31,863 reputation
341103
bio website inspirehep.net/…
location Duchy of Grand Fenwick
age 43
visits member for 3 years, 8 months
seen 4 hours 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.


Jul
15
answered Measurement in reciprocal metres
Jul
15
comment Does increasing diameter of a water pipe increase speed or volume?
Poiseuile is of course assuming laminar flow. The situation gets even more stark when turbulent flow is involved.
Jul
15
revised nuclear-physics wiki description
blue pencile stuff
Jul
15
reviewed Edit suggested edit on Why does the Walecka model not include pions?
Jul
15
revised Why does the Walecka model not include pions?
Walecka model is an effective field theory for nuclear interactions, so EFT tag is appropriate. Actually even more appropriate than QCD; extended to remove QCD in favor of the more general QFT ad also add nuclear physics; CApitalize the man's name while we're editting.
Jul
15
revised How hot is aurora?
Just Kelvin, please. "Degrees" are for non-absolute temperature measurements.
Jul
15
comment Why does the Walecka model not include pions?
No. I see that this does not answer the question as the pion is a pseudoscalar. So I have nothing to offer.
Jul
15
comment Why does the Walecka model not include pions?
Er ... isn't the $\sigma$ a stand in for all the light scalar mesons? I certainly don't recall him addressing this question when I took his class at W&M back in the late 90's (he generously threw it open to all JLAB grad-students and even intervened with the W&M parking office to get us permits).
Jul
14
comment Can an object reverse its direction of acceleration even though it continues to move in the same direction?
Many many students struggle with this so lets be very, very clear: there are no limits on the relative directions of position, velocity and acceleration at any given time. None what-so-ever. All possibilities are admitted. Every last one of them. Really.
Jul
14
comment Antipodes are mostly ocean - so what happens after digging that hole through earth?
You are positing that they can deal with the heat, pressure and in some places fluid environment of the deep Earth but are going to have trouble with a minor inconvenience like an ocean? Seriously? Just wave the same unobtanium at it that you use on the liquid part of the core. Problem solved.
Jul
14
comment Negative signal to noise ratio
This question appears to be off-topic because it has been cross-posted to a more appropriate site.
Jul
13
comment Evaporative cooling in a tropical environment
The effect of evaporative cooling in a humid environment is best summed up as "Not very #@~&#^"% much!". Lived with one of those things in New Mexico for a few years. It did a sweet and inexpensive job most of the time, but on the few even moderately humid days we did get It wasn't worth a thing.
Jul
13
comment What are non-conventional ways of neutron detection?
For energies above several hundred keV, scintillation due to hydrogen recoil works fine (and there are special scintillators that makes pulse shape discrimination easy). The conventional technique for thermal neutron detection is capture reactions (on B, Cl, Gd, H, C, etc etc) which release x- or gamma-rays afterward. I suspect that people have also done lattice phonon detection at sub-thermal energies, but I don't know that field. Not sure where TLDs fit in. There is a "too broad" close vote and I am inclined to agree until this is narrowed down a bit.
Jul
13
comment could it be possible to create a pentane steam engine?
Bart, because of the First Law of Thermodynamics (which is just Energy Conservation wearing a hat and fake mustache---he's such a kidder).
Jul
13
comment Does Uranium-235 always split into Krypton and Barium in nuclear fission?
In the case of large nuclei things are rarely always the same way. The usual question is "What is the branching ratio to [some particular state]?"
Jul
13
comment Does a rotating plank only acquire rotational kinetic energy?
The parallel axis theorem is your friend in this business. Once you understand (really understand) it there will be no mysteries left in this problem.
Jul
12
comment How does dark matter interact with light?
Non-baryonic dark matter (be it WIMPs or other things) is defined by it's non-interaction with light.
Jul
12
comment Gravitational force due to asymmetric Earth shell
Just a hint for reading this kind of thing: they wouldn't have put the qualifier (symmetric) in there if it didn't matter somehow.
Jul
12
comment Problem on speed of light
Related: physics.stackexchange.com/q/16018. That comes awfully closing to being a duplicate because the answer is "the question doesn't make sense because it presupposes a rest frame for one of the photons." Also physics.stackexchange.com/q/68600 .
Jul
12
revised How can a gas support tensile stresses?
Merge separate answers.