[ WP ] The world 's weight is set . If someone loses a pound , someone else gains it .

`` Conservation of mass. It makes sense, does n't it?'' The lecture hall seemed to shrug in unison, as if resigned to this ridiculous law of physics. `` What? Do you not believe me?'' the professor asked, a sly smile crossing his face. 
 
 A student towards the front of the class raised his hand. `` How can you prove it?'' he asked and the class nodded in agreement. The professor turned his back towards the class and lowered the projector screen. 
 
 `` Correlation, first of all,'' he explained. A graph appeared, faint at first but more clear as the projector powered on. `` The red line is the world population accented by important genocides such as the Holocaust, Tibet, Syria...'' He pointed to each in turn. `` And the blue line is the average weight in developed countries.'' Each time the red line dipped due to a genocide, the blue line spiked. Slightly, but significant enough. 
 
 `` Correlation is not causation,'' a student pointed out. `` The films Nicolas Cage appeared in and the number of people who drowned by falling into a pool correlate but are unlikely to be related. Per capita cheese consumption and number of people who died by becoming tangled in their bedsheets correlate but probably do n't cause each other. How do you explain that?'' 
 
 The professor smiled again. `` Experiments, which is what I was getting to.'' He pressed for the next slide and a picture of Auschwitz appeared, overlayed with a picture of a swastika. 
 
 `` Seems like correlation again,'' a student remarked snidely. The professor adamantly shook his head. 
 
 `` The Holocaust was not what you think it was,'' he stated matter-of-factly and the room fell silent, finally broken by a mighty guffaw from the back. `` Hear me out. There is evidence... Convincing evidence, in fact, that the Nazi's did not kill people on Earth.'' 
 
 `` What do you mean? Where else would they kill people? The moon?'' The class laughed but the professor nodded. 
 
 `` Exactly. The Nazis actually got to the moon before us thanks to a program overseen by Hans Kammler. They did n't just send spaceships up there. They sent people. Millions of people, specifically Jews and minorities.'' 
 
 `` Even if that were true, it proves nothing,'' a student pointed out and the class agreed but the professor held up a hand for silence. 
 
 `` They set up a moon base large enough to house these millions of people. A new planet, set to be colonized by the human race. And then they gassed half of them, immediately killing them and then dispatched the bodies into space, away from the gravitational pull of the moon. And you know what happened?'' 
 
 `` They died?'' a student ventured but was met by silence. 
 
 `` The weight of the other half increased. Not by a little... They did n't just eat out their depression. Their weight doubled immediately. Every last pound of weight sent off was gained by the people still on the moon.'' The class sat in silent shock and doubt. `` Conservation of mass is not just an earthly phenomenon. It is thought to occur on every planet in our solar system... every planet in the universe, in fact.'' 
 
 A lone hand arose from the mass of students listening in awe. `` Will we be tested on this?'' 
 
 `` No. That was just for your knowledge. Anyways, where were we? Ah, yes. Kinetic friction.'' 
 
 ***** 
 
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