# Does Greater Energy Equal Greater Mass in Classical Mechanics?

• Ibrahim Mustafa
In summary, the conversation discusses the concept of position-dependent mass in classical mechanics and its relation to the harmonic oscillator. The person asking for clarification has no understanding of the concept and asks for a brief explanation. They also mention a paper related to this topic but were unable to understand it. Another person in the conversation states that they have no knowledge of this concept being applied in physics and suggests asking others for more information. The conversation then shifts to discussing the relationship between energy and mass in the context of gravity.
Ibrahim Mustafa
Hello, I have some trouble understanding the position-dependent mass concept in classical mechanics especially with the lagrangian equation and the relation with the harmonic oscillator. Is there a person can provide a brief on the subject?.

I have no clue what you mean by "position-dependent mass concept". It doesn't make any sense to me anyway, but do you have a reference?

I upload paper related to this topic and there is more but I couldn't understand them.

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Ok, that's a funny mathematical study. I've no clue, where this is used to describe real physical systems. So what are your specific questions concerning the paper?

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• jpconf8_128_012053.pdf
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I want to know the meaning of "position-dependent mass", also why and where we use it?

As I said, I have no clue, where in physics this idea is applied. It looks to me as if this is a purely mathematical exercise. Perhaps other forum members are more knowledgeable about this subject.

vanhees71 said:
As I said, I have no clue, where in physics this idea is applied. It looks to me as if this is a purely mathematical exercise. Perhaps other forum members are more knowledgeable about this subject.
Thank you for paying attention.

I read in Professor Roger Penrose's book "The Road To Reality" in section 20 dealing with gravity's role in quantum state reduction that the total gravitational energy of two masses is different when they are separated than when closer together. So would this mean that in this case greater energy means greater mass?

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wwoollyyhheeaa said:
So would this mean that greater energy means greater mass?

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## 1. What is "The position-dependent mass"?

"The position-dependent mass" refers to a concept in physics where the mass of an object is not constant, but changes based on its position in space. This is in contrast to the traditional understanding of mass as a fixed property of an object.

## 2. What are the implications of position-dependent mass?

The existence of position-dependent mass challenges our understanding of Newton's laws of motion and the conservation of energy. It also has implications for theories of gravity and quantum mechanics.

## 3. How is position-dependent mass measured?

Currently, there are no direct methods for measuring position-dependent mass. It is typically inferred from experiments that observe the behavior of particles in specific systems.

## 4. What are some examples of systems with position-dependent mass?

Position-dependent mass has been observed in systems such as Bose-Einstein condensates, semiconductors, and graphene. It has also been theorized to exist in the early universe and black holes.

## 5. What are the potential applications of position-dependent mass?

The concept of position-dependent mass has potential applications in designing new materials and technologies, as well as furthering our understanding of fundamental physics. It may also have implications for future space travel and exploration.

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