Basically, we don't touch anything. We are always about an atom above the ground. The atoms in our body are very far apart. For example, if you made every atom in every human body touch then the whole earth's population could fit on a sugar cube. This is called the Pym law. The only reason I can't put my hand through the computer right now is since there is always one layer of electrons outlining our body. So the electrons stop us from falling into the center of the earth.
