Big Bang Theory Quick Check
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Question
How has scientific understanding about the composition of the universe changed over time? Select the two correct answers.(1 point)
Responses
The percentage of dark energy has shrunk in scientists' estimates.
The percentage of dark energy has shrunk in scientists' estimates.
The percentage of dark matter has shrunk in scientists' estimates since the 1980s.
The percentage of dark matter has shrunk in scientists' estimates since the 1980s.
The percentage of unknown material has grown in scientists' estimates since the 1970s.
The percentage of unknown material has grown in scientists' estimates since the 1970s.
The percentage of ordinary matter has grown in scientists' estimates.
The percentage of unknown material has grown in scientists' estimates since the 1970s.
The percentage of ordinary matter has grown in scientists' estimates.
To determine the correct answers, we need to understand how scientific understanding about the composition of the universe has changed over time.
One way to gather this information is by studying scientific literature and research from different time periods. Scientists use various methods such as observing cosmic microwave background radiation, studying galaxy rotation curves, and analyzing the distribution of matter in the universe to estimate the composition of the universe.
Now let's evaluate each response:
1. The percentage of dark energy has shrunk in scientists' estimates.
2. The percentage of dark matter has shrunk in scientists' estimates since the 1980s.
3. The percentage of unknown material has grown in scientists' estimates since the 1970s.
4. The percentage of ordinary matter has grown in scientists' estimates.
For response 1, dark energy is a mysterious force that is believed to be responsible for the accelerated expansion of the universe. Since its discovery in the late 1990s, scientific understanding of dark energy has actually increased, and its percentage has not shrunk in scientists' estimates. Therefore, response 1 is incorrect.
For response 2, dark matter is hypothesized to be a form of matter that does not interact with light or other electromagnetic radiation but exerts gravitational effects on galaxies and other structures. Since the 1980s, scientific understanding of dark matter has indeed increased, and its percentage has not shrunk in scientists' estimates. Therefore, response 2 is incorrect.
For response 3, the term "unknown material" is vague. However, it is important to note that scientific understanding has improved over the years, allowing researchers to identify and classify previously unknown forms of matter. So, it is plausible that the percentage of unknown material has grown in scientists' estimates since the 1970s. Therefore, response 3 is correct.
For response 4, ordinary matter refers to the matter composed of protons, neutrons, and electrons that make up atoms and form stars, planets, and living organisms. As our understanding of the universe has deepened, scientists have indeed discovered and observed more ordinary matter, leading to an increase in the estimated percentage of ordinary matter. Therefore, response 4 is correct.
In conclusion, the correct answers are:
- The percentage of unknown material has grown in scientists' estimates since the 1970s.
- The percentage of ordinary matter has grown in scientists' estimates.
Please keep in mind that this explanation is based on general knowledge and may not consider specific studies or recent advancements in cosmology.
The correct answers are:
1. The percentage of dark energy has shrunk in scientists' estimates.
2. The percentage of unknown material has grown in scientists' estimates since the 1970s.
How did dark matter affect the development of structures in the early universe?(1 point)
Responses
It became part of black holes.
It became part of black holes.
It cooled pockets of gas to form nebulae.
It cooled pockets of gas to form nebulae.
It seeded the development of galaxies.
It seeded the development of galaxies.
It seeded the development of quasars.
The correct answer is:
- It seeded the development of galaxies.
Dark matter played a crucial role in the formation and evolution of galaxies. It is believed to have provided the gravitational framework upon which ordinary matter, such as gas and dust, could accumulate and form galaxies. Dark matter's gravitational pull helped to bring together the necessary materials to initiate the process of galaxy formation. Therefore, it seeded the development of galaxies.
Which is evidence for the existence of dark energy?(1 point)
Responses
Supernovae that are moving away at an accelerating rate.
Supernovae that are moving away at an accelerating rate.
Pulsars that seem to be moving closer at an accelerating rate.
Pulsars that seem to be moving closer at an accelerating rate.
Black holes that are expanding at a constant rate.
Black holes that are expanding at a constant rate.
Galaxies that are rotating at a constant rate.
The correct answer is:
- Supernovae that are moving away at an accelerating rate.
One of the pieces of evidence for the existence of dark energy comes from observations of distant supernovae. It has been observed that these supernovae are moving away from us at an accelerating rate, implying that the expansion of the universe is speeding up. This acceleration is attributed to the presence of dark energy, which counteracts the gravitational pull and causes the expansion of the universe to accelerate. Therefore, the observation of supernovae moving away at an accelerating rate supports the existence of dark energy.