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Farsight
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Marlon: I'm having a bit of a crisis about particles. Can you tell me, what is your concept of a particle?
Hi Farsight,Farsight said:Marlon: I'm having a bit of a crisis about particles. Can you tell me, what is your concept of a particle?
A particle is a body having finite mass and internal structure but negligible dimensions.Farsight said:Marlon: I'm having a bit of a crisis about particles. Can you tell me, what is your concept of a particle?
As of today, that definition rules out the leptons and quarks (and Force-carrying bosons?) from being particles.Reshma said:A particle is a body having finite mass and internal structure but negligible dimensions.
That's a bit of a strange definition, no ? I mean i don't get the "internal structure" part. Does an electron have an internal structure ? If so, then what are elementary particles ?Reshma said:A particle is a body having finite mass and internal structure but negligible dimensions.
Sorry, I was just going by the definition of a "particle" and missed the keyword "elementary" . An elementary particle or fundamental particle would be a particle not known to have substructure.marlon said:That's a bit of a strange definition, no ? I mean i don't get the "internal structure" part. Does an electron have an internal structure ? If so, then what are elementary particles ?
I my opinion not particles but quantumfields are the most basic constituent of matter. Particles arise when such fields start to fluctuate. It is the energydifference dE associated with the transition from one field configuration to another that mimics a physical enetity with mass m and momentum p. This entity is what we call a particle. Keep in mind that both mass and momentum are concepts that come from classical physics. We just use them to describe the quantummechanical fenomena as well because such concepts are easy to grasp. For the same reason, the particle/wave duality does not imply that there are TWO ways in which nature can behave. This duality arises because we like to look at QM with "classical eyes"...
marlon
Reshma said:Sorry, I was just going by the definition of a "particle" and missed the keyword "elementary" . An elementary particle or fundamental particle would be a particle not known to have substructure.
Well, the explanation i gave is not just the QM version, it's the quantum field's version (QFT).Anyways, your quantum mechanical explanation takes care of any defintion of a particle. Since, we generally associate paticles with matter, QM also takes in account of photons as particles.
Ok, this is a definition that contains a lot of truth. But, don't you think we should be defining this "minimum region" ? I mean, let's take the photon as an example. A photon is not defined as a particle with finite spatial boundaries. The finite boundaries are defined in energy space. Photons are just chuncks of energy. What do you think ?Rade said:According to text by D. Bohm, 1951, Quantum Theory, page 24--a particle = an object that can always be localized within a certain minimum region, which we call its size.
Again, I refer to D. Bohm, p. 31, where he refers to photons as "equivalent particles" having energy = hv. I would think the issue of finite spatial boundary of a photon (or electron) results from the limitation on localizability that is inherent in the wave-particle nature of matter, but I may be incorrect.marlon said:Ok, this is a definition that contains a lot of truth. But, don't you think we should be defining this "minimum region" ? I mean, let's take the photon as an example. A photon is not defined as a particle with finite spatial boundaries. The finite boundaries are defined in energy space. Photons are just chuncks of energy. What do you think ?
A particle is a tiny piece of matter that makes up everything in the universe. It can be as small as an atom or as large as a planet, and it can be made up of smaller particles like protons, neutrons, and electrons.
Particles behave in different ways depending on their size and properties. Some particles, like electrons, can act as both particles and waves. They can also interact with each other through forces like gravity and electromagnetism.
There are four main types of particles in the standard model of particle physics: quarks, leptons, bosons, and fermions. These particles have different properties and are responsible for different interactions in the universe.
Particles are studied and observed using large machines called particle accelerators, which accelerate particles to high speeds and collide them together. Scientists also use detectors to analyze the particles produced in these collisions and gather data about their properties.
Understanding particles is important because it helps us understand the fundamental building blocks of the universe and how they interact with each other. This knowledge can lead to advancements in technology, medicine, and our understanding of the world around us.