User blog comment:DinoTaur/Welcome to Prof. Dino's Aurology Class!/@comment-25814498-20160218235631/@comment-25814498-20160221221834

My internet shit the bed and I'm kinda touchy right now, so I'll just summarise; the only reason Razors Nen Ball was so dense was because of how powerful Razor is. It is usually much more mobile as seen in the majority of the show. As for why objects seem to move away from Gon when he charges up Jajanken, the answer is simple. They don't... Below are three examples where objects and aura are clearly moving towards Gon's fist:

In this photo, we can see that a large amount of aura is clearly being condensed and attracted towards Gons hand.

In this picture it is even more obvious as several streams of aura are being absorbed from around Genthru and into Gons fist, Genthru's clothes shaking in fact.

This last gif is perhaps the most confusing, but hear me out. I will not deny that air is clearly being pushes away from Gon in the instance of Jajanken, but I do in fact believe that this Gif illustrated my point the best. Every reaction must have an equal and opposite reaction. When a nuclear bomb(or miniature rose) explodes, there just as much force pushing away from the blast as there is "sucking towards it". Gon may be pushing the air away from himself here, but look at the ground under his feet. It is physically cracking from the pressure being put on it, not because just as air is being pushed away from Gon's fist,it is being attracted towards him with just as much force.