Does gravity push or pull us?


Does gravity push or pull us?

In: Physics

It depends on your frame of reference. If you are standing holding a ball straight out and drop it, it accelerated towards earth according to your frame of reference. If your frame of reference is planetary in scale, the ball actually *slowed down* until it smacked the earth. In other words, the earth ‘caught up to it’.

Einstein’s genius was showing that the effects of gravity are entirely dependent on your frame of reference. Specifically, a non-accelerating frame of reference. If you are in a box in space and you are blasted at 1 G using a rocket, the feeling is exactly the same as if someone had attached a winch to the top of the box and pulled you along at 1 G of acceleration.

Depending on the context of the conversation, it is worth asking ‘what frame of reference are we talking about’. It would be confusing to explain to a 10 year old that really you are pressing up against the air (to create air pressure) instead of it pressing against you – even though that explanation is correct. The issue I have, is explaining it the way it is popularly explained, causes much consternation when you start actually learning physics. You have to break apart the way we understand the world with our subjective experiences and look at them a little differently. That is easier to do if we don’t teach simple physics first.

Gravity neither pushes nor pulls. Gravity is not a force. It’s not a cause. It is an effect.

Mass warps the space around it, like a lens. If something passes by, going in a straight line, its path changes shape, curving through the lens.

The object is still going straight along its path. It is only the path that bent.

When the path curves, it looks as if the object is being shoved (or pulled) sideways. It feels like a force has acted on it. It FEELS like the object has been pulled (or shoved).

But no force was applied. All that changed was the geometry of the path.

Neither. But for simplicity sake, we’ll say that it pulls. Large objects pull other objects towards themselves.

I’m not quite familiar with this stuff, so I can’t sufficiently simplify the real answer.