Is there anything with a constant weight?

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    Constant Weight
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Discussion Overview

The discussion revolves around the concept of weight in physics, specifically whether there exists a particle or object that has a constant weight regardless of its environment, particularly in relation to gravity. Participants explore the distinctions between weight and mass, the effects of local gravitational acceleration, and the implications of these concepts in various contexts.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • Some participants assert that weight is defined as mass times local gravitational acceleration, which varies depending on location, thus implying that weight cannot be constant.
  • Others propose that mass is a constant property of an object, while weight changes with gravitational force, leading to the idea that no object can have a constant weight across different environments.
  • A participant questions if there is a particle that maintains a constant mass and weight, suggesting that all known particles vary in mass and weight under different conditions.
  • Some argue that light does not have a constant weight, as it is not directly affected by gravitational forces in the same way as massive objects.
  • There is a discussion about the relationship between weight and acceleration, with references to scenarios such as being in an elevator or rocket, where perceived weight can change without the presence of a massive body.
  • Participants discuss the implications of gravitational equations, including Newton's law of universal gravitation, and seek clarification on these concepts.
  • One participant expresses a desire to find a particle that has a stable mass in a vacuum, indicating a search for constancy in physical properties.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the existence of a particle with constant weight. There are multiple competing views regarding the definitions and implications of weight and mass, leading to an unresolved discussion.

Contextual Notes

Participants highlight the dependence of weight on local gravitational conditions and the distinction between mass and weight, but the discussion remains open-ended regarding specific examples or particles that might meet the criteria of having constant weight.

jmiller0921
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Is there any particle in physics that has a constant weight regardless of the environment it is in, with respect to gravity? something like light, roughly 300000000m/s always, but in terms of weight instead of speed. Everything that I have seen at this point is always relative to something its next to or something to that effect. I'm looking for something that is always the same weight with respect to gravity. I was thinking a light photon would be , from what I've seen this varies.
 
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weight is given by an object's mass times the local gravitational acceleration. Since the local gravitational acceleration varies from place to place, the object's weight must change from place to place. I get the feeling that's not what you intended to ask. But that's the answer to the question you asked.
 
What I mean is, is there anything that has a constant mass that would also have a constant weight with respect to gravity? It seems like there could be something that was always the same mass when it is observed. from what I've read everything varies in mass and weight. I am looking for something that is always the same no mater what.
 
No, mass is a physical property of an object and does not change. Only weight changes.
 
jmiller0921 said:
What I mean is, is there anything that has a constant mass that would also have a constant weight with respect to gravity? It seems like there could be something that was always the same mass when it is observed. from what I've read everything varies in mass and weight. I am looking for something that is always the same no mater what.

What you are asking is this: I have this apple. Is there a place where price of this apple will always remain the same, no matter where I go and how long I have it?

Now see if you can understand the responses that you have been given.

Zz.
 
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jmiller0921 said:
Is there any particle in physics that has a constant weight regardless of the environment it is in, with respect to gravity? something like light, roughly 300000000m/s always, but in terms of weight instead of speed.

Light does not have a constant speed regardless of environment. It travels slower in water than in air and slower in air than in intergalactic space.
 
Make it simple, weight = mass x gravity, gravity is not a constant but mass remains the same, you know weight will change proportion to local gravity.
 
Weight is directly dependent on the mass of X and the gravitational body of something even more massive. To technically answer your question, everyone on this planet has a constant weight, to some degree. So, your weight is directly dependent on the force of G. Therefore, I don't think there exists a 'constant' weight.

When you start talking about particles of light (which may not be an accurate description), the particles or sometimes waves, don't have weight; because particles that small are not observed to be directly affected by gravitational forces.
 
llstanfield said:
Weight is directly dependent on the mass of X and the gravitational body of something even more massive.

Not necessarily.
 
  • #10
adjacent said:
Not necessarily.


Care to elaborate on my mistake? Really interested. Thanks.
 
  • #11
llstanfield said:
Care to elaborate on my mistake? Really interested. Thanks.

You can feel "weight" when you are accelerating "upwards", with no need of the presence of another large body to generate the effect of gravity.

Zz.
 
  • #12
llstanfield said:
Care to elaborate on my mistake? Really interested. Thanks.

Your statement:
Weight is directly dependent on the mass of X and the gravitational body of something even more massive.

