Refrigerator magnets have a striped pattern of magnetization

I always enjoy hearing about the Physics of everyday objects, and there were several such presentations at the Michigan AAPT meeting. One of these, by David A. Van Baak, was about refrigerator magnets.

It turns out that refrigerator magnets, because of the way they are made, have a striped pattern of magnetization (N-S-N-S-N-S, though the magnetization actually varies continously). You can see this easily yourself if you hold one behind one of those magnetic films (pictured above), or if you just take two magnets, hold them back to back, and then try to slide one along the other. Every couple of millimeters or so is a “happy spot” where north on one magnet meets south on the other, and the magnets will try to freeze in position there.

One consequence of this striped magnetization is that a magnetic field only exists on one side of the magnet. (I’m still trying to wrap my mind around exactly why.) Try putting the magnet onto your refrigerator backwards – won’t work. And not because of the thin sheet of paper in the way.

UPDATE: @mskblackbelt sends along a Wikipedia link to the Halbach array, a similar array of magnets that has, indeed, a magnetic field on only one side.

Feynman on the social sciences

A while back I was blogging through Alistair McGrath’s trilogy on A Scientific Theology. I largely gave up on that project – they were difficult books to follow, and I didn’t feel I was gaining much for my effort. But one thing that surprised me about McGrath was that he was very accepting of the social sciences, and felt that while different, they were as truly sciences as Biology or Physics. Many physicists, I know, don’t think so, and here is one famous physicist offering his opinion. Feynman’s big point seems to be that he has learned just how difficult it is to reach a point where you can really say, with certainty, that you know something, and the social sciences don’t often reach that point.

Naturalism, consistently applied, makes life unlivable

I came across a speech yesterday by Andrew Sach entitled Science and God: do we have to choose?. I couldn’t find a current profile of him, but from his speech he’s a neuroscientist. His big point is that not only are science and Christianity NOT contradictory, but that in fact many of the people who argue that they are are really arguing for a certain philosophy (specifically, naturalism), and only acting as if they’re arguing science. Click the link to hear the entire thing, but I just wanted to share the portion near the middle where he argues that none of us really lives – and indeed couldn’t live – like we really believe in naturalism.

I want to read to you an excerpt from this book by John Gray. He’s a professor of European Thought at the LSE and apparently was Tony Blair’s favorite philosopher – I don’t know if that commends him to you or not! But this is what he says. Basically John Gray is arguing that we’ve failed to be consistent with our beliefs of naturalism. He himself isn’t a Christian. He gets to a kind of Gaia belief later in the book, but he’s of the opinion that we’ve failed to follow our beliefs to their logical conclusion, and he’s lambasting us for that.

“Man must accept that his or her existence is entirely accidental. He must awake out of his dream and discover his total solitude, his fundamental isolation. He must realize that like a gypsy he lives on the boundary of an alien world, a world that is deaf to his music, and as indifferent to his hopes as it is to his suffering, and his crimes.”

That last part is very perceptive – a world that is indifferent to your hopes, and to your suffering, my suffering. And to our crimes. A universe that is just random cannot be asked the question “why?”. See, here’s this dear friend of ours from church, he’s in hospital at the moment with a stroke, age 29. If you’re a naturalist you cannot even ask why. There is no one behind it. It is just an accident and your suffering is just bad luck, basically. No purpose behind it. And similarly your crimes.

And then later he relays a conversation he had with another neuroscientist.

“Kate, I can’t understand, if you’re right about the universe, why me killing you would be wrong. Now if I took out a dagger and kind of cut you in half all I would be doing would be increasing the entropy of the universe by a factor of two. Why would that be any different from cutting a grapefruit in half for my breakfast? Just rearranging the atoms in the universe in a slightly different way.

She thought for a moment and then she said “well, it’d be wrong because my mother would be upset with you!”

Good answer. But we were neuroscientists, so I said to her “Kate, what is ‘upset’? ‘Upset’ is just the increase in the concentration of a certain chemical in the random collection of atoms which is your mom’s brain. What’s it matter? What is the significance in anything that we do?

Compromise between the Church and the World

“…there is in truth no such thing as harmonious coexistence between the church and the world, for where there is no conflict it is because the world has taken over.” ~M. Wilcock

We read that quotation in our church small group last night – it was referenced in a Tim Keller Bible study on lessons from the life of Samson. But appropriately enough, I’m also reading Dietrich Bonhoeffer’s book The Cost of Discipleship at the moment, and as you might imagine he has much to say about Christian compromise with the world, at one point describing the Christian life as nothing but “hand-to-hand combat” with the world. (Do we feel that?) And “the world” is not only outside our churches – he spends much time speaking against the proclamation of “cheap grace” from the pulpit, a sort of message that says “God will forgive you, so don’t worry too much about your sin”.

Cheap grace is the preaching of forgiveness with requiring repentance, baptism without church discipline, Communion without confession, absolution without personal confession.

