Of course, the acceleration of twice 186,000 miles per second, as used in escaping the field of the great "dud" star, as told in "Skylark of Space" was impossible. Nothing could withstand that strain. Further, no gravitational field could be that intense. It would have exactly the effect Dr. Smith describes and allots to the zone of force in "Skylark Three"--it would make a hole in space and pull the hole in after it. Light would be too heavy to leave the planet. The effect on space would be so great as to curve it so violently as to shut it in about it like a blanket. The dud would be both invisible and unapproachable. The astronomical error? I wonder how Dr. Smith solved the problem of three--or more--bodies? Osnome is a planet of a sun in a group of seventeen suns, is it not? The gravitational field about even two suns is so exceedingly complex that a planet could take up an orbit only such that one sun was at each of the two foci of the ellipse of its orbit, and then only provided the suns were of very nearly the same mass, and stationary, which in turn means they must have _no_ attraction for each other. No, I think his complex system of seventeen suns would not be so good for planets. Celestial Mechanics won't let them stay there. And I really don't see why it was necessary to have so complex a system. Further, I wonder if Dr. Smith considered the proposition of his ammonia cooling plant carefully? The ammonia "cooling" plant works only to _transmit_ heat, not to remove it. The heat is removed by it from the inside of an icebox for instance, and put outside, which is what is wanted. However, it must have some place to dump the heat. In the fight with the Mardonalians, Seaton has an arenak cylinder on his compressor, and runs it very heavily, but if he can't get the heat outside the ship, and away from it, he wouldn't cool the machine at all. Since the Mardonalians kept the outside so hot, and the story says the compressor-cooling was accomplished by a water cooler which boiled--some amount of water, too, if it would absorb all the heat of that Mardonalian fleet in any way--and this heat was then merely transferred from outside to inside--where they DIDN'T want it! Again, in this battle, to protect themselves against ultra-violet radiation, they smear themselves with _red_ paint--presumably because red will stop ultra-violet. Personalty, I'd have picked some ultra-violet paint--if any were handy as that would _reflect_ the rays. Red wouldn't affect them at all, so far as I can see--he might as well have used blue. What he wanted, was a complementary color of ultra-violet, and I don't believe it is red--green is the complement of red. (Green light won't pass through red glass.)