Q. Why is there sometimes a short space between paragraphs in the Torah and sometimes a longer space, with the next paragraph starting a new line?
A. The Hebrew words for the two kinds of spacing are parashah s’tumah (“a closed paragraph”), where there is a short space before the next paragraph begins later in the same line, and parashah p’tuchah (“an open paragraph”), where the next paragraph begins on a new line. The difference between them usually depends on whether a completely new unit of thought or story is about to commence.
The word s’tumah comes from a root that means to stop up. In the Mishnah s’tam is used for a law which is not ascribed to an individual sage; s’tam yayin is wine whose history is not clear; s’tam in modern Hebrew indicates “without rhyme or reason”.