42,610 reputation
458136
bio website inspirehep.net/…
location Duchy of Grand Fenwick
age 44
visits member for 4 years, 9 months
seen 10 mins ago

Experimental nuclear and particle physicist. These days I'm teaching, but I've spent a lot of time on nucleon structure in fixed target electron scattering and neutrino oscillations using reactors and beam sources.

Been reading Zemansky & Dittman's book on thermodynamics recently. Quote: ``The concept of temperature is rich in interpretations and levels of abstraction.'' Nice.


Aug
23
comment Why do electrons and positrons exhibit opposite helical motion in a magnetic field?
Not by the definition of "answer" that you adopted in the question. Every single piece of science is founded—after you peel back the layers of increasingly fine exposition—on "this is the way the world is observed to behave", and you rejected an observation that rests directly on that foundation as "a non-answer".
Aug
23
answered Why do electrons and positrons exhibit opposite helical motion in a magnetic field?
Aug
23
comment Why do electrons and positrons exhibit opposite helical motion in a magnetic field?
If you take the attitude 'Saying "they move like they do because of the force on them" doesn't explain anything at all. It's a non-answer.' then science ultimately never provides any "answers", it only provides useful predictive capabilities. Which is fine as far as it goes, but does leave you needing certain verbal gymanstics to express yourself.
Aug
23
comment The underlying chemical interactions behind torque
In any case, there is no immediate relationship between the bonding details and plain ole mechanical advantage: you can describe the latter just find with a strainable continuum approximation.
Aug
23
comment The underlying chemical interactions behind torque
Wait, you think wood is simpler than metal?!?
Aug
23
comment How does temperature relate to the kinetic energy of molecules?
physics.stackexchange.com/questions/96327/… and a couple more in the "Linked" sidebar therein.
Aug
23
revised How much do the rear and front, side-parts of this 2,400 lb. car weigh?
edited tags
Aug
23
comment Barycenter and relative coordinates for schroedinger equation of the hydrogen atom
Expressions with the Laplacian in them are second order, but written with $\Delta$ they have the first blush appearance of being first order. While one can get used to that very quickly it offends the principle of least astonishment.
Aug
23
comment Barycenter and relative coordinates for schroedinger equation of the hydrogen atom
This is the same canonical change of variable made in classical mechanics at the start of finding the form of general two-body orbits. The search term you want is "reduced mass". Then you just need to think about the properties of differentials to finish the job. As an pointless aside I had forgotten how much I hate the notation $\Delta$ for $\nabla^2$.
Aug
22
comment Can quarks be considered elementary?
Related: physics.stackexchange.com/questions/32476/… physics.stackexchange.com/questions/16048/… and candidate duplicates: physics.stackexchange.com/questions/137541/… physics.stackexchange.com/questions/36108/… .
Aug
22
comment How to calculate the Refractive index of a glass sheet
You may be running into some resistance here for several reasons: (a) you seem to be just asking for a formula without understanding the physics and without caring about understanding the physics; (b) the is closely related to a question you asked only a few hours before and you don't seem to have fully accepted the answers you got; (c) your wording is ambiguous: do you want a theory and table based answer or an experimental answer; and (d) You seem to answer comment requesting clarification by simply repeating the original question and not offering any clarification.
Aug
22
comment what make orbitals and can they be destroyed?
@Nukul "As Bohr said that there are orbits with almost same energy as that of electrons where they revolve agree. " physics.stackexchange.com/search?q=bohr+model+wrong The Bohr model gets exactly one thing right for exactly one kind of atom. It's only value is as a teaching tool.
Aug
22
comment Magnets And Charges
A variety of comments that were not contributing to improving the question deleted.
Aug
22
comment Optical properties of a glass
My take on this is in several parts: (a) the question is far too vague right now, what property do you think you'd like to measure; (b) it could be a really good [home-experiment] question if better specified; and (c) interferometric measurement are harder than they sound and often difficult to do at home or in a introductory lab.
Aug
22
comment Niagara Falls mist
For Niagra in particular it is worth noting that they divert a large fraction of the flow for power generation (which means that, yes, what you oohed and aahed about is only a patch on the natural state of the falls!), and that they take much more at night than during the days (because they want to continue to benefit from the tourist value of the site).
Aug
21
comment What are some surprisingly insightful predictions of classical thermodynamics?
"For instance, if you read through the first chapter of Callen's *Thermodynamics, you get the impression the author has done little more than [...]"* Which proves, at a minimum, that Callen has a talent for illuminating the material. However this would seem to be a make-a-list.
Aug
21
comment Is it possible to plot a quantum particle's position with respect to time?
In the context of "If you try to watch it then you just find out how watched electrons move." it might be useful to mention the quantum Zeno effect.
Aug
21
answered What type of neutrinos do we detect
Aug
21
revised A follow up on “Double Slit Experiment in a Bubble Chamber”
Put this link on some words other than "here". Tag addition.
Aug
21
comment A follow up on “Double Slit Experiment in a Bubble Chamber”
Notice that I discuss liquid noble gas TPC's in my answer to the original. That's the up to data technological equivalent. Also, bubble chambers have made a partial comeback for use in direct dark-matter detection in the last few years.