Sunday, January 08, 2006

can you hear me now...?

One of the most important additions to my bag of technological tricks in the past few years has been the use of my iPod to record each lecture. What makes it work is the simplicity of the process... plug in the voice recorder at the beginning of each lecture, hit record, turn it off at the end, sync it with my laptop once a week, drag the .wav files to a folder for each course. There is a little maintenance involved (renaming the files to include the course name) but the payoff is definitely worth it. The payoff being, a simple straightforward answer to the student question - "What do I do if I miss a class?"

But the delivery end of the process is more complicated. One obvious tactic would be to make the lectures downloadable. I haven't figured out a way to do this yet. Each lecture is about 1h 40m long, producing a 70-80Mb file. This means that, over the course of the semester, I might require 6 GB of storage or more. Plus the bandwidth to frequently deliver 75Mb files at a reasonable speed to students. There is no part of the university web presence that I'm aware of that is capable of handling these storage and bandwidth requirements.

The first semester I did this, I told students they could request a lecture (or several lectures) and I would burn them a CD. Big mistake. The volume of requests was high and I would often find myself sitting around and burning stacks of CDs before an exam. More recently I shifted part of the burden onto the student - if you BRING me a blank CD-R, I will burn you lectures after class. This quickly cut down on the number of frivolous requests. (Suuuure, you're going to listen to these 8 lectures while you study!) And while I still sometimes dream about making the files downloadable, I think that may actually be a mistake. Besides adding an additional upload step to the process for ME, I think it would be too tempting for students to take the attitude of, "Why GO to class when I can DOWNLOAD it instead?". The same consideration stops me whenever I consider adding video recording, or integrating the audio recording with a Quicktime output of my Keynote presentations. As big a fan as I am of classroom technology, I really don't want to wind up lecturing to a video camera in an empty lecture hall. Besides... once they have a few semesters of my lectures on DVD... why exactly would the university need to keep ME around?

Thursday, January 05, 2006

on the shoulders of giant mistakes...

With all the news about Intelligent Design in the air, I am frequently struck by the fact that all too many things written during the still-incomplete "Scientific Revolution" remain relevant today. They serve as cautionary tales and reminders of how hard it can be to accept all of the implications of new ideas - even for some of the greatest minds in the history of science.

Consider the following excerpt from a letter written by Isaac Newton to Reverend Dr. Richard Bentley in 1692, in which he describes some of the implications of his Law of Gravitation...

" [...] To your second query I answer that the motions which the planets now have could not spring from any natural cause alone but were impressed by an intelligent agent. For since comets descend into the region of our planets and here move all manner of ways, going sometimes the same way with the planets, sometimes the contrary way, and sometimes in cross ways in planes inclined to the plane of the ecliptic at all kinds of angles, it's plain that there is no natural cause which could determine all the planets both primary and secondary to move the same way and in the same plane without any considerable variation. This must have been the effect of counsel."

As scientists, it's easy for us to ridicule modern-day proponents of "Intelligent Design" while making excuses for folks like Newton. After all, that was the 17th century! This is 2005! Shouldn't we have outgrown this kind of thinking by now? But I think it is important to recognize that even great genius is no defense against the failure of imagination that lies at the heart of the design explanation.

Like today's Intelligent Design creationists, Newton fell back on the argument of - I can't imagine how something this complex could just "happen", therefore, God must be responsible. It is all too perfect. Too precise. Too ordered. It practically screams - "Designer"!

The parallel with evolution is closer than one might realize. The formation of a solar system is a process which is, like natural selection, "random" at the root level and yet "guided" by certain laws and forces at a higher level. In evolution, random variations are pruned by the process of natural selection. The ill-adapted die. The better adapted become better adapted. Species evolve. The formation of a planet is a selective process as well, governed by the inexorable pull of gravity. Large chunks of matter become selectively larger. Those chunks of material that just happen to be in near-circular orbits sweep out a clear path, avoiding head-on collisions that would threaten to break them apart. When it comes to growing a large planet, there is a sort of "selective pressure" that favors nearly-circular orbits. The tinkering hand of the Creator is not necessary to set the planets in their places. They just grow that way.

Today, we can run computer simulations and watch solar systems form in a virtual world governed by Newton's laws. More and more we are gaining the ability to look out into the galaxy and pinpoint alien solar systems in various stages of formation. But Isaac Newton didn't have the advantage of supercomputer simulations of planetary accretion or observations of extrasolar planets. All he had were his own newly-minted laws of motion and his imagination. And despite his great genius, in this instance, Newton's imagination was clearly not up to the task. We should take heart in this. And so, to paraphrase Isaac Newton, I suggest the following new motto for the ID movement: "If we see less far than others, be consoled that we stand in the company of shortsighted giants."

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featured in Tangled Bank #29

Monday, January 02, 2006

the osiander sticker...

In January of 2005, a federal judge in Georgia ruled that a suburban county school district would be required to remove a sticker from the front of its high school biology textbooks. The stickers were placed in the textbooks in Cobb County in 2002 as a sort of compromise after widespread outrage over a decision to remove the word "evolution" from Georgia textbooks entirely. The word evolution stayed in, but what the textbooks received instead, by way of the introductory sticker, was the following disclaimer...

"This textbook contains material on evolution. Evolution is a theory, not a fact, regarding the origin of living things. This material should be approached with an open mind, studied carefully and critically considered."

The court order to remover the stickers in Cobb County Georgia should be viewed as a victory for science educators. But the battle is far from over. In my own home state of Alabama, public school biology texts contain an even more detailed warning against the "unproven belief that random, undirected forces produced a world of living things."

