# Can a Massless Photon create Mass?

• Symmetry777
In summary, the conversation discusses the relationship between mass and photons, and whether photons can create or transfer mass. It also touches on the concept of electromagnetic fields and their role in heat transfer. The participants also mention the creation of electrons through two photon pair production and the role of photons in the equation E=mc^2, where c is the speed of light. Ultimately, it is concluded that mass is not converted by photons, but rather energy and mass are interchangeable forms.

#### Symmetry777

Can a Massless Photon create Mass?

Is Electrostatic Induction a form of “Mass Transfer through the process of Absorption”?

A new star is created. The star generates massive Magnetic Fields. What happens to the hydrogen particles, Nebula, when they are influenced by the Magnetic Field?

If the entity is sending out magnetic fields, photons, massless particles, through the top and the bottom and those fields intersect at a perpendicular angle is Mass being created, aligned?

Are these newly created Mass Particles, Mass attracting Mass, Centripetal force, causing the rotational inertia (angular momentum) of the star?

Electromagnetic Fields are made of Photons.

Photons are Massless Particles.

The question is concerning, “Mass Transfer through the process of Absorption”.

Is Electrostatic Induction a form of “Mass Transfer through the process of Absorption”?

In physics, a charged particle is a particle with an electric charge.

Electric charge is the physical property of matter that causes it to experience a force when placed in an Electromagnetic Field.

“If a Magnetic Field connects between two objects a mechanical coupling between the two objects is created. Such a coupling will couple vibrations, therefore heat will be conducted by the magnetic field.”

“A varying magnetic field (not a constant magnetic field) will induce an electric charge on a particle and can produce heat. For example all the copper atoms in the wire of a stator (electrical generator) produce heat then current.”

The main idea or question is: “Can Massless photon creating Mass?”

If the entity is sending out magnetic fields, photons, massless particles, through the top and the bottom and those fields intersect perpendicular to the entity is Mass being created. Are these newly created Mass Particles, Mass attracts Mass, Centripetal force, causing the rotational inertia (angular momentum) of the star?

Convective heat transfer is one of the major types of heat transfer, and convection is also a major mode of mass transfer.

“In physics, mass–energy equivalence is the concept that the mass of an object or system is a measure of its energy content. For instance, adding any form of energy to any object increases its mass by 1 microgram (and, accordingly, its inertia and weight) even though no matter has been added.”

Thank You

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Symmetry777 said:
[ ... ]Electromagnetic Fields are made of Photons. [ ... ]Thank You
Absolutely wrong. Photons are the mediating boson of EMF.

https://en.wikipedia.org/wiki/Photon

Symmetry777
Would you explain these sources sited?

“In quantum physics, the electromagnetic field is quantized and electromagnetic interactions result from the exchange of photons”

“When a photon of light hits an atom three things can happen: it can bounce off; it can pass through as if nothing had happened; or it be absorbed and turned into heat.”

“Heat consists of random vibrations in a material. If a magnetic field connects two objects, then it creates a mechanical coupling between the two objects. Such a coupling will couple vibrations, therefore heat will be conducted by the magnetic field.”

Thank You

Symmetry777 said:
“In quantum physics, the electromagnetic field is quantized and electromagnetic interactions result from the exchange of photons”

Quantum Field Theory explains the electromagnetic interaction in terms of VIRTUAL photons that don't really exist - they are simply a product of the formalism:
http://www.mat.univie.ac.at/~neum/physfaq/topics/virtual

Symmetry777 said:
“When a photon of light hits an atom three things can happen: it can bounce off; it can pass through as if nothing had happened; or it be absorbed and turned into heat.”

That's from a beginner text - Quantum Field theory says that's not really what happens - its much more complicated than that. But in general terms - yes its true.

Symmetry777 said:
“Heat consists of random vibrations in a material. If a magnetic field connects two objects, then it creates a mechanical coupling between the two objects. Such a coupling will couple vibrations, therefore heat will be conducted by the magnetic field.”

Sure - heat can be transferred by interactions, but its relation to your original question I can't follow.

Thanks
Bill

Symmetry777
Mass is not created anywhere. The emission or absorbtion of a photon transfers energy, and hence mass, to or from an object. The mass already existed prior to the creation of the photon.

2 gamma photons can create an electron, but I'm not sure where I've read it.

You wrote, "The mass already existed prior to the creation of the photon." I agree.
It seems like this Mass, Dark Energy or Dark Matter is being converted by photons.
Metaphorically speaking in the equation E=MC2. It seems like the infinitesimal "C" photons at the speed of light are encapsulating this infinite M, Dark Energy or Dark Matter?

jerromyjon said:
2 gamma photons can create an electron, but I'm not sure where I've read it.
Google for "Two photon pair production". It's not a very common process (the single photon plus nucleus process is far more common on earth), but it happens.

