Science by Email 14 October 2011

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	14 October 2011
The Universe has been expanding since the Big Bang. This expansion is accelerating. News: Dark energy discovery earns Nobel Prize By Patrick Mahony Professor Brian Schmidt from the Australian National University is joint winner of the 2011 Nobel Prize in Physics. Brian is one of three astronomers awarded the prize for “the discovery of the accelerating expansion of the Universe through observations of distant supernovae”. What does this mean? It may not feel like it, but the entire Universe is expanding. Astronomers believed it was the energy of the Big Bang that was driving this expansion. However, there is another force in the Universe that tries to do the opposite: gravity, which pulls matter together. One idea was that eventually the expansion would slow down enough for gravity to take over. All the matter in the Universe would be attracted to each other and would end in a Big Crunch. Brian formed one of two teams to study distant exploding stars called supernovae. The teams found about 50 suitable supernovae. They were expecting to find the deceleration of the Universe, but there was a problem – the light wasn’t as bright as it should be. If the expansion was slowing down, the supernovae should be brighter. These observations indicated the opposite: that cosmic expansion is accelerating. In order for this acceleration to be taking place, there must be a force at work. Astronomers now refer to this mysterious force driving the expansion of the Universe as dark energy. The Universe is composed of energy and matter. Physicists don’t know exactly what dark energy is but it makes up more than 70% of the Universe. Dark energy is one of the great mysteries of physics and one we didn’t even know existed until the work of Brian and his colleagues. More Information The Nobel Prize in Physics 2011: Written in the stars CSIRO link: Australia Telescope Outreach and Education Try a Science by Email activity demonstrating the expansion of the Universe Careers Astronomical Society of Australia
You'll need these materials.   Pour 100 mL water into 4 cups, and 100 mL vinegar into the other 2 cups.   Add 2 tsp bi-carb soda to two of the water cups. Stir to dissolve.   Set up your cups with the different types of aspirin ready to go.   Drop an aspirin, enteric coated or regular, into each cup.   Try this: Acidic aspirin Warning: This activity uses chemicals. Read any packet safety instructions, do not consume the chemicals used and wash your hands after completing the activity. See the CSIRO Education safety page for more information. You will need 6 plastic cups Water Vinegar Bi-carb soda A spoon 3 ‘regular’ aspirin tablets 3 enteric coated aspirin tablets* Marker *These can be low dose aspirin used to reduce the risk of heart attack and stroke. Ask your pharmacist if you are having trouble finding them. What to do Pour 100 mL water into 4 glasses. Label 2 of these ‘H2O’ and the other 2 ‘bi-carb soda’. Pour 100 mL vinegar into the each of the remaining glasses and label these ‘vinegar’. Add 2 tsp bi-carb soda to each of the appropriately labelled glasses. Stir to dissolve. Add 1 regular aspirin tablet to each of the 3 types of glasses. Observe what happens. Add 1 enteric coated aspirin tablet to each of the remaining glasses. What happens now? Leave the glasses for 1 hour. What has changed? What's happening? Aspirin is the common name for acetylsalicylic acid, which is soluble in water. When you put the regular aspirin into the water and the vinegar, the tablet will dissolve slowly. This is an example of a physical reaction. Bi-carb soda is a base and will react quite readily with an acid. When you put the acidic aspirin into the basic solution, they react, forming bubbles of carbon dioxide. This is an example of a chemical reaction. In many cases, a patient wants aspirin to work fast, so they want it to be absorbed in their stomach. Sometimes, it might be better for the aspirin to be absorbed slowly, not in the stomach, but in the small intestine. The enteric aspirin has a coating that won’t dissolve easily in water or an acid, but will dissolve faster in a base. The stomach is a highly acidic environment, while the small intestine is basic. Using this coating means the aspirin is absorbed in the right part of the body. Applications Acid-base chemistry is used in many different industries, including pharmaceuticals, food production, mining and manufacturing. Acids and bases can be very reactive, and may cause damage to pipes and equipment used in industrial processes. Using acid and base resistant coatings protects the equipment and extends its working life. Acids and bases can also cause harm to people, so many labs require workers to wear protective clothing such as goggles and gloves. Different parts of the human body have different levels of acidity, depending on their function. The stomach is highly acidic, as this assists the break down and digestion of food, while the blood is less acidic than the stomach, but at the right level to transport oxygen efficiently.       Try a tasy Science by Email activity about acids and bases More information Experiments with acids and bases View online version Quiz questions 1. What colour is liquid oxygen? 2. Where might you find wigglers and undulators? 3. What would you most likely do with a Solanum lycopersicum? 4. What is a neutrino? 5. When is northern Australia’s tropical cyclone season? Did you know? Introducing ore sorting to just one major mineral processing operation could reduce carbon dioxide emissions by up to 33 000 tonnes per year. CSIRO’s Minerals Down Under Flagship is conducting research to improve the sustainability of Australian mines. Website Watch it! What have penguins, waves and thermodynamics got to do with each other? Find out in this video! Do it! Can you build a sustainable energy grid for your city? Events International: Spirit of Innovation Challenge The Spirit of Innovation Challenge is an annual competition for teams of high school students to use science, technology, maths and engineering skills to devise innovative solutions to real world problems. If you are at high school, aged 13 to 18 and have an interest in aerospace exploration, clean energy or health and nutrition then this might be the competition for you! This is an international competition – there are no geographic restrictions on eligibility. The first round is the General Entry round – entries close on 11 November 2011. For more information, visit the Spirit of Innovation Challenge website. Floods, Saturday 15 October at 9.00 am on Network Ten There’s a lot more to floods than just too much water! This week we look at the prevention, forecasting, modelling and impacts of floods! So join Dr Rob as he dives head first into the science of this all-too-familiar natural disaster and once again proves that the ordinary really does become extraordinary, under the SCOPE!    Next episodes: Thursday 20 October: Waste Saturday 22 October: Big machines 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. Liquid oxygen is pale blue. 2. Wigglers and undulators are types of magnets found in synchrotrons. A synchrotron is a large particle accelerator that accelerates electrons close to the speed of light to produce radiation. Australia’s synchrotron is in Melbourne and is used by Australian and international scientists. 3. You would most likely eat a Solanum lycopersicum – it’s a tomato. 4. A neutrino is a subatomic particle with no net charge and nearly zero mass. 5. Northern Australia’s tropical cyclone season typically lasts from November to April. CSIRO’s Climate Adaptation Flagship is conducting research to better understand tropical cyclones. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science By Email. Editor: Jasmine Leong | Manage your subscription | FAQ

 

 

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