<p>The semantic meaning of the term force is now quite confusing.  Perhaps, it has always been.  We still say the four forces of nature are the weak force,the strong force, electromagnetism, and gravity.  (Or, the three forces are electroweak, strong, and gravity.) So, gravity is a force of nature.</p>
<p>It is often useful, when solving problems, to define a force by <span class="math-container">$\vec{F} = m\vec{a} = m\frac{d\vec{v}}{dt}$</span>, and gravity still causes 3d velocity vectors to change.  Astrophysicists commonly use the term force in this way when describing gravitational effects. But it is understood that, in the theory of General Relativity, the change in velocity happens indirectly by the bending of space which makes trajectories curved in 3-space.</p>
<p>However, in some quantum gravity theories, gravity is an interaction mediated between particles by gravitons and is not a bending of space time.  It therefore could be, fundamentally, a force.  In other words, we don't know yet.</p>

CC BY-SA 4.0
2024-05-07T16:26:01.470Z
You left out the Pauli force. It must be quite confusing to you to be stuck on Earth's surface ツ
John Doty
CC BY-SA 4.0
2024-05-08T16:02:52.497Z
@JohnDoty  Yes. How exactly the anti-symmetric wavefunction of fermions results in a force is confusing, as is all of quantum mechanics.
eshaya
CC BY-SA 4.0
2024-05-08T16:14:54.387Z
I don't find it particularly confusing theoretically, and in any case that part of the theory emerges from simple, everyday, concrete observations of matter.
John Doty
CC BY-SA 4.0
2024-05-05T14:45:55.700Z
2024-05-07T04:57:16.800Z
2024-05-07T04:57:16.800Z
eshaya
<p>It is considered as force in Newtonian physics, which's property is to attract objects which are smaller. But in modern time , According to Einstein's General Relativity theory, gravity is defined as bending of space-time. Objects curls the space-time with it's mass resulting bending of space-time and object that are in contact with that object will get closer due to the bending.</p>

CC BY-SA 4.0
2024-05-05T17:23:40.770Z
*"which's property is to attract objects which are smaller. "* What do you mean? In Newtonian physics, the gravitational force exerted by the Earth on you has the same magnitude (but opposite direction) as the gravitational force that you exert on the Earth.
PM 2Ring
CC BY-SA 4.0
2024-05-05T06:10:02.067Z
2024-05-05T06:10:02.067Z
N.N das
<p>Energy (and mass) &quot;suck&quot; spacetime (I don't think that &quot;warps&quot; conveys the picture well). It creates an inward flow of spacetime, which is an elastic fabric. A smaller object (small mass) interacts with a bigger object being pulled by the stronger flow. Elasticity of spacetime means that if you disturb it, it stores energy (like a compressed spring), so disturbances reach equilibrium as &quot;forces&quot; counteract. So, masses do attract each other, keeping both Newton and Einstein happy, except that Einstein's model allows for disturbances traveling through spacetime.</p>

CC BY-SA 4.0
2024-05-19T22:19:13.903Z
2024-05-19T22:19:13.903Z
R. Castro
<p>A force gauge is one of the simplest physical instruments to construct and use. Such instruments are the true foundations of physics. Despite the vanities of theorists, mathematical abstractions are not fundamental: they are stories we tell about measurements using things like force gauges. Since you can measure gravity with a force gauge, it must be considered a force.</p>
<p>The &quot;four forces&quot; story is kind of a mess. You can't measure the strong or weak nuclear forces with a normal force gauge, although it is perhaps reasonable to generalize the notion to include the subatomic processes used to probe these. The commonality of electromagnetism and nuclear forces is the microscopic abstraction that relates these to bosonic fields, so there are some who have redefined &quot;force&quot; in bosonic terms. That's problematic for gravity: although it superficially looks like it might be modelable as a bosonic field, there is no successful bosonic model of gravity. And then there's the leptonic <a href="https://en.wikipedia.org/wiki/Pauli_exclusion_principle#Stability_of_matter" rel="nofollow noreferrer">Pauli force</a> that keeps you from falling through your chair: easily measurable with a force gauge, but not one of the bosonic forces.</p>

CC BY-SA 4.0
2024-05-05T19:14:55.833Z
2024-05-05T19:14:55.833Z
John Doty
<p>If gravity is just the result of the bending of space-time, how does that make it a force? Isn’t it just an interaction between celestial bodies?</p>

CC BY-SA 4.0
2024-05-05T05:18:17.950Z
What do you mean "it's a force"?   a "force" is part of the model of Newtonian mechanics.  All "forces" are interactions of bodies. In the model of GR, gravity is an interaction of mass/energy with spacetime.  These are different ways of describing.  They are models of reality.
James K
CC BY-SA 4.0
2024-05-05T07:49:29.950Z
There are several questions on this topic on our sister site. Here's a recent one: https://physics.stackexchange.com/q/811815/123208 & an old one https://physics.stackexchange.com/q/3009/123208
PM 2Ring
<gravity><space-time>
How is gravity a force if it is the result of space-time warping and bending?
Prince Pugs
# How is gravity a force if it is the result of space-time warping and bending?

