Friday, April 26, 2013
Monday, December 26, 2011
Christmas Fun (well, fun for math types)
12 drummers drumming,
22 pipers piping,
30 lords a-leaping,
36 ladies dancing,
40 maids a-milking,
42 swans a-swimming,
42 geese a-laying,
40 golden rings,
36 calling (or colly) birds,
30 French hens,
22 turtle doves, and
12 partridges in a pear tree (or pear trees; this last has not yet been ascertained).
For those who really really care, the graph resembles a parabola.
A merry, joyous, happy, holy and blessed Christmas to all!
Wednesday, December 14, 2011
Sacred Mathematics

Monday, December 5, 2011
After reading The Hitchhiker's Guide
Forty-two!
There is an infinite number of even numbers.
There is an infinite number of odd numbers.
The infinite number of all numbers is equal to the infinite number of even numbers and to the infinite number of odd numbers.
Do not think about this too much.
The amount of information coded into the single 46-chromosome cell we all once were
is also mind-boggingly large.
Wednesday, November 16, 2011
Math, Carpentry, and Culture: a Facebook Rant
It's a mathematical axiom that through a point an infinite number of lines can be drawn. It's also an axiom that two points determine a line. But statistically speaking, the closer together those two points are, the less reliable are any predictions made from them. In the real world, it's easy to lay a 10-foot 2x4 across two sawhorses six feet apart. Now try balancing the 2x4 across one sawhorse. Then try balancing it on a 1/2" rebar stuck into the ground. The smaller the base, the harder the balancing act.
The real-life analogy to this is that (all other things equal) we old folks have a longer, and therefore better, view of life and especially American culture than you young folks do. Culture is like the air you breathe: you don't notice it unless it changes or you have something to compare it to.
I grew up in the late 40s and through the 50s, and I can say that American culture has largely degenerated since then. I can smell the stink of it, but you young folks can't, because you grew up in it and don't know any better. You think it's fine and normal, I know it's rotten and abnormal.
Saturday, March 12, 2011
Sex Education and Physics
When I was in Physics 1 as a freshman engineering student at the University of Minnesota, one of the topics of study was falling-body problems. (No pun intended.) An object dropped from a height will cover distance downward according to the formula
s = (1/2 * g * t^2) where g is the acceleration due to gravity (and * means times, and t^2 means t-squared)
and the velocity of the object will be
v = g*t
To make things more interesting (read: complicated), the downward acceleration is independent of any forward motion the object might have, such as if the object were dropped from a moving airplane. Thus both downward and forward motions need to be analyzed. The math will show that a falling body in motion when dropped will follow a curve called a parabola, and its point of impact can be easily calculated.
But it's not as easy as that. There is air resistance, which increases proportionally to the mass and shape of the falling body, and (to make things even more interesting) changes the path of the falling body from a parabola to a cycloid.
So I asked the professor, "When do we get to figure air resistance?" and he replied, "Come back when you've had about five quarters of calculus."
Translated, this means: "You don't have the need or ability to understand that yet."
So with sex education. Little kids don't need to know about the "mechanics" of sex, because they don't have the need or ability to understand it (and though I'm not a parent, I would bet all my blog dollars they don't care either.)
I would venture to say that almost all little kids, when asking why Mommy's belly is getting big, being told that their little brother or sister is growing in there, will ask "Well, how'd he or she get there?" Parents correct me on this one, but I bet it will be quite enough to tell a small child, "God put him / her there."
Parents can tell their kids the equivalent of what the physics prof told me.
And I cannot state strongly enough that it's nobody's business but the parents' to give the child any more information, because the parents know their child better than any teacher possibly could, and they know when the child is able to absorb and assimilate the information.
(This applies only to ordinary kids in ordinary families, of course. The "special cases" are something else entirely.)
Tuesday, June 22, 2010
The Bell Curve 6 - More on cognitive stratification
Saturday, June 12, 2010
The Bell Curve 5 - What they're talking about
(It has been quite a while, so you might want to go back and read my first four essays - Jan.9, Feb. 1, Feb. 2, and Feb. 6)To quote the authors' preface: "This book is about differences in intellectual capacity among people and groups and what those differences mean for America's future."
In Part I, "The Emergence of a Cognitive Elite," the authors argue that in past ages and cultures, most notably western Europe, social class was determined largely by lineage and money rather than by intelligence. Therefore one would probably find a pretty normal distribution of intelligence at all class levels: that is, one could find smart peasants and stupid aristocrats.
