The Echo of Creation: Big Bang Theory Quiz

If a galaxy moves toward the observer, then the light waves it emits are compressed. If light waves are compressed, then their frequency increases and wavelength decreases. If the wavelength decreases, then the light shifts toward the blue end of the spectrum (Blueshift).

If the universe is currently expanding, then it must have been smaller in the past. If we trace this expansion back billions of years, then all matter and energy must have been concentrated into one infinitesimal, hot, and dense point. Therefore, the theory posits the universe began from a single point.

If we observe light from distant galaxies, then we see their spectral lines are shifted toward longer, redder wavelengths. If the wavelengths are stretched, then the distance between the Earth and those galaxies must be increasing. If the distance is increasing, then the universe must be expanding.

If the Big Bang occurred, then the early universe was extremely hot and filled with high-energy radiation. If the universe expanded, then that radiation would have stretched and cooled over time into microwaves. If we detect these microwaves everywhere in space today, then they represent the cooled remnants of the initial explosion.

If the Big Bang theory is correct, then the early universe was hot enough for nuclear fusion for only a few minutes. If fusion occurred for a short window, then mostly light elements like Hydrogen and Helium would form. Since Hydrogen makes up about 75% of the universe's mass, then this matches the predicted outcome of the Big Bang.

If a source of waves moves toward an observer, then the waves are compressed. If the source moves away, then the waves are stretched. If this phenomenon describes the shift in light or sound frequency due to motion, then it is defined as the Doppler Effect.

If Hubble measured the distance and redshift of various galaxies, then he found a mathematical relationship between them. If the redshift (speed) increases proportionally with distance, then galaxies further away from us are receding at higher velocities.

If an atom absorbs or emits energy, then electrons jump between specific energy levels. If these levels are unique to each element, then the resulting light patterns are unique. If the patterns are unique, then they can be used to identify the composition of stars and galaxies.

If we measure the current rate of expansion (the Hubble Constant), then we can calculate how long ago the expansion started. If we factor in the Cosmic Microwave Background data, then the calculation points to approximately 13.8 billion years.

If a theory requires evidence of origin and expansion, then it must explain current motion, thermal remnants, and chemical makeup. If Redshift explains expansion, CMB explains the cooling glow, and light element ratios explain the early heat, then these three are the primary pillars of the theory.

If a galaxy is moving away, then the light waves are "stretched" as they travel through space. If the waves are stretched, then the distance between peaks (wavelength) becomes longer. If the wavelength is longer, then the light is shifted toward the red end of the spectrum.

If we want to analyze the specific wavelengths of light from a star, then we must separate the light into a spectrum. If a device uses a prism or grating to reveal these absorption/emission lines, then that device is a spectroscope.

If the Big Bang occurred, then space itself is stretching between galaxies. If space stretches, then the light traveling through it stretches as well. Therefore, Redshift is primarily a result of the expansion of space itself, not just galaxies moving like cars on a road.

If the early universe was extremely hot and dense, then it was a plasma where photons (light) were constantly bouncing off electrons. If light was constantly trapped and scattered, then it could not travel freely. If light couldn't travel freely, then the universe was opaque until it cooled enough for atoms to form.

If we observe the universe in any direction on a massive scale, then it looks roughly the same. If the laws of physics and the distribution of matter are consistent everywhere, then the universe is both isotropic and homogeneous. This is the definition of the Cosmological Principle.

If a scientist specializes in the large-scale properties of the universe as a whole, then they are studying cosmology. Therefore, those scientists are called cosmologists.

If the early universe acted as a giant fusion reactor, then it could only fuse the simplest nuclei before cooling down. If Hydrogen is the simplest, and Helium/Lithium are the next lightest, then these were the only ones formed. Heavier elements like Oxygen and Iron require the intense pressure of later star formation.

If there is no relative motion between the source and the observer, then there is no Doppler effect. If there is no Doppler effect, then the wavelengths of the light are not compressed or stretched. Therefore, the spectral lines will appear at the exact wavelengths measured in a laboratory on Earth.

If the universe expands uniformly, then the amount of expanding space between us and a galaxy increases with distance. If there is more space expanding, then the light from that galaxy has to travel through more "stretching." Therefore, more distance results in a greater redshift.

If the early universe was hot, it emitted short-wavelength, high-energy radiation. If the universe expanded and cooled, then the energy decreased. If energy decreases, then the wavelength must increase (stretch). Therefore, cooling led to the shift from high-energy light to low-energy microwaves.