Month: April 2010

Half plant – half animal

The sea slug.

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 in the natural world

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.

Meanings

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.

Energy inefficiency: Checks and balances

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)

The Energy Star investigation was done by the Government Accountability Office (GAO), which is often tasked with checking up on the other branches of the government. The GAO website is a great information source because they post very readable summaries of their reports, and a highlights page that answers the question, “Why GAO Did This Study” and “What GAO Found”.

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.