The Density Wave Theory for the Formation of Spiral Arms

question 58

Multiple Choice

The density wave theory for the formation of spiral arms predicts that

• A)The arms will wrap up in the lifetime of the galaxy.
• B)The arms contain newborn stars triggered by the density waves
• C)The arms are caused mainly by tidal interactions
• D)Elliptical galaxies will eventually become barred spirals
• E)The arms have a high density of solar-type stars

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Definitions:

Nobles

Members of the highest social class in some societies, typically holding hereditary titles and offices.

Wealth and Status

Refers to the accumulation of valuable resources or material possessions and the social standing or prestige one holds in society, often interrelated.

Thomas Malthus

An English cleric and scholar influential in the fields of political economy and demography, best known for his theory that population growth would outstrip food supply, leading to societal constraints.