29,752 reputation
33994
bio website inspirehep.net/…
location Duchy of Grand Fenwick
age 43
visits member for 3 years, 5 months
seen 54 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.


Mar
29
comment Why are non-horizontal levers not considered to be in equilibrium?
This is a good question and the answer depend in detail on how the balance is constructed.
Mar
29
comment Why are non-horizontal levers not considered to be in equilibrium?
The damping magnets server to cause any swinging to settle out faster, I don't believe they impart any force on the bar when it is at rest.
Mar
29
revised What will happen to water at $0^\circ$ Celsius kept in large evacuated chamber
mior LaTeX improvements
Mar
28
comment Horsepower at certain RPM point without knowing torque?
For real engines I think the correct answer is "You measure a sufficiently dense selection of points and interpolate"; that is, you can't do it ab initio.
Mar
28
revised Tsunami dampening mechanisms
added 2 characters in body
Mar
28
comment What happens when we bring an electron and a proton together?
"Most likely" expression a notion of probability. Why is capture more likely than a simple scattering? Especially as $\alpha$ is small.
Mar
28
comment What happens when relativistic effects stop?
I'm a partisan of calling the older relativity "Galilean" rather than "Newtonian", but both names appear in the literature.
Mar
28
comment What stabilizes neutorns against beta decay in a neutron star?
The site uses the MathJax rendering engine for LaTeX-alike math. In-line between single $s and block equations between $$s. Given the way you wrote the above equation I imagine that you can figure out the rest.
Mar
28
revised What stabilizes neutorns against beta decay in a neutron star?
latexify
Mar
27
comment electron in the nucleus
For at least some nuclei @Negin is simple wrong. "Electron capture" refers to reaction where a nuclear proton captures an electron turning into a neutron and a neutrino: $e^- + p^+ \to n + \nu_e$. It's not a common mode because most nuclei are neutron rich, but it does occur.
Mar
27
comment Scattering geometry question
I'm quite sure that when $\vec{A} = \vec{C}$ the two evaluation orders are equivalent.
Mar
27
comment Is there any scientific instrument right now to monitor complicated chemical reaction between atom?
Can you explain what you mean by "monitor"? I'm guess that you are asking about detailed measurements of electron cloud behavior and nuclear separation as a function of time. If so you may want to think about how the measurement might affect the things that you are trying to observe...
Mar
26
comment Is there anyway to use a scientific instrument to measure the density of electron around the atomic orbital?
When you do a scattering experiment like this you actually measure the momentum distribution, but as the system is bound it is possible to show that it is related to the spacial distribution by a Fourier transform.
Mar
26
comment What kind of a particle has this mass?
While the PDB is a bit of a tome, the particle listings are pretty simple. They are divided into four groups and each group is ordered by mass. You will quickly be able to discard the leptons and bosons leaving you to leaf through the first through few pages of mesons and baryons.
Mar
25
revised How do I see things of the bright room, being in the dark room?
rolled back to a previous revision
Mar
25
comment Simultaneous Charging and Discharging Capacitor
You may be trying to ask about the behavior of a capacitor in parallel with some other circuit elements (though that is not what you have draw---you drew it in parallel with a bare wire). That is an easy thing to analyze when the other elements are also capacitors, but the difficulty grows from there. Have you encountered Kirchoff's Rules yet?
Mar
25
comment Why the center of our galaxy doesn't absorb us?
gdp, your post here has been flagged by another user who thinks the tone is too critical of the questioner. As a group the moderators seem to feel it is below the threshold for us to take peremptory action, but you might consider re-reading the post with a view to how it will sound to future visitors. Perhaps an edit is in order?
Mar
24
comment How to calculate error of parallax and sextant based navigation?
Polar explorers used sextants at both ends. But then, they were trying to reach a particular latitude and needed to know what position they occupied in the planetary coordinate scheme whilst standing in an unmapped wilderness.
Mar
23
comment More about the Right Hand Rule?
An interesting point is that we usually end up using RHRs in pairs to get observables. That is, to compute the force between two currents we use one RHR to find the field due to current $A$ and another RHR to find the force on current $B$ due to the field from current $A$. This procedure would have given the same final force using left hand rules (though the direction of the field you found in the middle would be reversed; but recall that the assignment of magnetic poles was arbitrary in the first place).
Mar
23
comment More about the Right Hand Rule?
"an electron is defined as negative when it should really have been positive)" See physics.stackexchange.com/questions/17109/… and physics.stackexchange.com/questions/68471/…. It might have been more convenient in your first circuits class to have electrons positive, but it is purely a convention and there is no "should" involved.