Science by Email 20 July 2012

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	20 July 2012
News: On your marks By Patrick Mahony Analysis of reaction times from Beijing Olympics' participants suggests that women might be getting away with false starts. Nothing represents the Olympics like the 100‑metre sprint. The races to determine the world's fastest man and woman are often the highlights of the athletics program. And it is certainly fast – the men's race is often over in less than ten seconds, while the women don't take much longer. In a race where mere hundredths of a second separate first from last, sprinters need to be almost perfect, right from the start. Reacting just a tiny bit too slow on the blocks could allow your competitors to build an unbeatable lead. There's a catch though – react too quickly, and you will be disqualified for a false start. In the past, officials relied on their vision to detect false starts. Today, they use technology. Force sensors in the starting blocks detect changes in pressure from the feet of the runner, and use this to determine exactly when they started running. When this technology was first introduced, tests indicated that it is impossible for a human to hear the sound of the starter's gun and react in less than 0.1 seconds. The sensors are linked to the starter's gun – when the gun fires, this starts the timers in the sensors. If a sensor detects that a runner started moving before 0.1 seconds after the gun, the starter will stop the race. The offending runner is disqualified. The 0.1 second threshold might not be accurate. The tests used to establish the criteria only used a few male sprinters, none of whom were elite Olympic sprinters. Researchers analysed the starts data from hundreds of male and female sprinters from the 2008 Olympics, and found that men reacted on average 0.023 seconds faster than women. This research implies that the expected reaction is incorrect, so women may be false starting. For example, if the fastest possible reaction time for a woman is 0.15 seconds, a woman who reacts after 0.12 seconds has actually started early, but won't be disqualified for a false start. This gives her an unfair advantage. There are currently no plans to change the false start rules due to these findings, but keep your eyes peeled for sneaky starts in London 2012! More information Women may get away with false starts CSIRO: Future of Australian sport Careers link Australian Institute of Sport careers This news story is from The Helix. Take a running jump and launch yourself into this Olympics-themed issue. There's plenty of info on the science of sport that will get your pulse racing. Get your copy from selected newsagents Australia-wide from 1 August, or call (02) 6276 6643 to order your copy today!
You will need these materials.   Scoop up a spoonful of honey, and time how long it takes to run off.   Heat the honey in the microwave, and time how long the warm honey takes.   Try this: Runny honey   You will need Jar of honey Teaspoons Microwave Stopwatch What to do Scoop up a spoonful of honey from the jar. Twist the spoon a few times so that you have a blob of honey on the spoon. Hold the spoon above the jar. Start the stopwatch. Invert the spoon so that the honey runs off the tip. Time how long it takes most of the honey to fall off the spoon back into the jar. Put the jar of honey into microwave and heat for 20 seconds. Carefully remove the jar from the microwave. Repeat steps 1 to 4 with the warm honey. How do the times compare? What's happening? Like water, honey is a liquid. Unlike water, honey feels much thicker and flows slower at room temperature. Viscosity is a property of liquids, and describes a liquid's resistance to flow. The more viscous a liquid, the slower it flows. The viscosity of a liquid usually depends on its temperature. Raising the temperature of a liquid lowers its viscosity meaning that it flows more readily. In this activity we observe honey falling off the spoon faster. Applications The viscosity of liquids is an important consideration in industrial processes. For example, if crude oil in an oil refinery gets too cool, its flow will slow down and may stop all together. The same thing goes for other oil refinery products such as lubricating oils, diesel and bitumen. The viscosity of these products is monitored to make sure it is in the appropriate range. Motor oils are used to lubricate moving parts in engines. The heat generated in this environment affects the motor oil viscosity. If the viscosity of the oil drops too low, it might flow off the parts it is supposed to be lubricating, leading to equipment damage or failure. The viscosity of motor oil can be changed by carefully controlling its chemical composition.           By Patrick Mahony Try another Science by Email activity about viscosity More information Viscosity explorer View the online version Quiz questions 1. Where would you find the smallest bones in the human body? 2. How many planets in the Solar System have rings? 3. How many eyes do scallops have? 4. Is a photon a fermion or a boson? 5. What do the beetles Onthophagus vacca and Bubas bubalus eat? Did you know? Researchers on a recent field trip to the Northern Territory found two lizards that may represent new species. Websites   Do it! Check out Antarctic explorer Robert Scott's hut using Google Street View. Watch it! See what an astronaut sees with these videos from NASA! Collision – it's subARTomic! Are you feeling creative, aged 15 to 25 and interested in particle physics? Why not enter Collision? This competition is looking for paintings, animations, comics and more that explore the fascinating world of particle physics. The winning entries will be featured in an exhibition in Melbourne during National Science Week. For more information head over to the Collision website. Entries close 2 August 2012. Quiz answers 1. The smallest human bones are the stapes, or 'stirrups' – there is one in each ear. 2. Four planets in the Solar System have rings: Saturn, Jupiter, Uranus and Neptune. 3. Depending on the species, scallops can have up to 100 bright blue eyes. 4. A photon is a boson. 5. Onthophagus vacca and Bubas bubalus eat dung. CSIRO Ecosystem Sciences plans to release the dung beetles to help improve pasture productivity in Australia. Science by Email is a CSIRO publication. bankmecu is a proud partner of Science by Email. Editor: Jasmine Leong| Manage your subscription | FAQ

 

 

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