Why Did Hubble Have to Rely on Cepheids to Find

question 109

Essay

Why did Hubble have to rely on Cepheids to find the distance to M31, unlike Shapley's use of RR Lyrae stars with the Milky Way?

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Definitions:

Inferior Good

An inferior good is a type of good whose demand decreases when consumer income rises, unlike normal goods, where demand increases with rising consumer income.

Normal Good

A type of good for which demand increases when income increases, and vice versa, displaying a positive correlation between income and demand.

Cross Elasticity of Demand

A measure of how the quantity demanded of one good responds to a change in the price of another good, indicating the degree of substitutability or complementarity between the two goods.

Motor Oil

A lubricant used in internal combustion engines to reduce friction, protect against wear, and maintain engine cleanliness.