(Asked by: username_0 on 2024-05-05)

If gravity is just the result of the bending of space-time, how does that make it a force? Isn’t it just an interaction between celestial bodies?

**Tags:** gravity, space-time

> **Comments:**
> **username_1**: What do you mean "it's a force"?   a "force" is part of the model of Newtonian mechanics.  All "forces" are interactions of bodies. In the model of GR, gravity is an interaction of mass/energy with spacetime.  These are different ways of describing.  They are models of reality.  
> **username_2**: There are several questions on this topic on our sister site. Here's a recent one: https://physics.stackexchange.com/q/811815/123208 & an old one https://physics.stackexchange.com/q/3009/123208  

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## 4 answers

### Answer by username_3 on 2024-05-05. Score: 3 | Accepted answer

The semantic meaning of the term force is now quite confusing. Perhaps, it has always been. We still say the four forces of nature are the weak force,the strong force, electromagnetism, and gravity. (Or, the three forces are electroweak, strong, and gravity.) So, gravity is a force of nature.

It is often useful, when solving problems, to define a force by $\vec{F} = m\vec{a} = m\frac{d\vec{v}}{dt}$, and gravity still causes 3d velocity vectors to change. Astrophysicists commonly use the term force in this way when describing gravitational effects. But it is understood that, in the theory of General Relativity, the change in velocity happens indirectly by the bending of space which makes trajectories curved in 3-space.

However, in some quantum gravity theories, gravity is an interaction mediated between particles by gravitons and is not a bending of space time. It therefore could be, fundamentally, a force. In other words, we don't know yet.

> **Comments:**
> **username_4**: You left out the Pauli force. It must be quite confusing to you to be stuck on Earth's surface ツ  
> **username_3**: @JohnDoty  Yes. How exactly the anti-symmetric wavefunction of fermions results in a force is confusing, as is all of quantum mechanics.  
> **username_4**: I don't find it particularly confusing theoretically, and in any case that part of the theory emerges from simple, everyday, concrete observations of matter.  

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### Answer by username_5 on 2024-05-05. Score: -2

It is considered as force in Newtonian physics, which's property is to attract objects which are smaller. But in modern time , According to Einstein's General Relativity theory, gravity is defined as bending of space-time. Objects curls the space-time with it's mass resulting bending of space-time and object that are in contact with that object will get closer due to the bending.

> **Comments:**
> **username_2**: *"which's property is to attract objects which are smaller. "* What do you mean? In Newtonian physics, the gravitational force exerted by the Earth on you has the same magnitude (but opposite direction) as the gravitational force that you exert on the Earth.  

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### Answer by username_6 on 2024-05-19. Score: -2

Energy (and mass) "suck" spacetime (I don't think that "warps" conveys the picture well). It creates an inward flow of spacetime, which is an elastic fabric. A smaller object (small mass) interacts with a bigger object being pulled by the stronger flow. Elasticity of spacetime means that if you disturb it, it stores energy (like a compressed spring), so disturbances reach equilibrium as "forces" counteract. So, masses do attract each other, keeping both Newton and Einstein happy, except that Einstein's model allows for disturbances traveling through spacetime.


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### Answer by username_4 on 2024-05-05. Score: -6

A force gauge is one of the simplest physical instruments to construct and use. Such instruments are the true foundations of physics. Despite the vanities of theorists, mathematical abstractions are not fundamental: they are stories we tell about measurements using things like force gauges. Since you can measure gravity with a force gauge, it must be considered a force.

The "four forces" story is kind of a mess. You can't measure the strong or weak nuclear forces with a normal force gauge, although it is perhaps reasonable to generalize the notion to include the subatomic processes used to probe these. The commonality of electromagnetism and nuclear forces is the microscopic abstraction that relates these to bosonic fields, so there are some who have redefined "force" in bosonic terms. That's problematic for gravity: although it superficially looks like it might be modelable as a bosonic field, there is no successful bosonic model of gravity. And then there's the leptonic [Pauli force](https://en.wikipedia.org/wiki/Pauli_exclusion_principle#Stability_of_matter) that keeps you from falling through your chair: easily measurable with a force gauge, but not one of the bosonic forces.


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