This is a mobile that should resemble the cosmos. The four hanging bars are from middle to outside mercury, venus, earth and mars in correct ratio and distance to each other. It is a symbol of the sameness and infinite repetition of life, universe and everything, causing a kind of nausea in the person whom is reflecting on it.

The mere narcotizing effect which cosmic forces have on a shallow and brittle personality is attested in the relation of such a person to one of the highest and most genial manifestations of these forces: the weather. Nothing is more characteristic than that precisely this most intimate and mysterious affair, the working of the weather on humans, should have become the theme of their emptiest chatter. Nothing bores the ordinary man more than the cosmos. Hence, for him, the deepest connection between weather and boredom. How fine the ironic overcoming of this attitude in the story of the splenetic Englishman who wakes up one morning and shoots himself because it is raining. Or Goethe: how he managed to illuminate the weather in his meteorological studies, so that one is tempted to say he undertook this work solely in order to be able to integrate even the weather into his waking, creative life.

Benjamin, Walter: The Arcades Project, [D1,3], 1982

It can be looked at when it is raining outside.