Here's why it's not always directly vertical:
* Earth isn't perfectly spherical: The Earth is slightly oblate, meaning it bulges at the equator. This means the center of mass isn't exactly at the center of the Earth's surface.
* Earth's rotation: The Earth's rotation creates a centrifugal force that slightly counteracts gravity, making it seem slightly weaker at the equator and stronger at the poles.
* Local variations: The Earth's crust has uneven density, and nearby mountains or underground mass concentrations can slightly deviate the direction of gravity.
So, while gravity generally acts vertically, it's more accurate to say that it acts towards the center of mass of the object, which may not be perfectly vertical due to the factors mentioned above.
However, for everyday purposes, we can usually approximate gravity as acting directly downwards due to the relatively small deviations.
