May 2012 – Montessori Muddle

The Adolescent Sleep Cycle

Bora Zivkovic compiles some information on how kids circadian rhythms change during adolescence, and advocates for later school starting hours.

He points out the interesting concept of chronotypes:

Everyone, from little children, through teens and young adults to elderly, belongs to one of the ‘chronotypes’. You can be a more or less extreme lark (phase-advanced, tend to wake up and fall asleep early), a more or less extreme owl (phase-delayed, tend to wake up and fall asleep late). You can be something in between – some kind of “median” (I don’t want to call this normal, because the whole spectrum is normal) chronotype.

— Zivkovic (2012): When Should School Start in the morning in Scientific American (blog).

And how your chronotype gets phase-delayed at puberty:

No matter where you are on these continua, once you hit puberty your clock will phase-delay. If you were an owl to begin with, you will become a more extreme owl for about a dozen years. If you are an extreme lark, you’ll be a less extreme lark. In the late 20s, your clock will gradually go back to your baseline chronotype and retain it for the rest of your life.

— Zivkovic (2012): When Should School Start in the morning in Scientific American (blog).

Bonding

A cute little video about ionic and covalent bonds by 10th grade chemistry student Eli Cirino.

↬ Miss Cellania

U.S. Senators’ 10th Grade Speeches

NPR presents the results of a Sunlight Foundation study that showed that U.S. senatorial speeches average at a 10th grade reading level. The maximum is about 16th grade (high school + 4 years of college), while the minimum is about 8th grade. The average is down one and a half grade levels from just 10 years ago.

Note that the U.S. constitution was written at an 18th grade level.

Networks versus Trees: Ways of Analyzing the World

Manuel Lima contrasts the traditional, hierarchical, view of the world (evolution’s tree of life for example) to a more network oriented perspective.

One interesting part is the interpretation of the history of science as having three phases, dealing with Problems of:

Simplicity: Early scientific efforts (17th-19th centuries) was focused on “simple” models of cause and effect — embodied perhaps in Newton’s Laws, where every force has an equal and opposite force.
Disorganized Complexity: Think early 20th century nuclear physics — Heisenberg’s uncertainty principle for example — where the connections between events are complicated and sort of random/probabilistic.
Organized Complexity: Systems science sees the interrelatedness of everything: ecologic food webs; the Internet; horizontal gene transfer across the limbs of the tree of life.

ᔥ RSA Animate ↬ The Dish

Butterfly on the Bench

speyeria-5008 — Great Spangled Fritillary (*Speyeria cybele*). View of the underside of its wings (ventral view).

This little guy seemed to like hanging out on the bench near the back door. I believe it’s a Great Spangled Fritillary (Speyeria cybele).

speyeria-5005 — Dorsal (top down) view of a Great Spangled Fritillary (*Speyeria cybele*).

speyeria-5010 — Great Spangled Fritillary (*Speyeria cybele*).

speyeria-5015 — Great Spangled Fritillary (*Speyeria cybele*).

There’s no Becoming a Writer

If … you had asked, “Should I become a professional writer?” the answer would have been No. And why not? The answer would have been that if you were destined to become a professional writer, you wouldn’t have asked the question; you would have known the answer for yourself and to hell with what anybody told you.

— Malcolm Cowley in a letter to Richard Max ᔥ Rebecca Davis O’Brien (2012): Malcolm Cowley, Life Coach, in the Paris Review of Books.

Advice from a writer to a potential writer. A career in writing is a difficult choice: “the rewards come late”; “most writers are failures”. You need to want to write. Intrinsic motivation.

ᔥ Rebecca Davis O’Brien (2012): Malcolm Cowley, Life Coach ↬ The Dish.

Momentum

A ball rolling down a ramp hits a car which moves off uphill. Can you come up with an experiment to predict how far the car will move if the ball is released from any height? What if different masses of balls are used?

For my middle school class, who’ve been dealing with linear relationships all year, they could do this easily if the distance the car moves is directly proportional to height from which the ball was released?

The question ultimately comes down to momentum, but I really didn’t know if the experiment would work out to be a nice linear relationship. If you do the math, you’ll find that release height and the maximum distance the car moves are directly proportional if the momentum transferred to the car by the ball is also directly proportional to the velocity at impact. Given that wooden ball and hard plastic car would probably have a very elastic collision I figured there would be a good chance that this would be the case and the experiment would work.

It worked did well enough. Not perfectly, but well enough.