However,weight of an object is usually taken to be the force on the object due to gravity.

It doesn't have to be possessing more gravity than the mass of X.
Weight of me in terms of Earth is 600N.
Weight of Earth in terms of me is ##m_2a##.
Find ##a## using ##F=\frac{Gm_1m_2}{r^2}##
 
  • #13
ZapperZ said:
You can feel "weight" when you are accelerating "upwards", with no need of the presence of another large body to generate the effect of gravity.

Zz.

Oh I see. Please correct me if I'm wrong, but is this effect related to Einstein's theory of general relativity? Now that I think about it, maybe I was wrong by saying the effect of weight was necessary of having a greater massive object force. But, perhaps it's more dependent on the mass times the acceleration on any interacting body? For instance, even in an elevator or rocket ship given this force, aren't those two things much more massive than the obvious body that's being exerted on? I mean, can you provide me any other example where something with less mass of a heavier one determines the weight? Thanks for your time.
 
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  • #14
adjacent said:
Your statement:


However,weight of an object is usually taken to be the force on the object due to gravity.

It doesn't have to be possessing more gravity than the mass of X.
Weight of me in terms of Earth is 600N.
Weight of Earth in terms of me is ##m_2a##.
Find ##a## using ##F=\frac{Gm_1m_2}{r^2}##

Oh okay, and you are absolutely right. That's what I intended to say, as in the mass of an object related to weight, is subject to the gravitational force...so, you or I, would weigh much more on Jupiter or the Sun for instance. I understand the simple equation of F=mxg, but can you explain the equation that you have given? As far as telling me what r squared and Gm1 stands for? Thanks for your contribution and feedback. Much appreciated.
 
  • #15
"What you are asking is this: I have this apple. Is there a place where price of this apple will always remain the same, no matter where I go and how long I have it?

Now see if you can understand the responses that you have been given.

Zz."

yes. This is what I mean. Is there any measurable particle that is always the same mass "exactly" in vacuum? It seems to me that all particles have variable sizes and eventually some decay into other particles. I am looking for something that is stable and always has the same mass (no variance) in vacuum.
 
  • #16
llstanfield said:
Oh okay, and you are absolutely right. That's what I intended to say, as in the mass of an object related to weight, is subject to the gravitational force...so, you or I, would weigh much more on Jupiter or the Sun for instance. I understand the simple equation of F=mxg, but can you explain the equation that you have given? As far as telling me what r squared and Gm1 stands for? Thanks for your contribution and feedback. Much appreciated.

What is your educational level?
##F=\frac{Gm_1m_2}{r^2}## is the Universal[/PLAIN] Law of Gravitation

F is the force.
G is the Universal[/PLAIN] Gravitational Constant.

##m_1## is the mass of you or me.(In my example)
##m_2## is the mass of Earth (In my example given)
##r## is the distance between the center of mass of Earth and you.

Let your mass be 100kg :smile:
Let the mass of Earth be ##5.97219 × 10^{24}##kg.
You stand 1m away from earth.
##F=m_1a=\frac{Gm_1m_2}{r^2}##
Simplifying gives,
##a=\frac{Gm_2}{r^2}## - where a is the acceleration of you.
Again do the same with m_2
##a=\frac{Gm_1}{r^2}## where a is the acceleration of earth.
So Weight =mass x acceleration.
Find the weight of Earth and you yourself.
 
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  • #17
adjacent said:
What is your educational level?
##F=\frac{Gm_1m_2}{r^2}## is the universal law of gravitation.
F is the force.
G is the Universal[/PLAIN] Gravitational Constant.

##m_1## is the mass of you or me.(In my example)
##m_2## is the mass of Earth (In my example given)
##r## is the distance between the center of mass of Earth and you.

I have a BA in Sociology. However, physics has just recently grabbed my attention, which is why I asked for that elementary understanding of the equation, and respond to the original post to the best of my ability. I signed up on this site to give my understanding of the subject, and ask questions about it in order to learn more.
 
Last edited by a moderator:
  • #18
llstanfield said:
I have a BA in Sociology. However, physics has just recently grabbed my attention, which is why I asked for that elementary understanding of the equation, and respond to the original post to the best of my ability. I signed up on this site to give my understanding of the subject, and ask questions about it in order to learn more.

You are welcome here.
It's actually not very elementary.I'll study it at A-level. However,I know how it works.
 
