Astronomy
Studying the Universe flashcards
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- What is meant by “Astronomy” in this lesson?Observations, Models, and Evidence
- Astronomy studies celestial objects and phenomena using observations and physical explanations.
- What is meant by “Observation” in this lesson?Observations, Models, and Evidence
- An observation records a measured or perceived feature under stated conditions.
- What is meant by “Inference” in this lesson?Observations, Models, and Evidence
- An inference interprets observations using reasoning and assumptions.
- What is meant by “Model” in this lesson?Observations, Models, and Evidence
- A model represents selected mechanisms and makes testable predictions.
- What is meant by “Uncertainty” in this lesson?Observations, Models, and Evidence
- Uncertainty characterizes limits in measurements or interpretations.
- What is meant by “Independent evidence” in this lesson?Observations, Models, and Evidence
- Independent evidence tests an interpretation using observations with different relevant limitations.
- What is meant by “Celestial sphere” in this lesson?Mapping the Sky
- The celestial sphere is an imaginary surface used to describe sky directions rather than a physical shell.
- What is meant by “Altitude” in this lesson?Mapping the Sky
- Altitude is angular height above an observer's horizon.
- What is meant by “Azimuth” in this lesson?Mapping the Sky
- Azimuth specifies a direction around the horizon under a stated convention.
- What is meant by “Celestial pole” in this lesson?Mapping the Sky
- A celestial pole is the sky direction of Earth's rotational axis.
- What is meant by “Constellation” in this lesson?Mapping the Sky
- A constellation defines a sky region and associated apparent patterns, not necessarily a physically connected star group.
- What is meant by “Sky-coordinate system” in this lesson?Mapping the Sky
- A coordinate system provides a consistent way to describe directions.
- What is meant by “Astronomical unit” in this lesson?Astronomical Units and Scales
- An astronomical unit is a standardized length approximately Earth's mean distance from the Sun.
- What is meant by “Light-year” in this lesson?Astronomical Units and Scales
- A light-year is the distance light travels in vacuum in one Julian year.
- What is meant by “Parsec” in this lesson?Astronomical Units and Scales
- A parsec is a distance unit tied to one arcsecond of annual parallax in the standard definition.
- What is meant by “Angular size” in this lesson?Astronomical Units and Scales
- Angular size is the angle an object's apparent extent subtends.
- What is meant by “Look-back time” in this lesson?Astronomical Units and Scales
- Look-back time is the interval since received light was emitted, with cosmological interpretation requiring care.
- What is meant by “Scale hierarchy” in this lesson?Astronomical Units and Scales
- A scale hierarchy distinguishes planetary, stellar, galactic, and larger distances.