang model.

What is the fine-structure constant and how does it relate to Big Bang assumptions?

The fine-structure constant is a fundamental constant; its uniformity over cosmic time supports the assumption that physical laws are universal.

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