  • #19
jmiller0921 said:
"What you are asking is this: I have this apple. Is there a place where price of this apple will always remain the same, no matter where I go and how long I have it?

Now see if you can understand the responses that you have been given.

Zz."

yes. This is what I mean. Is there any measurable particle that is always the same mass "exactly" in vacuum? It seems to me that all particles have variable sizes and eventually some decay into other particles. I am looking for something that is stable and always has the same mass (no variance) in vacuum.

But that isn't what you asked originally, is it?

We know about "mass". A look in the Particle Data Book confirms that there ARE plenty of elementary particles with unambiguous mass that we can clearly define. These do not change, or else we will never be able to identify them.

Note that in my example, the apple did not change!. Its value may, but the apple itself hasn't.

Zz.
 
  • #20
adjacent said:
You are welcome here.
It's actually not very elementary.I'll study it at A-level. However,I know how it works.



I appreciate that and this site. And I will definitely refer to you in the future. But for a layman, attempting to understand these complicated physical questions, the equation that you've recently posted in my opinion, is "elementary' or a Newtonian understanding of the world. For instance, regarding the original post, I'm not sure how much a particle would 'weigh' in a vacuum. Because that level of physics transcends classical physics in my opinion.
 
  • #21
llstanfield said:
For instance, regarding the original post, I'm not sure how much a particle would 'weigh' in a vacuum. Because that level of physics transcends classical physics in my opinion.

I am not sure why this would be a problem. In particle physics, gravity is irrelevant. When they do those collisions at the LHC, gravity is a non-entity. Yet, as you can see already, they were able to extract the mass of many of these particles and identify them!

So being in a vacuum, or being in a zero-gravity environment, has no bearing on determining the mass of particles.

Zz.
 
  • #22
ZapperZ said:
I am not sure why this would be a problem. In particle physics, gravity is irrelevant. When they do those collisions at the LHC, gravity is a non-entity. Yet, as you can see already, they were able to extract the mass of many of these particles and identify them!

So being in a vacuum, or being in a zero-gravity environment, has no bearing on determining the mass of particles.

Zz.

I think I get that, and I appreciate your post. However, if gravity is irrelevant, wouldn't that make weight irrelevant as well? Or aren't particles at these levels based on 'strong' and 'weak' fundamental forces, connected to the gravitational force as well related to weight? If that makes sense?

Thanks for your time.
 
  • #23
llstanfield said:
I think I get that, and I appreciate your post. However, if gravity is irrelevant, wouldn't that make weight irrelevant as well? Or aren't particles at these levels based on 'strong' and 'weak' fundamental forces, connected to the gravitational force as well related to weight? If that makes sense?

Thanks for your time.

It is irrelevant because it plays an insignificant role in the behavior of these particles. For example, do you think we consider the gravity from alpha centauri when we design buildings and send spacecraft s to various planets in our solar system? It is there, it is non-zero, but it is so weak, it is ridiculous to take that into account when other factors are more dominant by orders of magnitude.

Zz.
 
  • #24
ZapperZ said:
It is irrelevant because it plays an insignificant role in the behavior of these particles. For example, do you think we consider the gravity from alpha centauri when we design buildings and send spacecraft s to various planets in our solar system? It is there, it is non-zero, but it is so weak, it is ridiculous to take that into account when other factors are more dominant by orders of magnitude.

Zz.

This is absolutely true; but it doesn't change the fact that it does have a force. Now, trying to talk about a "weight" given these weak gravitational forces because it is inversely squared as the distance increases, the vacuum particles do not have this "weight" that the OP was trying to refer to. I was referring to the four fundamental forces because they all have something in common. But, one nuclear force on a particular scale, is completely different from the gravitational one.
 
  • #25
llstanfield said:
This is absolutely true; but it doesn't change the fact that it does have a force. Now, trying to talk about a "weight" given these weak gravitational forces because it is inversely squared as the distance increases, the vacuum particles do not have this "weight" that the OP was trying to refer to. I was referring to the four fundamental forces because they all have something in common. But, one nuclear force on a particular scale, is completely different from the gravitational one.

I don't quite understand what you said here. The OP also didn't mention about these fundamental forces.

Let's be clear here. In practically 99.999% of the cases, the only forces relevant in the dynamics of a particle is the electromagnetic forces. I can determine the mass of a charge particle, for example, by just using those forces. I have zero need for gravity. (Refer to any of the e/m experiment for electrons).

