Why Is Flatness a Problem in Cosmology

question 156

Multiple Choice

Why is flatness a problem in cosmology?

• A) The total amount of known matter (even if we include dark matter) is not enough to make the universe flat.
• B) The universe appears to be flat to within observational error, yet the universe is expanding, and it is impossible for an expanding universe to be flat.
• C) The universe appears to have a hyperbolic geometry to within observational error, yet the universe is expanding, and expanding universes have to be flat.
• D) Matter is known to create bumps in the geometry of spacetime; therefore, the universe cannot be flat.

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Definitions:

Short Run

A period in economics where at least one input is fixed and cannot be changed, limiting adjustments in production.

Long Run

A period in which all inputs, including capital assets, can be adjusted by firms in response to market conditions.

Unit of Account

A standard monetary unit of measurement of the market value/cost of goods, services, or assets.

Real Value

The value of an object or service adjusted for inflation, reflecting its true purchasing power.