Byung Kyu Park's Personal Website

President Obama seems to think that we can end the nuclear era by simply “leading by example”, cutting our stockpile and hoping that others would follow.

How is this exactly supposed to work? When you are held up by a robber, do you fall prostrate on the ground and hope the robber will do the same?

The real solution to nuclear weapons lies in science. What science has wrought, science will destroy. The real end to nukes will only come with technology designed to neutralize it.

So, what can neutralize nukes? In the past, projects such as “Star Wars” focused on the delivery system. But that can easily be bypassed with development of some other delivery system (such as a well-shielded suitcase nuke).

What if we could target the radioactive elements, such as U-235 itself? Nuclear weapon, by design, consists of sub-critical pieces of radioactive elements. What if we could induce decay of these elements while they remain as sub-critical pieces? If we could do something like this by methods that work from long distance (I don’t know … maybe some kind of gamma ray or X-ray bombardment?), we could decimate the nuclear stockpile of other nations as we reduce our own. We can diffuse nuclear bombs that future terrorists may carry.

But then, I’m not a particle physicist, so maybe I’m just rambling and saying things that make absolutely no sense physically.

While I was thinking about my GSI duties for the upcoming 7A midterm, it occurred to me: once a grading rubric with enough detail is written, the grader is nothing more but a set of trained eyes—that is, anyone else with enough competence to spot mistakes and not make his own mistakes will end up assigning, for each exam, the same grade as I do, if we work out of the same grading rubric.

Perhaps this will be … relevant for properly judging the merits of the so-called holistic grading. One of the “merits” of holistic grading, even in the science courses, that I hear is that the resulting grade is more consistent—i.e. two graders grading using holistic grading assign more similar grades than two graders using standard method (i.e. grading by rubric). If there is any basis in this claim (as in, someone did a study and found that), I wonder if that basis is simply that of a bad study, in particular, poor control.

If holistic grading seemed to yield a more consistent grade, that may be more a result of holistic graders having a common guideline (after all, holistic grading does have guidelines, and for essays, “anchor papers”), while the graders-by-rubric did not—at least when we grade midterms, we write our own rubric, often with little central guideline common for all graders.

After all, how could a grading system which basically says, “I’m giving you a 5 because I think you deserve it, and I’m giving you a 3 because I think you deserve that, and no, I don’t need to justify myself to you—my personal judgment is better than any line-by-line justification,” can be more consistent than a grading system that requires that the grader justify every point being taken off?

At the moment, I don’t have the time to look for the actual studies which would either confirm or contradict the above scenario (i.e. the study supporting holistic grading had poor controls … or not), but I should … at some point.

And if this turns out to be true, then, well, the only benefit of holistic grading (at least the way it would be done for classes, with a single grader, i.e. the GSI, using the so-called “holistic grading”, rather than actual two separate readers, like they do for the standardized tests) is that it’s easier. But then, you know, cutting corners when building a dam is also easier. Does that mean the contractors should cut corners?