Unraveling the Mystery of Photons: What Are They Made Of?

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Discussion Overview

The discussion revolves around the nature of photons, specifically questioning what they are made of and how they relate to other particles like protons and neutrons. Participants explore concepts from quantum mechanics and the Standard Model, addressing the particle-wave duality of photons and the implications of their properties.

Discussion Character

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

Main Points Raised

  • Some participants assert that photons are elementary particles and not composed of smaller constituents, contrasting them with protons and neutrons, which are made of quarks.
  • There is a discussion about the wave-particle duality of photons, with some arguing that photons exhibit both particle-like and wave-like behaviors depending on the context of observation.
  • One participant suggests that the concept of 'matter' is ambiguous in relation to photons, questioning how a photon can be considered a particle without having mass.
  • Another viewpoint emphasizes that photons are generated by changes in the energy state of electrons, raising questions about the nature of energy and mass in this context.
  • Some participants challenge the definitions of terms like 'field' and 'wave', suggesting that these concepts are not synonymous and that the understanding of photons may depend on the models used to describe them.
  • There is a debate over whether the observed behaviors of photons can be fully understood or if they remain fundamentally mysterious, with some expressing skepticism about the ability to define their true nature.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the nature of photons, with multiple competing views regarding their classification as particles or waves, the implications of their properties, and the definitions of related concepts like matter and energy.

Contextual Notes

Limitations in the discussion include varying definitions of terms such as 'matter' and 'wave', as well as unresolved questions about the fundamental nature of photons and the models used to describe them.

anj16
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what are photons made off??

this might be a stupid question but
lets take a proton or a neutron these
"elementary" particles are made up of quarks,
does photons in its particle state follow the same pattern??
if yes then what constitutes into a photon??

thanks
 
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In the Standard Model, photons are elementary particles, i.e. not composed of other particles.
 


Moreover, protons and neutrons are not considered elementary particles in the standard model.
 


A photon is the quanta, the local 'particle' character, of a wave...[electromagnetic radiation, like light] ...hence it is composed of energy.

More here:
http://en.wikipedia.org/wiki/Photon
 


But a photon has spin. So how can it be a wave?
 


The photon is not a wave, it does however appear to act LIKE a wave in many circumstances due to the uncertainty in the movement of elementary particles
 


mal4mac said:
But a photon has spin. So how can it be a wave?

Photon is not a wave it is a particle.
 


Naty1 did NOT say a photon was a wave. He said it was a quantum of an electromagnetic wave.
 


HallsofIvy said:
Naty1 did NOT say a photon was a wave. He said it was a quantum of an electromagnetic wave.

A photon can be sometimes considered the quanta of electromagnetic field. «Field» is not synonym for «wave»: both are different physical concepts.
 
  • #10


in my prior post, 'field' IS better than 'wave',,,,,I meant to draw no distinction here.

"what constitutes [into] a photon??"

What 'constitutes' any particle is it's measured/observed behaviors...We create models to replicate those.
So we can observe, describe, and model other characteristics of photons as well but those descriptions depend on what models we use...different model behaviors can manifest as 'spin' for example. What's 'really' there is
anybody's guess unless we can smash something apart and look at the constituents...[which still seems like an odd approach, but it works. Like taking a car apart to see how its made by beating it!]

from the link I posted:

The quanta of an Abelian gauge field must be massless, uncharged bosons, as long as the symmetry is not broken; hence, the photon is predicted to be massless, and to have zero electric charge and integer spin.
That's a mathematical statement.

Meantime, string theory, another theory, also describes photon characteristics but I don't know enough about the math to divine exactly how [or if] AdS/CFT precisely relates string theory to gauge theory strictly enough to make direct characteristic 'spin' comparisons...

Seems that things like spin pop out of mathematical models and clever physicsts exclaim "Oh that looks just like 'spin'...and so it is...but it takes a lot of work to compare the origins of such different mathematical model outcomes...
 
  • #11


A "photon" (that we perceive as a "particle) is generated by a change in the energy state of an electron. As the electron moves from a high energy state to a low energy state the energy that is lost by the electron is the "photon". It is a state of energy, mass without matter, how can it be a particle without matter?

