A cute little video about ionic and covalent bonds by 10th grade chemistry student Eli Cirino.
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.
Butterfly on the Bench
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).
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.
Alexandria to Constantinople: Traveling the Roman World
Say I wanted to get from Alexandria, Egypt, to Constantinople, I don’t trust boats, and it’s 1800 years ago. Well, instead of mapping it with Google I’d have to use ORBIS instead. ORBIS tells me that it would take two and a half months and cost me 3000 denarii (about $30,000).
Which seems like a bit much. But, since I absolutely have to get to the capital, I think I’ll price out a coastal boat route. That reduces the price by 80%, and the time to three weeks.
If I was really cheap, and was willing to risk the open Mediterranean, the time could be chopped down to less than two weeks, at a cost of only 374 denarii.
In ORBIS, Walter Scheidel and Elijah Meeks have created a fascinating resource for the study of the geography and history of Roman civilization.
Eclipse
It pays to remember that a solar eclipse occurs when the Moon passes between the Sun and the Earth. A lunar eclipse occurs when the shadow of the Earth passes over the Moon.