Assume(s) that the expansion rate of the universe always stays the same. predict(s) that the universe is expanding today. predict(s) that the universe will someday contract. predict(s) that the average density of mass in universe is exactly the critical density. predict(s) that the universe is expanding faster now than it was in the distant past.

The coasting model assumes that the expansion rate of the universe always stays the same. All four models (coasting, recollapsing, critical, and accelerating) predict that the universe is expanding today. Recollapsing model predicts that the universe will someday contract. The critical model predicts that the average density of mass in universe is exactly the critical density. The accelerating model predicts that the universe is expanding faster now than it was in the distant past.

Mantle convection is the process that drives plate tectonics. the theory of plate tectonics states that the crust is divided into plates that float on the semi molten mantle below. the circular motion of the magma as it slowly rises and falls or move though convection cells drags the plates along causing them to move. the heat source in the lamp would represent the earth's core. the core is the source of energy that drives convection in the mantle. the lava represents molten magma under the earth's surface. if the lava lamp had floating pieces they would move as the circular motion of the lava in the lamp as it rises and falls would move them along the surface. these floating pieces would represent pieces of the earth's crust.