serious question about the world

Ddaddy said
It extends as far away in light-years as the earth is old. And farther, if you include the various things that eventually coalesced into the earth.

So the earth’s gravitational field is approximately a sphere about 4.5 billion light-years in radius.

you're assuming gravity is limited by the speed of light.

Treblig said
Well............... you were close......The distance at which Earth's gravity is "zero" is dependent on the mass of the object that is trying to free itself from Earth's gravitational force. The greater the mass the further away the object must be. So, something "light" like a feather doesn't need to be nearly as far as something that weighes millions of tons.
Of course we're taking into account the "orbiting" speed, which changes the equation completely!!!

It's all relative!!!!!!!!!
treblig (The Science Guy)

I was not postulating how far away something could be to not fall back to earth, just that the effects are felt to the edge of the universe. Gravity is a force, without mass, so even though earth is 4.5 Bn years old, the gravitational effects would be theoretically measured, infinitesimally, out at the edge. Other objects with greater mass would mitigate some of the effects but the force itself, would be felt way farther than is measurable to us.