[OAB 56] In a paper published in a young-Earth journal (Creation Research Society Quarterly, v.20, pp.105-108 (Sept 1983)), former young-Earth advocate Glenn R. Morton attempted to calculate the time it would take for lunar craters to be erased by the slow flow of rock. The central parameter in the calculation is the viscosity of the rock (its resistance to flow). As a rock's temperature approaches its melting point, its viscosity becomes low enough (although still a trillion trillion times higher than that of honey) for some flow to be observed over long time periods. This phenomenon allows, for example, convection in the Earth's mantle, which is crucial to Plate Tectonics, and in turn to many geophysical processes. Viscous flow can also be observed in many other solids, from glass to Silly Putty, but always at temperatures that are rather close to the melting point of the solid. Morton attempted to apply this process to rocks on the surface of the Moon. However, by failing to understand viscosity's extreme dependence on temperature, he grossly underestimated the viscosities of lunar rocks. Morton assumed that the viscosity of the Moon's surface rocks would be comparable to the highest measured rock viscosities (those of Earth's mantle). However, since a rock's viscosity increases exponentially as its temperature falls (and the Earth's mantle is very hot while the Moon is very cold), the viscosities of moon rocks are exponentially higher than the viscosities in Earth's mantle. In fact, moon rock viscosities are so high that they are practically infinite, meaning that no flow will occur (i.e., rocks are more likely to break or fracture than to flow). Since the flow of rock is basically impossible at the temperatures that exist on the Moon's surface, there will be no relaxation of lunar craters, and thus no problem with the age of the Moon.