HBD is not-nice.

Taking my cue from John Derbyshire, I've been having "the talk" with my daughters. I believe explaining to them the provenance of their immediate experience and the features of the larger reality to be both right and necessary.

But, honestly, I feel kinda dirty.

Regarding this Newsweek article on racial attitudes in children (via Discriminations and at least one other blog that I can't remember at the moment):

[UT professor Rebecca Bigler's] reasoning is that kids are developmentally prone to in-group favoritism; they’re going to form these preferences on their own. Children naturally try to categorize everything, and the attribute they rely on is that which is the most clearly visible.
We might imagine we’re creating color-blind environments for children, but differences in skin color or hair or weight are like differences in gender—they’re plainly visible. Even if no teacher or parent mentions race, kids will use skin color on their own, the same way they use T-shirt colors. Bigler contends that children extend their shared appearances much further — believing that those who look similar to them enjoy the same things they do. Anything a child doesn’t like thus belongs to those who look the least similar to him.

My experience with my older daughter causes me to doubt this assessment. In the city we used to live in, Γ₁ attended kindergarten and 1st grade part-time classes as part of the "homeschool program" of a public charter school. I liked the program in general, but it was here where she was presumably exposed to the diversity dogma.

It took me years to de-program this nonsense. Every evening, I would give Γ₁ an opportunity to tell me "what she learned in homeschool", with particular interest in the history and science lessons. Typically, I used these lessons as a springboard to discuss HBD/race-realism. Now that she's older and more perceptive, however, I've been more forthright about putting all the cards on the table. Γ₁ used to tell me how "everybody is equal", but the message seems to have gotten through. (Although she probably still thinks her Dad is a bit of a crank, which is fair enough, I guess.)

I think the diversity dogma is intrinsically appealing to children, or at least children living comfortable middle-class suburban lives. "Equality" is "nice"; realism about the world and its dangers is "not nice". And who wants to be not-nice?

OTOH, maybe Γ₁ is exceptional in this regard. Before Φ could afford all-white neighborhoods, Γ₁ was exposed to somewhat more playmate diversity than, say, her younger sister. And never, to my recollection, did I detect the least bit of reticence in playing with children of other races. She really was colorblind. Not in the literal sense -- she knew children had different color -- but she never invested the kind of meaning in that difference that Bigler predicts.

Younger sister, in contrast, hasn't had occasion to play with minority children. The only time she has seen them is during Halloween when the more "urban" children descend on Φ's lily-white little burg. While not expressing anything specific, I can tell that she gets very . . . reserved is the way I would put it. But Γ₂ is also attending 2nd grade in public school, and I think my discussions with Γ₁ make her . . . uncomfortable. After all, who wants to be not-nice?

Who make the best teachers?

Laura McKenna, guest posting for Megan, writes:

The bad news is that a growing number of faculty at state or public colleges are adjunct instructors. Adjuncts are temporary faculty members who teach classes for low pay, no benefits. They do not have the protections of tenure. They are often not unionized. 1 million of the 1.5 million people teaching in American colleges are adjuncts. The number of adjunct faculty has increased dramatically over time. LinkedIn reports that it is the fastest growing job description.

Doing some back of the envelope computations using data from the Chronicle of Higher Education, I found some depressing news about my alma mater and other public colleges. At SUNY Binghamton, of the 812 faculty, 383 are adjuncts. That's 47 percent of their total faculty. At Penn State, of their 3,187 full time faculty, 1,428 are not tenured or on tenure track positions. In other words, 49 percent of their faculty do not have job security, equal pay, or benefits. If you attend University of Tennessee at Knoxville, you are highly likely to be taught by a graduate assistant. Of, their 4,235 teachers, only 1,295 are tenured or tenure-track professor. 2,062 of their teachers are graduate assistants.

In a report released last year, 56 percent of all classes at community colleges in Pennsylvania were taught by adjunct or non-tenure track professors. They receive $2,500 per class. If the adjuncts taught a staggering five classes per semester, their salary would be $25,000 per year. They often receive no benefits.

All these adjuncts are bad news for undergraduates at the public colleges. Many adjuncts are excellent teachers, but their temporary status and their exclusion from faculty meetings means that students can't rely on them for advice on course selection. It's difficult to develop relationships with faculty that may not have their own offices or might teach at multiple schools. It's also hard to be an excellent professor when you're poor and your career is unstable.

There are several overlapping themes here.  One is the age-old conflict of interest between undergraduate and graduate student priorities.

