Science by Email 18 May 2012

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	18 May 2012
News: About face on facial expressions By Patrick Mahony One of the animated faces used in the experiment. How do you tell if someone is happy or sad? They might say something, but often you can tell just by looking at them. Humans use facial expressions to convey a wide range of emotions quite effectively: a smile usually means a person is happy, while a frown means they’re probably not. Basic facial expressions were once thought to be common across all cultures. These simple expressions include happiness, anger, sadness, fear and disgust. This idea was supported by research that showed that even an isolated people in Papua New Guinea labelled a number of facial expressions in the same way as other cultures. Recent research suggests that facial expressions might not be universal after all. Psychologists used a computer program to randomly create animated faces, some of which showed recognisable expressions. They showed the animations to a group of observers from a western European background, as well as an equal number of observers from an East Asian background. The observers were then asked them to identify the emotion, as well as its intensity. The psychologists found that the observers from more western cultures agreed on six emotions, as well as the relative intensity of the expressions. However, the observers from Asian cultures showed a high degree overlap between emotions. For example, the Asian observers often did not agree on whether a face showed fear or surprise. It was a similar case for anger and disgust. They also found that the Asian observers looked at movement around the eyes to determine emotion, while the European observers used cues from other parts of the face. These results indicate that facial expressions and their interpretation are not as uniform as once thought and that cultural factors play an important role. In our increasingly globalised society, this has potential important implications for international business and diplomacy. More information Perceptions of facial expressions differ across cultures Surprise! Facial expressions aren’t necessarily universal Careers link Job guide: Psychologist
You will need these materials.   Blow up a balloon, tie the end and bounce it on your hand. How does it move?   Place a marble into another balloon. Blow it up and bounce it on your hand. How does it move?   Try this: Wobbly balloon   You will need Balloons Marble What to do Blow up a balloon and tie the end. Bounce the balloon into the air with your hand and observe how it moves. Place a marble in another balloon. Blow this balloon up and tie the end. Bounce this balloon into the air with your hand. How does it move? What’s happening? The first balloon has a relatively small mass compared to its volume. The balloon falls due to gravity, while air resistance slows its fall. Another way of saying this is that the force of air resistance has an effect on its inertia. The materials making up the balloon (the air and the rubber skin) are spread fairly evenly around the middle, making the balloon fall smoothly.                                 The marble in the second balloon doesn’t behave like the balloon around it. It is denser, meaning the force of air resistance on its movement has less of an effect on its inertia than on the balloon’s inertia. It hits the side of the balloon and bounces back. The balloon also feels an equal force from the marble, but in the opposite direction, pushing it away from the marble. This is a good example of Newton’s first law of motion on inertia, and third law of motion on opposing forces. The marble keeps moving and bouncing around inside the balloon, which results in the wobbly motion of the balloon. Applications Air resistance is an important consideration in the design and function of aircraft. The higher up in the atmosphere, the thinner the air. This lowers the air resistance meaning planes require less fuel to achieve the same speed. In the case of parachutes, a high air resistance is required. The large surface area of a parachute results in a large air resistance. This slows down the person so that they are able to land safely. By Patrick Mahony Try another Science by Email activity using balloons More information Gravity and air resistance View the online version Quiz questions 1. If you were engaging your zygomaticus major muscles, what would you be doing? 2. Which are heavier: alpha or beta particles? 3. What do angiosperms have that gymnosperms don’t? 4. True or false: Australia is currently drought-free for the first time in over a decade?  5. What is the most common blood type in Australia? Did you know? Research from the University of Melbourne shows that more colourful bird species evolve faster than others. Websites Watch it! Learn about the physics of the circus in these videos. Do it! Can you use your knowledge of friction and air resistance to save the day? Crystals, Saturday 12 May at 9.00 am on Network Ten Trampolining, fencing, badminton, archery and ten pin bowling! Join Dr Rob as he saddles up and SCOPEs out all the science behind some solo sports that you might not know a lot about! Next episodes: Thursday 24 May, 4.00 pm: Round Saturday 26 May, 9.00 am: Recycling Want to have your own episodes of SCOPE to watch whenever you feel like it? Click here to download them directly into your iTunes folder, or go here to download iTunes. Charges apply. Quiz answers 1. The zygomaticus major muscles are used to smile. 2. Alpha particles are heavier than beta particles.            3. Angiosperms are plants that have flowers. 4. True. Australia is drought-free following the end of drought declarations in two regions of New South Wales. 5. O is the most common blood type in Australia. Researchers from Monash University recently developed a new method for testing blood type inspired by the Harry Potter books. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science by Email. Editor: Mike McRae| Manage your subscription | FAQ

 

 

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