Action-at-a-distance and force fields are opposing hypotheses. Speaking of a magnet, Einstein says "we have come to regard action at a distance as a process impossible without the intervention of some intermediary medium." It is not the case "that the magnet acts directly on the iron through the intermediate empty space, but . . .that the magnet always calls into being something physically real in the space around it, that something being what we call a “magnetic field.” In its turn this magnetic field operates on the piece of iron . . ." He makes a similar case for gravity.
Is saying matter "produces in its surroundings a gravitational field" less magic than saying "gravity is an attribute of matter"?
The field hypothesis requires time and is not instantaneous. The attribution hypothesis assumes gravity is coexistent with matter and is instantaneous.

• The velocity of gravity has been measured. - duordi - April 24, 2003 - 16:49 UTC
  • Gravitational displacement - jetty - April 26, 2003 - 05:37 UTC
    • The infinite gravity velocity game. - duordi - April 26, 2003 - 18:58 UTC