The undergraduate experience is 90% platform instruction, and thus the kind of instructor they want is one with the ability to be engaging, to be sufficiently interested in the fundamentals to have a firm idea of how they are best apprehended.

The graduate experience, especially at the Ph.D. level, is mostly research.  Their most significant faculty interaction will be with their advisor, and secondarily with their other committee members.  What they want, first, is someone capable of directing them towards and managing them through a properly scaled, feasible, and dissertation-worthy research topic.  Second, they want money.  Which preferably means sponsorship for the research, and if not that, then a teaching assistantship.

The skill sets involved are only accidentally related.  A professor skilled at managing a productive (and well-funded) research program does not for that reason have any ability at delivering a disciplined lecture; a good and enthusiastic lecturer of the basics only developed that ability because he wasn’t interested managing research.

The institutional incentives are even worse.  With a few exceptions (Rose-Hulman, the Service Academies), most public universities reward successful research programs, not teaching.  While at some schools it is theoretically possible to win tenure on the strength of academic instruction (which usually includes higher-order activities like course development and textbook writing), in practice most tenure-track faculty don’t take this route.  So little effort is put into teaching.  And the need to get money to their graduate students often puts those grad students in front of undergraduate classrooms.

I experienced these conflicts from both sides.  As an undergraduate, I suffered hatefully through any number of professors, famous for their research programs, droning indifferently in barely intelligible English at the head of 200-seat lecture halls.  As a graduate student, those same professors (figuratively speaking) became vital to my research success.

What to do?

I think the Armed Services get the solution exactly right:  separate institutions – e.g. USAFA and AFIT – separate budgets, separate faculty.  Thus, no opportunity to treat undergraduates like cannon-fodder for the research programs.

Alternatively, one school I knew specifically created something of a career track for lecturers, and paid them salaries a lot higher than the adjunct numbers quoted above, though not as high as professors whose research programs brought money directly to the university.

But I want to push back against McKenna’s suggestion that the solution is to put more tenured faculty in front of undergraduates.  In my experience, these professors were not obviously better, and sometimes a lot worse, than a TA or adjunct.

I also submit that the poor pay for adjunct lecturers probably reflects the supply and demand.  Last year, I myself applied for a handful of those poorly-paid adjunct positions on the strength of a Ph.D. and prior college instruction experience.  I was unsuccessful, so I can only assume that the successful candidate was more qualified than me.  Which made them pretty qualified, if you don’t mind me saying.  So, yeah, more money for lecturers would be nice, but I can hardly blame the schools if they can get qualified people to do the work for less.

Radiometric Error Evaluation, Part V: Results

In the last post, I promised to evaluate the integral:

This is only partially true.  I have no idea how to solve an equation like this analytically, although I know the correct answer.  What I can do, however, is solve it numerically, setting our constant radiance = 1000, the radius of our emitting sphere = 1:

function [R,E]=intE()
    L = 1000;
    re = 1; 
    l1 = 0; % Sensor nadir
    figure;
    for i = 1:200,
        R = 10.^(-1+.02*i);
        l2 = acos(re./(R + re)); % Limit of field of view;
        E(i) = quad(@irradiance,l1,l2);
    end;
    function E = irradiance(phi)
        Rprime = sqrt((R + re)^2 + re^2 - 2*(R+re)*(re).*cos(phi));
        gamma = asin(((R + re)./Rprime).*sin(phi));
        theta = asin((re./Rprime).*sin(phi));
       
        E = (2*pi*L*re^2./Rprime.^2.*sin(phi).*cos(gamma).*cos(theta));
    end
end

I graphed the value of E vs. R, along with the value of our estimate from two lessons ago:

The estimate appears to be pretty good for R >> r_e.  But before I graph the error, I decided to add to the estimate E = π L r_e²/R² the estimate E = π L r_e²/(R +r_e)²:

Well, how about that.  It turns out E = π L r_e²/(R +r_e)²: was so good an estimate it completely overwrote the true value across all values of R.

Let’s plot the error.

By the looks of it, the error of E_s2 (taken as an absolute value to graph on a log scale) is pretty much limited to accumulated random rounding errors, although these errors might be getting larger the farther away my receiving aperture is, and the smaller the emitting surface appears.