Symmetry777
Symmetry777 said:
You wrote, "The mass already existed prior to the creation of the photon." I agree.
It seems like this Mass, Dark Energy or Dark Matter is being converted by photons.
Metaphorically speaking in the equation E=MC2. It seems like the infinitesimal "C" photons at the speed of light are encapsulating this infinite M, Dark Energy or Dark Matter?

There's nothing metaphorical about ##E=mc^2##, the ##c## in that equation is the speed of light ##3\times{10}^8## meters/sec, and there's nothing infinitesimal or infinite anywhere. The equation is just saying that rest mass is another form of energy, just as ice is another form of water. The ##c^2## is there to convert between the units that we usually use for mass and the units that we usually use for energy; it has about the same significance as the constant 15.5 in the equation ##W=15.5I## where ##W## is the amount of water you have in ounces and ##I## is the amount of ice you have in pounds.

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bhobba and vanhees71
Symmetry777 said:
You wrote, "The mass already existed prior to the creation of the photon." I agree.
It seems like this Mass, Dark Energy or Dark Matter is being converted by photons.

It is not. An object that emits light will have less mass, but if we look at the object plus the light as a single system then we see that the mass of the system is unchanged. Mass is not converted to anything.

Metaphorically speaking in the equation E=MC2. It seems like the infinitesimal "C" photons at the speed of light are encapsulating this infinite M, Dark Energy or Dark Matter?

The equation allows us to calculate the change in mass of a system when it gains/loses energy. It also let's us calculate the amount of energy gained/lost from a system by measuring the change in mass. That's about it. Dark matter and dark energy have nothing to do with it.

Symmetry777
Mass (and I only use mass in the modern sense as the invariant mass of an object) is not conserved in relativistic physics. If a photon gets absorbed by some body, which means that it's energy adds to the internal energy ("heat") of the body, enhances the mass of the body by the corresponding mass ##\Delta m=E_{\gamma}/c^2##, where ##c## is the speed of light (within relativistic physics it's just a conversion factor between the units of time and length which we are used to choose differently for convenience in our everyday rather "non-relativistic" world; in relativistic physics the natural choice is ##c=1##, i.e., measuring time and spatial distances in the same unit (usualy fm in nuclear and high-energy physics).

The notion of mass is a subtle concept, which can be fully understood only with some pretty complicated (but also utmost beautiful) group-representation theory. From a mathematical point of view the proper orthochronous Poincare group, which is the symmetry group of special-relativistic spacetime realized in nature (as far as we know today), the relativistic case is simpler: Here ##m^2## is a Casimir operator of the Lie algebra and thus one of the characteristics of any irreducible unitary Poincare group representation in relativistic quantum field theory. The ray representations can all be obtained from the unitary irreps of the covering of the Poincare group. The covering group is the Poincare group with the SO(1,3) boost-rotation group substituted by its covering group, SL(2,C). There are no non-trivial central charges.

This is all worked out in great detail in Weinberg, The Quantum Theory of Fields, vol. 1.

For non-relativistic space time the proper orthochronous Galilei group is the symmetry group. There the ray representations of the covering group admit a non-trivial central charge, which turns out to be the mass. This implies that mass is conserved in non-relativistic physics. It also implies a superselection rule, according to which there must be no superpositions of states with different mass. The unitary representations of the classical Galilei group do not lead to physically sensible quantum theoretical models.

Symmetry777 and bhobba
Rest energy and momentum are conserved [caveat: not necessarily true in general relativity, on universal scales]. Mass, on the other hand, is or is not conserved, depending on what definition of mass you use. Historically, the law of conservation of mass was developed in 1700s after carefully observing results of chemical experiments. But we know a lot more now than then, and the old law of conservation of mass is only approximately true, and not true for photons being converted into matter and antimatter. Total rest mass of all particles is not conserved, since new particles are created.

A more precise and correct restatement of the conservation of mass is the conservation of invariant mass. This term (invariant mass) is less ambiguous than rest mass which isn't consistently defined for a loose collection of particles treated as a single object. Invariant mass is conserved when photons are converted to matter and vice versa. Invariant mass is just equivalent to energy though, so the entire concept is redundant, and the conservation of energy is sufficient.

(vanhees71, I'm not sure why you say invariant mass is not conserved in relativistic physics. If you include the photon in the system, then invariant mass is conserved.)

No, it's not! Total energy is conserved, not invariant mass. If a photon gets absorbed by an atom its invariant mass get. larger by the corresponding amount.

