# Massless things

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Strange    2430

Ok, so It's only the mass change that is involved.

Only what mass changed that is involved in what?

Nevertheless, there are only certain conditions where any measurable conversion is going to take place

True. As already noted, the mass change in chemical reactions is (as far as I know) too small to measure. That doesn't mean it doesn't happen. So how is it relevant?

Nuclear fission requires high speed neutrons

So what?

. Nuclear fusion requires extremely high temperature environment.

So what?

The mass change involved in energy flowing through medium would undetectable.

What does "energy flowing through medium" mean?

The mass change would be measurable if the energy change were large enough so, again, so waht?

Since the first one is measurable it is particularly interesting, but strange things happen at the atomic scale.

What strange things?

And how is it relevant?

In summary, you have said nothing relevant to mass-energy equivalence, so what is your point?

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Only what mass changed that is involved in what?

Obviously, in mass energy equivalence.

True. As already noted, the mass change in chemical reactions is (as far as I know) too small to measure. That doesn't mean it doesn't happen. So how is it relevant?

A mass change is expected to occur in chemical reactions, but until it is proven with measured quantities, it's just theoretical principle . Do you really need to ask the relevancy for something that may or may not happen?

So what?

So what?

Strict conditions

The mass change would be measurable if the energy change were large enough so, again, so waht?

How large of an energy change? Until direct measured quantities of mass change are recorded from mechanical waves, it is only a theoretical principle so why make that assumption? Maybe mass energy equivalence occurs only during strict conditions.

What strange things?

An earlier post just gave two examples.

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Mordred    833

Lets take an everyday tested example. The LHC, in order to increase a proton to the speeds it reaches the energy requirements to accelerate the proton matches those predicted by relativity due to inertial mass increase. Or top quarks at the LHC

In fact relativity is tested daily with the LHC, CERN etc. That is precisely how CERN created the Higgs boson whose rest mass exceeds the combined mass of both protons. Or top quarks at the LHC.

Edited by Mordred
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Strange    2430

Obviously, in mass energy equivalence.

A mass change is expected to occur in chemical reactions, but until it is proven with measured quantities, it's just theoretical principle . Do you really need to ask the relevancy for something that may or may not happen?

Strict conditions

How large of an energy change? Until direct measured quantities of mass change are recorded from mechanical waves, it is only a theoretical principle so why make that assumption? Maybe mass energy equivalence occurs only during strict conditions.

An earlier post just gave two examples.

So you think the theory is only valid for specific values where it is measured?

Do you apply this to all theories? For example, we have Newton's F=ma. Do you think that is only proven correct for the specific values of F, m and a that have been tested? And for other values it might not work?

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J.C.MacSwell    172

Obviously, in mass energy equivalence.

A mass change is expected to occur in chemical reactions, but until it is proven with measured quantities, it's just theoretical principle . Do you really need to ask the relevancy for something that may or may not happen?

Strict conditions

How large of an energy change? Until direct measured quantities of mass change are recorded from mechanical waves, it is only a theoretical principle so why make that assumption? Maybe mass energy equivalence occurs only during strict conditions.

An earlier post just gave two examples.

Occam's razor. Until we have an example where mass energy equivalence does not occur, or it would explain something that is otherwise unexplainable. it is the simplest assumption based on current physics...similar to assuming undetectable pink unicorns do not exist when no one is looking, even though no one has proven they don't exist.

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Lets take an everyday tested example. The LHC, in order to increase a proton to the speeds it reaches the energy requirements to accelerate the proton matches those predicted by relativity due to inertial mass increase. Or top quarks at the LHC

In fact relativity is tested daily with the LHC, CERN etc. That is precisely how CERN created the Higgs boson whose rest mass exceeds the combined mass of both protons. Or top quarks at the LHC.

There is no question of the empirical evidence and practical applications in mass energy equivalence at the particle level.

So you think the theory is only valid for specific values where it is measured?

No. That does not mean that the practical applications occur throughout all physical spatial scales.

For example, we have Newton's F=ma. Do you think that is only proven correct for the specific values of F, m and a that have been tested? And for other values it might not work?

Yes.

Newton's Second Law as stated below applies to a wide range of physical phenomena, but it is not a fundamental principle like the Conservation Laws. It is applicable only if the force is the net external force. It does not apply directly to situations where the mass is changing, either from loss or gain of material, or because the object is traveling close to the speed of light where relativistic effects must be included. It does not apply directly on the very small scale of the atom where quantum mechanics must be used.

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

Very interesting. Newton's second Law does not apply in the only scenarios where mass energy equivalence has been observed.

