What is Gravity: Learn How It Attracts Objects

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Discussion Overview

The discussion revolves around the concept of gravity, specifically how it attracts objects and the nature of gravitational forces. Participants explore theoretical models, mathematical formulations, and the implications of mass in relation to gravity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants express uncertainty about the nature of gravity, noting that current theories model it as a curvature of spacetime influenced by mass.
  • One participant suggests that gravity is a pull from the Earth's mass and that all objects, including humans, possess gravity based on their mass.
  • There is mention of the gravitational equation GM*m/r, with some participants discussing its components and implications for calculating gravitational strength.
  • Another participant points out the distinction between the force of gravity and acceleration due to gravity, suggesting that the terms may refer to different concepts in the context of the discussion.
  • Clarifications are made regarding the use of variables in gravitational equations, particularly the roles of small m and big M in calculations.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the nature of gravity, with multiple competing views and interpretations of gravitational concepts remaining present throughout the discussion.

Contextual Notes

Some statements rely on assumptions about the definitions of gravity and its mathematical representation, which are not universally agreed upon. The discussion includes unresolved questions about the application of gravitational equations in different contexts.

Who May Find This Useful

Individuals interested in the theoretical and mathematical aspects of gravity, as well as those seeking clarification on gravitational concepts and equations.

nathankco
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I want to know what's gravity. <:D
How's it attract objects?
Anything that are massive and dense consist gravity?
 
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We don't really know.

Current theory models gravity as a curvature of spacetime. Objects follow null geodesics (fancy phrase for 'straight lines') through this curved space so that, to our eyes, they appear to curve (like how a baseball curves back toward the ground).

It is the presence of mass that curves space, so anywhere there is mass (even the smallest atom), there will be some curvature of spacetime.

Mass tells spacetime how to curve; spacetime tells mass how to move.


There are a gazillion PF threads on the this topic for the reading.
 
nathankco said:
I want to know what's gravity. <:D
How's it attract objects?
Anything that are massive and dense consist gravity?

Gravity is a pull from the Earth's mass.

Everything has gravity EVEN YOU. We try to attract things by our Gravitational field.

The more your mass the stronger gravational field.

Hence the reason why the moons gravity is less than the Earth's.

The equation to this is GM*m / r

GM is a gravitational constant m is the mass r is radius from center.

So for ex if you want to find your gravitational strength you muliply the constant (I forgot it) by you mass in Kg devided by how far the object is from you in m.
 
brno17 said:
Gravity is a pull from the Earth's mass.
Or anything else.
brno17 said:
The equation to this is GM*m / r
F = G . m/r^2

(And you only need M and m if you are figuring total force between two objects)
 
Thankyou guys! Thankyou!
 
DaveC426913 said:
F = G . m/r^2
You left out M.
(And you only need M and m if you are figuring total force between two objects)
What do you mean by 'total force'? As opposed to what?
 
Gravity can mean force of gravity or acceleration due to gravity. I think that's what Dave is getting at. Though, usually the little m is the one reserved for test mass, and big M is used for body generating the pull.

Naturally, if two masses are comparable, you cannot use this formula directly.
 

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