I:28) What was the density of energy released of fusing 25% of all the hydrogen in the universe into helium, at time when T = 10^9 K. Express your answer in J/m^3.
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I:28) What was the density of energy released of fusing 25% of all the hydrogen in the universe into helium, at time when T = 10^9 K. Express your answer in J/m^3.
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