Occam's razor. Until we have an example where mass energy equivalence does not occur, or it would explain something that is otherwise unexplainable. it is the simplest assumption based on current physics...similar to assuming undetectable pink unicorns do not exist when no one is looking, even though no one has proven they don't exist.

True at least for the now.

If one measures the weight of quantum objects, such as a hydrogen atom, often enough, the result will be the same in the vast majority of cases, but a tiny portion of those measurements give a different reading, in apparent violation of E=mc2. This has physicists puzzled, but it could be explained if gravitational mass was not the same as inertial mass, which is a paradigm in physics.

https://phys.org/news/2013-01-einstein-emc2-outer-space.html

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Mordred    833

Then perhaps you should clarify what you are truly stating as the energy/mass relations also apply to any field as well

Einstein's Mass-Energy is equivalence is applicable in only two special cases.

Yes, the total energy for entire wave would be constant but those values would vary at a set point. A similar example would be a charge flowing through a medium. However, in that case the flow of electrons would contribute to added mass.

All particles are essentially field excitations under boundary binding conditions. ie a quanta in a finite (point-like )region.

Mass and energy is literrally different mathematical treatments to describe the properties of what is commonly referred to as particles.

mass is resistance to inertia change
energy is the ability to perform work.
A field being an abstract device to describe any collection of objects/events

They are fundamentally two properties of the same thing. Much like an object has properties of length/volume (3d object)

Or density/pressure and temperature.

OK I recognize this is far too advanced for most people but lets look at a Spinless particle under QFT treatment.

the state of a system is governed by the Schrodinger equation

$i\hbar\frac{\partial}{\partial t} |\psi,t\rangle=H|\phi,t\rangle$ where H is the Hamilton for the notation $\langle | | \rangle$ this is the Dirac bra-ket notation which is a convenient vector notation.

so a simple system with no forces acting upon it of a spinless non relativistic particle is

$H=\frac{1}{2m}P^2$

where m is the particles mass and P the momentum operator.

in the position basis the first equation becomes

$i\hbar\frac{\partial}{\partial t}\psi (x,t)=\frac{\hbar^2}{2m}\nabla^2\psi(x,t)$

where $\psi(x,t)=\langle x|\psi,t\rangle$

to generalize this spinless particle above in relativistic motion take

$H=+\sqrt{P^2c^2+m^2c^4}$

$H=mc^2+1/2m P^2+......$ the ..... denoting higher order corrections

with the Hamilton and Schrodinger the above becomes

$i\hbar\frac{\partial}{\partial t}\psi(x,t)=+\sqrt{-\hbar^2c^2\nabla^2+m^2c^4\psi(x,t)}$

there I just described a spinless particle in both relativistic and non relativistic treatment. However the last equation requires some limits to avoid infinities. Without going into detail as the above is tricky enough to understand we end up with the Klein_Gordon equation

$i\hbar^2\frac{\partial^2}{\partial t^2}\psi(x,t)=(-\hbar^2c^2\nabla^2+m^2c^4)\psi(x,t)$

the point being is the above shows a particle is not some bullet but a field excitation. how we measure that field excitation requires observer treatments described by relativity.

How one measures a field of the above spinless objects are also under observer corrections via the redshift equations regardless of whether you are measuring a vacuum/field/object/particles the observer influence is always a factor.

One can correlate the above to any particle via its spin ie electrons spin 1/2 etc

Edited by Mordred

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Bender    132

Very interesting. Newton's second Law does not apply in the only scenarios where mass energy equivalence has been observed.

I think it does apply if you write it as $F=\frac{dp}{dt}$

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Then perhaps you should clarify what you are truly stating as the energy/mass relations also apply to any field as well

Yes in theory. Beyond particle matter, are there practical applications where mass energy equivalence has negligible significance?

In the wave example, if there is a gain of mass during the wave cycle, then by the mass energy equivalence, there should be an equal loss of mass once the medium returns to an equilibrium state.

I think it does apply if you write it as $F=\frac{dp}{dt}$

No, Newton's Second Law only applies to rather large objects at least compared to those on the atomic scale. If atomic particles are involved then Schrödinger or Dirac equations applies depending on the particle speed.

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Bender    132

How are Schrödinger and Dirac equations in conflict with Newton's second law?

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How are Schrödinger and Dirac equations in conflict with Newton's second law?

The equations are not necessary in violation with Newton' second law but simply cannot account for the additional factors.

The laws which govern the behavior of the sub-atomic particles are completely different. It is impossible to assign a specific position and velocity to a particle. Each particle can be in a superposition of different states, which means that in some sense it is located at the same time in a whole region of space and has a whole range of velocities.

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