Archive for November, 2005

Hey y’all, watch this here sodium and water!

Friday, November 11th, 2005

In this age of computer simulations replacing real laboratory experiments in our classes, we sometimes forget that real science can expose us to real danger. A news story from Spartanburg SC illustrates the point well.

15 high school students are recovering after a science experiment exploded in a Spartanburg County classroom.

Instructors at Woodruff High School were attempting to show the volatility of mixing sodium and water, creating sodium hydroxide, when the mixture exploded in a Pyrex dish. Glass and other debris hit some students nearby. The mixture also got onto several of the students. School nurses immediately washed down the students, but at least two of the students were sent to local doctors for treatment.

Sodium and water makes for a cool chemistry demonstration. Heck, I remember it from my tenth grade chemistry class because it burned a hole in the ceiling. Still, having to send several students to off-campus doctors makes it sound like someone wasn’t being very careful.

I hope, at least, that this demo was done in a lab setting (with access to eye wash stations and safety showers) and the students were wearing some eye protection.

Updated: Here’s another news story about the accident.

Fifteen students were hit by debris or chemicals from the reaction.

Either it was a heck of a violent explosion, or someone forgot to tell the kids to stand back.

A revision of the WYFF article above includes a picture of a student with a red mark from "flying debris" right below the eye. It sounds more and more like the students were gathered round the demonstration with no safety equipment on. Bad policy for something that’s potentially explosive.

The new Kansas science standards have been posted

Thursday, November 10th, 2005

The new Kansas science standards have been posted. It looks like it’s the same as the working draft I read yesterday.

Maybe I’m missing it, but news articles on the subject say that Kansas has "redefined science". I don’t see that. I just see Kansas ignoring good science and substituting bad science when it comes to biology.

Which is worse – redefining science to include nonsense or not being able to see that nonsense is not science?

Why does Kansas hate science?

Wednesday, November 9th, 2005

I’m a science teacher at my local technical/community college. I teach chemistry, but the teaching of all kinds of science is important to me. I follow the creation-evolution "controversy" with interest because it could affect the quality of all science teaching.

Why does Kansas hate science?

In Kansas, the state board of education has approved a new set of science standards that takes aim at the most fundamental theory of biology – evolution. The standards seek to paint evolution as a theory in trouble because of a host of imagined problems (the main one being that it doesn’t agree with the beliefs of some overly restrictive religious sects).

I’ve not been able to dig up the final draft of the standards, but I have pulled a working document from August which should be enlightening. The document starts off with a Rationale section, which explains pretty clearly that these school board members are after evolution.

We believe it is in the best interest of educating Kansas students that all students have a good working knowledge of science: particularly what defines good science, how science moves forward, what holds science back, and how to critically analyze the conclusions that scientists make. Regarding the scientific theory of biological evolution, the curriculum standards call for students to learn about the best evidence for modern evolutionary theory, but also to learn about areas where scientists
are raising scientific criticisms of the theory.

Two sentences in and already they’re mentioning "scientific criticisms" of evolutionary theory. (Yes, those are literally the first two sentences of the document.) Of all the scientific theories out there, why pick on evolutionary theory and act as if it’s the only one in trouble?

These curriculum standards reflect the Board’s objective of: 1) to help students understand the full range of scientific views that exist on this topic, 2) to enhance critical thinking and the understanding of the scientific method by encouraging students to study different and opposing scientific evidence, and 3) to ensure that science education in our state is “secular, neutral, and non-ideological.”

See that statement about the "full range of scientific views"? Those are code words for taeching creationism (which now goes under the name of "Intelligent Design&quot) instead of biology or teaching them as equivalente. What’s wrong with that? You have your pick: Either it’s discredited science (in the sense that the claims it makes have been rather thoroughly refuted over the past few hundred years) or it’s non-science (in the sense that the new claims it makes do not explain anything and are not testable). Why waste time teaching that sort of stuff in a science class that will have its hands full teaching current science?

Evolution is accepted by many scientists but questioned by some.

This statement is simply misleading. A more accurate rendition would say something like Evolution is accepted by nearly all biologists, but questioned by a tiny minority of scientists – most of which have little to no biological training. The statement is about as silly as saying that The roundness of the Earth is accpeted by many scientists, but questioned by some.

The Board has heard credible scientific testimony that indeed there are significant debates about the evidence for key aspects of chemical and biological evolutionary theory.

At the hearings that scientists refused to participate in?

All scientific theories should be approached with an open mind, studied carefully, and critically considered. We therefore think it is important and appropriate for students to know about these scientific debates and for the Science Curriculum Standards to include information about them.

There are debates about evolution, just as there are debates about the nature of the atom. But the debates are not about what the board implies. The debates about evolution aren’t over whether evolution occurs, but are largely about the relative importance of different evolutionary mechanisms. Just like a debate over the way a nucleus of an atom is held together is not a debate over whether the atom exists.

