What Do Astronomers Believe Is Currently Having the Largest Effect

question 17

Multiple Choice

What do astronomers believe is currently having the largest effect on the change in the expansion rate of the present-day universe?

• A) dark matter
• B) baryonic (normal) matter
• C) dark energy
• D) radiation pressure
• E) gravity

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Definitions:

Decibels

A unit of measurement for sound intensity or loudness, indicating the level of noise in comparison to a reference sound.

Hertz

The unit of frequency in the International System of Units (SI), signifying one cycle per second.

Basilar Membrane

A structure in the cochlea of the inner ear that plays a key role in the perception of sound, vibrating in response to sound waves and thereby stimulating hair cells to send nerve impulses to the brain.

Eardrum

A slender membrane dividing the external ear from the middle ear, which oscillates when hit by sound waves.