The entirety of the human race could be condensed into the size of one sugar cube
If you remove the empty space between subatomic particles (the vast amount of space between electrons and their nucleus for example) that make up the human body, they actually amount to very little. If you remove the empty space of all 6.7 billion people in existence, it would reduce down to about the size of a sugar cube.
If that doesn’t blow your mind, maybe you should consider heavy-duty explosives.