Skipping a bit…

We also emphasize that the Science Curriculum Standards do not include Intelligent Design, the scientific disagreement with the claim of many evolutionary biologists that the apparent design of living systems is an illusion. While the testimony presented at the science hearings included many advocates of Intelligent Design, these standards neither mandate nor prohibit teaching about this scientific disagreement.

We don’t mandate teaching creationism – wink, wink. And it’s a good thing that the science standards don’t mandate teaching intelligent design creationism, since not even the intelligent design creationists can figure out exactly what intelligent design creationism is. (Mostly, it’s versions of We don’t like evolution because it doesn’t completely explain every last detail of this bodily function. But Intelligent Design doesn’t provide an explanation for these details either.) They advocate teaching "criticisms" because that’s literally all they have.

Moving on, let’s see what Kansas students will hear in their biology classes.

However, in many cases the fossil record is not consistent with gradual, unbroken sequences postulated by biological evolution.

They’re actually going to teach students that the fossil evidence contradicts evolution. That’s a notion with basically no support from biologists. What they probably should say here is that the fossil record might suggest that some mechanisms of evolution are more important than others – not that the fossil record is inconsistent with evolution. Of course, that would presuppose that the school board here is trying to be honest.

The view that living things in all the major kingdoms are modified descendants of a common ancestor (described in the pattern of a branching tree) has been challenged in recent years by: i. ii. Discrepancies in the molecular evidence (e.g., differences in relatedness inferred from sequence studies of different proteins) previously thought to support that view. A fossil record that shows sudden bursts of increased complexity (the Cambrian Explosion), long periods of stasis and the absence of abundant transitional forms rather than steady gradual increases in complexity,and iii. Studies that show animals follow different rather than identical early stages of embryological development.

It’s at this point that biologists start frothing at the mouth. Why? Because these parts of the Kansas science standards read like a laundry list of discredited critiques of evolution. You can find the scientific response to all of this stuff at places like the talk.origins web site. I’ve linked in a few examples for you already.

Whether microevolution (change within a species) can be extrapolated to explain macroevolutionary changes (such as new complex organs or body plans and new biochemical systems which appear irreducibly complex) is controversial.

The keywords "irreducibly complex" are from the creationist playbook. And evolution explains those systems, too.

Also, the idea that cumulative small changes can add up to large change is hardly controversial. It’s about as controversial as a walk across the neighborhood. Humans walk slowly, and if I appear several miles from my house without my car, you probably wouldn’t have a lot of problem with me saying I walked there. Why wouldn’t you? Because even though I walk slowly, if I walk for a long time, I can go a large distance. Even though changes between generations are small, given enough time the overall change can be large. This is controversial?

Look at these quotes – from two different sections of the document.

These kinds of macroevolutionary explanations generally are not based on direct observations and often reflect historical narratives based on inferences from indirect or circumstantial evidence.

Middle level students have the capability of inferring characteristics that are not directly observable and stating their reasons for their inferences. Students need opportunities to form relationships between what they can see and their inferences of characteristics of matter. We cannot always see the products of chemical reactions, so the teacher can provide opportunities for students to measure reactants and products to build the concept of conservation of mass.

The first paragraph is from the life science part of the dicument, while the second part is from the physical science part. Why is it bad to use some indirect evidence in biology but not in chemistry?

Some of the scientific criticisms include: a A lack of empirical evidence for a "primordial soup" or a chemically hospitable pre-biotic atmosphere; b. The lack of adequate natural explanations for the genetic code, the sequences of genetic information necessary to specify life, the biochemical machinery needed to translate genetic information into functional biosystems, and the formation of proto-cells; and c. The sudden rather than gradual emergence of organisms near the time that the Earth first became habitable.

We’re hitting a little closer to my field here – chemistry. I find it fascinating that Miller/Urey-type experiments are successful at producing the building blocks of life from chemicals and conditions that were likely similar to those on the early Earth. Maybe it appeals to the mad scientist in me: Mix chemicals, add lightning. Collect the building blocks of life – amino acids. I also think that high schoolers would find it fascinating (which may have something to do with it being controversial. The teens might end up becoming scientists, of all things!

The controversy here is that the original experiments were done with slightly different conditions than we currently believe was on the early Earth. Not that big of a deal, really. There’s also a molecular structure issue dealing with how the atoms in the amino acid are arranged. (Chemists call this stereochemistry.) Life on earth uses one type of arrangement, while the Miller/Urey experiment produces two arrangements for each amino acid (a racemic mixture). I’m not really clear on why creationists see this as a problem, since some surfaces will selectively attach to one kind of amino acid but not the other (they are stereoselective). Neat stuff!

To wrap up, the Kansas science standards appear to throw science out of the window and introduce the speculation of a bunch of fringe groups as its substitute. So far, it’s mainly biology in the crosshairs. But who says that my favorite science – chemistry – isn’t going to be next?