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01. BRIGHTSPARKS - Glitches fixed!
Last week we launched Brightsparks the very handy quiz-style interactive revision aid. Those of you who gave it a try will have noticed that the physics and chemistry questions didn't download properly. Grovelling apologies; we are so SO sorry about that! It was definitely us, not you. Please forgive this technical hitch and give Brightsparks another chance. It really is highly useful both for your pupils (primary up to A Level) to do alone, or for you to have up on the white board and discuss the questions with your class as they come up (or phone a friend!). Here's what two teachers thought ..."excellent idea"..."Wonderful stuff, must get it on to our school's network :-))))))". So, let Brightsparks into your life! Brightsparks: http://www.planet-science.com/sciteach/bright_sparks/ P.S. Advanced warning - only one more week to win a fabulous Dirt Devil by entering our March Spring Cleaning quiz: http://www.planet-science.com/wired/comp_quiz/springclean  |
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| 02. ACTIVITY OF THE WEEK: The Great Balloon Experiments Balloons are great - they're fun and they can demonstrate the most amazing array of science. You will need: * Balloons, all sorts of different colours! * Sticky tape * A round metal or wooden skewer A needle or pin What to do - Part One: 1. Inflate lots of balloons and rub them on your hair or jumper 2. Press the rubbed bit of the balloon against a wall and watch it stick! You can keep doing this until you have a wall covered in balloons. What's going on? Balloons are made of rubber and this is an insulator; it doesn't allow electric current to flow through it. When you rub the balloon, the balloon collects negative charge, called electrons, from your hair or jumper. These electrons can't move around on the balloon. When pressed against the wall, positive charges in the wall attract the electrons but since they can't move this attraction holds the entire balloon in place. What to do - Part Two: Finally, when you want to get rid of the balloons, try this if you don't like to pop them: 3. Put a piece of sticky tape on the balloon, then a second piece of sticky tape across the first. If you use clear tape no-one need know it is there! 4. Now without fear - well, maybe a little fear - prick the balloon through the tape with a needle! Be prepared it may pop, but most of the time it won't! 5. For those who like a bit more drama, try the same thing with a skewer; by twisting the skewer it should pierce the tape and the balloon. 6. Having trouble? Make the hole with the needle first then push the skewer through. Be careful not to leave the needle or skewer in the balloon as it may pop later - always keep hold of the needle or skewer! What's going on? Rubber has another property - it is made of molecules that are all tangled up together. When you pop a balloon, a tiny hole rapidly spreads into huge tears as the air rushes out. By putting sticky tape on the balloon you can hold these tears together, at least for a short time, so there is no pop. |
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| 03. MANCHESTER SCIENCE: DISCOVERIES THAT CHANGED THE WORLD. Atoms, energy and cosmic rays - what do they all have in common? They're part of the Museum of Science and Industry in Manchester's new gallery celebrating some of the greatest scientists' works. These men; John Dalton, James Joule, Ernest Rutherford and Sir Bernard Lovell, were all Manchester-based, and the exhibition explores their work and personalities and shows how Manchester has always been at the cutting edge of science - right up to today! The new gallery opens to the public on April 2nd and during the opening weekend there will be loads of activities, workshops and science shows. Want to find out more? Have a look at their website: www.msim.org.uk |
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| 04. THIS WEEK IN SCIENCE HISTORY: HITTING WALLS On March 29, 1981, 6,255 people completed the very first London marathon. Since then it has become ever more popular and more than half a million people have crossed the finish line. There is lots of training to be done in the months before the race. This training develops a competitor's muscles and improves how their heart and lungs supply oxygen to these new muscles. Can all this training allow the competitor to avoid the infamous 'wall'? Efficient muscles and good oxygen supply are obviously vital but perhaps more important is how well the competitor paces themselves and how much fuel they have to keep going... The wall sets in after about 20 miles and marks a change in how the body is operating. At the beginning of the race the competitor is using mainly their carbohydrate fuel. But eventually this fuel is used up and the body has to switch to burning fat. The more carbohydrate they have to start with, the longer it will be before the wall is reached. The body needs loads of oxygen to burn fat so the heart has to work harder and