For Ockham, a demonstration arising from natural efficient causes takes the following pattern: "When there is no opaque medium between the moon and the sun, the moon will be illuminated by the sun, when the moon is in such a place, there will be no opaque medium between the moon and the sun; therefore the moon is then illuminated".
Once it was on the ground, the moon was a pockmarked, sandy boulder, so dull and opaque that it was incredible to think that it had once illuminated the sky with its shining reflection.
There is an analogy between the earth and the moon based on the fact that both are large, solid, opaque, spherical bodies, receiving heat and light from the sun, revolving around their axes, and gravitating towards other bodies.
Unlike the physical obstacles to reaching the moon, the physiological causes of obesity and their remediation are more opaque: In theory it's all about calorie consumption vs. expenditure; in practice, it's not quite so simple.
Before the arrival of Voyager 1 in 1980, Titan was thought to be slightly larger than Ganymede (diameter 5262 km) and thus the largest moon in the Solar System; this was an overestimation caused by Titan's dense, opaque atmosphere, which extends many kilometres above its surface and increases its apparent diameter.
They are sometimes similar to altostratus and are distinguishable from the latter because the sun or moon is always clearly visible through transparent cirrostratus, in contrast to altostratus which tends to be opaque or translucent.
Ernst's bizarre painting Max Ernst Showing a Young Girl the Head of his Father, with its sinister nursery moon, the young figures below all shock-haired and staccato, has always seemed (to me at least) remarkably opaque.
