How has scientific understanding about the composition of the universe changed over time? Select the two correct answers. (1 point)
[ 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 dark energy has shrunk in scientists' estimates.
The percentage of dark matter has shrunk in scientists' estimates since the 1980s.
The two correct answers are:
- The percentage of unknown material has grown in scientists' estimates since the 1970s.
- The percentage of dark matter has shrunk in scientists' estimates since the 1980s.
The correct answers are:
1. The percentage of unknown material has grown in scientists' estimates since the 1970s.
2. The percentage of dark matter has shrunk in scientists' estimates since the 1980s.
The correct answers are:
1. The percentage of ordinary matter has grown in scientists' estimates.
2. The percentage of unknown material has grown in scientists' estimates since the 1970s.
Here's an explanation of how we arrived at these answers:
Scientific understanding about the composition of the universe has evolved over time as new discoveries and advancements in technology have been made. Our understanding of the universe is based on observations, measurements, and theoretical models.
1. The percentage of ordinary matter has grown in scientists' estimates: Initially, scientists believed that ordinary matter (atoms and molecules that make up stars, planets, and everything we can see) made up most of the universe's composition. However, with new observations and measurements, it was realized that there is also a significant amount of dark matter and dark energy in the universe. Dark matter is a form of matter that does not interact with light or other electromagnetic radiation, making it invisible to our telescopes. Dark energy, on the other hand, is a mysterious force that is causing the universe's expansion to accelerate.
2. The percentage of unknown material has grown in scientists' estimates since the 1970s: Over the years, as our knowledge and technology have advanced, scientists have recognized that there is a substantial amount of material in the universe that we have yet to fully understand. This unknown material includes dark matter and dark energy. The existence of dark matter was first proposed in the 1930s, but it was in the 1970s that the evidence for its presence started to accumulate. Since then, scientists have been trying to understand its nature and role in the universe. As for dark energy, its existence and dominant role in the expansion of the universe were discovered in the late 1990s.
On the other hand, the following statements are incorrect:
- The percentage of dark energy has shrunk in scientists' estimates: Dark energy is believed to make up a significant portion of the universe's composition and its existence was only discovered in the late 1990s. Our understanding of dark energy is still an active area of research.
- The percentage of dark matter has shrunk in scientists' estimates since the 1980s: While our understanding of dark matter has evolved, with ongoing research and new observations, there is no evidence to suggest that the percentage of dark matter in scientists' estimates has decreased since the 1980s. In fact, it is still believed to be a substantial component of the universe's composition.