Progress for giant laser instrument http://www.bbc.co.uk/news/science-environment-29168676
Sep 12 2014
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Jun 24 2014
Insecticides put world food supplies at risk, say scientists
Regulations on pest sprays have failed to prevent poisoning of almost all habitats, international team of scientists concludes Damian Carrington.
The world’s most widely used insecticides have contaminated the environment across the planet so pervasively that global food production is at risk, according to a comprehensive scientific assessment of the chemicals’ impacts. The researchers compare their impact with that reported in Silent Spring, the landmark 1962 book by Rachel Carson that revealed the decimation of birds and insects by the blanket use of DDT and other pesticides and led to the modern environmental movement. Billions of dollars’ worth of the potent and long-lasting neurotoxins are sold every year but regulations have failed to prevent the poisoning of almost all habitats, the international team of scientists concluded in the most detailed study yet. As a result, they say, creatures essential to global food production – from bees to earthworms – are likely to be suffering grave harm and the chemicals must be phased out. The new assessment analysed the risks associated with neonicotinoids, a class of insecticides on which farmers spend $2.6bn (£1.53bn) a year. Neonicotinoids are applied routinely rather than in response to pest attacks but the scientists highlight the “striking” lack of evidence that this leads to increased crop yields.
“The evidence is very clear. We are witnessing a threat to the productivity of our natural and farmed environment equivalent to that posed by organophosphates or DDT,” said Jean-Marc Bonmatin, of the National Centre for Scientific Research (CNRS) in France, one of the 29 international researchers who conducted the four-year assessment. “Far from protecting food production, the use of neonicotinoid insecticides is threatening the very infrastructure which enables it.” He said the chemicals imperilled food supplies by harming bees and other pollinators, which fertilise about three-quarters of the world’s crops, and the organisms that create the healthy soils which the world’s food requires in order to grow. Professor Dave Goulson, at the University of Sussex, another member of the team, said: “It is astonishing we have learned so little. After Silent Spring revealed the unfortunate side-effects of those chemicals, there was a big backlash. But we seem to have gone back to exactly what we were doing in the 1950s. It is just history repeating itself. The pervasive nature of these chemicals mean they are found everywhere now. “If all our soils are toxic, that should really worry us, as soil is crucial to food production.”
The assessment, published on Tuesday, cites the chemicals as a key factor in the decline of bees, alongside the loss of flower-rich habitats meadows and disease. The insecticides harm bees’ ability to navigate and learn, damage their immune systems and cut colony growth. In worms, which provide a critical role in aerating soil, exposure to the chemicals affects their ability to tunnel. Dragonflies, which eat mosquitoes, and other creatures that live in water are also suffering, with some studies showing that ditchwater has become so contaminated it could be used directly as a lice-control pesticide. The report warned that loss of insects may be linked to major declines in the birds that feed on them, though it also notes that eating just a few insecticide-treated seeds would kill birds directly. The report is being published as a special issue of the peer-reviewed journal Environmental Science and Pollution Research and was funded by a charitable foundation run by the ethical bank Triodos.
The EU, opposed by the British government and the National Farmers Union, has already imposed a temporary three-year moratorium on the use of some neonicotinoids on some crops. This month US president Barack Obama ordered an urgent assessment of the impact of neonicotinoids on bees. But the insecticides are used all over the world on crops, as well as flea treatments in cats and dogs and to protect timber from termites. However, the Crop Protection Association, which represents pesticide manufacturers, criticised the report. Nick von Westenholz, chief executive of the CPA, said: “It is a selective review of existing studies which highlighted worst-case scenarios, largely produced under laboratory conditions. As such, the publication does not represent a robust assessment of the safety of systemic pesticides under realistic conditions of use.” Von Westenholz added: “Importantly, they have failed or neglected to look at the broad benefits provided by this technology and the fact that by maximising yields from land already under cultivation, more wild spaces are preserved for biodiversity. The crop protection industry takes its responsibility towards pollinators seriously. We recognise the vital role pollinators play in global food production.”
