It surprised me recently when I realised that so many people didn't know very much about gravity at all. Even my freind Luke, who's very good at general science thought it only came from planets. As the title suggests, however, that is very wrong.
The point is, all mass has gravity. Everything you can see and some things you can't. A particle of H2O. A polar bear. And, yes, your face. With gravity, though, size really does matter. The bigger something is, the stronger its gravitational pull, and this is why you don't feel the gravity from your face, or a polar bear or a particle of H2O - your face is attached to you anyway, so it contributes to your internal gravity, a polar bear is very far away, so (assuming you don't live in the artic circle) is to distant to have any effect, and a particle of H2O is far too tiny to pull you (in fact, you would pull the H2O!)
Here's the sciencey bit.
There are four dimensions - up-down, left-right, forwards-backwards and time.
Combined, these make space-time and we are all moving 'through' space and 'along' time right now. In order to help you comprehend this incomprehensible dimension of space-time and the effect that mass has on it, i have an analogy originaly devised my Marcus Chown.
Imagine an ant on a trampoline. All it ever sees is left-right and forwards-backwards, there's nothing for it to climb up. Then imagine you put a connonball in the centre in the middle of the trampoline and the ant suddenly slides in, down the curve. "wow!" says ant "I can go up and down aswell!". Even though he can't talk and never really said that, he's suddenly realised a new dimension that he would never normaly be able to see.
Well space-time is our unseen dimension, we are the ant and planet earth is our cannonball. We are pulled towards the earth because it's obviously very close, it's evidently very large and there's clearly nothing near and big enough to pull us away.
That's how gravity works, the bigger something is, the more mass it has and the stronger its gravitational pull. The closer something is, the closer its curve in space-time is and the more control it has over you.
Everything has gravity. Except waves (like sound, not sea).
The point is, all mass has gravity. Everything you can see and some things you can't. A particle of H2O. A polar bear. And, yes, your face. With gravity, though, size really does matter. The bigger something is, the stronger its gravitational pull, and this is why you don't feel the gravity from your face, or a polar bear or a particle of H2O - your face is attached to you anyway, so it contributes to your internal gravity, a polar bear is very far away, so (assuming you don't live in the artic circle) is to distant to have any effect, and a particle of H2O is far too tiny to pull you (in fact, you would pull the H2O!)
Here's the sciencey bit.
There are four dimensions - up-down, left-right, forwards-backwards and time.
Combined, these make space-time and we are all moving 'through' space and 'along' time right now. In order to help you comprehend this incomprehensible dimension of space-time and the effect that mass has on it, i have an analogy originaly devised my Marcus Chown.
Imagine an ant on a trampoline. All it ever sees is left-right and forwards-backwards, there's nothing for it to climb up. Then imagine you put a connonball in the centre in the middle of the trampoline and the ant suddenly slides in, down the curve. "wow!" says ant "I can go up and down aswell!". Even though he can't talk and never really said that, he's suddenly realised a new dimension that he would never normaly be able to see.
Well space-time is our unseen dimension, we are the ant and planet earth is our cannonball. We are pulled towards the earth because it's obviously very close, it's evidently very large and there's clearly nothing near and big enough to pull us away.
That's how gravity works, the bigger something is, the more mass it has and the stronger its gravitational pull. The closer something is, the closer its curve in space-time is and the more control it has over you.
Everything has gravity. Except waves (like sound, not sea).
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