Later: 'Why is there a book hovering over the trash can?'
In an attempt to learn to juggle Cueball begins practicing after reading an instruction book. In the third panel, it seems as though he is juggling normally after tossing the balls into the air. However, in a baffling phenomenon, the balls he throws into the air seem to stop adhering to the strict laws of physics part of the way through his throw. As can be proven in simple demonstrations things tend to fall toward the largest center of gravity, and items in motion do not remain statically suspended, unless other forces are at play as well.[citation needed]
The joke here is partially making fun of the idea that in a comic, the visuals of juggling would be the same as the visuals sitting in place in the air. So at first while reading, we assume Cueball is juggling, until it is revealed he has no control over the position of the balls at all.
Cueball is understandably perplexed, but instead of ascribing the event to some inexplicable supernatural agent, he concludes that the book's juggling instructions were faulty and throws it away. The title text furthers the joke by implying the book too seems to have become caught up in this phenomenon, which might now occur whenever Cueball throws something.
Many things could be taken away from this. Perhaps Cueball is so spectacularly bad at juggling that his failure breaks the laws of physics. Or perhaps the book assumes gravity and momentum are present where you choose to juggle. Or perhaps the book merely instructs you how to juggle like the picture on the front of the cover, where the balls can also be thought to hover.
However, it seems that for some reason physics has only stopped acting on these objects as Cueball himself jumps and falls back down without any trouble and the book was previously on the floor, implying it had been dropped there.
While it is possible to reach zero gravity (or at least microgravity), there is no place in our universe where objects with mass have no momentum. Some possible explanations might be that Cueball is outside of our universe, he has just discovered something that's theoretically impossible, or he is just dreaming, or Randall has taken comedic license on the "momentum" part for the sake of the joke. Or he could be in a place where the surrounding fluid, instead of having the normal properties of earth's atmosphere, is a very thick or viscous fluid in which things simply become stuck. Or, perhaps the fourth wall is broken, and Cueball doesn’t recognize he’s in a webcomic, but we do.
This may also be a reference to a motto often brought up in the Hitchhikers Guide to the Galaxy series: if you forget about physics, they will forget about you.
This comic is part of the following unpublished comic from the Five-Minute Comics; specifically the unpublished fourth part.