A Bulgarian beekeeper grabs dead bees during a demonstration in Sofia to call for a moratorium on the use of neonicotinoid pesticides in April. The new report, called the Worldwide Integrated Assessment on Systemic Pesticides, analysed every peer-reviewed scientific paper on neonicotinoids and another insecticide called fipronil since they were first used in the mid-1990s. These chemicals are different from other pesticides because, instead of being sprayed over crops, they are usually used to treat seeds. This means they are taken up by every part of the growing plant, including roots, leaves, pollen and nectar, providing multiple ways for other creatures to be exposed. The scientists found that the use of the insecticides shows a “rapid increase” over the past decade and that the slow breakdown of the compounds and their ability to be washed off fields in water has led to “large-scale contamination”. The team states that current rules on use have failed to prevent dangerous levels building up in the environment. Almost as concerning as what is known about neonicotinoids is what is not known, the researchers said. Most countries have no public data on the quantities or locations of the systemic pesticides being applied. The testing demanded by regulators to date has not determined the long-term effect of sub-lethal doses, nor has it assessed the impact of the combined impact of the cocktail of many pesticides encountered in most fields. The toxicity of neonicotinoids has only been established for very few of the species known to be exposed. For example, just four of the 25,000 known species of bee have been assessed. There is virtually no data on effects on reptiles.
Permanent link to this article: http://www.animatedscience.co.uk/2014/insecticides-put-world-food-supplies-at-risk-say-scientists
Jun 21 2014
Mountain blasted to build telescope http://www.bbc.co.uk/news/science-environment-27902611
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Jun 14 2014
The metal that can store power for a small town http://www.bbc.co.uk/news/magazine-27829874
The metal that can store power for a small town
Pile of Vanadium oxide
Hawaii has a problem, one that the whole world is likely to face in the next 10 years. And the solution could be a metal that you’ve probably never heard of – vanadium.
Hawaii’s problem is too much sunshine – or rather, too much solar power feeding into its electricity grid.
Generating electricity in the remote US state has always been painful. With no fossil fuel deposits of its own, it has to get oil and coal shipped half-way across the Pacific.
That makes electricity in Hawaii very, very expensive – more than three times the US average – and it is the reason why 10% and counting of the islands’ residents have decided to stick solar panels on their roof.
The problem is that all this new sun-powered electricity is coming at the wrong place and at the wrong time of day.
Hawaii’s electricity monopoly, Heco, fears parts of the grid could become dangerously swamped by a glut of mid-day power, and so last year it began refusing to hook up the newly-purchased panels of residents in some areas.
And it isn’t just Hawaii.
“California’s got a major problem,” says Bill Radvak, the Canadian head of American Vanadium, America’s only vanadium mining company.
“The amount of solar that’s coming on-stream is just truly remarkable, but it all hits the system between noon and 4pm.”
That does not marry well with peak demand for electricity, which generally comes in the late afternoon and evening, when everyone travels home, turns on the lights, heating or air conditioning, boils the kettle, bungs dinner in the microwave, and so on.
What the Golden State needs is some way of storing the energy for a few hours every afternoon until it is needed.
And Radvak thinks he holds the solution – an electrochemical solution that exploits the special properties of vanadium.
Vanadium mine, Nevada
Back in 2006, when Radvak’s company decided to reopen an old vanadium mine in Nevada, electricity grids were the last thing on their minds.
Back then, vanadium was all about steel. That’s because adding in as little as 0.15% vanadium creates an exceptionally strong steel alloy.
“Steel mills love it,” says Radvak. “They take a bar of vanadium, throw it in the mix. At the end of the day they can keep the same strength of the metal, but use 30% less.”
It also makes steel tools more resilient. If the name vanadium is vaguely familiar to you, it is probably because you have seen it embossed on the side of a spanner.
And because vanadium steel retains its hardness at high temperatures, it is used in drill bits, circular saws, engine turbines and other moving parts that generate a lot of heat.
So steel accounts for perhaps 90% of demand for the metal.
Ford production in the early 1900s
Vanadium’s alloying properties have been known about for well over a century. Henry Ford used it in 1908 to make the body of his Model T stronger and lighter.
