Photographer Julian Tryba sent us this crazy time-lapse of Boston which, actually, is not a time-lapse but a layer-lapse: The objects in each sequence—buildings, vehicles, the sky—run at different speeds and times than others. That's because he has layered them, animating each layer separately.
He explains how he did it:
Traditional time-lapses are constrained by the idea that there is a single universal clock. In the spirit of Einstein's relativity theory, layer-lapses assign distinct clocks to any number of objects or regions in a scene. Each of these clocks may start at any point in time, and tick at any rate. The result is a visual time dilation effect known as layer-lapse.