Astronomy Flashcards Chapter 1-6

Questions and Answers

Your mass on the Moon would remain the same.

True

Why are telescopes put into space?

To avoid starlight distortion due to the atmosphere.

What is the speed of light in a vacuum?

3 × 10^8 m/s

How can light travel slower than its maximum speed in a vacuum?

When it travels through different materials. Signup and view all the answers

What is the advantage of launching satellites from spaceports near the equator?

A 500 km/hour faster advantage after launch. Signup and view all the answers

Why are satellites never launched toward the west?

Because they would risk going against the Earth's rotating velocity. Signup and view all the answers

What is the difference between speed and velocity?

Velocity is speed with a direction; speed does not have a direction. Signup and view all the answers

Who was Galileo?

The first to use a telescope for astronomical observations. Signup and view all the answers

Who discovered the moons of Jupiter?

Galileo Signup and view all the answers

Who discovered the phases of Venus?

Galileo Signup and view all the answers

Which of the following ranks the sizes of the listed objects in the correct order, from smallest to largest?

Asteroid, solar system, galaxy, universe Signup and view all the answers

What is astronomy?

The study of the universe. Signup and view all the answers

What is the biggest challenge for astronomers?

To measure the distance to the stars and galaxies. Signup and view all the answers

What is a light year?

The distance light can travel in a year. Signup and view all the answers

What element was the early universe filled with?

Hydrogen Signup and view all the answers

How are new stars, planets, and humans made in the universe?

Hydrogen collapse gravitationally to form stars. The stars fuse hydrogen into heavier elements. Dying stars then eject these heavy elements into space, in the form of stardust. Signup and view all the answers

A pattern in nature can reveal an underlying physical law.

True Signup and view all the answers

Once a theory is proved in science, scientists stop testing it.

False Signup and view all the answers

What is the difference between hypothesis and theory?

A hypothesis is an idea that can explain a phenomenon before the research has taken place. A theory is a hypothesis that has already been supported by data, which tests have failed to disprove. Signup and view all the answers

What is the heliocentric model?

The sun is the center of the solar system. Signup and view all the answers

What is the ecliptic?

The Sun's apparent path along the celestial sphere. Follows a 23.5 degree path. Signup and view all the answers

On the vernal and autumnal equinoxes, what happens?

All of the above. Signup and view all the answers

What is cosmology?

The study of the origin, properties, processes, and evolution of the universe. Signup and view all the answers

How does science make progress?

It is all conditional. Our understanding can change due to additional experimental findings. Signup and view all the answers

What is the cosmological principle?

The testable assumption that the same physical laws apply here and now also apply everywhere and at all times. Signup and view all the answers

Study Notes

Astronomy and the Universe

Astronomy is the scientific study of the universe.
The solar system consists of a star (the Sun) and its planets, dwarf planets, comets, asteroids, and one star, all within a galaxy.
Understanding our place in the universe includes studying our astronomical origins.
Hydrogen was the primary element present in the early universe, crucial for the formation of stars and planets.

Distance Measurement in Space

Astronomers face challenges in measuring distances to stars and galaxies, often using the travel time of light.
A light year, the distance light travels in one year, serves as a key unit for measuring astronomical distances.

Scientific Concepts and Theories

A hypothesis is an initial idea that can explain a phenomenon, while a theory is a well-supported explanation backed by evidence.
The cosmological principle posits that the universe is homogeneous and isotropic on a large scale.
Scientific knowledge evolves through testing and refining theories, demonstrating that current understanding is improved over time.

Celestial Mechanics and Coordinates

Celestial coordinates (right ascension and declination) are used to determine star positions in the sky.
Kepler's laws of planetary motion describe the orbits of planets around the Sun, emphasizing elliptical paths, area sweeping, and distance relationships.

Phenomena and Observations

Patterns in nature, such as those observed in celestial movements, can reveal fundamental physical laws.
Stars might appear to twinkle due to atmospheric effects instead of actual variations in brightness.
The phases of the Moon and the occurrence of eclipses are influenced by the alignment of the Earth, Moon, and Sun.

Historical Contributions to Astronomy

Eratosthenes calculated the Earth's circumference and created a geographical coordinate system.
Copernicus introduced the heliocentric model, stating that planets revolve around the Sun.
Galileo, the first to use a telescope for astronomical observations, discovered the moons of Jupiter and the phases of Venus.

Light and Electromagnetic Waves

Visible light is part of the electromagnetic spectrum, which varies in wavelength and frequency.
Light travels at a speed of approximately 3 × 10^8 m/s in a vacuum but can slow down in different materials.
The concept of blackbody radiation explains how hot objects emit energy at high wavelengths.

Telescope Use and Design

Reflecting telescopes focus all colors of light and are not affected by glass imperfections, offering advantages over refracting telescopes.
Telescopes positioned in space help avoid atmospheric distortion, improving observational quality.
The James Webb Space Telescope's mirror diameter is about 7 meters, enhancing its viewing capabilities.

Seasons and Earth's Motion

Earth's axial tilt affects seasonal changes, leading to variations in sunlight and temperature throughout the year.
Events like solstices and equinoxes mark significant points in the Earth's orbit relative to the Sun.

General Physics Principles

Weight differs from mass; mass remains constant while weight changes due to gravitational forces.
Gravity influences the trajectory and speed of celestial bodies, governing their orbits.

Cosmic Addressing and Expansion

A cosmic address includes details of locations from a star or planet down to the broader structures like the galaxy and universe.
The universe continues to expand, affecting the perception of celestial objects.

Key Vocabulary

Celestial sphere: An imaginary sphere where all celestial bodies appear to reside.
Zenith: The point directly above an observer's head.
Horizon: The apparent line where the Earth meets the sky.
Ecliptic: The Sun's apparent path along the celestial sphere.

Examining Cosmic Events

Partial solar eclipses are more frequently observed due to the alignment of the Earth and Moon.
Cosmological phenomena, like the reddish hue of an eclipsed Moon, arise from atmospheric light scattering.

Final Insights

Scientific revolutions reflect the progression of knowledge, revealing that past beliefs may evolve with new discoveries.
Understanding the universe’s complexities relies on a combination of observation, experimentation, and theoretical development.

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Description

Explore the fundamental concepts of astronomy with this set of flashcards covering the Solar System, the study of the universe, and our place within it. Perfect for students seeking to enhance their understanding of this fascinating subject. Delve into key terms and definitions that define the universe around us.