For the same reasons – and also for its heat resistance – it was used to make portable artillery pieces and body armour in the First World War.
But vanadium’s history seemingly goes back even further. Indeed, mankind may have been unwittingly exploiting the metal as far back as the 3rd Century BC.
That is when “Damascus steel” first began to be manufactured.
Swords made of the steel were said to be so sharp that a hair would split if it were dropped on to the blade.
Damascus steel scimitars were credited with enabling Muslim warriors to fight off the Crusades.
Circa 1250, A crusader and Muslim warrior in hand-to-hand combat.
Samples taken from a handful of antiques were found to contain tiny amounts of impurities, including – crucially – vanadium.
Bizarrely, this two-millennium-old steel-making tradition vanished in the mid-18th Century. The vanadium-rich iron deposits in southern India from which the steel was fashioned must finally have become exhausted, or so the theory goes.
Today, vanadium mainly goes into structural steel, such as in bridges and the “rebar” used to reinforce concrete.
It is a small and sometimes volatile market. Supply is dominated by China, Russia and South Africa, where the metal is extracted mostly as a useful by-product from iron ore slag and other mining processes.
China – which is midway through the longest and biggest construction boom in history – also dominates demand.
A recent decision by Beijing to stop using low-quality steel rebar has bumped up forecast demand for vanadium by 40%.
Yet the biggest source of future demand may have nothing to do with steel at all, and may instead exploit vanadium’s unusual electro-chemical nature.
Freyja, Freya or Vanadis – Norse goddess of fertility, love and marriage, beauty and light and peace
“Vanadium was actually discovered twice, and one of the discoverers was the Swedish chemist Nils Sefstrom, who named it after the Norse goddess of beauty, Vanadis,” says the Italian chemist, Prof Andrea Sella of University College London.
To explain why, Sella produces a flask of an easily misidentified yellow-coloured liquid.
It is, he says, a solution of “oxidised” vanadium in sulphuric acid – that is, vanadium that has been stripped of all five of its outermost electrons (it inhabits column five of the periodic table).
He then adds a shiny lump of a zinc-mercury amalgam and begins to shake the concoction violently.
“The zinc is going to allow us to put electrons back onto the vanadium – the chemical process we call ‘reduction’,” he explains.
The solution quickly turns green, and then gradually becomes blue. “And if we keep shaking for another few minutes, we will eventually end up with a violet colour.”
Each change of colour represents one further electron being passed on to the vanadium.
“The ease with which you can hand electrons to the vanadium and take them away – this is the basis of a very, very stable battery.”
Vanadium “redox flow” batteries are indeed stable. They can be discharged and recharged 20,000 times without much loss of performance, and are thought to last decades (they have not been around long enough for this to have been demonstrated in practice).
They can also be enormous, and – in large part thanks to their vanadium content – expensive. The smallest of the “Cellcube” batteries that American Vanadium is producing in partnership with German engineering firm Gildemeister has a footprint the size of a parking bay and costs $100,000.
How does a Vanadium Redox Flow Battery work?
Vanadium – yellow, blue, green and violet
Consists of two giant tanks of different solutions of vanadium dissolved in sulphuric acid, separated by a membrane
• The battery produces an electrical current as the fluids are pumped past electrodes on either side of the battery
• In one tank, the vanadium releases electrons, turning from yellow to blue
• In the other tank, the vanadium receives electrons, turning from green to violet
• The electrons pass around a circuit, generating a current, while at the same time a matching number of protons (hydrogen ions) pass across the membrane between the two solutions
The BBC’s headquarters in London – home to 7,000 employees – would need one the size of two 12-metre trailers, Radvak says, perched up on the roof or perhaps buried underground.
His firm is providing the batteries’ key ingredient, the electrolyte (the fluid in the battery).
It is the same chemical solution as in Sella’s demonstration, and – conveniently enough – is also the end-product of the standard process of using sulphuric acid to leach the vanadium out of its ore.
