Carbon in the Ground and Free Oxygen in the Air

A couple new article relevant to our study of Earth History.

Carbon

Image by Rajdeep Dasgupta, via pyhs.org.
Image by Rajdeep Dasgupta, via pyhs.org.

Research on the high pressure and temperature conditions at the Earth’s core suggest that most of the carbon in the early Earth should have either boiled off into space or been trapped by the iron in the core. So where did all the carbon necessary for life come from? They suggest from the collision of an embryonic planet (with lots of carbon in its upper layers) early in the formation of the solar system.

Free Oxygen

Typical surface view of purple mat surface at Middle Island showing purple filaments. Some white filaments can also be observed. Image from Thunder Bay Sinkholes 2008 via oceanexplorer.noaa.gov.
Typical surface view of purple mat surface at Middle Island showing purple filaments. Some white filaments can also be observed. Image from Thunder Bay Sinkholes 2008 via oceanexplorer.noaa.gov.

It took a few billion years from the evolution of the first photosynthetic cyanobacteria to the time when there was enough oxygen in the atmosphere to support animal life like us. Why did it take so long? NPR interviews scientists investigating purple microbial mats in Lake Huron.

Emotional Words

The NRC Word-Emotion Association Lexicon (aka EmoLex) associates a long list of english words with their emotional connotations. It’s stored as a large text file, which should make it easy for my programming students to use to analyse texts.

David Robinson used this database to help distinguish tweets sent by Donald Trump from those sent by his staff (all on the same twitter account).

Emotional sentiment of Donald Trump's Twitter feed. From Variance Explained
Emotional sentiment of Donald Trump’s Twitter feed. From Variance Explained

John Snow: How to be a Scientist

These three excellent, short videos on John Snow’s life and work on cholera do a nice job of describing what makes for good science–careful observation; good notes; creative analysis of data, etc. They should make a good “spark your imagination” introduction to biological science.

They also have an excellent explanation of all the ‘lies’ and liberties they took in the making of the video.

Bloom’s Taxonomy

From Wikimedia: https://commons.wikimedia.org/wiki/File:BloomsCognitiveDomain.svg
From Wikimedia: https://commons.wikimedia.org/wiki/File:BloomsCognitiveDomain.svg

Bloom’s cognitive taxonomy offers a useful model for defining learning objectives. You start with the basic knowledge of the subject that requires some memorization: fundamental constants like the speed of light; fundamental concepts like conservation of mass and energy; and basic equations like Newton’s laws. On the second level, you use these basic facts and concepts to extrapolate and generalize with questions like: is the Earth an open or closed system with respect to mass and energy? And then we can start to apply our knowledge and understanding to problem solving: determine the average temperature of the Earth based on conservation of energy. Finally, at the highest level, we can analyse our models and evaluate their advantages and disadvantages.

Grit versus Passion

David Brooks argues that grades discourage students from following their passions (they have to spread their attention to keep up their GPA). And grit is easier to have if you’re following your passion.

Suppose you were designing a school to help students find their own clear end — as clear as that one. Say you were designing a school to elevate and intensify longings. Wouldn’t you want to provide examples of people who have intense longings? Wouldn’t you want to encourage students to be obsessive about worthy things? Wouldn’t you discuss which loves are higher than others and practices that habituate them toward those desires? Wouldn’t you be all about providing students with new subjects to love?

In such a school you might even de-emphasize the G.P.A. mentality, which puts a tether on passionate interests and substitutes other people’s longings for the student’s own.

— Brooks (2016): Putting Grit in its Place