Eliminating empty space in every atom in a human body would fit the rest
into a space smaller than the tip of a pin.

It is true that atoms are mostly empty space. In fact, if all of the space
from the body’s atoms were eliminated, the leftover result would be so
tiny, the body could fit into an opening that is less than 1/500th of a
centimeter -- or the point of a pin. Although atoms are small and comprised
of empty space, they are numerous; the average adult human body is
estimated to contain 7 octillion (or 7 followed by 27 zeros) individual
atoms. Each atom is believed to contain material that was created billions
of years ago. For instance, hydrogen is thought to be nearly 14 billion
years old, and oxygen was thought to be created about 12 billion years ago.