The gravitational force an object exerts on other objects is inversely proportional to the square of the distance. Hence if you move to twice the distance, the gravitational force falls to one quarter.

So, every single person is currently affected by the pull of even the distant galaxies and black holes. But this is quite hard to detect or feel anyway as everything else is affected too, and accelerates freely in those directions.

There’s the classic elevator thought game by Einstein – if you are in an elevator and you feel the floor pushing you up at more than one gee times your mass, you can not know if it’s gravity strengthening or the elevator perhaps accelerating up (or slowing down when traveling downwards). Gravity is indistinguishable from acceleration in that way. In a windowless space station, it would be impossible to detect gravity changes (if there were such things), as everything would simply accelerate where the gravity pulled. You couldn’t detect any changes as gravity would accelerate the station and all objects inside the station the same – their relative positions or forces between them would not change.

Low earth orbit works because things accelerate towards Earth at roughly 1 gee but they move constantly at 8 km/s so that the acceleration is perpendicular to the velocity (in circular orbits at least). If the Earth’s gravitational force was stopped, all the satellites and the space station would separate and fly in a straight line (or actually they’d start orbiting the sun).

With higher orbits (like geostationary) the lessening of gravity plays a more significant effect. But you still need to circle the earth.

At “Earth escape velocity” the object launched travels so fast that even when Earth’s gravity stretches to infinity, the object has so much speed that it will never stop or reverse. That is a hard concept to grasp and relates to the fact that the integral of 1/x² is finite. When going to other planets, Earth escape velocity is needed, at minimum. That’s 11.2 km/s.

If you want to get away from the solar system altogether, I think you need about 40 km/s (if you launch from Earth).

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