I also don't understand this "vacuum" issue. The only reason why we would need a vacuum is because the air molecules collide with the particles, thus destroying its path. Otherwise, the fact that they are in a vacuum has no bearing on its mass, its weight, etc.

So I think you need to clearly explain these things you are using here, because I am totally confused on why you are using them.

Zz.
 
  • #26
OP: "Is there any measurable particle that is always the same mass "exactly" in vacuum? It seems to me that all particles have variable sizes and eventually some decay into other particles. I am looking for something that is stable and always has the same mass (no variance) in vacuum"

I was simply replying or repudiating to his post, as in an attempt of him describing these particles in a vacuum as "weighing" something. They don't have weight, and this corroborates your post as to how gravitational effects are negligible. So, even for a charged particle mass, there would be no "weight" in measuring that right?

In addition, the only reason why I brought up the fundamental forces, is because there is a general attractive force between vacuum particles, magnets, macroscopic objects, atoms, gravity and electrons.
 
  • #27
llstanfield said:
OP: "Is there any measurable particle that is always the same mass "exactly" in vacuum? It seems to me that all particles have variable sizes and eventually some decay into other particles. I am looking for something that is stable and always has the same mass (no variance) in vacuum"

I was simply replying or repudiating to his post, as in an attempt of him describing these particles in a vacuum as "weighing" something. They don't have weight, and this corroborates your post as to how gravitational effects are negligible. So, even for a charged particle mass, there would be no "weight" in measuring that right?

In addition, the only reason why I brought up the fundamental forces, is because there is a general attractive force between vacuum particles, magnets, macroscopic objects, atoms, gravity and electrons.

I think the OP has a ton of "particles" to choose from. Our good old electron has a "stable mass", and no one has observed a proton decay either. The "vacuum" requirement is still puzzling to me.

Next, every single particle with mass has "weight" in the presence of gravity or similar effects. You cannot say that they don't. However, the influence of gravity, which is the weakest force out of the 4 fundamental forces, in most cases, is negligible for elementary particles. Accounting for the particle's weight gives you nothing - it doesn't appreciably affect its trajectory, its behavior, etc...etc. So here, weight can be ignored. But it doesn't mean it doesn't have one.

I don't understand this "general attractive force between vacuum particles" or where it came from or why it is relevant. Two electrons in my vacuum tube do not have a "general attractive force" between them.

Zz.
 
  • #28
ZapperZ said:
I think the OP has a ton of "particles" to choose from. Our good old electron has a "stable mass", and no one has observed a proton decay either. The "vacuum" requirement is still puzzling to me.

Next, every single particle with mass has "weight" in the presence of gravity or similar effects. You cannot say that they don't. However, the influence of gravity, which is the weakest force out of the 4 fundamental forces, in most cases, is negligible for elementary particles. Accounting for the particle's weight gives you nothing - it doesn't appreciably affect its trajectory, its behavior, etc...etc. So here, weight can be ignored. But it doesn't mean it doesn't have one.

I don't understand this "general attractive force between vacuum particles" or where it came from or why it is relevant. Two electrons in my vacuum tube do not have a "general attractive force" between them.

Zz.


Yes, you are probably right regarding the electron and proton decay, and how that relates to having weight. I'm not knowledgeable about these metric particles having 'weight'; and I was referring to elementary particles in gravity, and I thought that was what the OP was talking about. I was saying that vacuum particles have such a low gravitational force of attraction, which is related to weight, that it's close to zero. However, technically speaking, it DOES have some weight IF these particles that we are talking about have some verifiable mass, according to what you were saying.

The fundamental forces have something in common however. Consider a copper wire, and how the electrons are repelling each other across this wire, while at the same time being attracted to an atomic nucleus; Now notice the word attraction, even having a reverse property. Isn't that the same "attractive" force we see with gravity? And forces that put the neutron and proton together? And the
 
  • #29
The one thing the OP ought to learn from this thread is that if he wants to know something about mass, than he ought to ask about mass, not weight. Assuming he's learned that much, it's probably safe now to stop punishing him and quit all the talk about weight and answer the question about mass. The answer is that all stable objects have stable mass. In the subatomic particle realm the electron is the best example.
 
  • #30
never mind.
 

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