Is it true that there is a gravitational field everywhere in the known universe?
According to Newtonian gravity, gravitational force is -GMm/r^2. Any mass experiences a gravitational force toward every other mass in the universe, proportional to the product of their masses, and inversely proportional to the square of their distance. This means my body experiences a certain gravitational force from the sun, no matter what else is happening in the universe. That says it would be impossible to shield me from the sun’s gravity. To find the net gravitational force on me, simply do a vector sum of all the gravitational forces on me from all other masses in the universe. Simple to say, not so simple to do. That sum is zero at the center of mass of the universe, wherever that is. Unless the expansion of the universe is perfectly uniform, that point will shift with time. I could find other points where the sum is zero. I move away from that center of mass but toward a large nearby mass, just close enough that the pull of that nearby mass exactly balances the pull of the res
