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Course: American Museum of Natural History > Unit 2
Lesson 4: Universe- The Universe
- The Known Universe
- Exploring the Dark Universe: Dark matter
- Will Dark Energy Please Come to Light?
- Exploring the Dark Universe: Dark energy
- The Cosmic Microwave Background
- The Cosmic Microwave Background: A New View From the South Pole
- Our Expanding Universe
- Universe Glossary
- Quiz: Universe
- Exploration Questions: Universe
- Answers to Exploration Questions: Universe
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Exploration Questions: Universe
1. Explain this sentence and how it relates to our understanding of the universe: The farther out into space we look, the further back in time we see.
2. What did astronomers Arno A. Penzias and Robert W. Wilson discover with their microwave radio telescope in 1964? How did their discovery affect our understanding of the universe?
3. Explain how this graph shows the effects of dark energy. How does this graph represent a major change in how scientists once thought of the expanding universe?
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1. The speed of light is the fastest speed in the universe. Because of the huge distances and the fact that nothing can travel faster than light, you and something you're observing aren't in the same point in time. You see the moon as it was a second ago, because the light takes a light second to reach your eyes. You see the sun as it was 8 minutes ago, because the light takes 8 minutes to reach your eyes. In a sense, you look back in time whenever you see the night sky.
2. Penzias and Wilson were trying to block all background sound, but couldn't eliminate a microwave signal that was coming from all directions. This turned out to be leftover radiation from the beginning of the universe, and an important piece of evidence for the Big Bang.
3. Scientists had assumed that the universe would decelerate over time. Now we know that the universe is expanding, and is increasing speed. This could suggest a "repulsive force", or mean that the theory of gravity has something wrong.(2 votes)
If gravity becomes weaker at a distance, then it stands to reason that the moving of the galaxies would be speeding up as they become farther apart. Where does my logic fail?(2 votes)
It fails because it assumes constant acceleration. The problem is that the energy that began the initial motion is being counteracted by gravity. Unless there constantly is additional force being applied, the object will not speed up. It will slow down at a constantly decreasing rate of deceleration. It can not accelerate unless there is a positive net force being applied. If there is dark energy pulling it apart, as it moves farther from the gravitational center it will accelerate. Is Dark Energy the antigravity of ultimate space? Is it possible that beyond the measurable universe there is space so complete (perhaps devoid of Dark Matter) that it creates a vacuum pulling all matter/energy out towards it in all directions?(1 vote)
- 1.The universe expanding.
2. They discovered the cosmic microwave background radiation.
3.it shows either how it grows and travels around .(1 vote) 
When the universe was created, there were dense pockets of mass and less dense areas the pockets became known as super clusters, gravity has power in the pockets but dark energy has the upper had when it comes to outside the pockets. So basically the pockets are being pushed away and also it is said its gonna merge. So are we gonna get crushed in to one galaxy and then get crushed to form a super massive star, or are the super clusters gonna stay the same?(1 vote)
explain the formation of solar system?(1 vote)
so yeah if there were stuff in space that did certin thing s would it be stuff(0 votes)
You think space will get bigger and explode?(0 votes)- well maybe it would because eventually it would implode on itself so perhaps it could so no it was not a stupid question. then again it might just freeze or something you never know when it comes to the universe .(0 votes)