Frederick Sparber wrote: > Harry Veeder wrote. >> >> Frederick Sparber wrote: >> >>> Interesting reading Harry. >>> But you can bring a bucket of minus 77 K cold Tc from a >>> comet in space and let it do work in compliance with the >>> Carnot efficiency by letting it warm to 300 K Th >>> ( room temperature) using an "engine". >>> >>> Carnot efficiency = .1 - Tc/Th or delta T/Th. = 74.33 % >>> >> >> This is correct if you are only considering the work produced after you > have >> the ice. However, will more work be produced than used in retrieving the > ice >> from the comet? The second law says no. >> > The 1908 Tunguska Event says yes. > > http://www.galisteo.com/tunguska/docs/splitsky.html > > "Some have suggested it was a black hole. Others have wondered if it was a > piece of anti-matter. A Japanese UFO group (Sakura), headed by Kozo Kowai, > are convinced that it was the explosion of the nuclear power plant of an > errant vehicle belonging to extraterrestrials. A number of science-fiction > accounts have degraded the event to fantasy. Some critics hold that the > entire history of nearly five decades of field work represents little more > than a chain of mistakes. Most scientists disagree and point to a comet or > an asteroid being the cosmic culprit." > > It's mass and velocity were estimated from it's energy release. > > Fred
This is still consistent with the second law, because the comet came to Earth. In other words you did not have to do work by sending a spacecraft to mine ice from the comet. Harry
