Balancing Brooms - finding the centre of mass Listen Now Download as mp3 from the show Should I Lie Down to Tan? What you Need What to do Point the index fingers of both hands and hold your hands apart but parrallel. Get someone to balance the broom horizontally on your two index fingers, making sure you keep them level. Now gently move your fingers together. What may happen You should find that as long as you keep your fingers level the broom stays balanced, even as they get very close together. Why does it happen? When you start off holding the broom inevitably one finger will be closer to the centre of mass than the other. This means that more of the weight will be sitting on the closer finger, so it must be pushing upwards harder. The larger the force between the finger and the broom the larger the maximum frictional force it can provide before it slides. The finger furthest from the centre of mass will therefore be able to slide the most easily, and it moves until it is no longer the furthest from the centre of mass. Dave Ansell Multimedia
How do eyes work & how do glasses help us see? The Blind Astronomer of Nova Scotia Tim Doucette is legally blind, yet he sees the stars better than most people. A childhood diagnosis of congenital cataracts forced doctors to remove Doucette's lenses and widen his pupils. That left the amateur astron... Why do some people have seasonal allergies? If you've ever experienced watery eyes, sneezing, runny nose, itchy throat, and other allergic reactions during springtime, or you haven't but you know someone who has, this beautifully animated TED Ed by Eleanor Nels... This is What Outer Space Does to Your Body NASA astronaut, engineer, and former football player Leland Melvin explains how the human body changes when it leaves the confines of Planet Earth. The benefits of a good night’s sleep – TED Ed Sleep to remember! What are those floaty things in your eye? Have you ever seen something small and strangely transparent float into your field of vision? How do wounds heal & how do scars form? What happens when we get cut and bleed?
Hot water freezes faster than cold - and now we know why. Hot water seems to freeze faster than cold water, known as the Mpemba effect. The effect was named after the Tanzanian student who in 1963 noticed that hot ice cream mix freezes faster than a cold one. The effect was first observed by Aristotle in the 4th century BC, then later Francis Bacon and René Descartes. Mpemba published a paper on his findings in 1969. Theories for the Mpemba effect have included: faster evaporation of hot water, therefore reducing the volume left to freeze; formation of a frost layer on cold water, insulating it; and different concentrations of solutes such as carbon dioxide, which is driven off when the water is heated. Unfortunately the effect doesn’t always appear - cold water often does actually freeze faster than hot, as you would expect. Now a team of physicists from the Nanyang Technological University in Singapore, led by Xi Zhang, have found evidence that it is the chemical bonds that hold water together that provide the effect.
Keep it Cool | TryEngineering Lesson Focus Lesson focuses on the engineering behind keeping food and other items cool. Students work in teams to develop a system to make an insulated liquid container that will keep chilled water as cool as possible for an hour using everyday items. Students will need to devise a way to have a thermometer rest in the water and be able to read the temperature throughout the hour. Age Levels: Objectives Learn about insulation, heat transfer, and vacuums.Learn about engineering design and redesign.Learn how engineering can help solve society's challenges.Learn about teamwork and problem solving. Anticipated Learner Outcomes As a result of this activity, students should develop an understanding of: insulationvacuumheat transferengineering designteamwork Lesson Activities Students explore how engineers have developed systems to keep liquids cool and learn about heat transfer, insulation, and vacuums. Resources/Materials Alignment to Curriculum Frameworks
Gravity Sketch VR software for creative professionals launches beta testing platform A beta version of a virtual-reality programme that gives designers the option to draw and manipulate 3D objects has launched. The Gravity Sketch software, which was first unveiled last year, allows designers to draw, edit and manipulate forms in three dimensions as opposed to on a screen. Since the product was announced, it has been tested among 50 artists and designers that use virtual reality (VR) in their work. Having fixed the majority of bugs and glitches, the company has finally put the application live on the Steam Early Access website for beta testing – trialling in the final stages of development – from the general public. "Unlike other artistic VR creation tools, Gravity Sketch is focused on workflow for creative professionals and bases the creation of geometry in non-destructive solid modelling," said co-founder Oluwaseyi Sosanya. "Designers, architects and engineers can create quick 3D mock-ups of ideas and seamlessly bring them to more complex CAD software."