". . . a large majority of the smart people in Cheop's (sic) Egypt, dynastic China, Elizabethan England, and Teddy Roosevelt's America were engaged in ordinary pursuits, mingling, working, and living with everyone else. Many were housewives. Most of the rest were farmers, smiths, millers, bakers, carpenters, and shopkeepers. Social and economic stratification was extreme, but cognitive stratification was minor." (p. 27)
One of the major premises of the book is that what they call cognitive stratification is a product of a high-tech society. Before the 20th century, ". . . the number of very bright people was so much greater than the number of specialized jobs for which high intelligence was indispensable." (ibid.) But during that century, assert the authors, a class structure based on intelligence emerged.
Chapter 1, "Cognitive Class and Education, 1900-1990," gives some information that I find highly interesting. The authors point out that from 1900-1990 there was a fifteen-fold increase in the proportion of people getting college degrees, and that students wishing to enter college were being more effectively selected for high IQ. They also mention that "Starting in the 1950s, a handful of institutions became magnets for the very brightest of each year's new class. In these schools, the cognitive level of the students rose far above the rest of the college population." (p. 29) They show with graphs (which one needs the smattering of statistics to interpret for oneself) that:
1, during the 20th century, the "prevalence" of the college degree went from about 2% to about 33% of the population;
2, starting about 1950, more of the top (high-school) students went to college;
3, between the 1920s and the 1960s, college attendance became more closely correlated to IQ, and
4, the cognitive sorting continued throughout one's college career.
"By the early 1960s," say the authors, "the entire top echelon of American universities had been transformed. The screens filtering their students from the masses had not been lowered but transformed. Instead of the old screen -- woven of class, religion, region, and old school ties -- the new screen was cognitive ability, and its mesh was already exceeding fine." (p. 42)
Saturday, February 6, 2010
The Bell Curve 4 - Correlation and Regression
Tuesday, February 2, 2010
The Bell Curve 3 - Centrality and variability
If you have a copy of the book, go to Appendix 1; Herrnstein and Murray say it better than I do. If not, above is an imagined overhead view of a high school senior class of guys (including girls would complicate matters in more ways than mathematically!) lined up in columns according to their height in inches:
We all have heard the word "average" many times: batting average, earned-run average, and so on. For everyday use the word is fine; for statistics it's not precise enough. The preferred term in statistics is "mean"; the mean is simply the sum of the occurrences of something divided by the number of occurrences. In the case of the high-school seniors, there are 250 guys, ranging in height from 5'2" to 6'6". The mean height (as a round number) is 70" or 5'10", calculated by multiplying each "x" (height) by its "y"+ (number of times x happens), and dividing that by the sum of the y's; that is, the sample size, n, 250. (to be precise, the mean height is about 70.26".)
This is a good example of how very many natural phenomena are distributed. There is a center, which can be calculated. There is distribution about the center, which is expressed in standard deviations. So what's a standard deviation? Basically, it's a measure of comparing apples to apples.
To quote the book: "When it comes to high school students, you have a good idea how big a six-inch difference is. But what does a six-inch difference mean when we are talking about the height of elephants? About the height of cats? It depends. And the things it depends on are the average height and how much height varies anong the things you are measuring. A standard deviation gives you a way of taking both that average and that variability into account, so that "6 inches" can be expressed in a way that means the same thing for high school students relative to other high school students, elephants relative to other elephants, and cats relative to other cats." (pp. 578-579; Emphasis theirs.)
Now a "true normal distribution," a perfect bell curve, is a mathematical abstraction, never observed exactly in nature. But if the sample of high school seniors were of 2500 boys, or 25,000 boys, or of 250,000 boys, the curve would tend to "smooth out" and approximate the ideal. In the mathematical ideal, the normal distribution extends to infinity in both directions, but for practical purposes, talking about populations of people, a normal distribution, or bell curve, is about six standard deviations (sd) wide, symmetrical, and centered on the mean.
The essential thing to remember is that in any normal distribution (or close approximation to it),
you will find that from the mean to +1sd or -1sd is 0.3413 or 34.13% of the population. Between 1sd and 2sd (either way) there
Add it all up -- 0.3413 + 0.3413 + 0.1359 + 0.1359 + 0.0213 + 0.0213 - and you get 0.997, which means that 99.7% of any distribution falls within the range -3sd to +3sd. The remaining three-tenths of one percent (three out of a thousand) fall outside this range. And as the authors explain, extremes tend to be rarer than the average. "It is worth pausing a moment over this link between a relatively simple measure of spread in a distribution and the way things in everyday life vary, for it is one of nature's more remarkable uniformities." (p.581)
Or as I like to say, as the understatement of the cosmos, "God is pretty smart."
