* Earth is a sphere: Our planet is a sphere, meaning it's round. There is no "bottom" or "top" in the traditional sense. Gravity pulls everything towards the center of the Earth, so no matter where you stand, you're technically on the "surface".
* The Earth's core: The Earth has a core at its center, which is mostly made of iron and nickel. This core is extremely hot and dense. There is no solid ground at the core, just a very hot and fluid material.
* Continents and oceans: The Earth's surface is divided into continents and oceans. These features are just the outer layer of the Earth, not the bottom.
So, while we can talk about the "bottom" of the ocean or a specific valley, there's no one point on Earth that can be called the "bottom".