Basically, this is saying that for purposes of analysis,

Investigating Irradiance Error, Part IV: True E

Let’s imagine a differential emitting area dA_s on a spherical emitting surface of radius r_e at a distance R from a differential receiving surface dA_R.  dA_s is at distance R’ and aspect angle γ from dA_R; dA_R is at aspect angle θ to dA_s.  Also dA_s is at an angle φ from the point of nadir to dA_R.  In summary,

Applying the Law of Sines gives us:

allowing us to solve for both θ and γ in terms of φ:

The Law of Cosines gives us:

These relationships will be important later.

Radiance is the amount of power emitted into each differential solid angle from each differential area perpendicular to that angle.  For a lambertian surface, it is by definition a constant:

In units of steradians, a differential solid angle dΩ measures the ratio between the surface of a sphere subtended by that angle and the square of the sphere’s radius, much in the way an angle in radians measures the ratio of the length of the arc it subtends and the radius of the circle.

We must also bear in mind that the perpendicular area (i.e. the cross-sectional area as it appears from the direction of observation) bears the relationship to the true area shown in the figure below.

Thus:

Substituting into our equation for radiance gives us:

The quantity in which we are interested is irradiance E, the power per unit area entering our differential receiving area, dA_R.  Solving for this quantity yields:

The differential surface area of a sphere, dA_s, is the standard calculus formula:

where dα integrates around the circle of the visible surface to 2π, and the interior body angle ranges from 0 to the point where  γ is a right angle.  A simple application of the definition of a cosine yields:

Substituting in these values gives us our final integral:

We will evaluate this integral in our next lesson.

Obama didn’t build it, either.

Mr. Obama, having run with apparent impunity the most lawless administration in the history of the presidency, has now got himself in a spot of bother for . . . speaking without a teleprompter:

If you were successful, somebody along the line gave you some help. There was a great teacher somewhere in your life. Somebody helped to create this unbelievable American system that we have that allowed you to thrive. Somebody invested in roads and bridges. If you've got a business. you didn't build that. Somebody else made that happen. The Internet didn't get invented on its own. Government research created the Internet so that all the companies could make money off the Internet. The point is, is that when we succeed, we succeed because of our individual initiative, but also because we do things together.

Obama’s legion of apologists, after flailing about for a bit, have argued that, notwithstanding its grammatical construction, what he intended by the bolded portion was that individual businesses and their creators do not directly build the infrastructure on which they rely to be successful; rather, this is the fruit of collective effort.  This point is, on one reading, trivially true – we aren’t yeoman farmers anymore – but has this really been a contested insight since, I dunno, 1920 maybe? 

Among cultural anthropologists, perhaps not.  But they have very little say in how a people actually mythologizes itself.  America’s dominant economic myth is one of individual achievement, and this mythology has played no small part in our success.  Obama is attempting to inspire a counter myth of collectivism, a mythology that gave us . . . well, Soviet Russia, Red China, etc.

I’m quite comfortable having a national myth that doesn’t quite match the facts on the ground, so long as it pulls its weight in utility.  If Obama was running neck-and-neck with the Libertarian Party, then it could be plausibly argued that “individualism” might have jumped the shark.  But with Romney?  These two are arguing over a couple of inches on collectivism’s 40 yard line*.

But that’s not really what bothers me.  There are two things that bother me.

First, the flip side of the observation that the potential for private wealth – up and down the economic scale – is made greater by public infrastructure is that public infrastructure also doesn’t spring wholly formed from the mind of government bureaucrats:  it relies on some amount of pre-existing private wealth to finance it. whether the “money” representing that wealth is taxed, borrowed (which is deferred taxation), or simply printed (which is a tax of a different sort).  Now, with double-digit unemployment, trillion-dollar deficits, and a debt-to-GDP ratio of around one, it’s pretty apparent that Obama is worrying about the wrong side of this relationship.

The second thing that bothers me goes even deeper:  Obama’s fundamental dishonesty in his framing.  I will happily stipulate that we are none of us as “individual” as we like to think.  Never mind infrastructure:  we did not even “build” the very DNA from which we draw the intelligence and energy to make something of ourselves.  We did not “build” the Anglo-Saxon culture – especially those of us that aren’t Anglo-Saxon – that enables the civic trust and cooperation necessary for enterprise beyond the subsistence level.  We did not “build” the discoveries and inventions on whose shoulders we stood to exercise our own creativity.  We did not fight the wars that expanded and secured our nation’s territory.  We are, in these respects, merely heirs of the hard work and self-discipline of our ancestors.  A well-governed country – Japan, say, or Iceland – respects the heritage it has received and seeks to preserve it.

