Astronomy

This flashcard set covers the foundational definitions of astronomy, natural science, and objects within the universe, including the Big Bang theory and the expansion of the cosmos.

What is the definition of Astronomy according to the notes?

Astronomy is a natural science that studies celestial objects and the phenomena occuring in the cosmos.

What are the celestial objects of interest mentioned in the study of astronomy?

Planets, moons, stars, nebulae, Galaxies etc.

What are some examples of Phenomenas occurring in the cosmos?

Supernova explosions, pulsars, blazars etc.

Which three subjects does astronomy use to explain the origin and evolution of celestial objects?

Mathematics, physics and Chemistry.

How is Natural Science defined?

A branch of science in which we describe understand and predict natural Phenomenon based on empirical evidence from observation and experimentation.

What is a CeIestial Object?

A naturally occuring physical entity that exists within the Universe.

What is the definition of the UNIVERSE?

Everything that exists - space, time, matter, stars, planets, galaxies.

When did the universe begin and with what event?

It began about $13.8$ billion Years ago with the big bang.

What has been the state of the universe since the big bang?

The universe has been expanding—galaxies are generally moving farther apart.