Do Atomic Particles Have a Defined Size or Shape?

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    Atomic Particles
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Discussion Overview

The discussion revolves around the question of whether atomic particles, such as protons, neutrons, and electrons, possess a defined size or shape. Participants explore the implications of particle size in the context of quantum mechanics and the nature of fundamental particles.

Discussion Character

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

Main Points Raised

  • Some participants suggest that atomic particles do not have a "particular" size or shape, instead existing as clouds of probability influenced by their energy levels and interactions.
  • One participant questions the significance of size for fundamental particles, noting that traditional measures of size, like those for macroscopic objects, may not apply.
  • Another participant introduces Heisenberg's Uncertainty Principle, arguing that it complicates the measurement of a particle's size or shape due to the inherent motion of particles.
  • A participant proposes that a particle's shape could be conceptualized through string theory, suggesting that particles might be represented as vibrating strings, although this idea is not fully elaborated upon.
  • There is a discussion about the existence of mass and volume for particles, with questions raised about whether they have definite shapes or densities.
  • One participant shares their experience as an amateur theorist, mentioning various experiments that have measured atomic and particle sizes, noting a general agreement in measurements across different elements.
  • Another participant emphasizes the challenge of visualizing particles and fields, suggesting that the conservation of field forces is more relevant than the size or mass of particles.

Areas of Agreement / Disagreement

Participants express differing views on the nature of size and shape in atomic particles, with no consensus reached on whether these concepts apply in the same way as they do for macroscopic objects. The discussion remains unresolved regarding the implications of particle size and shape.

Contextual Notes

Limitations include the dependence on interpretations of quantum mechanics, the challenges of measuring particle properties, and the conceptual difficulties in visualizing fields versus particles.

gendou
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does anyone know if the atomic particles (protons, neutrons, electrons) have a particular size/shape? perhaps the idea of them having a certain radius is an imaginary concept? i would love to hear a knowledgeable opinion!
 
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No "particular" size or shape, at that level you have clouds of probability, depending on how they're packed, their energy levels, that sort of thing. One thing they are NOT are tiny little balls, as usually illustrated.
 
Actually, I just wonder... What is the significance of size relating to a fundamental particle? I mean, when we talk of a billiard ball or whatever, our measure of size comes from the structure of EM force interactions it maintains, holding the individual bits apart a certain distance where they are in equilibrium and so on. But when we talk of individual leptons... how can we measure them?
 
See http://www.vicphysics.org/news/oconnor1.doc
 
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thanks FZ+ and garys_2k! i was wondering the same thing, i would agree that the classic model of "shape" doesn't work in a subatomic context.
 
What Garys_2k was saying about "clouds of probability" is also known as Heisenberg's Uncertainty Principle. This states that it is impossible to measure the momementum and the position of a particle simultaneously. This implies that an object is always in motion. So we can't measure a particle at a standstill, which makes it impossible to determine it's size or shape, but we can measure one more accurate and another not so accurate. This is what garys_2k means by clouds of probability.

I think that a particle's shape is determined by a 1-dimensional string that is vibrating at different frequencies with different tensions to the string. A.k.a String theory. But I won't get into that.
Paden Roder
 
they have mass though right? do they not have volume? or just not definite shape? and hows about desnity?
 
As an amateur theorist I take an interest in the size of atoms and particles. The size of both have been detected using various types of experiments, there is even an experiment for measuring the nucleus of atoms based on the average of thousands of X-rays.
Earlier experiments based on blocks of material produced atomic radii in physics and molar radii in chemistry. I used both to determine the volume and compared the results; there is a general agreement in about 90% of the elements.
I have also found a theoretical agreement between mass and volume of fundamental particles using arbitrary numbers.
The problem in grasping the reality of particles comes from our inability to visualise fields and our determination to see particles and atoms in terms of mass and/or energy. It is the field force(not the size or mass) that is always conserved.
 
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