What is the Science Behind Gravity and Its Universal Acceleration?

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Discussion Overview

The discussion revolves around the nature of gravity, its mechanisms, and why objects experience the same acceleration due to gravity. Participants explore various theories, including personal hypotheses and established scientific models, while questioning the fundamental reasons behind gravitational attraction.

Discussion Character

  • Exploratory
  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant suggests that gravity is a result of the Earth being an "electron reserve" that attracts masses due to their positive protons, questioning why all objects fall at the same rate.
  • Another participant explains that the acceleration due to gravity is constant because the increased gravitational force on a more massive object is balanced by its greater inertia, leading to the same acceleration for all objects.
  • Some participants argue that gravity is not a force but rather the curvature of space-time, as described by Einstein's general relativity, and express uncertainty about why mass curves space.
  • There is a mention that the question of why gravity exists may not even be a scientific question, highlighting the mysterious nature of gravity.
  • One participant emphasizes that personal theories are not permitted in the forum, reinforcing the focus on mainstream scientific understanding.

Areas of Agreement / Disagreement

Participants express a range of views on the nature of gravity, with some supporting established scientific models while others propose personal theories. There is no consensus on the fundamental reasons behind gravitational attraction, and the discussion remains unresolved.

Contextual Notes

Some claims rely on interpretations of general relativity and Newtonian physics, with participants noting the limitations of current understanding regarding the fundamental nature of gravity.

Sam Ku.D
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I have been wondering about this for a while! What exactly is GRAVITY? How does it work?? How are things pulled towards the earth? or any other mass??
So I came up with a kind of a theory about this! If you don't mind!
As you know the Earth is a huge electron reserve. As every matter is made up of protons and electrons! Right? My suggestion is that the Earth attracts other masses as there is a force of attraction between the Earth(electron reserve) and the mass as every mass contains positively charged protons. But the problem is, why do every things have the same acceleration due to gravity? Its 9. something right? why is it the same?
So I would be very glad if you could give your own opinions about this! And correct me if I am wrong! And tell me what Gravity is in your opinion!
Thank you
~ Sam Ku.D~
 
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Sam Ku.D said:
But the problem is, why do every things have the same acceleration due to gravity?

Welcome to PF :wink:
https://www.physicsforums.com/showthread.php?p=2211980#post2211980 explains why acceleration of gravity is a constant.

And for the Gravity's reality, I think This article from Wikipedia explains How gravity actually work.
 
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but why are masses attracted towards one another? O.o
 
Sam Ku.D said:
but why are masses attracted towards one another? O.o

I don't think anybody knows. According to Einstein's general relativity, gravity isn't even a "force" that attracts or repels or anything. It's the curvature of space, which is caused by the presence of mass.
Why does mass curve space? I don't think anybody knows that either.
 
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as u have known, most of masses is neutral,because they have the same amount of protons and electrons.so, what i want say is that maybe u must give up your opinion. if you had learned universal gravitation, u would find the reason is the mass itself. if u want to know the deeper reason, maybe u should learn something about relativity theory.
 
Sam Ku.D said:
I have been wondering about this for a while! What exactly is GRAVITY? How does it work?? How are things pulled towards the earth? or any other mass??

The basics of gravity can be found on plenty of websites online. Wikipedia is a good place to start.

So I came up with a kind of a theory about this! If you don't mind!
As you know the Earth is a huge electron reserve. As every matter is made up of protons and electrons! Right? My suggestion is that the Earth attracts other masses as there is a force of attraction between the Earth(electron reserve) and the mass as every mass contains positively charged protons.

First, please be aware that personal theories are not allowed here at PF per the rules. The forum exists to teach people about current mainstream science, not to discuss non-mainstream theories from either amateurs or professionals.

That being said, your idea is not correct. Gravitation is not due to any "electron reserve". The Earth is, on average, very close to electrically neutral and would not experience any attraction or repulsion.

But the problem is, why do every things have the same acceleration due to gravity? Its 9. something right? why is it the same?

Consider two objects, A and B. A has 1 kg of mass while B has 2 kg's of mass. The force of attraction from the Earth's gravity on object B is twice as much as A because it has twice the mass. However, this added mass also has twice the inertia and will be harder to accelerate. The increased attraction from gravity and the increased resistance to acceleration exactly cancel each other out so that all objects accelerate at the same rate.

You can easily see this by plugging in numbers to the equation F=MA.
Rearrange to A=F/M and you can see that if F doubles and M doubles, then A MUST remain the same since no matter what you plug into F and M the ratio is always the same.
 
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Drakkith said:
Consider two objects, A and B. A has 1 kg of mass while B has 2 kg's of mass. The force of attraction from the Earth's gravity on object B is twice as much as A because it has twice the mass. However, this added mass also has twice the inertia and will be harder to accelerate. The increased attraction from gravity and the increased resistance to acceleration exactly cancel each other out so that all objects accelerate at the same rate.

You can easily see this by plugging in numbers to the equation F=MA.
Rearrange to A=F/M and you can see that if F doubles and M doubles, then A MUST remain the same since no matter what you plug into F and M the ratio is always the same.
A very nice example.That was pretty understandable for a secondary student.:smile:
 
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Drakkith said:
.
Consider two objects, A and B. A has 1 kg of mass while B has 2 kg's of mass. The force of attraction from the Earth's gravity on object B is twice as much as A because it has twice the mass. However, this added mass also has twice the inertia and will be harder to accelerate. The increased attraction from gravity and the increased resistance to acceleration exactly cancel each other out so that all objects accelerate at the same rate.

You can easily see this by plugging in numbers to the equation F=MA.
Rearrange to A=F/M and you can see that if F doubles and M doubles, then A MUST remain the same since no matter what you plug into F and M the ratio is always the same.

agreed! :biggrin:
 
adjacent said:
I don't think anybody knows. According to Einstein's general relativity, gravity isn't even a "force" that attracts or repels or anything. It's the curvature of space, which is caused by the presence of mass.
Why does mass curve space? I don't think anybody knows that either.
More accurately, it's curvature of space-time. This is an important detail. The concept as I understand it, which is not hugely, is that a component of the object's movement along its time axis appears to an observer to be acceleration in a spatial dimension. This immediately explains why inertial mass and gravitational mass should be always in proportion (the remarkable coincidence which led Einstein to his theory).
 
  • #10
This might be a little aside from the topic, but gravity is deeply mysterious. The question "why does gravity exist" isn't even considered a scientific question. When a raindrop falls, it doesn't even experience acceleration due to gravity because of its buoyant force.
 
  • #11
haruspex said:
More accurately, it's curvature of space-time...

In Einstein's model it's curvature of space-time. But this is just a model, just as "gravity is a force" is part of Newton's model. No one knows *exactly* what gravity is, and they might never know. How could you ever know that you had the final answer?
 
  • #12
Drakkith said:
First, please be aware that personal theories are not allowed here at PF per the rules. The forum exists to teach people about current mainstream science, not to discuss non-mainstream theories from either amateurs or professionals.
Drakkith is correct, this thread is closed.
 
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