Q
How fast is the universe expanding?
A
Expert Answer
The Hubble constant (expansion rate) is approximately 73 km/s per megaparsec (local measurements) or 67 (CMB measurements)—the 'Hubble tension' discrepancy remains unresolved. Dark energy drives accelerating expansion. The rate isn't constant; it has changed throughout cosmic history.
Key Insight
The Hubble constant (expansion rate) is approximately 73 km/s per megaparsec (local measurements) or 67 (CMB measurements)—the 'Hubble tension' discrepancy remains unresolved.
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