This chain was "lost" in a previous thread and disappeared into the ionosphere. The question was based on the principle expounded in 1828 by Sadi Carnot (1796 - 1832) - some French military physicist and engineer - died kind of young.). I never knew the man. W = efficiency as a fraction of 1.00, T2 = higher temperature Kelvin, T1 = lower temperature Kelvin, Q2 = higher energy level (ratio measurement meaning there is a real "0"), Q1 = lower energy level W = (T2 - T1)/T2 or, using other energy level units: W = (Q2 - Q1)/Q2 Now, it has been stated that there is an energy density in the universe... 1) If the universe is expanding, is the energy density dropping and are we, in effect, bleeding off our potential energy for accomplishing work 2) If all the energy is at one energy level, even though not at zero (0), no work can be generated because the numerator in either equation above is zero (T2 - T1 = 0, Q2 - Q1 = 0), no matter how high T2 or Q2 are. Is this really true? Was Sadi Carnot a really brilliant guy, or, was he "blowing smoke" at us? What are the implications of this? If we can get solid answers to this I can tell you about a mathematician named Camille Jordan (1838 - 1922), another French guy who did "blow smoke" but the assertion is true. I didn't know this fellow either but I sure would have liked his sales pitch.