harder when the carbohydrates are used up and this makes running even more difficult. Getting water as well as sugar can help the body burn the fat and get the runner through the last 6 miles. But there may be other reasons for hitting the wall. Chemicals in the brain change during the race and the brain begins signalling, quite correctly, that the body is tired. Studies seem to show that carbohydrates again can slow this brain fatigue making the runner feel more alert. It seems that the wall is hard to avoid but careful preparation and running at the correct pace can hold it off as long as possible. After the race there is plenty of time for the competitor to recover. Well, unless they're planning to compete in the next one! Thinking of running in the London marathon next year? (Or any other marathon!) Check out their website and read up on their advice for training: http://www.london-marathon.co.uk/ Not sure how to get started or why you should bother? Have a look here: http://www.bbc.co.uk/health/fitness/active_jog.shtml |
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| 05. RECOMMENDED WEBSITE OF THE WEEK: Finally some good astronomy... Fed up with not being sure just what information is correct and what isn't on the internet? Bad Astronomy is the website for you! http://www.badastronomy.com/ Read movie reviews where bad astronomy is exposed or look at the flawed science behind the conspiracy theories. It also contains some of the best explanations of astronomy and physics on the web, from why are there two tides a day to clearing up questions about the spinning Moon. If you haven't visited the site before, get clicking now. |
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| 06. AWKWARD QUESTION OF THE WEEK Last week's Awkward Question may have left a few of you dangling... Why bother flying around to the other side of the world when a hole right through the middle could get you there so much faster? What would happen if you jumped into such a hole? Would you fall right through and end up in space? Not to keep you suspended any longer... If you jumped into a hole that went straight through the centre of the Earth, you would keep falling towards the centre where you would be completely weightless. But instead of falling all the way through to the other side of the Earth, you would only overshoot the centre a little bit, quickly slowing down and eventually falling back the way you came, back towards the centre! In fact, you would fly backwards and forwards a smaller distance each time until you settled in the centre - with the enormous task of trying to climb out again! This is all because the amount we are pulled by gravity depends on our distance from the object pulling us, and by mass of that object... Imagine the Earth isn't one big ball of rock, but is made up of lots of separate rocks, all the same size and mass. If you are standing on the surface of the Earth they are all different distances away, from the closest ones you are standing on to the ones furthest away at the opposite side of the planet. Now imagine that right through the middle of this cluster of rocks there is a hole. As you fall down the hole, the principle of gravity says that you are pulled by all the rocks, those below you and those above you. The rocks above you are closer and so pull you strongly, the rocks on the far side of the Earth are further away and are only pulling you weakly, but there are lots more of them. The gravity from the rocks either side of you cancel each other out, but surprisingly, the strong pull of gravity from the rocks above also cancel with the lots of weaker pulls of gravity from the rocks on the other side of the planet! So if you have climbed down 10 metres you no longer feel the gravity from the top 10 metres of the Earth. But the rest of the rocks below you are still pulling you down. The closer you go towards the centre of the Earth, the more the gravity from the rocks on either side of you are cancelled out. By the time you reach the middle, all the rocks pull you equally, and ultimately you feel no resultant force at all. You are weightless as you float around in the centre.  What about this one? Maybe the answer could save your life... Trevor works on the tenth floor - he takes the lift every day. One day, on his way up in the lift, he hears a crack and suddenly the lift is plummeting back to the ground. With only seconds until the lift hits the ground floor he has to decide what to do. Is it possible for Trevor to avoid the impact by jumping off the floor just before the lift hits the ground? Can he survive? Answer next week! |
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| 07. JOKE OF THE WEEK As a physicist I feel obliged to share this joke with you all... A student sees Einstein in a train and asks: 'Excuse me, professor, but does New York stop by this train?'. That's all for this week. Future contributions are most welcome, and should be sent to: : anne@planet-science.com Have a great week! |
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