Paul
 
  • #12


PaulS1950 said:
A "photon" (that we perceive as a "particle) is generated by a change in the energy state of an electron. As the electron moves from a high energy state to a low energy state the energy that is lost by the electron is the "photon". It is a state of energy, mass without matter, how can it be a particle without matter?

Paul

A photon is just as much of a particle as an Electron is EXCEPT that it has no invariant mass. (Commonly known as "rest mass") Both photons and electrons have particle-like and wave-like properties, as the commonly performed Double-Slit experiment will show with either one. There is nothing that says a particle MUST be matter.
 
  • #13


Where does the photon get its matter? The electron has none to provide and preserve its existence yet the change in energy state is all that is required to make the photon.

We perceive the effects of what we don't understand and make them understandable by expanding the improbable. Hiding behind the multiple definitions only delays the truer understanding of the reality of the universe.

Photons only "behave" like particles and waves depending on the perceptions of the tests to which we subject them.

Paul
 
  • #14


PaulS1950 said:
A "photon" (that we perceive as a "particle) is generated by a change in the energy state of an electron.

I hope you realize that photons are generated by more than electronic transitions.

You keep using the word 'matter', but I don't really know what you mean by it. I'd define matter as 'stuff made of hadrons and leptons', but apparently you seem to disagree. What exactly is this 'matterness' that you seem to think the photon has that is confusing you?
 
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  • #15


PaulS1950 said:
Where does the photon get its matter? The electron has none to provide and preserve its existence yet the change in energy state is all that is required to make the photon.

Matter is typically defined as objects that have mass. A photon does not and isn't matter. In fact, the matter isn't "something" in and of itself, it is merely a way to classify things. Similarly a proton is a Hadron and an Electron is a Lepton. Photons are Bosons, a type of subatomic particle that has spin 0. Leptons, Quarks, and Bosons are the 3 types of fundamental particles that everything else is made up of. Matter is simply another type of classification.

We perceive the effects of what we don't understand and make them understandable by expanding the improbable. Hiding behind the multiple definitions only delays the truer understanding of the reality of the universe.

Nonsense. You simply don't know the differences in the terms that are used. And there is no "truer" understanding of reality other than science.

Photons only "behave" like particles and waves depending on the perceptions of the tests to which we subject them.

Paul

No, they act like both a particle and a wave all the time.(Edit: Rather they act like waves and particles whenever appropriate, regardless of whether or not we are observing them) We can see the wave-like part of them when we look correctly, and we pretty much always see the particle-like part when we interact with them during a measurement.
 
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  • #16


JHamm said:
The photon is not a wave, it does however appear to act LIKE a wave ...

If it walks like a duck, and talks like a duck, then (surely) it is a duck?!
 
  • #17


HallsofIvy said:
Naty1 did NOT say a photon was a wave. He said it was a quantum of an electromagnetic wave.

The OED defines quantum to mean an "amount; share; portion" of something. A portion of cake is ..er.. cake. So how can a quantum of an electromagnetic wave not be an electromagnetic wave?
 
  • #18


Naty1 said:
What's 'really' there is
anybody's guess

So we can't say what photons are made of? We can't even say if they are particles or waves or strings?
 
  • #19


Drakkith said:
No, they act like both a particle and a wave all the time.

How do you know that? How *can* you know that? You certainly can't observe them all the time, without the observation interfering with them...
 
  • #20


mal4mac said:
How do you know that? How *can* you know that? You certainly can't observe them all the time, without the observation interfering with them...

Nope. We can't 100% know this. However I don't believe the universe works one way when we observe something and another way when things interact without us to observe them.
 
  • #21


mal4mac said:
If it walks like a duck, and talks like a duck, then (surely) it is a duck?!
It walks like a duck, and talks a dog. The debate was then if it is a duck or a dog. I would say that a duck resembles it in the way a duck walks, and a dog resembles it in the way a dog talks. :-p

The problem is largely in the descriptors: real "particles" such as electrons can have wave behaviour, and real waves such as sound waves can have particle behaviour.
 
  • #22


anj16 said:
this might be a stupid question but
lets take a proton or a neutron these
"elementary" particles are made up of quarks,
does photons in its particle state follow the same pattern??
if yes then what constitutes into a photon??

thanks

For most practial applications you can forget about electromagnetic radiation being particles and just treat it as a wave as prescribed by Maxwells laws of electrodynamics. When you have light interacting with atoms or molecules they can typically only emit/absorb energy from the radiation in "chunks" corresponding to differences between energy levels in the atom/molecule.