The irony about Obama is that he has spent his rule actively undermining those very conditions.  Obama’s immigration policies have flooded the nation with illiterate Mexican peasants, driving down wages, driving down civic trust, and eating away at both the physical and cultural capital on which the nation survives.  Obama’s trade policies have flooded the nation with cheap Chinese imports, destroying the high-paying jobs from which taxes can be paid to fund public services.  Obama’s foreign policies have frittered away the nation’s blood and treasure on endless undeclared foreign conflicts inimical to our national interest.  Obama’s crime policies have exposed its historic majority to a rising tide of predatory black (and brown) criminality while plundering our wealth and opportunity for the benefit of minorities.  Obama’s social policies have undermined families and the parental investment that go with them, setting ever greater percentages of the nation morally adrift.  Obama’s government policies have had nothing to do with improving public services, and everything to do with gross redistribution of wealth.

In these, Obama may haves merely expanded the policies of his predecessors – but expand them he did.  Romney’s claim to succeed Obama may be that he only aspires to be marginally less destructive to the common good than Obama – but he will be less destructive.  So I don’t really care about whether this little kerfuffle is some kind of proxy battle over top marginal tax rates or whatever.  The Japanese and Icelanders pay much higher taxes than we do – because their productive enough to afford them and receive high-quality public services in return.  No, what I do care about is that Obama is lying through his teeth when he talks about the common good of the nation.

UPDATE: Chris already said this better.

Investigating Irradiance Error III: Estimated E

In the last two posts, we set out to find the relationship between four radiometric quantities:

• Exitance (M): the power density emitted by a surface, measured in Watts / m². We will reserve B for the per-micron un-integrated quantity.
• Radiance (L): the power density emitted by a surface into each solid angle, measured in Watts / m² / steradian.
• Intensity (I): the power emitted by a point source into each solid angle, measured in Watts / steradian.
• Irradiance (E): the power incident upon a receiving surface, measured in Watts / m².

We discovered that the relationship between exitance and radiance followed the simple formula for a lambertian surface:  M = πL.  We will now look at the relationship between these and  irradiance.  If anything, properly calculating this last is the most critical; as its name implies, radiometry is about using the power incident on our measuring device to infer the power being emitted from the surface of interest.

Let us assume that a spherical object of radius R_obj is sufficiently far away from our sensor that we can treat it as a point source of intensity I.  The total power Φ it emits is equal to the product of its exitance M and surface area A; its intensity I is that power divided by the total surrounding solid angle, 4π.  Thus:  

You will remember that intensity is in units of Watts / steradian.  Thus, if we assume that the sensor is looking directly at the emitting object, we can find the irradiance at the aperture of our receiver by multiplying the intensity by the solid angle Ω subtended by the aperture and dividing by the area A_rcvr of the aperture.  Remembering that the definition of solid angle is the ratio of the area of a sphere subtended by that angle divided by the square of the radius gives us:

where R_path is the distance from the emitting object to our sensor.

Alternatively, we can treat our emitting object as a disk of radius R_obj.  It’s radiance L is the exitance M divided by π as found previously.  The irradiance on a sensor at distance  is the product of the radiance, the solid angle Ω subtended by the sensor’s aperture, and the disk area A_obj = πR_obj², divided by the area of the sensor aperture:

Thus, we can see that whether we approximate our emitting object of radius R_obj as a point source or a disk, we get the same result for the amount of radiation incident on a sensor at distance R_path.  (The textbook irradiance of, for instance, the sun at the top of the earth’s atmosphere is 1480W/m², for instance.)

However, we must point out the obvious:  an emitting sphere is not a disk, and it may not appear as a point source.  For instance, the sun’s dimensions are apparent to an observer on the earth, 93M miles away.

In our next post, we will calculate the exact irradiance on the aperture of a sensor from a spherical emitting object.

(Note:  I apologize for the crappy looking equations.  I have a procedure for cleaning them up, but it’s tedious, and I’m tired.)

Hierarchies

I just received an Amber Alert on my teevee while watching Breaking Bad. I didn't know that Amber Alerts were sent out through the Emergency Broadcast System.

The alert proceeded as follows (the names have been changed):

The missing child is named John Smith, a black male [some number of months old, height and weight]. The suspect is also named John Smith, a black male, aged 27, 5'6", 150 lbs . . . .

So . . . the normal rule that the race of perpetrators (if they're black) should be censored is suspended when the perpetrator has "kidnapped" . . . his own son? I'll have a lot of egg on my face if the child comes to harm, but I couldn't help thinking this was interesting.