The journey of light (A Possible Hypothesis)

[CraigD]

(Like all bosons, photons don’t interact.) Craig your saying that photons don't interact with electrons?

No. Bosons (photons, gluons, Ws, Zs, and the as yet-unobserved Higgs) don’t interact with each other. Specific ones interact with specific fermions (up, down, strange, charm, bottom and top quarks, electrons, muons, and tau leptons, electron, muon, and tau neutrinos, and their antiparticles).

 

So quarks in protons and neutrons and electrons interact with photons, but photons don’t interact with one another, etc.

 

A basic understanding of the standard model is not difficult to obtain, and helpful in discussions of it. the poster is, IMHO, one of the best study guides for it.

[Little Bang]

Your right Craig, it was rather silly of me to suggest there might be something wrong with the standard model since it obviously answers all the questions about the universe.

[Tormod]

Your right Craig, it was rather silly of me to suggest there might be something wrong with the standard model since it obviously answers all the questions about the universe.

 

Mocking and ridicule is plain silly. You ask questions and get replies. Why keep aiming for the player if you want to kick the ball?

[CraigD]

Your right Craig, it was rather silly of me to suggest there might be something wrong with the standard model since it obviously answers all the questions about the universe.

To the contrary, I’d say it’s rather silly not to suggest there’s something wrong with the standard model. Its complete omission of any explanation of arguable the most significant large-scale fundamental force, gravity, tops my list of grievances.

 

However, the generation, propagation, and absorption of electromagnetic radiation appear to be very well explained by the standard model. One of its predictions is that light propagates through vacuum indistinguishable of that vacuum having a magnetic field (of virtual photons), or not having one, which was among the points I raised in post #15 in objection the hypothesis that light requires a magnetic field to propagate through vacuum made in post #1.

 

A good way for the hypothesis’s champions (Little Bang and others) to make a convincing scientific argument that the standard model’s prediction is wrong and post #1’s hypothesis is correct, is to answer objections to it, ideally by describing experiments and predicting outcomes of them that support the hypothesis over the standard model. Sarcastic self-denegation is not, IMHO, a very good approach.

[Little Bang]

I apologize for the attitude, you are correct. I can not see how you can say that the standard model explains how light propagates through a vacuum. To me thats like saying I don't care how my car works, I get in it, push on the gas and it goes. We can explain exactly how water waves and sound waves propagate but we can't do that for electromagnetic radiation. Again I apologize to you Craig, it's just that so many times we look to the standard model like some people look to the Bible, it's in the book. My idea about using the magnetic fields for light to propagate does not have to be the truth, but I suspect that it is some place around the truth.

[Little Bang]

Sorry people for ignoring my own thread over the past eight days, I’ve been out of pocket.. I realize that I am a layman when it comes to the standard model, therefore I don’t really have the right to question it but I do have the right to learn. I will ask a couple of questions that may seem unrelated to this thread but since they are about charged particles I feel that there is a relationship. If you look at the quark model it shows decay routes that some quarks can take to form other quarks. One of those is when a down quark becomes an up quark. Now this makes sense to me because we need some way for a free neutron to decay into a proton, electron, and electron antineutrino. How does the standard model explain the electron and electron antineutrino? During nuclear fusion a proton is converted to a neutron with the release of a positron and a neutrino. Doesn’t this imply an up quark decaying to a down quark and if so how did the positron and neutrino form?

[Little Bang]

Ok, I’ll try to ask the question in a different way by telling a story. A huge gas and dust cloud out in space collapses to form a massive star. At the core of the star one particular proton starts the fusion process with another. Our particular proton emits a positron and neutrino to become a neutron, then the next fusion process forms a helium atom. Over the next million years our atom winds up close to the surface of the star and the star goes super nova. Our atom comes into contact with another gas and dust cloud that forms an average star. Our atom becomes part of a comet. The race of people on the third planet see the comet and send a probe to meet it and collect samples of it’s tail. The samples they get back contain our atom. They hit the atom with a proton and split it apart. Our original neutron becomes free. After about fifteen minutes it decays by releasing an electron and antineutrino to become our original hydrogen atom. How does the standard model explain this atom that has given up a great deal of energy yet is the same atom with the same mass as when we started the process?

[snoopy]

Hi Littlebang,

 

I would suppose the standard model would explain it by saying its a hydrogen atom........ not sure exactly what all the rest of the historical interactions have to do with it..... you would need to explain why the universe should care about the history line of this particular atom.

 

As for your thing on light

One way to look at light is this its a self propelling electromagnetic wave

its `self propelling` therefore it needs nothing to `wave` through.

[Little Bang]

The point is snoopy I have just described the release of a gamma ray via the positron electron annihilation and yet wind up with the same atom that started the process. According to the laws of thermodynamics that is impossible. You can’t get free energy.

[snoopy]

To LittleBang,

 

In your story you start with a proton that becomes a helium atom that atom becomes a comet (partof) Then this atom is captured by a space probe and is subjected to a test that turns it into a hydrogen atom at what point do you see this as being the `same` and you make this reference to a gamma ray where do you get that from as its not clear from your original story.

 

You need to be clearer b4 I can see what you are trying to get at.

[CraigD]

… At the core of the star one particular proton starts the fusion process with another. Our particular proton emits a positron and neutrino to become a neutron, then the next fusion process forms a helium atom.

