Do you have any questions on it?

May I also ask: when do you expect to be presenting the results of your calculations concerning the collision of two plasma clouds?

Neutrons decay by the ‘beta decay’ process, in which a down quark converts to an up quark with the emission of a W- boson, which subsequently decays to an electron and an anti-electron neutrino (or is it electron anti-neutrino?). This is the weak (nuclear) force in action; viewed ‘from afar’, the neutron becomes a proton, an electron, and an antineutrino.

There is also an inverse beta decay process, in which a proton and electron become a neutron and an electron neutrino; this is the (weak force) process that is responsible for K-shell or L-shell electron capture radioactive decays.

As you would expect, there is also a form of beta decay (beta+ decay) in which a proton decays into a neutron, a positron, and an electron neutrino. And these decays are observed in isotopes which favour them, energetically.

And that’s the key to the stability of neutrons in a neutron star … they are not isolated, but are very tightly bound to the star itself, so beta decay is strongly suppressed. In fact, the neutron degeneracy pressure arises because the protons and electrons in the precursor object (the collapsing core of the supernova) undergo inverse beta decay, because it is energetically favoured.

Analogies are always risky, because it’s all too easy to take them too far, but neutrons are stable in a neutron star, but not on their own, in a way somewhat analogous to how some crystalline forms of ice are stable under very high pressure but not under low pressure.

Relating this to what happens on your lab bench: the two green [OIII] ‘forbidden’ lines (’nebulium’) have never been observed in any lab, because no lab can create a sufficiently hard vacuum for long enough, and also excite oxygen ions sufficiently to populate the metastable state (from which the nebular lines originate). Yet I’ve never found anyone who claims the identification of these very common lines (in planetary nebulae, for example) with those two forbidden transitions is unwarranted simply because it hasn’t been observed in a lab.

So too with the stability of neutrons in a neutron star: no earthly lab has come close to creating the physical environment experienced by neutrons in such objects, yet the underlying (nuclear, particle physics) theory is just as solidly based in lab work as the (atomic, quantum physics) theory underlying [OIII] lines. Please let me know if you have any further technical questions on this.

When do you expect to be able to get back with the results of your calculations?

I think it’s worth going back to where you first used this, to see if this can now be closed.

In the “M83’s nursing arms” blog (2 Sept 08), you said: “@shane: Everybody who reads comments at all knows, now, that Phil’s pulling a fast one. I will mention that the “gas” could not “slam” (presuming that’s what’s really going on at all) if it were not ionized; it would just pass right through, because it’s what in the lab we would call a “hard vacuum”, and gas particles barely interact unless they actually collide. Plasma particles, by contrast, interact at macroscopic distances, so it really matters that, and how much, these “gases” are ionized.”

Leaving aside the simple fact that Phil didn’t use the word “slam” in his blog anyway (does that make your comment a strawman argument?), we come to the question of whether two blobs of gas would “slam” together in a substantially different way than two blobs of plasma with the same density and atomic composition. And in particular whether the timescale for the plasma blobs’ slamming would be substantially shorter than months.

Can you show us the relevant calculations to make such points?

The OP (opening post) is by “DeiRenDopa”; in light of your recent comment about the limits of knowledge, in another blog, I’ll leave it up to you do decide whether the OP (opening poster) is the same person who is writing this comment or not.

If you choose to not read that JREF Forum thread, or read it but choose not to discuss the observational evidence, I’d appreciate it if you’d be honest about that, and say so here.

If you choose to read that JREF Forum thread, I’d be pleased to try to answer any questions you may have about the observational evidence presented in it.

I’d be particularly happy if you were to present a case against the existence of CDM, within the framework of modern astrophysics.

However, if you are more interested in discussing your own views of the nature of modern astrophysics, as a branch of contemporary science, I’d prefer that you do so in the 19 Sept blog (Swift bags etc), where there is already a discussion of that topic (sorta) under way.