Category Archives: Spin-boson

Numerical spin-boson model, part 1

As I mentioned in the last post, I have some concerns about the spin-boson model of cold fusion that are probably most easily settled via computer calculations. But before I jump into calculating something new, I want to make sure I understand the basics. So, in this post I am simply reproducing the computer calculations in Figs. 1-2 of the 2008 paper Models Relevant to Excess Heat Production in Fleischmann-Pons Experiments by Peter Hagelstein and Irfan Chaudhary. This was a fun and straightforward exercise in freshman quantum mechanics. I did not unearth any problem in the paper, nor did I expect to (at this stage). But now I have my first bit of working spin-boson code, and a bit more concrete understanding of the model. Time well spent! So without further ado…

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Spin-boson model – quick update

This is a quick progress report on my studies of the “spin-boson” theory of cold fusion advocated by Peter Hagelstein at MIT. I happen to work 2 blocks away from Dr. Hagelstein’s office, so he’s been nice enough to meet with me a couple times over the years to discuss some of the technical details. Despite those meetings, and much time spent reading his papers, and many posts about the theory, there are still plenty of aspects of it that I haven’t yet tried to understand in detail.

That said, there are currently a number of aspects of the spin-boson model where I’m that seem implausible or wrong to me. I don’t think any of these complaints is fleshed-out and detailed enough that I could, say, write up an airtight disproof of the whole theoretical program tomorrow. But together, they make me pretty confident that this is not a path to a viable explanation of cold fusion. Let me list them:

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Mystery of the missing radiation: Sense and nonsense

I’ve mentioned before (here and here) one of the main challenges of explaining cold fusion. In conventional nuclear fusion, nuclear energy is transformed into the kinetic energy of a few (usually 2 or 3) very-fast-moving particles. But if cold fusion is a real thing, then the nuclear energy would seem to be transformed into something else. The reason we know this is, very-fast-moving particles create radiation (I mean neutrons, gamma-rays, etc.), and people have looked for it and found that there is very little of it (see here). For example, some people have been doing cold fusion experiments for many years, without dying of radiation poisoning. Well, I mean, I’m not an expert, but they don’t look dead. So, this is the mystery of the missing radiation. The mystery has been approached in sensible ways and in nonsense ways, and in this post I’ll give some examples of both. Edmund Storms’s “hydroton theory” will be my nonsense example.

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Spin-boson interaction term scaling

For those who haven’t been following along, cold fusion is a set of disputed experiments, in which there is (allegedly) indirect evidence that nuclear fusion is occurring, under circumstances where it seems impossible for nuclear fusion to occur. One problem: Everyone knows that when nuclear fusion releases energy, the energy usually winds up as the kinetic energy of fast-moving particles, but such particles are not seen in cold fusion experiments; the only energy that anyone sees is heat energy. This leads us to the lossy spin-boson model of cold fusion, which says that the fusion energy gets directly transferred into creating a billion phonons in a single phonon mode. It seems crazy, but the authors (MIT Professor Peter Hagelstein and collaborators) have produced intricate arguments in favor, which I have been gradually working my way through over many blog posts.

Anyway, here is another post on some details of the theory: Why cooperative effects over large volumes are not really helpful for making this reaction more likely to start.

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The “lossy” part of the “lossy spin-boson model”

Readers of this blog (if any exist lol) may notice that I’m on my sixth post about the lossy spin-boson model without really writing the model down. You’ll have to wait a bit longer, sorry! This post is more background.

Here I’m chronicling my progress in conceptually understanding the “lossy” part of the “lossy spin-boson model”. It is discussed most clearly in the paper “Energy Exchange in the Lossy Spin-Boson Model”.

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Spin-boson model: a·cP take 2

As described in the last post, I want to understand this paper, “Including nuclear degrees of freedom in a lattice Hamiltonian” by Peter Hagelstein and Irfan Chaudhary. It’s an important ingredient in the lossy spin-boson model of cold fusion. I will summarize what I said in the last post and expand on it in light of ensuing discussion and clarification from PH.

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Stimulated Emission in quantum mechanics

As I explained in the last post, about superradiance, we are gearing up to discuss Peter Hagelstein’s spin-boson model” theory of cold fusion. The theory relies very heavily on two effects that make it easier to transfer energy to an oscillation mode: Dicke superradiance and stimulated emission. This post goes over how stimulated emission works in quantum mechanics. It’s much simpler than the last post, don’t worry. As before, experts can skip this post.

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