29,719 reputation
33994
bio website inspirehep.net/…
location Duchy of Grand Fenwick
age 43
visits member for 3 years, 5 months
seen 7 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.


4m
comment What is the meaning behind the neutrino oscillation parameter?
@Danu: the flavor basis and the mass basis are both valid and equivalent descriptions of the system. The flavor states do not have a well defined mass, but just as importantly the mass states do not have well defined flavor.
11h
comment What is an intuitive explanation using forces for the equatorial bulge?
The way to understand it in terms of forces is to use the centrifugal pseudo-force (i.e. work in the rotating frame), but unless you are very clear on the difference between real forces and inertial pseudo-forces this is likely to cause confusion at a later date.
12h
comment If the axis of rotation is fixed, is it ok to say clockwise torque?
Compare to physics.stackexchange.com/questions/71455/…. Just because you are perfectly clear on what you mean does not imply that your listener is perfectly clear on what you mean. In order for "clockwise" to be clear you have to be have agreed on a "forward" first.
12h
comment Protons (as opposed to neutrons) to mediate nuclear fission?
@GODPARTICLE He means the Coulomb force ... the electrostatic interaction between the positively charged nucleus and the positively charged proton is repulsive and quite significant on the scale of kinetic energies in a nuclear reactor.
1d
revised Looking for the name of a physical phenomenon in fluids' mechanics
added 3 characters in body
1d
comment Does the unit of Inertia include radians?
You'll find essentially the same question expressed in different ways in physics.stackexchange.com/q/33542 and elsewhere.
1d
revised Looking for the name of a physical phenomenon in fluids' mechanics
added 389 characters in body
1d
answered Looking for the name of a physical phenomenon in fluids' mechanics
1d
comment Reason for the experiment
Eh?? For the same reason it is important for every other piece of scientific knowledge...
1d
comment Does timbre consist in pitch and volume?
Timbre is almost entirely in the overtones, but this is emphatically not a physics question.
2d
comment Protons and Electrons Occupying the Same Space
The question isn't "What force holds it out?" the question is "What force holds it in?", because quantum states tend to spread out. And the answer is that the electromagnetic interaction (mostly electrostatic) is what holds it in.
2d
comment Loop-the-loop question
As @Floris says, the solution you give is for a slideing block of negligible height. The solution you are supposed to get is for a negligible block of height $2r$ (allowing for the height of it's CoM, and the correct solution must also allow for the angular kinetic energy of the ball (which means it depends on whether the ball is solid or hollow).
2d
comment Precessing gyroscope torque
Yes. There is more when you look at it in detail, but that is how you explain the biggest effect.
Apr
14
comment Precessing gyroscope torque
Look again at the definition of torque. Look in particular at the direction in which it is defined.
Apr
14
comment Why does light seem so slow when compared to everyday observations here on Earth?
The flipped version is "Why is space so big?" (which gives us the chance to bring up Douglas Adams' quote yet again...
Apr
13
comment Mandelstam variables 1 positive 2 negative
@LDC3 The $p$s that appear are 4-momenta. So no, you cannot guarantee that the squares are positive.
Apr
12
comment What can I say about compatibility between predictions and results?
If your uncertainty estimates are good (on both theory and experiment) than the error is 2.5--4 times the uncertainty. The small size of the error makes this a precise measurement but does not change the basic fact that you are several sigma out in three of four channels.
Apr
12
comment Very short decay: A bare quark?
You might find the comments under a post where I relayed this tidbit useful.
Apr
12
revised Very short decay: A bare quark?
edited tags; edited tags
Apr
12
comment Very short decay: A bare quark?
Do you know what the word "hadronize" means in this context?