The Elegant Universe's Teachers' page is excellent.
Created in 2003, when string theory was making it’s big splash in the popular consciousness, The Elegant Universe starts with Newton’s observations of gravity, shows Einstein’s separate explanations of why gravity works and the nature of the sub-atomic world, and finally delves into string theory which tries to reconcile Einstein’s two theories into a unified whole.
We don’t usually get past Newton in middle school, but this PBS program introduces such a wider and weirder view of the universe that it can help strike the imagination. It also presents complex concepts in an intelligible way.
Next year we’ll be going into the differences between plant and animal cells, as well as into the differences between plants and animals. There are a number of fundamental differences, starting with the fact that plants can photosynthesize to convert sunlight directly into energy and animals can’t. Except for the sea slug. Sea slugs have found a way to pirate chloroplasts from green algae (found via Immersion Blog).
Chloroplasts are the green cellular bodies (organelles) that perform photosynthesis. The species Elysia chlorotica eats the algae when they are young and instead of digesting them entirely, keep the chloroplasts in their gut.
Young E. chlorotica fed with algae for two weeks, could survive for the rest of their year-long lives without eating – Brahic, 2008
What’s even more intriguing is that there is evidence that the sea slugs have incorporated parts of the algae into their own DNA so they can maintain the right conditions for the chloroplasts to survive in the new host (Rumpho et al., 2008). The Sea Slug Form has a nice page on other solar-powered slugs.
Mathematics is the language of science. Scientists refine and refine their observations of the complexity of the natural world and try to boil these complex observations down to simple relationships, relationships that are expressed in mathematics. This, I think, is part of the human condition. Our brains are designed to extract simple relationships, heuristics, rules of thumb, from the observations of our senses. It is why Einstein’s equation, E=mc2, has captivated our imagination for so long, why physicists struggle to find the unified theory, and why fractals are so fascinating.
Cristóbal Vila’s short video (found via The Daily Dish) captures some of the magic of the relationship between mathematics and the world.
We all love the Schoolhouse Rock video, “How a bill becomes a law” but with the recent passage of the health care bill we are reminded that the theory can get a little more nuanced in practice. NPR’s On The Media has an updated version.
Humpty Dumpty sat on a wall;
Humpty Dumpty had a great fall.
All the King’s horses
And all the King’s men
Couldn’t put Humpty together again!
I often tell my students that the meaning of a piece of literature, or really any piece of art, depends both on the intended meaning of the author and the experience-colored interpretation of the observer; any piece can have as many meanings as there are observers.
We also sometimes talk about the multiple meanings the author may be trying to convey; when they use metaphor in a single sentence or thread subtle, acerbic, poignant satire through a piece.
I can’t remember ever getting to the point of talking about unintentional meanings that seep into the work from the author’s unconscious, but these, sometimes I suspect, tell us the most about the nature of our shared humanity than intended meaning can.
The government’s Energy Star program to label products that are more energy efficient was in the news recently (and there are a lot of different products that have the label). The New York Times ran a story on how auditors, when asked by congress, submitted 20 fake and often ridiculous products to be approved for the stickers many environmentally aware people look for when they buy appliances like refrigerators (an AP report is also available).
GAO obtained Energy Star certifications for 15 bogus products, including a gas-powered alarm clock. – (GAO, 2010)
This Energy Star poster now takes a somewhat sinister (Orwellian) cast.
This study highlights the lesson that while we want to be environmentally aware, we must always remain skeptical of claims pushed by manufacturers, even if they are supported by government certification. It also highlights an excellent application of the concept of checks and balances. One branch of government (congress) checks up on others (EPA and DOE who run the Energy Star program are part of the executive branch) and the others are forced to improve.
Adolescents like to tick you off. Push all of your buttons to see what happens. And you want to ask, “Who are you really?” and, “Do your really not care?” We probably did the same when we were that age, but do you also remember how idealistic we were? The video below, from Penguin Publishing (found via The Dish) captures a bit of that duality of the adolescent mind. The use of white space and of just simply words also ties it quite nicely into our ongoing discussion of poetry in a “spark the imagination” kind of way.
Normal distribution with 95% unshaded. Adapted from Wikimedia Commons.
A discussion of statistical significance is probably a bit above middle school level, but I’m posting a note here because it is a reminder about the importance of statistics. In fact, students will hear about confidence intervals when they hear about the margin of error of polls in the news and the “significant” benefits of new drugs. Indeed, if you think about it, the development of formal thinking skills during adolescence should make it easier for students to see the world from a more probabilistic perspective, noticing the shades of grey that surround issues, rather that the more black and white, deterministic, point of view young idealists tend to have. At any rate, statistics are important in life but, according to a Science Magazine article, many scientists are not using them correctly.
One key error is in understanding the term “statistically significant”. When Ronald A. Fisher came up with the concept he arbitrarily chose 95% as the cutoff to test if an experiment worked. The arbitrariness is one part of the problem, 95% still means there is one chance in twenty that the experiment failed and with all the scientists conducting experiments, that’s a lot of unrecognized failed experiments.
But the big problem is the fact that people conflate statistical significance and actual significance. Just because there is a statistically significant correlation between eating apples and acne, does not mean that it’s actually important. It could be that this result predicts that one person in ten million will get acne from eating apples, but is that enough reason to stop eating apples?
It is a fascinating article that deals with a number of other erroneous uses of statistics, but I’ve just spent more time on this post than I’d planned (it was supposed to be a short note). So I’d be willing to bet that there is a statistically significant correlation between my interest in an issue and the length of the post (and no correlation with the amount of time I intended to spend on the post).