In case this is discouraging anyone, it has taken me about four hours to write this; and it also happens that I started reading Peter Kreeft's A Shorter Summa last week, so I have to learn a whole new vocabulary too.
But we're getting close to the book. The only thing I see a need to talk about first are the concepts of regression and correlation. I bet you just can't wait!
Monday, February 1, 2010
The Bell Curve 2 - what looks random maybe isn't
So I started an experiment. I would flip the thing ten times, and see how many times out of ten flips it would seat itself perfectly. The results surprised me. In 187 trials of ten flips each, the numbers came out to be:

0 "perfect seatings" - 0 occurrences
1 ps - 2 occurrences
2 ps - 6
3 ps - 15
4 ps - 35
5 ps - 51
6 ps - 43
7 ps - 24
8 ps - 11
9 ps - 0
10 ps - 0
Note especially here that the data form a bell-shaped curve which is almost symmetrical. There is a pattern in what looks like randomness or chaos. I won't bore you with the math used to compute the "expected value" of X, the number of perfect seatings out of ten flips, but the answer, given the data, is about 5.18, which means that on average, in general, there is a slightly better than even chance that on any given flip, the strainer will seat itself perfectly.
Here's another example, a game called "coincidences." You shuffle a deck of cards, cut it, and deal thirteen cards off the top; as you lay down the first card, you say "ace"; as you lay down the second card, you say "deuce," as you lay down the third, you say "trey," and so on up to jack, queen, and king. The question is: what is the chance that you'll get at least one "coincidence" as you lay out the cards -- that, for example, as you say "six" you turn up a six? It would seem far-fetched -- until you do it. I played the game 150 times and got:
zero coincidences 54 times
one coincidence 56 times
two coincidences 29 times
three coincidences 9 times
four coincidences 2 times
which means the odds (chance, probability) of getting at least one coincidence are slightly under 2/3; for this group of trials, p(x) = 0.6204. Note "p(x)" means "probability of x happening," where p by definition is a decimal between 0 and 1, where 0 means impossibility and 1 means certainty.
(I mention in passing that this game can be used to win beers at your local watering hole, because the results are counter-intuitive. You never heard me say this.)
And of course a pattern strongly implies a pattern-Maker.
Friday, January 29, 2010
The Bell Curve 1 - to scare off the wimps
These are shown on the "bell-curve" graph.
Enough with the numbers already. There are two important things to especially notice here:
1, the distribution of probabilities is symmetrical.
Monday, September 21, 2009
Connecting Some Ideas
I was just reading Alan Keyes' essay on the 80/20 fallacy (for which see his blog http://loyaltoliberty.blogspot.com/) and a few things occurred to me.Friday, May 1, 2009
Science and Religion
In short, there is no real conflict between real science and real religion. Science tells us how the heavens go, religion tells us how to go to heaven. (I didn't make that up; I'm stealing from, and paraphrasing, one of the prelates involved with the Galileo affair.)
While I was working as an engineering technician, I had the equivalent of four university-level courses in statistics. (I got good enough -- or arrogant enough -- that I argued with management about the best tools for predicting traffic growth.)
Take ten coins, and flip them all at once. Now the chance of any one coin coming down heads or tails is exactly 50-50 (assuming the coin doesn't land on its edge or hang in the air). So you would maybe expect to get five heads and five tails tossing ten coins. But in fact your chance of getting exactly that is a bit less than 1 in 4, that is, it's 252 out of 1024; because there are 1024 different ways ten coins can fall when you flip them all at once.
The reason for this is that a coin has two faces, you have ten of them, and the number of ways they can fall is 2^10, 2 to the 10th power, 2x2x2x2x2x2x2x2x2x2, 1024.
One more example. Say you get into a crap game. Each die has six faces, you have two of them, and the number of ways they can fall is 6^2, 6 squared, 6x6, 36. If you analyze the 36 combinations, you will find that you can throw a seven only 6 ways, so your chances of getting a win, "take all the money," on your first toss is only 6 out of 36, or 1 in 6. Some places, an 11 on the first throw is a winner, and the chance of a win on the first toss is then 8 out of 36 or a bit less than 1 in 4, but the principle is the same, and the point is your chances of getting exactly what you want are not in your favor. Moral: don't get into crap games.
The basic point is that the toss of one coin or ten, or the toss of one die or two, is a random event, but when you start collecting and recording a large number of them, you will see a pattern.
Behind what looks like chaos there is order.
And the order was put there by God. It didn't happen by itself, because nothing can come from nothing.