Strange Temperatures Part of the show Hot Nectar, Warming Weather and Birds Missing the Spring What you Need Three bowls or washing up basins large enough to put your hand in. Warm water (NOTE - be careful not to make the water too hot!) Cold water with a few ice cubes in it Luke warm water What to do 1 - Fill one bowl with warm water, one with iced water and one with medium water. 2 - Put one hand into the warm water and one in the iced water for one minute. 3 - Take your hands out of the water and put them both into the medium water. What may happen When you put your hands into the medium temperature water, the hand that's been in the cold water feels warmer while the one that was in the warm water feels cold, even though they are both feeling water that is the same temperature. Why does it happen? It's because your senses are relative. Multimedia Part of the show Hot Nectar, Warming Weather and Birds Missing the Spring Related Content
Inspire Her Mind Science There’s a young 4-year old girl shuffling through a chest full of various dress-up clothes. The copy asks: Does dress-up determine her future? Scroll to the left, and the girl picks up a princess dress from the chest. She walks over to a mirror and holds the dress in front of her. The girl in the mirror, representative of her imagination, is wearing the dress and holding a wand. Scroll to the right, and the girl picks an astronaut suit out of the chest. Technology There’s a father and daughter working on an electronic helicopter. Scroll to the left, and the father takes a soldering iron and starts working on the helicopter while the daughter watches. Scroll to the right, and the daughter reaches forward to connect a wire on the helicopter, making it work, as the rotor blades twirl. Engineering An 8-year-old girl sits on a deck and looks at some playhouse toys, such as a pink couch, and a pile of wood. Math A girl sits in a classroom looking ahead at the teacher.
Why is your breath sometimes warm and sometimes cold Listen Now Download as mp3 Part 1,2 from the show What Happens to a Tankful of Fish in Orbit? What to do Hold your hand about 15cm from your mouth Purse your lips and blow at your hand open your mouth and blow on your hand. Do you notice a difference in temperature? Now try holding your hand very close to your mouth when blowing with pursed lips or a long way away with an open mouth. What may happen You should find that at 15cm your breath feels cold with pursed lips, but warm with an open mouth. But if you feel very close with pursed lips it feels warm and cold when you feel a long way away, even with an open mouth. Why does it happen? If you create a jet of fast moving air through stationary air it tends to drag the stationary air along with it, essentially due to friction. When your mouth is open the air coming out will entrain some cold air, but the air which reaches your hand will still be dominated by the warm air from your mouth. asd Dave Ansell Multimedia Related Content
Teaching with TLC: 10 ways to make physical science FUN! This month we've been completing lots of physical science lessons that my kids do not want to put down. I just love it when they are hooked on learning! My kids have been learning all about simple machines, matter, and electricity from the best science teachers at the Edison Home. What better place to learn about science than Edison's home! As you may already know, I REALLY like hands-on learning because those are the lessons that make learning stick. We watched Bill Nye, The Science Guy teach about Atoms in this great video! The kids used cereal to model the different spacing of atoms in matter. We made a 3-D atom using an orange, candy, and toothpicks. Here my boys are watching the video that is mentioned above. The teacher in the video had them make negatively charged and positively charged atoms. I was on a quest to make an edible atom. When we were creating the atom, one of my sons exclaimed, "Oh, now I get it! I can't believe how much learning took place during this lesson.
Why Hot Water Freezes Faster Than Cold—Physicists Solve the Mpemba Effect — The Physics arXiv Blog Water may be one of the most abundant compounds on Earth, but it is also one of more mysterious. For example, like most liquids it becomes denser as it cools. But unlike them, it reaches a state of maximum density at 4°C and then becomes less dense before it freezes. In solid form, it is less dense still, which is why standard ice floats on water. Then there is the strange Mpemba effect, named after a Tanzanian student who discovered that a hot ice cream mix freezes faster than a cold mix in cookery classes in the early 1960s. The Mpemba effect is the observation that warm water freezes more quickly than cold water. None of these explanations are entirely convincing, which is why the true explanation is still up for grabs. Today Xi Zhang at the Nanyang Technological University in Singapore and a few pals provide one. What’s so odd about the bonds in water? But put water molecules together and hydrogen bonds also begin to play an important role. Voila!
Physicists Achieve Quantum Teleportation of Photon Over 25 Kilometers For the first time, a team of physicists have successfully teleported a quantum state of a photon to a crystal over 25 kilometers away through a fiber optic cable. This effectively showed that the photon’s quantum state, not its composition, is important to the teleportation process. The team was led by Nicolas Gisin of the University of Geneva and the results were published in the journal Nature Photonics. With this new paper, Gisin’s team has successfully squashed the previous record they set a decade ago by teleporting a quantum state of a proton 6 kilometers. The quantum state of the photon is able to preserve information under extreme conditions, including the difference between traveling as light or becoming stored in the crystal like matter. To test this and ensure what they were observing was actually happening, one photon was stored in a crystal while the other was sent along optical fiber, over a distance of 25 kilometers.
Physics – News, Research and Analysis – The Conversation – page 1 The energy needed to pull magnets apart comes from you, and you get it from the food you eat. And the plants or animals you eat get their energy from other plants and animals, or from the Sun. All energy comes from somewhere. The award of a Nobel Prize in physics to Donna Strickland is an opportunity to build support for women in science, says one female physics professor. Donna Strickland is the first woman in 55 years to be awarded the Nobel Prize in Physics. Using lasers to trap and move particles changed the way we're able to study microscopic life. The way science is currently taught in southern African countries ignores the fact that the whole environment is a laboratory for learning. The new physics syllabus for year 11 and 12 students in NSW contains no mention of specific women who have contributed to the field, nor their work. Astronomers are voting to rename one of the laws of physics. Machine learning is changing the world in ways that we are just beginning to appreciate.