Where do Earth's gravity come from?

[FireCat]

Here's a trick question for you all.
[del]OOPS!!! thewrongvine [/del]

Well, where do "mystery" Earth's gravity come from? As far as I understand gravity comes from mass. But that still does not explain where it comes from? hmm

And why can't we feel the earth move or rotate?

 

[Vellu]

First of all, gravity is one of the four interactions, and it's the weakest of them. Scientists are not 100% sure HOW gravity works and WHY. But it is known that an object with mass will pull an another object towards it. Gravity's also a two-way force, meaning that Object A (100 kg) and Object B (500 kg) pull each other closer at the same force. But Object A will move a lot more, because it has lower mass than Object B.

This also explains why black holes suck things. Black holes are collapsed "dead" stars which are extremely thick and high on mass.

So Earth pulls us down (and we pull it up) because of it's mass. Where does the gravity come from? Mostly from the metallic core of Earth.

Spoiler

Yay physics

 

[Sim]

Gravity comes from the influence 2 masses have between each other, not just from mass. In fact, you are currently attracting the planet with your own gravity... which is negligible.

We can't feel the earth move or rotate because force vectors are created by acceleration, not velocity. We are moving at very great speed, but what matters are force vectors, not speed. Since we are rotating around the sun, and around the center of the galaxy, there is still a small acceleration vector coming from the centripetal force, but it is neglected by the huge force called gravity we feel at any given moment.
Think about it, when you're in a bus which is moving very fast (let's say 50 mph on the highway), you have no problem standing up. You start having problems when the bus hits a bad spot on the road, or slows down, or turns, or accelerates even further (yay!). This stability is called velocity, and starts affecting matter when it nears the speed of light. Before that, it is negligible.

Naturally, the more speed (velocity) you have, the more affected by acceleration you are, but the velocity in itself does nothing, unless you are nearing the speed of light.

 

[Vellu]

So you want to go to quantum physics eh? I'm out.

PS. I just told OP what I was tought in school.

Spoiler

The rope can be any length

 

[FireCat]

So Earth pulls us down (and we pull it up) because of it's mass. Where does the gravity come from? Mostly from the metallic core of Earth.

Hmm well
One thing I found out that "gravity exists everywhere"

First, the most important thing to know is that gravity exists absolutely everywhere in the universe. Every bit of matter exerts a force on every other bit of matter. This means that you are attracted, and attract, everything in the universe! The force exerted depends on the distance of the object and the mass. The Earth exerts the most force on you because it is close (right here!) and very massive.

Forces add like vectors, so their direction is very important. If you could be at the exact center, the forces that each bit of Earth matter exerted on you would cancel out (up cancelling down, east cancelling west, etc.). This only occurs for a single point, though, and you would still feel a gravitational force on the rest of your body.

Remember, gravity is universal and exists everywhere. This is the fundamental law of physics.

 

[13lade619]

Mostly from the metallic core of Earth.

Nope..

AFAIK, Gravity does not 'come' from a single source.
In fact, gravity does not exist in a system with only a single object.

Gravity is a fundamental interaction and it exists between at least 2 objects with mass.

 

[The Helper]

FYI...

Spoiler: Why Gravity is NOT a Force