Thursday, October 23, 2014

Ask me something.

I haven't done this in a while.  Are there any particular subjects that you would like me to address, or concepts to explain?  It's a busy semester, but I can try....

14 comments:

Anonymous said...

j_eff=1/2 SOC Mott transitions..
(i.e. Slater transition).
Is this really something different, or is it a new (hyped) name for an old animal?

Anonymous said...

What's a skyrmion?

Anonymous said...

Can you explain PRL?

David Brown said...

What are the odds that 't Hooft can derive testable predictions from his deterministic interpretation of quantum mechanics ( The cellular automaton interpretation of quantum mechanics May 2014)?

David Brown said...

Does the following make sense? What does Milgrom's acceleration law mean? I think that Einstein ("Meaning of Relativity" 5th edition p. 84) erroneously assumed that a = -1/2. It should be a = -1/2 + dark-matter-compensation-constant. Photons and gluons cannot escape from the universe in which they are located. Gravitons travel at the speed of light on average. A statistically significant few gravitons travel slower than the speed of light. These slow gravitons cause the Fernández-Rañada-Milgrom effect. A statistically few gravitons travel faster than the speed of light and escape from the boundary of the multiverse into the interior of the multiverse. These fast gravitons cause the nonzero cosmological constant and the inflaton field. Electromagnetic radiation from the inflaton field shows up as the space roar. If the fast gravitons never escaped from the universe in which they are located, then the slow gravitons and the fast gravitons would average out, yielding Einstein’s field equations with cosmological constant = zero and dark-matter-compensation-constant = zero.

Douglas Natelson said...

Anon@8:53, Good question - I need to think a bit before I respond. I'm not sure I know enough right now to make a strong statement.

Anon@5:58, I can write something about that. Topological excitations are cool. This'll give me a chance to talk about boojums and hedgehogs, too (and that's not a euphemism for anything).

Anon@7:46, Short answer, no. Long answer: Insert old joke about PRL containing no new information so it's understandable that it can expand at superluminal speeds. More seriously: If you have something in particular in mind, I can try to take a stab at it.

David: I need to read t'Hooft's paper. In my limited experience, people proposing classical/hidden variable approaches then have to jump through some amazing hoops to avoid conflicts with Bell's Inequality experiments. Regarding graviton stuff and MOND, I plead deliberate ignorance. My understanding is that gravitons are (funky, spin-2, self-interacting, hypothesized) massless bosons, so it would not make sense to talk about some moving faster than others, in the same way that it doesn't make sense to talk about some photons moving faster than others in vacuum.

Anonymous said...

Could you explain the difference between a band-to-band transition and possible excitonic states in Raman scattering experiments?

Anonymous said...

About PRL, I do have a concrete question. You've been around for some time, I am new in the business. Can you explain what happened to it? Twenty years ago it used to be the journal to publish in, now it is an afterthought.

Anonymous said...

Would it be possible for you to write something about the use of soft matter concepts in condensed matter? I am particularly thinking of nematicity. It seems to me that there is a pretty broad range of usage, from the worthy in materials like Sr3Ru2O7, to some pnictides which an old fashioned guy like me would just call orthorhombic!

Mark Knight said...

Hi Doug -

You've written nicely before about tone, why and how often, and types of referees. That does leave me with a lingering question: how do you handle a second peer review when the editor sends it back out?

I would like to see a post addressing how to handle a paper sent back by the editor for another round of reviews. Of particular interest to me: what do you do if you notice errors that escaped notice (or weren't present) in the original manuscript? What if the authors answered your issues well in the response letter, but didn't include those modifications in the manuscript? What advice would you have if the authors have clearly done the experiments and theory well, and the results are worth publishing, but the writing/figures are still not at a publishable level following their revisions?

Thanks!
Mark

Tobias said...

Will the giants close the WS out tonight?

Anonymous said...

Would you be in favor of "expanding" the anonymous part of the review process to include anonymous submissions too?

Douglas Natelson said...

Thanks, everyone - this is great fodder for blogging. I am trying to dig out from under some other writing, but I will get to this. I've started a draft post about skyrmions, and I do want to write something about soft matter in general. The super short version: Somehow as a grad student I was skeptical that all of the things called phases by the soft matter folks were really true thermodynamic phases. Then I read Chaikin and Lubensky and looked at the figures in there showing the transitions in, e.g, liquid crystals, and I realized I'd been wrong.

Anon@3:14, can you point me to a reference so I know what you're specifically asking?

Anon@6:54, I would like to write about PRL and I'll do so soon. I think you overstate things, but you are absolutely right that the journal "marketplace" is much different than it used to be, and I think PRL is having a tough time competing.

Mark, I can address this.

Tobias, my magic 8-ball says "Ask again later!"

Anon@1:06, I think that's very hard to do as a practical matter. It's often very easy to deduce the authors based on the writing of the paper anyway.

Raf said...

I'd love to hear your thoughts on the substance and status of triggered metal-insulator transitions as logic switches. I'm not talking about inhomogeneous phase transformations, as in non-volatile memory. I'm talking about the concept of using electric fields to switch between insulating and metallic thermodynamic ground states. What are the most interesting science questions, and what's the outlook for technology?


Mott-FETs and all that.