Estimate the critical density of the universe if the Hubble's constant was 100 km/s/Mpc.
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Q: Estimate the critical density of the universe if the Hubble's constant was 50 km/s/Mpc.
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- The Hubble constant is (approximately) 70 kilometers per second per megaparsec. At approximately how far in the future, will the scale-factor be 1% larger than it is today?At what temperature is the thermal radiation in the universe energetic enough to produce nucleons and antinucleons?A galaxy is observed to recede at speed 140 km/s. If the Hubble constant is 70 km/s/ Mpc, how far is the galaxy?