From: jclarkeusenet@cox.net   
      
   In article , rl3166pls@excite.com says...   
   >   
   > T987654321 wrote:   
   > > Oblivion   
   > > 2013  PG-13  124 minutes   
   > >   
   > > High above a war-torn future Earth, Cmdr. Jack Harper is maintaining   
   > > the planet's defensive drones when a crippled starship enters his   
   > > territory. Its sole occupant, a mysterious woman, leads Harper to   
   > > shocking truths about humankind's legacy.   
   > >   
   > > Cast:Tom Cruise, Morgan Freeman, Olga Kurylenko, Nikolaj   
   > > Coster-Waldau , Melissa Leo, Zoe Bell, Andrea Riseborough, James   
   > > Rawlings   
   > > Director: Joseph Kosinski   
   > >   
   > >   
   > >   
   > > Very good action SF film.  Cruise delivers another excellent   
   > > performance,  as does Freeman.  The plot device of the alien whatever   
   > > needing earths water of course makes no senesce (the galaxy is full   
   > > of H2O),   
   >   
   > I remember something that made me thing the water harvesters were stupid,   
   > but that fact is that LIQUID H2O is very rare in our solar system (and   
   > probably in most systems), and the fact that we have so much could be   
   > meaningful to those aliens.   
      
   The reason that this is silly is the energy required for interstellar   
   transportation.   
      
   There's nothing magic about water--it's just hydrogen burned in oxygen.   
   There's plenty of oxygen around, and plenty of hydrogen around, they   
   just aren't all in the same place.  Bring them together and burn them   
   and you've got water.   
      
   In our solar system, Earth, Mars, Venus, Mercury, the moons of the giant   
   planets, all have vast quantities of oxygen.  The reason you don't see   
   it in the atmosphere is that it's chemically bound in the rocks.  The   
   Sun, Jupiter, Saturn, Uranus, and Neptune all have even more vast   
   quantities of hydrogen.  Bring the hydrogen and the oxygen together and   
   you have vast quantities of water.   
      
   It costs vastly less to move a ton of hydrogen from Jupiter to Mars and   
   using it to extract water from them than it does to ship a ton of water   
   several light-years.  So the whole idea of crossing interstellar   
   distances for water is just doesn't pass the giggle test.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)