Because it is unconcerned with obedience, it becomes a message that justifies the sin, instead of the sinner. He says,

…do we realize that this cheap grace has turned back upon us like a boomerang? The price we are having to pay today in the shape of the collapse of the organized Church is only the inevitable consequence of our policy of making grace available to all at too low a cost. We gave away the word and sacraments wholesale, we baptized, confirmed, and absolved a whole nation unasked and without condition. Our humanitarian sentiment made us give that which was holy to the scornful and unbelieving. We poured forth unending streams of grace. But the call to follow Jesus in the narrow way was hardly ever heard. Where were those truths which impelled the early Church to institute the catechumenate, which enabled a strict watch to be kept over the frontier between the Church and the world, and afforded adequate protection for costly grace? What had happened to all those warnings of Luther’s against preaching the gospel in such a manner as to make men rest secure in their ungodly living? Was there ever a more terrible or disastrous instance of the Christianizing of the world than this? What are those three thousand Saxons put to death by Charlemagne compared with the millions of spiritual corpses in our country today? With us it has been abundantly proved that the sins of the fathers are visited upon the children unto the third and fourth generations. Cheap grace has turned out to be utterly merciless to our Evangelical church.

The Party of Irreligion

A friend passed along an article called “Our secularist Democratic party”, written by Louis Bolce and Gerald De Maio and published in The Public Interest.  A PDF is available here.  It received a sympathetic ear from someone (me) who thinks we regularly underestimate the importance of religion in politics.  The big theme of the article is that while the media loves to talk about the influence of the fabled “Religious Right” in the Republican party, it has largely ignored the rise of an equally powerful political group, the secular Left, which has had a powerful voice in the Democratic party since the 1970s, and helped foment many of the culture wars we still fight today.  I’m a numbers guy, so I’ll just share a few, often numerical, facts I found interesting, and you can read the whole article if you’d like.  Note that the article was published in 2002.

1. In 1972, approximately 5% of the American public could be identified as “secularist” – meaning they espoused no religion and seldom or never attended religious services.  However, over a third of white delegates to the Democratic National Convention fit this description.

2. In 1992 (20 years later), 60% of first-time white delegates to the Democratic National Convention either claimed no attachment to religion or displayed no attachment (by attending worship services “a few times a year” or less, according to surveys).  About 5% of first-time delegates to the Republican convention identified as secularists, with 2/3 saying they attended religious services at least once a month.

3. Democratic delegates were surveyed regarding their “warmth” (rated on a “thermometer” scale) toward various groups – the rich, the pro-life, big business, etc.  “Christian fundamentalists” received the lowest average score of all groups, with over half of delegates individually giving fundamentalists the absolute minimum score possible.

4. Surveys by the American National Election Survey have shown that about 70% of secularists oppose any law restricting a woman’s right to abortion, while most religious moderates and traditionalists favor some restrictions (parental consent laws, outlawing partial-birth abortion, etc.).

5. The religious gap among white voters in the 1992, 1996, and 2000 presidential elections was more important than many other more often discussed gaps (including gaps caused by gender, age, occupation, income, marital status, and difference in education.)  In these elections, white women on average gave Democrats 9% more of the vote than white men – secularists gave Democrats 42% more of the vote than religious traditionalists.

The coming college brokers?

We had our Arts & Sciences Division meeting this morning, and one interesting comment the dean made was that we might begin seeing the formation of what are essentially college brokers in the next few years.  These businesses would look at a student and say, ‘OK, you took these AP courses in high school, and these online courses from University of Phoenix, and these courses from your local community college, and you want a degree in X’.  Then they’d go make a lot of phone calls about transferability and try to find the best deal for the student.  ‘It looks like you could take these two online courses from the College of Maine and they’d give you a degree, or here is another option from Seattle University.  What institution would you like on your diploma?’. Interesting idea.

It’s just part of the decentralization of education that everyone seems to agree is happening.  Another idea I’ve heard suggested is the outsourcing of degree granting to third parties – as long as you can pass the right exams, it doesn’t matter how you gained your knowledge and skills.  (Think something like the bar exam for lawyers, but for all fields of study.). I could see this working for Associate and Bachelor degrees at least.  Above that level learning becomes more like a specialized apprenticeship and exactly where you studied is of increased importance.

You can imagine that both these ideas could increase competition among colleges, who would find themselves having to attract students to individuals classes as much as attracting them to the institution as a whole.  Fun times we live in.

A few thoughts from the right-to-work protests yesterday

1. You have to give the unions a hand when it comes to organization. I could probably come up with 50 issues I think more important than right-to-work that don’t generate this level of civic involvement simply because it isn’t organized. (I was going to also write that the conservative personality is simply less inclined to protest – but I remember the Tea Party and, maybe even more remarkably, pro-life protests, which are bigger and occur more often than you’d ever guess by watching the coverage, or lack thereof, that they receive in many media outlets.)

2. Conservatives have been rather mopey lately, but there are two big issues that we’ve been winning – right-to-work, and school choice. (And the latter, I’d say, really is one of the most important issues in America.) Maybe it’s no coincidence that both are state-level issues, and also that both issues are rare examples of when the default language of our society benefits conservatives. “Right-to-work” sounds pretty positive, doesn’t it? And what do you call people who oppose it? Well, sometimes they’re called “pro-union”, but more often it’s simply said that they “oppose right-to-work”. Which doesn’t really sound very good.

3. Was surprised yesterday as I was again reminded that not everyone is a political nerd – I had several students who wondered just what all those people were doing downtown! And even more surprisingly several faculty members, whom you might expect to be more well informed, didn’t seem to really know what right-to-work was about, didn’t know what was motivating the protestors, etc. That might sound like an insult but I don’t really intend it that way – it’s a complicated world, nobody can keep track of everything that is happening, we all pick and choose.

(Some additional photos I took of the protest.)

(Lansing’s “hot dog guy”, who normally sells hot dogs outside of city hall, had his cart destroyed by protestors yesterday. You can donate money to get him going again.)