Isotropy and anisotropy: When a material is attacked by a liquid or vapor etchant, it is removed isotropically (uniformly in. all directions) or anisotropic etching (uniformity in vertical direction).
Some Questions Do Remain: 1  If the Earth was flat, we could travel to the place where the Earth and sky met. But we canât. 2  If the Earth was flat, we could reach the place where we could reach out and touch the Sun. But we canât. 3  If the Earth was flat, we could fall off the horizon. But we donâ 4 t. If the Earth was flat, it would simply fall.
The Earth is an oblate spheroid. That is, it is roughly a sphere, but the speed of its rotation causes it to bulge out near the equator   Due to the tremendous size of the â¦earth, the laws of perspective, and the relative closeness to the surface of the earth that we typically use as our reference point, the earth appears flat to us.