Radvak says that among his target customers are large corporate electricity consumers such as the Metropolitan Transport Authority, which runs New York’s subway, and with whom his firm has just signed a pilot deal to supply Cellcube batteries.
Such companies are facing ever higher charges for the electricity they use during the peak hours of the day, and the Canadian claims they can cut their bills by a quarter if they use a battery to draw down the daytime electricity they need during the night, when it is cheapest.
By flattening out demand between the daily peaks and troughs, the batteries also help out the electricity companies.
One of their biggest expenses is investing in the extra power station capacity that is only ever called upon for a few hours each year when the weather, holidays and the time of day all conspire to produce the biggest peak in electricity demand.
That challenge of balancing electricity supply and demand is set to get a whole lot more difficult as ever more solar and wind energy is added to the grid.
Solar panel emergency call box in Hawaii
Which brings us back to Hawaii.
Rooftop solar panels don’t just produce electricity at the “wrong” time of day, they also produce it at a low voltage, which, according to the German renewable energy entrepreneur Alexander Voigt, means it is effectively trapped at the level of the local community.
“Our traditional electricity grid is built in a way that the energy flows from the high voltage to the low voltage, and not the other way round,” he says.
That means the solar energy can only be shared among the few households – typically just a village or a town neighbourhood – that happen to share the same transformer station that plugs them into the high-voltage national grid.
Voigt helped set up the vanadium battery company that was later bought up by Gildemeister. He foresees the batteries being built next to transformers, where they can store up each community’s daily solar surplus, before releasing it back again in the evening.
It is a rosy image, but it does prompt two obvious questions.
First, why should vanadium batteries be the technology of choice?
For example, there is a glut of cheap lithium batteries these days, after manufacturers built out their capacity heavily in anticipation of a hybrid and electric cars boom that has yet to arrive.
Lithium batteries can deliver a lot of power very quickly, which is great if you need to balance sudden unexpected fluctuations – as may be caused by passing clouds for solar, or a passing gale for wind.
But a lithium battery cannot be recharged even a tenth as many times as a vanadium battery – it’s likely to die after 1,000 or 2,000 recharges.
Nor can lithium batteries scale up to the size needed to store an entire community’s energy for several hours. By contrast, vanadium batteries can be made to store more energy simply by adding bigger tanks of electrolyte. They can then release it at a sedate pace, unlike conventional batteries, where greater storage generally means greater power.
At the other end of the scale, there are also plenty of large-scale energy storage systems under development, such as those exploiting liquefied air, and the 1,000-fold shrinkage in the volume of the air when it is cooled to -200C.
But these systems take up a lot of space, Mr Voigt says, and are better suited to the very largest-scale facilities that will be needed to serve for instance a large offshore wind farm plugging into the high-voltage national grid.
The second really big question for vanadium is whether the world contains enough of the stuff.
The immediate challenge is that the birth of the vanadium battery business is coming just as China is ramping up its demand for vanadium steel.
But there is also a longer-term problem – the quantities of vanadium added to steel alloys are so tiny that it is not economic to recover it from the steel at the end of its life. So for the battery market, that vanadium is effectively lost forever.
But Mr Voigt remains optimistic.
“Like with all raw materials, it’s always a question of how stable is the need of the market, and how big are the incentives for the industry to set up new mines.”
With demand on an upward trend, American Vanadium is not the only one trying to fill the gap. For example, rival battery-maker Imergy has developed a cheap ways of producing vanadium electrolyte from iron ore slag and the fine ash produced by coal-burning.
Over the longer term, demand for vanadium steel could be met by melting down and recasting old vanadium steel rather than making it afresh, so that freshly mined vanadium could be channelled into the energy market instead.
And in the very long run, perhaps we will harvest vanadium from sea squirts – there are plenty of them in the Pacific.
