Information about Smile

In physiology, a smile is a facial expression formed by flexing the muscles most notably near both ends of the mouth. The smile can be also around the eyes. Among humans, it's customarily an expression of pleasure, happiness, or amusement, but can also be an involuntary expression of anxiety, in which case it can be known as a grimace. There is much evidence that smiling is a normal reaction to certain stimuli and occurs regardless of culture. Happiness most often causes the smile to occur, though. Among animals, the exposure of teeth, which may bear a resemblance to a smile, are often used as a threat or warning display - known as a snarl - or a sign of submission. In chimpanzees, it can be a sign of fear.

Types of smiles

Researchers have identified two main varieties of smiles:

• The "Duchenne smile", after the researcher Guillaume Duchenne, is the most studied, and involves the movement of both the zygomaticus major muscle near the mouth and the orbicularis oculi muscle near the eyes. An example of the smile is shown in the girl's smile in the middle of the page. It is believed that the Duchenne smile is only produced as an involuntary response to genuine emotion, and is therefore what one could call the "genuine" smile. Due to the involvement of the muscle near the eyes, it is sometimes said that one can tell whether or not a smile is "real" by whether or not it "reaches the eyes".
• The "Pan American smile", on the other hand, is the voluntary smile involving only the zygomaticus major muscle to show politeness; for example, by a flight attendant on the former airline of the same name. Considered "insincere", this type of smile has also been called the "Professional Smile" by David Foster Wallace in his comedic short story "A Supposedly Fun Thing I'll Never Do Again".

Historical Background

Many biologists think the smile started as a sign of fear. Primalogist Signe Preuschoft traces the smile back over 30 million years of evolution to the "fear grin." Monkeys and apes used barely clenched teeth to portray to predators that they were harmless. Biologists believe the smile has evolved differently among species and especially among humans.

Biology is not the only academic discipline that interprets the smile. Those who study kinesics view the smile as an affect display. It can communicate feelings such as: love, happiness, pride, contempt, and embarrassment.

Examples

Researchers have come to the conclusion that smiles are innate. For example, blind people smile without learning it through observation. However, the use of smiles varies from culture to culture. For example, Middle Easterners think Americans are insincere because they smile so often. Another example is that the Japanese smile less because of societal pressures to hide emotions.

References

• Miller, Professor George A., et. al. Overview for "smile." Retrieved 12 December 2003 from this page.
• Conniff, R. (2007). What's behind a smile? Smithsonian Magazine, 38,46-53.
• Ottenheimer, H.J. (2006). The anthropology of language: An introduction to linguistic anthropology. Belmont, CA: Thomson Wadsworh.
• Scanner shows unborn babies smile

See also

• Laughter
• Emotion
• Emoticon
• Facial Action Coding System
• Frown
• Facial expression
• Smiley
• Social Psychology

Images

Girl with closed mouth smile.	Girl with open mouth smile.	Politicians and leaders are often shown smiling as this is considered a sign of confidence	Artwork on this ball is a common abstract representation of a smiling face.

External links

• See examples of genuine, false, and contempt smiles
• Spot The Fake Smile on BBC Science & Nature
• Expressions of Positive Emotion in Women's College Yearbook Pictures and Their Relationship to Personality and Life Outcomes Across Adulthood.

---

SmILE is a showcase car designed for Greenpeace to demonstrate how fuel efficient a car can be. The name stands for "Small, Intelligent, Light, Efficient'. It is based on the Renault Twingo, halving its fuel consumption to 3.3 l/100km (29 km/l or 78 mpg). The importance of this is that cars represent more than half the world's oil consumption (contributing about 20% to the world's greenhouse gas emissions), that the number of cars in the world is rising at twice the rate of the population growth and that car manufacturers were making no effort to develop more fuel efficient cars (as of 2006, however, the Honda Insight has a fuel consumption that is almost as good as that of the SmILE).

An important issue in the design was that it should use off-the-shelf technology (parts and knowhow). As a result, in mass production it should not cost significantly more than a 'heavier' equivalent. The engine should even be cheaper because it is made of fewer parts. However, parts that would be more expensive are supercharging (be it COMPREX or turbo-supercharger) and the wheels and the wheel suspension, which are made of aluminium.

The major changes made to the Twingo are:

• 23% lighter (650 kg instead of 845 kg):
• 80 kg less because of a smaller engine and lighter peripherals (battery, radiator and exhaust system)
• 80 kg less in vehicle interior and chassis through lighter seat structures (aluminium / plastic) and lighter metals for wheel suspensions, drum brakes, brake calliper and rims. To keep the cost down, no exotic materials (such as titanium screws or carbon gear boxes) were used.
• lighter wheels, which also have a rolling resistance that is 35% lower.
• Less air resistance, with a 30% improvement in the windtunnel (C_w value (drag coefficient) down from 0.37 to 0.25)
• A smaller and more efficient engine, a supercharged two-cylinder four-stroke internal combustion engine with four-valve technology in a boxer arrangement. A maximum torque of 75 Nm results from a swept volume of 358 cm³ at 2,900 rpm. The dynamic pressure supercharger makes sure the engine runs most efficiently at normal operating speeds. Most car engines are designed for optimum performance at maximum speed and load, which are in reality rarely used. At 55 bhp, the engine has the same performance as the original Twingo. Other performance parameters, such as maximum speed, elasticity and acceleration are the same or better.

The main consumption change of the engine stems from its more frequent use in the higher load range, which results in higher thermal stress. This is compensated for by an ingeneous cooling system. The mean piston velocities are in the customary range. The use of the latest technologies in materials and surface coatings guarantees stability of piston rings and cylinder bearing surfaces despite the higher pressures due to supercharging. Anyway, a car engine rarely reaches the end of its 'life' before the car is scrapped.

At least a further 80 kg weight reduction could be achieved through the use of fibre composite materials, a smaller tank and replacing the glass windows with polycarbonate. A further redesign could improve the fuel consumption even more, such as an even smaller engine, further weight savings, improving the aerodynamics (eg through a smaller rear interior), automatic inertia utilisation or engine switch-off systems, regenerative braking, etc.

The changes did not alter the safety standards of the Twingo and the airbag and lateral collision protection were kept in place.

Aluminium accounts for 45 kg of the weight of the SmILE (7%), through replacement of both axles, wheel suspension and seat structure. In average cars in Europe this is 65 kg (6%) and rising. One problem with aluminium is, however, the high energy cost of primary production. However,recycled aluminium has a much lower energy cost and identical mechanical properties.

In Germany, around 10% of all cars are replaced annually by new vehicles, so if all new vehicles had the SmILE standard that would mean an annual reduction of the CO2 emissions of the car fleet by 5%.

A similar reduction in fuel consumption would be possible for all petrol cars, but not diesels because they are heavier (and require heavier batteries). The Twingo was, however, chosen because of its favourable ratio between internal space and exterior and because it is a reasonable all-round car for everyone (it is the most imported car in Germany).

However, Greenpeace says that ultimately, this car is not a definitive solution. Reduction of the number of cars is still necessary, also to reduce other problems, such as traffic jams, the emission of toxic substances in cities, the death toll on roads (over a million per year) and the destruction (and carving up) of nature to build roads. Alternative fuels would be a better solution, but time is pressing, so an intermediate off-the-shelf solution like the SmILE is needed.

The car was designed by the Swiss company of Wenko. For this, they received a loan of roughly 1.3 million euro from Greenpeace, which they will return if the engine concept is taken over by a manufacturer for series production or profits are obtained from issuing licences.

See also

• Eco-marathon

External links

• technical data
• technical details
• design