While this may seem like a harmless enough statement to some, to many scientists it is a frustrating and embarrassing reminder that we still haven't advanced beyond the point where a group of people with a religious agenda and the supposed authority of Holy Scripture can deface a scientific work and circumvent it's most basic thesis. In both their wording and their intent, the Georgia textbook stickers hearken back to another infamous disclaimer, appended without the author's permission, and intended to dull the impact of one of the most important written works in the history of science.

In 1542, Nicolaus Copernicus was finally ready to publish his life's work - a treatise that would become known as "De Revolutionibus Orbium Coelestium", or, "On the Revolutions of the Heavenly Spheres." In this work, Copernicus painstakingly laid out his case that it was the Earth that moved about the Sun, and not the other way around. But by the time he had polished his work to the point that he was confident enough to release it for publication, Copernicus had become quite ill. He gave his manuscript to his protégé Georg Rheticus, who finished the work, then passed it along to a local Lutheran minister and theologian named Andreas Osiander.

It was Osiander then, who had the responsibility for proofing the final work and preparing it for publication. But apparently, Osiander was uncomfortable with the bold thesis of Copernicus. To be sure, there were valid objections that could be made to the theory in the 16th century - scientific objections, even. But Osiander's objections were based on the Holy Scriptures, which, many argued, made it quite clear that the Earth was at the center of the Universe, and that it was the Sun that moved across the sky. Perhaps fearing that the book might spawn an outbreak of heresy, Osiander added his own Preface to the work.

To the Reader Concerning the Hypotheses of this Work

There have already been widespread reports about the novel hypotheses of this work, which declares that the earth moves whereas the sun is at rest in the center of the universe. Hence certain scholars, I have no doubt, are deeply offended and believe that the liberal arts, which were established long ago on a sound basis, should not be thrown into confusion. But if these men are willing to examine the matter closely, they will find that the author of this work has done nothing blameworthy. For it is the duty of an astronomer to compose the history of the celestial motions through careful and expert study. Then he must conceive and devise the causes of these motions or hypotheses about them. Since he cannot in any way attain to the true causes, he will adopt whatever suppositions enable the motions to be computed correctly [...]. The present author has performed both these duties excellently. For these hypotheses need not be true nor even probable. On the contrary, if they provide a calculus consistent with the observations, that alone is enough. [...] For this art, it is quite clear, is completely and absolutely ignorant of the causes of the apparent [motions of the heavens]. And if any causes are devised by the imagination, as indeed very many are, they are not put forward to convince anyone that they are true, but merely to provide a reliable basis for computation. However, since different hypotheses are sometimes offered for one and the same [...] the astronomer will take as his first choice that hypothesis which is the easiest to grasp. The philosopher will perhaps rather seek the semblance of the truth. But neither of them will understand or state anything certain, unless it has been divinely revealed to him.

Therefore alongside the ancient hypotheses, which are no more probable, let us permit these new hypotheses also to become known, especially since they are admirable as well as simple and bring with them a huge treasure of very skillful observations. So far as hypotheses are concerned, let no one expect anything certain from astronomy, which cannot furnish it, lest he accept as the truth ideas conceived for another purpose, and depart from this study a greater fool than when he entered it. Farewell.

Osiander's message is clear. What follows is an interesting and admirable hypothesis, but it makes no claim to "truth". And why? Because it has not been "divinely revealed". So you can go ahead and use Copernicus's tables to predict where Jupiter will be next week, but don't take that to mean that the Earth REALLY moves! To do so would clearly be foolish. (If not heretical.) It should be "studied with an open mind", as they say in Georgia, and "critically considered". But it is only a theory. Not a fact. Like the stickers in Georgia, Osiander's preface was a desperate attempt to hold the Earth still in the face of scientific progress.

Of course, today we know that the "hypothesis" of Copernicus IS a fact. But it took a long time for the theory to escape from the objections of those who would use the Bible as the only true authority for knowledge about the natural world. How long? Fifty-seven years after the publication of "De Revolutionibus" Giordano Bruno was burned at the stake, in part for espousing the theories of Copernicus. Galileo was found "vehemently suspected of heresy" by the Inquisition in 1633 and placed under house arrest, where he remained until he died, almost 100 years after Copernicus's work left the printing press. And even though scientists had all but agreed that the Copernican system was indisputably correct by the close of the 17th century, theologians and popular writers on science continued to argue over whether or not to accept the theory for another 100 years. In terms of education, although it was taught in many schools from 1700 on, the Sun-centered solar-system did not become the sole model taught at Cracow Academy in Copernicus's native country of Poland until 1782. That's almost 240 years.

How is evolution doing by comparison? Well, Charles Darwin published "On the Origin of Species" in 1859. In 1925, at the time of the famed Scopes "Monkey Trial", there were still six states that had laws explicitly forbidding the teaching of evolution. By 1987, the U.S. Supreme Court ruled that the theories of "Creationism" or "Creation Science" were religious beliefs that could not be taught alongside evolution in public schools. And yet, here we are in 2004, with disclaimer stickers in our textbooks, and ideas of divine creation sneaking back into schools under the disguise of "Intelligent Design" theory. Luckily, there is no Inquisition, and nobody is being burned at the stake. (Although given the current political climate, I'm tempted to knock on wood here!) But there is obviously still a vocal and politically powerful minority determined to reject an idea about which scientists have long ago made up their minds. We clearly still have a long way to go. If we can take Copernicus as a guide, I look forward to writing a follow-up piece, and hopefully ripping off the stickers once and for all, on the 240th anniversary of "On the Origin of Species" in 2099.