I believe you’re omitting a critical part of your description of the first step of the proton-proton chain fusion reaction.

 

The reaction is: [math]p^+ + p^+ \rightarrow ( p^+ + n ) + e^+ + v_e[/math], which can also be written: [math]^1H + ^1H \rightarrow \, ^2H + e^+ + v_e[/math]

 

Note that the proton doesn’t just “emit a positron and neutrino to become a neutron” – it absorbs an entire proton first. After this step, the “other” proton that it “started the fusion process with” no longer exists. For the next step of the reaction, a third proton must enter the scene (not hard to find in huge ball of ionized hydrogen).

- EDIT: This paragraph is completely wrong! See post # 33.

How does the standard model explain this atom that has given up a great deal of energy yet is the same atom with the same mass as when we started the process?

At this or any step of the proton-proton, or any other fusion reaction, if you add up the mass/energy of the particles going into and out of it, you’ll find the 2 sides balance. There’s no need to explain how the proton (or the whole hydrogen atom) has “given up a great deal of energy yet is the same atom”, because it hasn’t.

 

This seems to be a straightforward discussion of proton-proton chain fusion. How does it relate to the thread’s original claim that we need some sort of medium for electromagnetic radiation to propagate, and that a “universal electromagnetic field” is that medium?

[snoopy]

This seems to be a straightforward discussion of proton-proton chain fusion. How does it relate to the thread’s original claim that we need some sort of medium for electromagnetic radiation to propagate, and that a “universal electromagnetic field” is that medium?

 

the above quote is from CraigD

 

Yes I would like to know that too. LittleBang`s explanations seem overly complex to me and seem to hide from things.

 

CraigD`s explanation of proton - proton fusion was fair enough but I get the feeling that it wasnt the question asked by Littlebang.

And also I would like to ask CraigD do you see where the gamma ray comes from ? cos I for one dont.

[CraigD]

And also I would like to ask CraigD do you see where the gamma ray comes from ?

2 of them come from the annihilation of the positron produced in step one of the reaction with any nearby electon:

[math]p^+ + p^+ \rightarrow ( p^+ + n ) + e^+ + v_e[/math],

[math]e^+ e^- \rightarrow 2 \gamma [/math]

 

Another one comes in step 2:

[math]( p^+ + n ) + p^+ \rightarrow (P^+ +P^+ + n) + \gamma [/math]

 

One more can come from one of the possible step 3s.

 

Although I’ve not compared it to any professionally edited print sources, I think the wikipedia article "Proton-proton chain reaction" is accurate.

[snoopy]

To CraigD

 

Oh right I see it now your explanation is a lot clearer that LittleBangs but I still fail to see the relevance. I cant help but shrug and say yeah so what ?

Not your fault of course CraigD just wish Littlebang could be a bit clearer thats all.

[Little Bang]

Snoopy your right, but since we were talking about fields generated by charged particles I thought that discussing how a proton changes into a neutron might help to shed some light on the subject.

 

Craig, the link you list, to me, shows two protons fusing to form one proton and one neutron, is the picture they show wrong?

[CraigD]

Craig, the link you list [Proton-proton chain reaction - Wikipedia, the free encyclopedia], to me, shows two protons fusing to form one proton and one neutron, is the picture they show wrong?

No. It is I who was wrong, completely and sloppily, when I wrote in post #28:

Note that the proton doesn’t just “emit a positron and neutrino to become a neutron” – it absorbs an entire proton first. After this step, the “other” proton that it “started the fusion process with” no longer exists.

The correct explanation (I hope I have it right this time – I did in Physics class 26 years ago!) is that the mass of a [math]^2H[/math] nucleus is less than the mass of 2 [math]^1H[/math] nuclei, the difference accounting for the mass/energy of the released positron ([math]e^+[/math]) and electron neutrino ([math]v_e[/math]).

 

At first glance, this explanation doesn’t appear to make sense. The mass of a free neutron (about 940 MeV) is slightly greater than that of a free proton (about 938 MeV), so how could a [math]^2H[/math] consisting of a proton and a neutron mass less than 2 protons?

 

The answer, in detail, is among the most complicated ones in physics. In summary, it’s not too complicated. Here it is:

 

As is commonly known, protons and neutrons (nucleons) are made of quarks – an U + U + D for a proton, an U + D + D for a neutron. Less commonly known is that they are held together by gluons (the force-carrying boson for the strong nuclear force), and that the sum of the mass of the quarks in a proton or neutron is only about 1% its mass. The remaining 99% is due to the relativistic mass of a very complex “swarm” of virtual gluons, and a few more exotic particles. Even though the gluon has zero rest mass, like the photon, it travels at the speed of light, so has mass.

 

Gluons not only hold together quarks within nucleons, but hold together nucleons within atomic nuclei. Although one would expect a proton and neutron together in a [math]^2H[/math] nucleus to have more gluons, and thus mass more than the sum of the masses of a free proton and neutron, theory predicts and evidence supports that they actually “share” gluons to have fewer, and thus have the observed lower mass.

[Little Bang]

When I buy into an idea I find it very difficult to give up on the idea when people start shooting darts at it, but if enough darts hit the target I will drop it. Is it possible that we're like that about the standard model? The model is what, 40, 50 years old? We just keep tinkering with it hoping that it will work. Granted that it answers 99% of all the questions but if it's the truth it should answer all.