In Our Modern View of the Expansion of the Universe

question 14

Multiple Choice

In our modern view of the expansion of the universe, we understand that it is space that is stretching; individual galaxies don't speed away from each other as if they were rockets. In that case, why do galaxies show a red-shift?

• A) as galaxies age, they get redder and redder
• B) as space stretches, the waves of radiation in space also stretch and their wavelength increases
• C) as space stretches, the presence of dark matter slows down the light between galaxies
• D) as time goes on, waves in space encounter more and more dust, and get redder
• E) astronomers cannot think of any good explanation for the red-shift if it's space that expands/stretches

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Definitions:

Grocery Store

A retail store that sells food and other household goods.

Retrieval Cues

Stimuli or signals that can trigger the recall of information from memory.

Memories

Information or experiences stored in the brain that can be recalled or accessed at a later time.

Primed

A psychological state where exposure to one stimulus influences the response to another subsequent stimulus, used often in memory and recognition tests.