Question

• How can the force of gravity apply to all objects?

Answer 1

Because earth has gravitational force thats why all objects have gravity

Answer 2

As per once said by Newton that gravity pulls things downwards apart from which direction. But then during the 20th century Albert Einstein came up with a new idea of a Time and Space fabric which covers all the universe as per as his special theory of relativity. And according to this fabric gravitation is created only by an object which consists of mass and every smaller objects relating to that large object will slide down the slope of curvature made in that fabric. As we think in real life the Earth is that giant object and we are those smaller masses.

And as you asked why it affects on all objects. It applies on all objects because all objects have that mass to fall in that curvature in space-time fabric.