42,610 reputation
458136
bio website inspirehep.net/…
location Duchy of Grand Fenwick
age 44
visits member for 4 years, 9 months
seen 1 hour 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
27
comment Quark model in particle physics
It might be helpful to clarify that a tetraquark is $qq\bar{q}\bar{q}$ and a pentaquark $qqqq\bar{q}$.
Aug
27
answered Does work done require interaction between system and surrounding?
Aug
26
comment Kinematics-Motion in one Dimension
Like most plain kinematics problems this is mostly an exercise in algebra.
Aug
26
comment Is it possible to determine the velocity of electron in its orbit?
An bound electron doesn't have a velocity because it is not in "orbit". It's a quantum object and it forms a bound state identified with an "orbital" and those words do not mean the same thing. The Rutherford/Bohr picture may be intuitively appealing but it is more wrong than right. What @JahanClaes suggests is at least defined, but you shouldn't think of that as giving an "orbital velocity".
Aug
26
comment How to let Pythia to output the complete event record in LHEF or StDHep format?
I'm afraid we don't have much expertise on Pythia, and most questions about it go unanswered or unhelpfully answered..
Aug
26
comment Why does the superposition principle work in method of images?
Hmmm ... it seems I misunderstood the question.
Aug
26
awarded  Nice Answer
Aug
25
comment Object pursuing exactly toward an uniformly moving object, with a twist
Note that just posting your effort is not enough to make homework (and homework-like) question on topic. See meta.physics.stackexchange.com/questions/714 for discussion. Questions need to have value beyond just answer are particular exercise, and this is achieved by asking about physics.
Aug
25
revised Hydrogen Spectra using Hydrogen Gas Discharge Tube
edited tags
Aug
25
comment Hydrogen Spectra using Hydrogen Gas Discharge Tube
If your tube is of commercial manufacture, get and check the data sheet for safe voltage levels.
Aug
25
comment If heat can't be transformed into other forms of entropy, why do hot things radiate electromagnetic waves?
The second law of thermodynamics ranks right up there with relativity and quantum mechanics in the "most misunderstood" sweepstakes. And almost every attempt to construct a pop-sci statement makes things worse, not better. The version that you have (or think you have here) is badly mangled and completely incorrect.
Aug
25
comment Theoretical physics
I was torn between choosing "unclear" and our "homework-like questions" close reason. It is possible that you really need to read meta.physics.stackexchange.com/questions/714 before asking again.
Aug
25
answered Why does the superposition principle work in method of images?
Aug
25
comment How did Ising pronounce his name?
It would be very nice if the answer to this question were promulgated throughout the physics community, but it still isn't on-topic.
Aug
25
comment How do we see? Where do the photons disappear?
Energy is a precise concept. It is the Noetherian current associated with the uniformity of the laws of physics in time.
Aug
25
comment Why a type of motion is relative and another is not?
You might take another look at frame dragging in GR. At least some people have interpreted it as giving Mach's principle a bit of a reprieve.
Aug
25
comment Why a type of motion is relative and another is not?
"Using only the CMB reference each observer can synchronize the clock and length units without resorting to Einstein procedure." Not in general they can't. Only if they are at rest relative one another.
Aug
25
comment Fractional number of particles in the universe?
Not quite in the same vein, but some QCD theorists find it useful to treat the number of strong-force colors $n_c$ as a parameter and take limits on it.
Aug
24
comment Why do electrons and positrons exhibit opposite helical motion in a magnetic field?
The Einstein-de-Haas experiment show that spin is angular momentum, which is a fact you'll find in every single treatment of the quantity. It does not show that it is $\mathbf{r} \times \mathbf{p}$, and moreover the quantization of spin disagrees with that of $\mathbf{r} \times \mathbf{p}$.
Aug
24
comment Why do electrons and positrons exhibit opposite helical motion in a magnetic field?
"The field is the same, the particles aren't, so what's the difference?" I have to say that this sentence confuses me. The difference is that the particles are not the same, and in particular that they have opposite charges. All positively charged particle bend in the sense that positrons do and all negatively charged particles bend in the sense that electrons do.