As I learned in high school physics class, every movement causes a reaction to whatever object the force is applied against. If I am born in one place and walk

As I learned in high school physics class, every movement causes a reaction to whatever object the force is applied against. If I am born in one place and walk further East or West before I die, my movement will have some infinitesimal affect on the Earth's rotation. We once had to work out a story problem about how a million people walking eastward for X number of miles would affect the rotation. The answer had many, many leading zeros to the right of the decimal point, if memory serves.