• Vanadium is an essential micronutrient for animals, but toxic in large dosages
• Some sea squirts accumulate vanadium in their bodies, turning their blood green, possibly in order to protect them from predators
• Closely related to vertebrates, in their larval stage sea squirts look like tadpoles and swim around
• But once they find an appropriate rock to attach to, they metamorphose into something resembling a brightly-coloured vegetable
• They never leave their spot, and feed by filtering tasty morsels from the sea water they pump through their bodies
• Having committed themselves to this life of tedium, they also digest their redundant brains
• Some fungi also accumulate vanadium, including the bright red and white poisonous, hallucinogenic mushroom known as the fly agaric
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BBC © 2014
Permanent link to this article: http://www.animatedscience.co.uk/2014/the-metal-that-can-store-power-for-a-small-town
Jun 11 2014
You mean you’re not on holiday yet? http://www.bbc.co.uk/news/business-27762108
You mean you’re not on holiday yet?
10 June 2014 23:05
By Sean Coughlan
BBC News education correspondent
If this article is of any interest to teenagers in Estonia or Latvia, it will only be to give them a chance to feel really smug – because their schools are already shut for the summer holidays.
They might be glancing at this on their mobiles on a beach somewhere, just to get a certain sense of satisfaction that they’re not stuck reading something even duller in English lessons.
Schools in Sweden, Iceland, Finland and Ireland are also empty – and Bulgaria’s primary schools have been closed since the end of May.
And don’t feel too sorry for pupils in Italy and Hungary, because they are almost ready for their end-of-year goodbyes.
Instead reserve your sympathy for another group of European countries with many more weeks to tear off the calendar before escaping into the sun.
Liechtenstein keeps going into the first week of July, while classrooms in England and Wales are running a school-year marathon, staying open until the third week of July.
But they are not the very last students in Europe to be stuck inside in summer. That honour is reserved for the Bavarians.
Germany has a six-week break staggered in different regions – and it means that pupils in Bavaria do not break up until the end of July, beginning a holiday that lasts until mid-September.
Here comes the summer
Unfortunately a late start to the holiday is usually no promise of a late return. Quite the opposite.
Those Latvian teenagers, already basking in their summer sojourn, stay off school for 13 weeks. The Italians are tucking into a big slice of the dolce vita with a 12 to 13 week break.
Those freewheeling Bulgarian primary school pupils are going to be out of the classroom until mid-September.
The Finns have 10 to 11 weeks off in the summer, Iceland, Portugal, Spain and Ireland have 12 weeks, Norway and Poland about eight weeks.
The length of a summer holiday seems to defy any clear geographical or cultural pattern. It’s not a case of the southern European countries taking the academic equivalent of a siesta.
There are even big differences within countries. Parts of Switzerland have the shortest holidays, five weeks, while other parts have 10 weeks.
Within the UK, there are different patterns. While England and Wales keep studying deep into July, schools in Scotland have emptied by late June to return in mid-August and in Northern Ireland they finish at the beginning of July for a two-month break.
It’s more about tradition and what’s come to be expected.
And it’s not all about a legacy of an agricultural past. There have been longstanding challenges to the idea that summer holidays were created to allow children to help with the harvest.
Many 19th Century state school systems were driven by the demands of an urban population, rather than rural. In the United States pressure for a longer summer break came from middle-class families wanting to get out of the unhealthy, overheated cities.
Packing it in: Just putting in a few things for the journey
Another theory is that the school holidays followed the pattern of other institutions, such as universities, law courts and private schools.
But is there any connection between the length of the summer holiday and achievement in school?
The evidence once again is inconsistent. Liechtenstein, with only a modest six-week summer break, has the highest maths results in Europe, according to the international Pisa tests run by the Organisation for Economic Co-operation and Development (OECD).
But the best in Europe at reading are youngsters in Finland and Ireland, who have some of the longest summer holidays. Perhaps they spend the time reading. Finnish schools are away from the beginning of June until mid-August and it’s even longer in Ireland, where they are on holiday until September.
If pupils are meant to forget everything they’ve learned over a long summer, then someone has forgotten to tell that to the Estonians, who combine a very long holiday with being among the most successful in both maths and reading tests.
And if long holidays were such a bad thing, why is it that high-achieving private schools often have more weeks off than their state school neighbours?
