Tag: science

Two faced

Facial symmetry: left=original picture; middle=left-left composite; right=right-right composite

A slight tilt of the face to the left or the right changes the emotional message you send. There’s a whole field of study on what’s called laterality that looks at how the asymmetry of your posture says things you might not realize.

Mike Nicholls has done some interesting work. In one study, he took two pictures of just the left side of peoples’ faces and reflected one half to make a composite image that basically had just two left sides or two right sides. The image above (which was not done by Nichols) shows an original photo, a left-left composite and a right-right composite. He found that:

… head turns of just 15 degrees can bring about significant changes in the perceived emotionality.

Nicholls discusses the implications with regards to the fact that portraits tend to feature the left side of the face. However, it is also interesting to think about what this means for non-verbal communication. Another paper, using 3D imaging of facial movements showed that:

Emotions are expressed more clearly on the left side of the face than the right … There was a trend, however, for left-sided movement to be more pronounced for negative than positive emotions.

Geometry and the height of the mountains on the moon

Galileo's image of the moon
Galileo's map of the moon.

Galileo Galilei matched careful observation of sunlight and shadows on the moon, with some beautiful geometry to estimate the height of lunar mountains, in 1609. He needed the Pythagoras’ Theorem and the quadratic formula, both of which middle school students should be familiar. Larry Phillips has a nice post describing how Galileo did the math. The image below (from Pioneers of Science shows how to get started.

From the Gutenberg Project eBook of Pioneers of Science by Oliver Lodge.

How to fly through space

Interplanetary spacecraft
Ion thruster spacecraft. Image from NASA.

To get anywhere in the solar system takes a long time and is not easy. The Mars rovers took years to get there and were built to be very light because heavier spacecraft are harder to lift into orbit and take more energy to get them where they’re going (and to slow the down when they get there). Getting humans to other planets, or even another solar system, is an even greater challenge. New Scientist magazine has a nice little article on different types of deep-space spacecraft that might work.

A sailing game that explores the trans-Atlantic triangular trade

Discovering America

Wind patterns over the North Atlantic Ocean had a huge effect on the colonization and history of the Americas because, after all, all they had were sailing ships. The circular, clockwise winds meant that it was easiest to sail south and west from Europe, and when you did, the first place you arrived at in the New World was the Caribbean or the northern edge of South America. This helps explains the first settlements of the Portuguese and Spanish, and why the latecomers, like the British, ended up further north up the coast of North America.

Using wind data from the University Corporation for Atmospheric Research (UCAR) and Google Maps I created an online sailing game I call Mariner AO. The game is pretty simple (basic instructions are here), you tell your ship which direction to go, starting off near Lisbon in Portugal and sail the Atlantic. What makes it interesting is that you can go wherever you like and make your own objectives. All that limits where you can go is the fact that you can only sail within 90 degrees of the wind. It’s very Montessori in that you have choice within limits.

The game is most interesting, I think, if you set objectives like trying to sail the triangular trade route, Europe (Portugal) to Africa (Dakar) to America (Charleston) and back to Europe again. The general clockwise wind pattern is persistent throughout the year, but sometimes you need to wait until the wind changes to be able to reach your objective.

Alistair Boddy-Evans has a nice article on the triangular trade of European manufactured goods to Africa, African slaves to the Americas, and plantation crops back to Europe.

I really like this game because it integrates so much. Atmospheric circulation, slavery, colonization, and even the physics of sailing if you can and want to get into it. In fact, I think it’s enough to base an entire cycle of work around. I’m still taking comments about how to improve the game.

Clouds on Mars

Clouds on Mars seen from the Mars Pathfinder

Discover Magazine blogger Phil Plait has a great post showing clouds formed by air rising over the volcanic mountains on Mars (orographic clouds). The simple animation is fascinating to see, but what’s even more interesting is how they were made. The images were taken by Emil Kraaikamp who uses a telescope in what appears to be his backyard. Each image in the series that makes up the animation is a composite from images taken with red, blue and green filters. Plait has a very good explanation of the process:

I love this, because it shows how using filters tells you a lot about what you’re seeing. Note that in the red Mars is fairly smooth, with some dark spots. The red dust covers the planet, so it smooths out features (though the ice caps are obvious). In the green you’re just starting to see a hint of clouds, and then in the blue the clouds pop right out.

Combine them, and you have Mars. Another world, seen through what most people would consider a small telescope here on Earth.

Photography is a wonderful medium for combining science and art as you manage the exposure to create interesting effects. If you understand a little about how cameras work, the page on the equipment used to take the pictures is quite fascinating.

The things you can do with vinegar and baking soda

Acetic acid and sodium bicarbonate

I like to do as much science as I can using everyday materials. When it comes to basic chemistry the vinegar and baking soda reaction is one of the easiest, safest and useful you can come across. Wayne from www.apple-cider-vinegar-benefits.com has a great page on simple experiments from basic volcano building, to stoichiometry (using a balloon) and demonstrating endothermic reactions (but you’ll need an accurate and fast thermometer).