About This Chapter
About This Chapter
In our fast-paced world, time is a precious commodity that we never seem to have in ample supply, but did you ever wonder how or why time is measured in hours, months, years, or leap years? The video lessons in this chapter help to explain the calendar, the measurement of time, and other events of the celestial sphere. When you have watched all of the lessons, you should feel more knowledgeable about the following:
- The use of solar time
- The purpose of leap years
- How the sun moves during the solstices
- The tropics of Capricorn and Cancer
|Units of Time: Solar, Sidereal and Synodic||Define these types of days, months and years.|
|Apparent Solar Time vs. Mean Solar Time||Learn about daylight savings, standard, and universal time as well as their relationship to the mean solar time.|
|The Origin and Purpose of Leap Years||Discuss the history of leap years.|
|Importance of the Tropic of Cancer and the Tropic of Capricorn||Explore the position of these latitudes as well as the circles on the Earth's poles in connection to how the sun moves during certain celestial events.|
|The Global Positioning System and Its Uses||Discuss the various purposes and benefits of global positioning systems (GPS).|
1. Units of Time: Solar, Sidereal & Synodic
This lesson will define solar day, sidereal day, synodic month, sidereal month, solar (tropical) year, and sidereal year, as well as tell you their exact lengths. After you've watched the video, take our brief quiz.
2. Apparent Solar Time vs. Mean Solar Time
This lesson will discuss the concept of the solar day and how long it is. You'll also learn what mean solar time, apparent solar time, time zones, and standard time have to do with it all.
3. The Origin & Purpose of Leap Years
This lesson will explain what the leap year is, why it was instituted, and why we bother using it compared to an alternative calendar that would mimic the solar year exactly.
4. Importance of the Tropic of Cancer & the Tropic of Capricorn
In this lesson, you'll learn about the significance of the Tropics of Cancer and Capricorn, and how they help explain the hot weather in the tropical zone and the cold weather above and below the Arctic and Antarctic Circles, respectively.
5. The Global Positioning System and Its Uses
This lesson will describe the global positioning system: who invented it, who runs it, how GPS works based on satellites and handheld units, and the many different uses for GPS. After you've completed this lesson, check out the quiz questions that follow.
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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
- Life in the Universe
- Relativity in Time and Space