Peal nodded. "That's what's driving me out of my mind at the moment, Jerry. Except when it reaches critical mass, uranium-235 is supposed to have an absolutely fixed half-life; it shouldn't increase under any circumstances, and the mass of each section in those bombs can't increase to become nearer critical, either. It simply can't happen, according to any physics I ever learned. But it's doing so." "What about the effects of cosmic rays?" Blane asked. Devlin might have learned more from Earth, and even if his story to Manners had been patently untrue, it might still offer some clue. Peal shook his head, but somewhat doubtfully. "On Earth, they're mostly only mesons from strikes by cosmic radiation. Out here, we get only the extremely hard radiation--the shielding of the ship is too thin to affect them. Maybe they might speed up the half-life a little--but they shouldn't make it increase. I've been thinking about them, too. Meteorites show a much greater decay of uranium to lead than the ores on Earth, which might indicate some effect from cosmic radiation. But unless they somehow produce another isotope from uranium that's raising the activity, I can't figure it out. We need a top level nuclear physicist for this, and we don't have one here." They discussed it at greater length, but without adding anything to their speculations. Blane felt the hairs on the back of his neck prickling, and was conscious of a vague picture in his mind of the warheads ticking away and getting set to blast spontaneously. But he put the idea aside. Earth might be a little careless of their welfare under the pressure of emergency, but right now Earth would never risk losing the station. It was only his overactive imagination. He finally assigned Peal and Manners back to the task of studying the matter as best they could, and tried to dismiss it from his mind. There were more than enough other worries about the station. The cryogenics lab was in trouble--the group from Earth who had used the labs had badly depleted supplies and been careless about equipment that was common enough below but difficult to obtain here. The evacuation of the laboratories near the bomb bay threw severe strains on research, and Earth was demanding that some of it be speeded up. And the weather study was being crippled by the need to waste too much attention on detailed studies of every section of Russia. The whole station was on emergency orders to do twice as much as could possibly be done. * * * * * He waited for news that supplies were being sent from Johnston Island to the _Sulky_, but no such news appeared. Instead, the news carried details that were only rumors of some effort of the United States to force Russia to disarm the _Sulky_ unilaterally in return for the loan of eight rocket ships and launching facilities. If such an offer had been made, it must have been turned down flatly. The next day there was not even a mention of it.