About This Chapter
Life in the Universe - Chapter Summary and Learning Objectives
In this chapter, video lessons provide you with a comprehensive overview of life in the universe, from the universal level to the planetary level. Explore the theories that explain how the universe itself formed. Identify the characteristics required for life on Earth and the techniques that life uses to maintain a foothold; extrapolate this knowledge to think about what kind of environment extraterrestrial life might need. After completing this chapter, you should be able to:
- Explain the theoretical origins of the universe
- Describe how the universe is observed
- Describe the past and current behavior of the universe
- Define concepts like evolution and natural selection
- Identify kinds of space missions and their ideal uses
|What is the Universe?||Define the universe and related concepts like Olbers's paradox, the edge-center problem, and cosmic expansion.|
|Solar System, Galaxy, Universe: What's the Difference?||Describe the differences among these three terms.|
|The Evolution of the Universe||Understand how and when the universe began, and discuss how scientists know this.|
|Origins of the Universe: The Big Bang and Expanding & Contracting Universes||Describe the Big Bang theory and how the universe is proposed to have formed.|
|Evidence for the Big Bang Theory: Background Radiation, Red-Shift, and Expansion||Explain how background radiation, red-shift, and expansion support the Big Bang theory.|
|The Steady State Theory vs. the Big Bang Theory||Identify the differences and similarities between these two theories.|
|The Scale of the Universe||Visualize a scale model of the universe, including what common astronomical objects look like.|
|Timescales in the Universe||Explain the passage of time in space, namely how to figure out the length of an event over a period of time; discuss the role a telescope plays in making that calculation.|
|The Observable Universe vs. the Entire Universe||Discuss the differences between the universe that can be observed and the full spectrum of possibilities.|
|Comparing the Human Lifetime to the Universe||Identify how humankind fits into the cosmic calendar that measures time in the universe.|
|The Expanding Universe: Observations & Models||Describe how and why the universe is expanding, using observations and models as evidence.|
|The Basic Nature of Life||Define key ideas like evolution, primordial soup, and the Miller experiment.|
|Elements & Structure of the Universe||Identify structural components of the universe, like stars, planets, and galaxies.|
|The Big Bang Theory||Define the Big Bang theory, as well as Hubble time and photon/particle soup.|
|Space, Time, Matter, & Energy||Describe the different kinds of matter.|
|Inflation and Acceleration of the Universe||Explain the concepts of inflation and acceleration with regard to the universe.|
|The Curvature, Age & Fate of the Universe||Describe how these ideas apply to the universe.|
|The Origin of Life on Earth: Theories and Explanations||Explain major theories of how life began.|
|The History of Life on Earth: Timeline and Characteristics of Major Eras||Describe major periods of time.|
|Geologic Time Scale: Major Eons, Eras, Periods and Epochs||Explain the geologic time scale and primary sub-divisions.|
|Theory of Evolution||Explain the theory of evolution.|
|Natural Selection and Adaptation||Describe the concepts of natural selection and adaptation.|
|Types of Natural Selection||Name the kinds of natural selection.|
|Environments Where Life Thrives on Earth||Discuss the characteristics of places where life is present on Earth.|
|What Makes a World Habitable?||Identify the qualities required for life.|
|Is There Fossil Evidence for Life on Mars?||Discuss the possibility of fossil evidence of life from Mars.|
|Planetary Predictors of Extraterrestrial Life||Explain different kinds of atmospheres and how they affect the chances of life on other planets.|
|The Advantages & Disadvantages of Different Space Mission Types||Identify and describe flybys, orbiters, landers, and probes, among others; name pros and cons of each.|
1. The Basic Nature of Life
What is life? This lesson will attempt to define this and what the basic nature of life is on Earth. We'll go over DNA, RNA, biological evolution, and natural selection.
2. Comparing the Human Lifetime to the Universe
Did you ever wonder how long your lifespan actually is compared to the lifespan of the entire universe if it's condensed to one year? This lesson will tell you that and much more.
3. The Origin of Life on Earth: Theories and Explanations
Ever wonder how living things came from non-living things? We will explore what conditions on early Earth may have created life from non-living items.
4. Geologic Time Scale: Major Eons, Eras, Periods and Epochs
The geologic time scale is an essential tool for understanding the history of Earth and the evolution of life. In this lesson, explore the principal eons, eras, periods, and epochs that help us track major events in geologic history.
5. The History of Life on Earth: Timeline and Characteristics of Major Eras
The Earth is over 4.6 billion years old. Ever wonder what happened during certain time periods in that large amount of time? We will look at the major eons and eras of Earth's history along with important characteristics of each.
6. Theory of Evolution
We'll look at the interplay between population genetics and environment. Are traits individually acquired or do entire populations evolve? The flying hamsters and a few other notable experiments will provide the answers.
7. Natural Selection and Adaptation
How does natural selection help shape the amazing types of animals we witness around us? In this lesson, we'll explore adaptations and what they can tell us about a species' past evolution.
8. Types of Natural Selection
We'll take a look at the types of natural selection that can occur. From flying hamsters to moths, you'll start to grasp the different paths organisms can take as they respond to their changing environments over time.
9. Intelligent Life in Our Universe
This lesson will explore the possibility of finding intelligent life beyond Earth by traveling to it or by detecting its signals, as well as the chances that such life exists in the first place.
10. Is There Life on Other Planets?
This lesson will explore the places and conditions in our solar system and beyond that may make life possible. We'll discuss extremophiles, the habitable zone, Mars, and Europa.
11. Planetary Predictors of Extraterrestrial Life
Investigate what is needed for life to exist anywhere and the implications for life in our solar system beyond Earth. Consider Mars and some of the moons of Jupiter and Saturn, including Europa, Callisto, Ganymede and Enceladus.
12. Planets Around Distant Stars
This lesson will describe how extrasolar planets can be found and if any have been found. Methods like Doppler shifts, microlensing, and transits will be defined.
13. Space Mission Types: Advantages & Disadvantages
This lesson will go over four different types of space missions scientists have conducted, including flyby, orbiter, rover, and human space explorations.
14. Stanley Miller: Theory, Experiment & Apparatus
How did life originate on Earth? We may never have a complete and definite answer to that question, but in 1953, chemist Stanley Miller conducted a famous experiment that would show how the early Earth could have produced the chemicals of life.
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Other chapters within the Astronomy 101: Intro to Astronomy course
- The History of Astronomy
- How Scientists Think and Work
- Matter in Astronomy
- Light in Astronomy
- Newton's Laws in Astronomy
- Momentum, Energy, Pressure, Temperature & Gas
- Rotational Motion in Physics
- Earth's Spheres and Astronomy
- Influences on Climate
- The Orbits of Celestial Bodies
- The Earth, Sky, and Moon
- The Moon: Formation & Phases
- The Atmosphere on Earth and Other Planets
- The Sun's Structure & Components
- The Solar System: Layout, Formation & Dating
- Characteristics of Our Solar System's Planets
- Small Celestial Bodies & Satellites in Our Solar System
- Measurement of Star Qualities
- Star Types and Significance
- The Birth and Life of Stars
- Star Death and Stellar Remnants
- The Milky Way Galaxy
- Galaxies: Properties & Characteristics
- The Universe: Key Concepts & Theories
- Celestial Navigation & Timekeeping
- Relativity in Time and Space