[BilboGrabbins (OP)]

"And the scientists’ measurements back that up, says laser plasma physicist Stuart Mangles of Imperial College London, who was not involved with the new study: “Everything they’re measuring about it makes it look like a real photon.” However, Mangles notes that the photons are still virtual by some definitions: Unlike normal photons, which have no mass, these photons do have mass."

https://www.sciencenews.org/article/colliding-photons-matter-particle-physics?fbclid=IwAR0xZeM1idBMmZ4pSLJ-1pa5ulemphxW1KWdHWj6O3E19cEFovrUgV0PdMo



Virtual particles are usually ground state particles. Virtual particles are mediator particles just as ordinary photons are. A good example of virtual particles is their interactions with other particles like muons. They exist around the muon in a haze fleeting in and out of existence. Virtual particles should not be mistaken for meaning they are not real, its just that they do not follow the ordinary Hermitian matrices making them strictly observsble, but thry can be obseved indirectly. In a way, they are very much a candidate for a type of dark matter in this sense. Virtual particles have a rich history. Yukawa predicted a hypothetical model where the virtual photon might bind nucleons, at the nuclear range, byt being massless he found it wouldn't provide the correct binding energies. This may be revised now that virtual photons do carry mass. Nevertheless, using the uncertainty principle he was able to calculate the mass of these virtual photons and they were soon vindicated as Pion exchanges that carried the strong force. His rudimentary calculation for the mass was a bit iff, but further experimentation gound there were other Pions and at least one class of these partickes did fit his mass prediction. They were detected in cloud chambers.

htt
p://hyperphysics.phy-astr.gsu.edu/hbase/Forces/exchg.html#c4

If Pions hold quatks together, the picture soon became more complicated because the Quarks had also another exchange particle, called the gluon. Sometimes articles gloss over the role of Pions being the strong force mediator and concentrate on the gluon phenonenon. But now, with it being confirmed that virtual photons can carry mass, they may actually play a role for binding that Yukawa once predicted.

Some intellectual discussions on Pion vs gluon exchange forces https://physics.stackexchange.com/questions/9663/is-it-pions-or-gluons-that-mediate-the-strong-force-between-nucleons

Yukawa wanted to find out what binding agent held a nucleus together. He knew it followed a distance law of 1/r ²  with it dropping from huge values inside the nucleus to negligible values at the rim. He first speculated it coukd have been a photon, possibly a virtual photon then presumed to have zero mass, but he soon found if it had no mass it could not act as the binding agent. The exchange particle had to have sone mass to fit the experinental knowledge of forces.

To form an orbit its DeBriglie wave would have to form a standing wave ring if radius r and the simplest ring was

λ = 2πr

but for any particle

λ = h/mv

 ∵ mv = h/2πr

if we say v = c that is an overestimate unless it was a photon with zero mass, but if we say m = m' the rest mass of a meson, that was an underestimate.

However, we make such exchanges in hope to find they will compensate, so Yukawa gave

m'c = h/2πr

by using

m' = h/2πrc we can now predict the value of m from the known values of h and c and the estimate of the nuclear radius r which is approximately 1.4 x 10^(-15) m. We get a value of

0.9 x 10^(-30) kg.

Comparing this with the rest mass if an electron, the exchange particle had to have roughly several hundred electron masses! This makes it five or ten times light than a single atom. At first, it wasn't believed, but a meson were soon experimentally varified inside of cloud chambers. The mass at first wasn't right but further experiments found more and one of them did fit his predicted mass.
​​​​​​​
So hopefully, you can see the opening of new doors to Yukawas originally binding hypothesis using photons, since he rejected that idea because he was using a now outdated idea of them containing "no mass."

[Zer0]

Re: Some Photons Have Mass! New Physics Report

Quite an attention Grabby Line.

Suits Equivalence Principle.

ps - 🎏

[yor_on]

Interesting and possibly connected to electromagnetic 'fields' :)

I've seen virtual particles connected to https://physics.stackexchange.com/questions/59333/why-on-shell-vs-off-shell-matters in where 'on shell' match classical definitions and calculations, and off shell, as far as I get it, then  represent the probabilities of a 'fields' interactions. And would it then be this 'off shell' definition that makes them contain a 'mass'?


spelling

[BilboGrabbins (OP)]

Interesting and possibly connected to electromagnetic 'fields'

I've seen virtual particles connected to https://physics.stackexchange.com/questions/59333/why-on-shell-vs-off-shell-matters in where 'on shell' match classical definitions and calculations, and off shell, as far as I get it, then  represent the probabilities of a 'fields' interactions. And would it then be this 'off shell' definition that makes them contain a 'mass'?


spelling

That's the technical name for virtual particles, we call them off-shell. Real particles are on-shell. Real particles are just longer lived virtual particles. Take the Bougliubov transformation, round a black hole. Virtual particles can be seperated before they annihilate. The virtual particle leaving a black hole becomes "real." In fact, all visible matter once came from a ground state virtual field.

There's a good quote here that is relevant

"Due to the bosonic nature of the photon, increasing the peak intensity through a combination of raising the pulse energy and decreasing the pulse duration will pile up more and more photons within the same finite region of space. In the absence of material, this continues until the vacuum is stressed to the point of breakdown and virtual particles become real. The critical intensity where this occurs for electrons and positrons – the so-called Schwinger limit – is predicted to be ~ 10^29 W/cm2."

There's still a lot of misconceptions about virtual particles, some still spout they don't exist when in reality we can measure their effects and without them quantum theory would not work or even make sense.

[BilboGrabbins (OP)]

In fact, the virtual particle leaving the black hole itself, becomes "boosted" by the black hole's gravitation into becoming real particles.

[Eternal Student]

Hi.

This is interesting and thanks for posting it.  I've not had time to study all the links you provided carefully.  However a quick survey of the first link brought me to an article that discusses the creation of matter and anti-matter by virtual photon interactions.   It's not really an article about photons having mass.  You have extracted only a small portion of that article and it's not the main thrust or gist of the article.

Virtual particles should not be mistaken for meaning they are not real

   I'm always very cautious about treating virtual particles as anything other than a convenient description of something without the mathematics.

I'll have to read more on this later, it's interesting and I'll enjoy studying it later.  Sadly, I have a few things to do first.   Thanks for posting and best wishes to you.

[BilboGrabbins (OP)]

Hi.

This is interesting and thanks for posting it.  I've not had time to study all the links you provided carefully.  However a quick survey of the first link brought me to an article that discusses the creation of matter and anti-matter by virtual photon interactions.   It's not really an article about photons having mass.  You have extracted only a small portion of that article and it's not the main thrust or gist of the article.

Virtual particles should not be mistaken for meaning they are not real

   I'm always very cautious about treating virtual particles as anything other than a convenient description of something without the mathematics.

I'll have to read more on this later, it's interesting and I'll enjoy studying it later.  Sadly, I have a few things to do first.   Thanks for posting and best wishes to you.

Well I can assure you, they are more than just mathematical convienience as we can not omly indirectly oberve them, but we alsi measure their effects in the real world.

Look up Forbes, "Are virtual particles real." Hopefully you'll come to understand they are not what you thought. As I said, quantum mechanics makes no sense without them, a good example are zero point energy fields that owe their existences to these residual energy states and is the reason why a system can never thermodynamically reach absolute zero Kelvin.

So do not be cautious, its what modern science teaches us. Apart from a very select few who still can't accept their existences. And I mean that they are the minority.