34,505 reputation
347118
bio website inspirehep.net/…
location Duchy of Grand Fenwick
age 43
visits member for 3 years, 11 months
seen 18 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.


2d
comment Scintillator Length Calculations
"so is my reasoning correct when I assume that I'm supposed to get my $constants * int(ta∗e−bt)=0.98$ ?" That's right. But there is no loop in the answer Wolfram gives and more than an integral that gives you $\sin (3x + 2)$ has gotten you into a "trig-loop". You just need the inverse function. Or numerical solutions are fine for this job. I'm afraid that as you move your colleagues will simply assume that you can find a solution to things like this without aid. That's why the sources don't mention it.
2d
comment Scintillator Length Calculations
Wolfram alpha gives answers mostly in Gamma-function forms. But in all seriousness there is no reason you need an exact solution. Use a numeric integration.
2d
comment Gamma Spectrum: What is causing this behavior?
In any case, that may just be the detection tail of the peak. I'm not sure why it would be so much more prominent on that line, though.
2d
comment Gamma Spectrum: What is causing this behavior?
Uhg. And you're using Ortec's software, too, aren't you? While there is nothing actually wrong with the data recording Ortec's display software does a rotten job of dealing with calibration drift and issues that these detectors are subject to.
2d
comment Gamma Spectrum: What is causing this behavior?
Worth while question: is the vertical axis on a linear, log or square-root scale?
2d
comment Gamma Spectrum: What is causing this behavior?
That shoulder looks vaguely like a Compton scattering peak, but I can't suss out why you would see it on only one peak. From the appearance of the data I assume this is from a Ge-detector and they rarely show such structures.
2d
comment Doesn't the second postulate of special relativity imply the existence of “luminiferous ether”?
@Geremia Both those statements are true if modified to read "with a definite velocity c in the rest frame of the medium", but for light the first is true without such modification (it applies to all inertial observers) and the second presumes the existence of a absolute rest which does not exist.
2d
comment Diffraction to be explained without Huygens principle
I could do the detailed math for a particular wave equation, but why? Huygens may have found it by intuition, but it is a consequence of the mathematical structure of linear wave equations. Avoiding it just makes everyone's life harder.
Oct
18
revised Question on acceleration of gravity
rolled back to a previous revision
Oct
17
comment Why heavy elements don't sink to the core?
Quite good answers, too.
Oct
17
comment Why heavy elements don't sink to the core?
This question is on-topic here and can stay, but it might very well find a better set of answers on Earth Science and I'll migrate if @LIUFA asks.
Oct
17
comment What causes damage, kinetic energy or momentum?
"it is energy that produces momentum" Uhg. It is not meaningful or helpful to try to build a hierarchy between energy and momentum, even in Newtonian physics (and less so in Einsteinian physics where they are components of a four-vector are mixed into different proportions depending on the observer).
Oct
17
comment Are there perfect elastic collisions in Nature?
You really shouldn't edit your question to invalidate an existing answer.
Oct
17
comment Are there perfect elastic collisions in Nature?
You do need to be careful here in the sense that mesons and baryons have substructure and can be excited. Now we usually write this as having a "different" species of particle in the final state, but still. All that you say is true for fundamental particle and for all particles at modest energies (because the excitation energies of hadrons are a significant fraction of their mass).
Oct
15
comment Collision force calculation with no future knowledge
You might also be interested in Computational Science.
Oct
15
comment Collision force calculation with no future knowledge
You keep finding those methods because they are easier than working the full problem involving deformational forces (and in particular non-reversible deformations). The full version almost has to include some kind of finite element analysis (FEA) which is a major field of computation in and of itself.
Oct
15
comment What is the significance of clamping the center of the spring?
@MohamedOsama This could be saved if you could explain what you don't understand. There are several parts to the explanation given. Surely there are some bits you get and some you don't. If you don't get any of it you would be well advised to look at a simple question first.
Oct
15
comment What is the significance of clamping the center of the spring?
@AlfredCentauri That's an elegant approach to explaining the solution, and perhaps I am in the wrong here, but at this point we haven't the slightest indication of what the OP has does or does not understand and a complete lack of identification of the "specific physics concept" at question.
Oct
15
answered Generic term comprising everything that can be represented with a number and a unit?
Oct
15
comment Why does nuclear waste have to be stored until the constituent elements decay naturally?
Of course almost any sufficiently active material can be used in a RTG, but ... (a) RTGs are scary, (b) while they are reasonable high in energy density RTGs are quite low in power density (c) aside from being scary, most isotopes do either produces some ionization outside the case or require heavy shielding exacerbating item b, (d) the chemistry of a decaying mixture of various isotopes is a mess which makes engineering the enclosure hard, and (e) if you want to avoid d by purifying first you get into issues of containment while you do that. So the cost engineering is tough.