Here are two night photos whose juxtaposition I think is instrumental to the questions night photography poses:

"The Signpost Time Forgot," by Larrie Thompson. Found at http://www.nightphotographer.com/.

A nightscape of New York City from the Chrysler Building. Found at http://night-hawks.blogspot.com/.

"The Signpost Time Forgot" is outside of the ghost town of Dorothy, Alberta. On his website, Thompson describes it as "a metaphor for the vanishing small towns to which it points the way." The remnants of ghost towns and the processes of decay are potent subjects that a number of photographers in the West depict. By capturing the spiralling movement of the stars over the tip of the sign, Thompson highlights the contradictory elements of time and timelessness with which we see these places. In the contemporary imagination, ghost towns become places out of time. But the decay that is central to this image is a physical product of time's passing.

The nightscape of New York also produces a sense of timelessness due to the distant viewpoint from which it was taken. There is no movement or change in this picture, despite the dynamism of the city below. As point sources of light, the city lights fill a similar role in this photo to that of the stars do above the Albertan signpost. But this structural similarity highlights the different notions of time these pictures communicate. The stars above the signpost frame decay and abandonment within the constantly changing natural world. The stillness of the city implies a false sense of permanence. The city lights appear fixed, and thus more permanent than the natural world. In truth this is a question of reference point, but it creates a complex commentary on the nature of time in cultural spaces.