Significance of Gravitational force

In summary: I'm sorry, I am unable to find a summary for this conversation as it is a mix of different discussions and questions. Could you please clarify which part you would like me to summarize?
  • #1
paras02
31
0
Hello friends !
I got confused in the point that how can a body exert a gravitational force on other body without coming in its physical contact ? Also please explain its mechanism or significance of gravitational force ?
 
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  • #2
welcome to pf!

hello paras02! welcome to pf! :smile:

in Newtonian physics: same way an electric charge can exert a force on another charge without contact … by a field

in einsteinian physics: there is no force, there is only the "warped" geometry of space-time :wink:
 
  • #3
Sorry I am unable to understand the answer given by you. Kindly clarify the question in more simple words.
 
  • #4
paras02 said:
Sorry I am unable to understand the answer given by you. Kindly clarify the question in more simple words.

The simplest answer is "we don't know." We don't know why. What physicists have are equations that enables them/us to predict what matter will do.
 
  • #5
you may be corect but I am still not satisfied
 
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  • #6
OK, so you're not satisfied. Sorry about that.
 
  • #7
Physics is not about "why", it describes "how". Sometimes, the level of "how" is so deep that it looks like a reason, but it is just a more fundamental description how.
"Why" is something for philosophy.
 
  • #8
Faraday pictured a way how to visualise 'action at a distance' by using the idea of a 'field'.
 
  • #9
sorry ! but science is based on proofs not on facts
 
  • #10
paras02 said:
[..] how can a body exert a gravitational force on other body without coming in its physical contact ? Also please explain its mechanism or significance of gravitational force ?
tiny-tim said:
[..] in Newtonian physics: same way an electric charge can exert a force on another charge without contact … by a field

in einsteinian physics: there is no force, there is only the "warped" geometry of space-time :wink:
That is in fact Einsteinian mathematics. Just as in Newtonian physics, in Einsteinian physics the effect is described with a gravitational field. That implies that something physical exists in vacuum that mediates the effect. However, we still don't know much about its "mechanism" (perhaps something for the Quantum forum?).

As this is the classical forum, do you want to know "classical" explanations such as by Newton?
 
  • #11
paras02 said:
sorry ! but science is based on proofs not on facts

No, the only proofs that exist are mathematical proofs. I like wikipedia's definition of a fact:

A fact (derived from the Latin factum, see below) is something that has really occurred or is actually the case. The usual test for a statement of fact is verifiability, that is whether it can be proven to correspond to experience. Standard reference works are often used to check facts. Scientific facts are verified by repeatable experiments.

Science is based on empirical evidence being gathered and explained using models, which are themselves based on scientific theories. A scientific theory is:

"a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment."[1][2] Scientists create scientific theories from hypotheses that have been corroborated through the scientific method, then gather evidence to test their accuracy. As with all forms of scientific knowledge, scientific theories are inductive in nature and do not make apodictic propositions; instead, they aim for predictive and explanatory force.

For example we explain gravity in classical physics as a force, where the magnitude of the force is based on a mathematical formula. This has been verified as being accurate to a very high degree, and only General Relativity is able to predict things more accurately, which is why it is now considered the modern theory of gravity. The fact that gravity acts at a distance, while surprising to many, is nothing special. ALL forces act through a distance. Nothing ever actually "touches" anything else the way you imagine it when you get down to the very small scale of atoms and molecules. Atoms and molecules themselves are not even solid objects. (In the normal everyday sense of "solid" that most people think of)
 
  • #12
paras02 said:
sorry ! but science is based on proofs not on facts

Science is based on facts. Mathematical relations that have been proved under certain assumptions may be used. But scientists can't prove that those assumptions are correct.

So natural science can never really prove anything. It's pragmatic: things are used because they work, or not used because they don't work.
 
  • #13
Drakkith said:
No, the only proofs that exist are mathematical proofs. I like wikipedia's definition of a fact:

A fact (derived from the Latin factum, see below) is something that has really occurred or is actually the case. The usual test for a statement of fact is verifiability, that is whether it can be proven to correspond to experience. Standard reference works are often used to check facts. Scientific facts are verified by repeatable experiments.

Science is based on empirical evidence being gathered and explained using models, which are themselves based on scientific theories. A scientific theory is:

"a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment."[1][2] Scientists create scientific theories from hypotheses that have been corroborated through the scientific method, then gather evidence to test their accuracy. As with all forms of scientific knowledge, scientific theories are inductive in nature and do not make apodictic propositions; instead, they aim for predictive and explanatory force.

For example we explain gravity in classical physics as a force, where the magnitude of the force is based on a mathematical formula. This has been verified as being accurate to a very high degree, and only General Relativity is able to predict things more accurately, which is why it is now considered the modern theory of gravity. The fact that gravity acts at a distance, while surprising to many, is nothing special. ALL forces act through a distance. Nothing ever actually "touches" anything else the way you imagine it when you get down to the very small scale of atoms and molecules. Atoms and molecules themselves are not even solid objects. (In the normal everyday sense of "solid" that most people think of)

i agree
 
  • #14
Thank you guys
 

1. What is the significance of the gravitational force?

The gravitational force is the force of attraction between two objects with mass. It is responsible for keeping planets in orbit around the sun, objects grounded on Earth, and the formation of galaxies. Without it, the universe as we know it would not exist.

2. How does the gravitational force affect our daily lives?

The gravitational force plays a significant role in our daily lives. It keeps us grounded on Earth, gives us our weight, and allows us to walk and move objects. It also affects the tides, weather patterns, and the rotation of the Earth.

3. What is the formula for calculating the gravitational force?

The formula for calculating the gravitational force is F = G * (m1 * m2)/r^2, where G is the gravitational constant, m1 and m2 are the masses of the two objects, and r is the distance between them.

4. How does the strength of the gravitational force vary?

The strength of the gravitational force varies depending on the masses of the objects and the distance between them. The force increases as the mass of the objects increases and decreases as the distance between them increases.

5. Can the gravitational force be shielded or canceled out?

The gravitational force cannot be shielded or canceled out. It is a fundamental force that exists between all objects with mass. However, its effects can be counteracted by other forces, such as the centrifugal force or the electromagnetic force.

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