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Cosmological Redshift and Scale Factor
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Astronomy
AST.244 Cosmological Redshift and Scale Factor
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A galaxy has z = 0. Which statement is true in the simplified cosmological-redshift model?
A
The observed wavelength equals the emitted wavelength.
B
The universe's scale factor must have been zero at emission.
C
The observed wavelength is twice the emitted wavelength.
D
The galaxy must be invisible to all telescopes.
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