1. The problem statement, all variables and given/known data If the energy density of the vacuum were the value 10^133 eV/m^3 , what would the value of the Hubble lookback time be for such a universe with no curvature and no other matter? 2. Relevant equations Possible equation... ...Lookback time = ln(1+z)/H 3. The attempt at a solution I am not sure what to assume for z? And should I convert the energy density to kg/m^3. I am very confused, any direction for this question would be IMMENSELY appreciated.