Maybe someone can remind me of when we need to treat electomagnetic radiation as consisting of particles?
 
  • #23


[/QUOTE]We perceive the effects of what we don't understand and make them understandable by expanding the improbable. Hiding behind the multiple definitions only delays the truer understanding of the reality of the universe.[/QUOTE]



We perceive the effects of what we don't understand

yes, sometimes...like dark matter and dark energy...Or "Is light a wave or a particle?" or the precession of Mercury...that's often the start of a 'new discovery'...or attempts at least.

and make them understandable by expanding the improbable

well some things ARE 'improbable'...like quantum theory...but if they turn out to be
incorrect, meaning proven false, they are usually set aside and a new understanding is sought.

...Hiding behind the multiple definitions only delays the truer understanding of the reality

I think you mean 'explanations' rather than definitions...but when first discovered an initial explanation is often incomplete, incorrect or only partially correct. For example when Einstein published his theory of general relativity, he did not see the unification of space and time into spacetime [that advance insight came from his college math professor, Minkowski] nor had he even solved in own equations [the first solution came from Karl Schwarzschild, I think]. And it took Einstein some ten years to uncover what he did publish...we learn stuff in pieceparts.

...delays the truer understanding of the reality of the universe

I'd argue just the opposite: publishing or sharing a partial or incomplete theory or working with colleagues speeds up an improved understanding...think of collaboration where multiple and conflicting perspectives and insights are argued out and a consensus is eventually reached.
 
  • #24


mal4mac said:
So we can't say what photons are made of? We can't even say if they are particles or waves or strings?

As is well-known in particle physics, photons are particles.

Photons, in the Standard Model of particle physics are structureless. This mean they are not made of anything, but are a basic 'building block' of nature, as fermions and quarks.
 
  • #25


Agerhell said:
Maybe someone can remind me of when we need to treat electomagnetic radiation as consisting of particles?

Lowest intensity radiation? You may have to assume photons proceed one-by-one in particle like fashion. For instance, there is a neat double-slit experiment where photons are detected one by one. Of course, the pattern they make (eventually) looks like an interference pattern, which can only (surely) come form waves. But they arrive one by one... :confused: Does even Feynman understand this stuff? :smile:
 
  • #26


juanrga said:
As is well-known in particle physics, photons are particles.

Photons, in the Standard Model of particle physics are structureless. This mean they are not made of anything, but are a basic 'building block' of nature, as fermions and quarks.

But the Standard Model is a ..er.. model. So it doesn't tell us *exactly* what photons are made of. So we don't know if photons are made of anything or not.
 
  • #27


mal4mac said:
But the Standard Model is a ..er.. model. So it doesn't tell us *exactly* what photons are made of. So we don't know if photons are made of anything or not.

The model brings together all the pieces and attempts to explain how different particles interact according to laws we have derived through observation and experiment. According to the model the photon is fundamental. That doesn't mean it CANNOT be composite, only that to the best of our knowledge it is not. So when we say that a photon is a fundamental particle and not made up of anything else it is given that we mean according to the standard model and could very well be incorrect. So, according to the standard model, a photon is an electromagnetic wave that interacts according to the rules of Quantum Mechanics and has wave-like and particle-like properties.
 
  • #28


mal4mac said:
But the Standard Model is a ..er.. model. So it doesn't tell us *exactly* what photons are made of. So we don't know if photons are made of anything or not.

You're going to have serious issues in physics with this kind of attitude. EVERYTHING is a model, we're merely doing our best to describe how the universe functions. If you want to start asking questions about what things REALLY are like, I suggest you go hit up a philosophy forum.
 
  • #29


mal4mac said:
But the Standard Model is a ..er.. model. So it doesn't tell us *exactly* what photons are made of. So we don't know if photons are made of anything or not.

It seems that anyone knows that the Standard Model is... a model. But the rest of your post clearly indicates that you do not know what a scientific model is and what does.
 
  • #30


mal4mac said:
But the Standard Model is a ..er.. model. So it doesn't tell us *exactly* what photons are made of. So we don't know if photons are made of anything or not.
Indeed - except that if they consist of nothingness, they can't exist. And we have no reason to think that they have rest mass.
 

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