If the earth is a sphere, as we walk on its surface, are we constantly walking imperceptibly uphill, or imperceptibly downhill? Or something else?

Question

My family members say you’re walking downhill from the north pole to the equator, and uphill going the opposite way, but that doesn’t make sense, because you’re still walking along an arc on the sphere. I’ve stared and stared and stared at this baseball in my hand, but can’t figure it out.

In: Physics

Answer 1

Walking from pole to equator, you’re walking uphill because the Earth is spheroid, fatter at equator than pole. So your distance from center of Earth would be larger at sea level at equator than sea level at pole.