38,941 reputation
354126
bio website inspirehep.net/…
location Duchy of Grand Fenwick
age 44
visits member for 4 years, 5 months
seen 15 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.


Apr
22
comment Physical reality of calculated wavelength from two measurable phenomena slit distance and fringes distance?
Huygen's principle does explain fringes behind a single edge. See for instance Fowles Introduction to Modern Optics figure 5.25. The math is harry enough to want to do it by Fourier's methods. Water will do it too, though it is experimentally difficult to set up.
Apr
22
comment Physical reality of calculated wavelength from two measurable phenomena slit distance and fringes distance?
Huygens principle. Huygens principle. Huygens principle. All of your questions---All of them---are answered by the application of Huygens principle. Students often resist this, thinking that various heuristics are "easier", but sooner or later they have to learn the underlying tool.
Apr
22
comment Is Einstein's characterization of “time” as “the position of the little hand of my watch” definitive and binding in the RT?
What would "binding" even mean beyond uncritical hero worship? It is, in any case perfectly compatible with the notion of proper time as that is what is measured by the observer (on in this case by his watch).
Apr
21
comment Naked Time ( Is there such a thing ?)
Time is the name we assign to the fact that two distinct events can occur in the same place without being coincident.
Apr
21
comment Naked Time ( Is there such a thing ?)
Try stating--precisely--what would be different between two worlds, one of which had "illusionary" time and the the other with "real" time. Take your ahem time. I'll wait.
Apr
21
comment Why aren't we affected by radium?
The basic issue here is one of scale. Don't just here "radiation" and think "bad", ask "How much?". xkcd.com/radiation is a kind of layman's guide to real-life doses and danger levels.
Apr
21
comment How to explain the momentum exchange of two solid particles collision at molecular scale?
@Abhijeet Momentum is conserved in all collisions without respect to elasticity.
Apr
19
comment Why does the period/frequency of a fan slow down significantly when I taped a piece of rubber band to it?
Every thrown a balance weight from the wheel of your car? Or even if you haven't, do you understand the consequences of such an event? How might that relate to the issue in front of you?
Apr
19
revised Why does the period/frequency of a fan slow down significantly when I taped a piece of rubber band to it?
edited tags
Apr
19
comment How does light manage to change its course at the boundary of two media of different optical densities?
Perhaps you could be more explicit about what you feel isn't covered in the answer to the questions that Qmechanics points out. They are pretty complete. (The QED question is where to look for help with the particle view---which is difficult unless you are highly conversant with the core concepts of quantum field theories).
Apr
19
comment Does elementary particle emit photon?
Event displays are commonly near-real time. I've worked on experiments where the delay was seconds and others where it was minutes. I've no actual experience with the online display at a LHC experiment so I won't hazard a guess as to how close to real-time they are. Part of the issue depends on how much processing you want. Where it is seconds the display is generally simply of what detector elements are activated and how much. If you want tracking you generally have to wait a little longer.
Apr
19
comment Q: Any standard terminology for “gold standard” Monte Carlo solutions
I'm not sufficiently conversant with the rules on Computational Science to be sure, but this might find a better home over there. If you are interested in having the question migrated, let me know and I'll ask the mods...
Apr
19
comment Can we predict the half-lives of radioactive isotopes from theory?
Weak universality has been mentioned around here from time to time. It is the claim that the weak coupling to leptons is always the same ($G_F$) and that there is a well defined relation ship between the lepton coupling and that to quarks.
Apr
19
answered Can we predict the half-lives of radioactive isotopes from theory?
Apr
18
comment How is the uniform gravitational field approximation $F_g\approx mg$ near Earth's surface derived from Newton's law $F_g=GMm/r^2$ of gravitation?
See also: physics.stackexchange.com/questions/35878/…
Apr
18
comment What is potential energy truly?
It might be helpful to eludicate that potential energy comes from the relative position of several components of a system. The boulder gets its bear annihilation capacity from its position relative the planet; take the planet away (and leave the bear an boulder floating is space) and the bear is safe again.
Apr
18
comment Simple question relating to physics prac reports
You have not been specific about what the measurements you are making are, but your reasoning would be appropriate for a lab I ask my students to do. I asked about the number of measurement because if you had a statistical set and their distribution was only 2% wide it would suggest that your error estimate was simply high for some reason, or at least that some parts of it were highly correlated. However, given the size of your data set it would not be safe to draw any such conclusion.
Apr
18
comment Simple question relating to physics prac reports
When you say "I have values for the elasticities that are all within 2% of eachother" how many measurements are you talking about?
Apr
17
revised Why can't a high intensity beam be injected into the LHC when the machine is empty
various fixes for problems identified by DarioP
Apr
17
comment Balancing an equation
I'm voting to close this question as off-topic because it is a chemistry question not a physics one.