Symmetry777
Khashishi said:
A more precise and correct restatement of the conservation of mass is the conservation of invariant mass. This term (invariant mass) is less ambiguous than rest mass which isn't consistently defined for a loose collection of particles treated as a single object. Invariant mass is conserved when photons are converted to matter and vice versa. Invariant mass is just equivalent to energy though, so the entire concept is redundant, and the conservation of energy is sufficient.
Invariant mass is the mass of an object which all observers will agree on, regardless of their relative motion with the object. Rest mass, invariant mass, proper mass, and intrinsic mass are all different words for the same thing.

Thank You,

I think I will focus on conservation laws, isolated system.

An isolated system implies a collection of matter which does not interact with the rest of the universe at all - and as far as we know there are really no such systems. There is no shield against gravity, and the electromagnetic force is infinite in range. But in order to focus on basic principles, it is useful to postulate such a system to clarify the nature of physical laws. In particular, the conservation laws can be presumed to be exact when referring to an isolated system.

http://hyperphysics.phy-astr.gsu.edu/hbase/conser.html

Khashishi said:
(vanhees71, I'm not sure why you say invariant mass is not conserved in relativistic physics. If you include the photon in the system, then invariant mass is conserved.)
vanhees71 said:
No, it's not! Total energy is conserved, not invariant mass. If a photon gets absorbed by an atom its invariant mass get. larger by the corresponding amount.

I believe the source of this mismatch is Khashishi is using "invariant mass" to denote the squared total 4-momentum of a system, while vanhees71 uses it as the sum of the invariant masses of all objects in the system. The first one is conserved, the second one is not.

Symmetry777
The squared total 4-momentum of a system is the total energy of the system in the center-momentum frame, not the sum of the invariant masses. Under mass conservation the latter is understood. The former's conservation describes the conservation of total energy written in a covariant way, which of course is true in SRT due to time-translation invariance of Minkowski space.

I am just saying that people tend to use "invariant mass of a system" to mean the total energy in the system rest frame. (Our experimental friends at CERN included, see e.g. http://arxiv.org/abs/1207.7214 and http://arxiv.org/abs/1207.7235, there are around 25 uses in each of these, for example the first sentence of sec 5.1 of the CMS paper "In the H → γγ analysis a search is made for a narrow peak in the diphoton invariant mass distribution in the range 110–150 GeV".) I do not think anyone with the proper education believes that the sum of the invariant masses of individual particles in a system needs to be conserved. In particular, the Wikipedia entry on the subject puts it quite succinctly:
Wikipedia said:
Again, in special relativity, the rest mass of a system is not required to be equal to the sum of the rest masses of the parts (a situation which would be analogous to gross mass-conservation in chemistry). For example, a massive particle can decay into photons which individually have no mass, but which (as a system) preserve the invariant mass of the particle which produced them. Also a box of moving non-interacting particles (e.g., photons, or an ideal gas) will have a larger invariant mass than the sum of the rest masses of the particles which compose it. This is because the total energy of all particles and fields in a system must be summed, and this quantity, as seen in the center of momentum frame, and divided by c2, is the system's invariant mass.
Just trying to clear up why you talk around each other.

bhobba and Symmetry777
Of course, I fully agree with this. "Invariant mass of a pair of particles" is usually understood as ##\sqrt{(p_1+p_2)^2}## in high-energy particle and nuclear physics. Nobody thinks that mass is conserved in relativistic physics.

Symmetry777

## 1. Can a massless photon create mass?

No, a massless photon cannot create mass. According to the theory of relativity, mass and energy are equivalent, so photons can contribute to the energy content of a system, but they do not have the ability to create mass.

## 2. How does a photon have energy if it has no mass?

Although a photon has no rest mass, it still has energy due to its momentum and frequency. The energy of a photon is directly proportional to its frequency, meaning that higher frequency photons have more energy.

## 3. Can photons be converted into mass?

Yes, photons can be converted into mass under certain conditions. This process, known as pair production, occurs when a high-energy photon interacts with a nucleus and creates a particle-antiparticle pair. The total mass of the particles created is equal to the energy of the photon.

## 4. How does the theory of massless photons relate to the Higgs boson?

The Higgs boson is a particle that is responsible for giving other particles mass. This includes photons, which interact with the Higgs field and acquire mass. However, the Higgs boson itself has a mass, so it is not considered a massless particle like the photon.

## 5. Is it possible for a photon to gain mass in the future?

At this time, there is no evidence or theoretical framework to suggest that photons can gain mass. However, as our understanding of physics and the universe evolves, it is always possible that new discoveries could change our current understanding of mass and energy.