Counting the weeks
The OECD has its own rather nuanced conclusion. It says there is “some relationship between the time students spend learning in and after school and their performance”. But looking across a range of countries and education systems there is “no clear pattern”.
A holiday month or still a long way to go?
It means that spending more time in school might help, but again it might not help that much. The quality of teaching and learning is going to be much more important than the quantity.
Of course it’s more complicated than counting the weeks off in the summer. There are other holidays during the school year and the length of the school day can vary.
As a more precise measure, the OECD makes comparisons about the average number of lessons in key subjects each year.
In this global ranking, the countries where pupils get the most lessons are Chile, Canada, the United Arab Emirates, Portugal and Singapore.
Again there is no clear link to how well pupils perform in the Pisa tests. Canada and Singapore have lots of lessons and are high achievers – but Portugal, with the most lessons in Europe, does not make the top 30.
Shanghai, the Chinese city which has topped the Pisa rankings, is in ninth place in terms of the volume of lessons, behind countries such as Tunisia and Peru. But where Shanghai really stands out – far above anyone apart from Singapore – is the amount of homework set by teachers.
The UK is ranked 23rd in terms of the amount of lessons each year – exactly the same place as its ranking in the maths test results.
On this global scale, the UK is above average in terms of the number of lessons per pupil each year, while France, Germany, Spain, Ireland, Finland and Poland are all below average.
Whether it counts as first place or last place – they’re on holiday so they probably won’t care – Bulgaria has the lowest number of lessons each year.
BBC © 2014
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Jun 05 2014
Diffusion in Solids, Liquids, Gases and Jelly
Diffusion in liquids: When substances dissolve in liquids (like salt dissolving in water) the substances spread out. We call this spreading out of dissolved particles diffusion. The end result of this is that the solute particles that have dissolved in water will spread out evenly. This movement or spreading out is due to the fact that in liquids the particles are moving randomly.
Diffusion in gases: When two or more different gases, like oxygen and nitrogen are mixed they will mix themselves evenly. We call this mixing of particles diffusion. This is due to the random movement of particles.
Diffusion in solids: Diffusion does not happen in solids because the particles are not free to move around and so they cannot inter-mix.
Diffusion in jelly: Jelly is a liquid before it has set and looks like a solid when it has set. However the truth is a little more interesting. After it has set jelly is not really a solid or a liquid, it is in fact a mixture of both of them. As shown in the diagram below there are long fibres of protein or carbohydrate which form the solid part of the jelly and between these fibres there are spaces where water molecules are free to move around. This is why substances can diffuse through jelly.
Using Jelly in science experiments… Because it allows diffusion through it, jelly is very useful as it allows us to track the movement substances through the jelly for example in Bioassay experiments testing the effectiveness of antibiotics as shown in the photograph below. In this photo it is easy to see which antibiotic is the best at killing bacteria (the biggest clear area). The antibiotic has diffused through the jelly.
The rate of Diffusion is affected by a number of factors:
- The surface area of the exchange surface
- The size of the particles
Experiment to determine how temperature affects the rate of diffusion through jelly
- Petri dishes
- Agar jelly with Universal indicator mixed into it
- Hydrochloric acid of the following concentrations: 1.0M, 0.8M, 0.6M, 0.4M 0.2M.
- Stop clock
- Ruler with mm graduation
1) Pour equal volumes of the hot Agar/Indicator mix into a different petri dish, leave to cool and set overnight.
2) Use the cork borer to cut 5 wells into the jelly making sure all the jelly is removed from the well.
3) Use a pipette to carefully fill the first well with 1.0 M Hydrochloric acid and start stop-clock.
4) As the acid diffuses through the agar the indicator will turn red. After 5 minutes use the ruler to measure how far the red colour has moved.
Permanent link to this article: http://www.animatedscience.co.uk/2014/diffusion-in-solids-liquids-gases-and-jelly
May 29 2014
Cheese Rolling – Gravitational Potential Energy to Kinetic
Funny really as I always think of this as a simple topic. However, my students always find it hard, especially the formulae.
First place to start is the hill near to the village (Brockworth) where I grew up where they still do Cheese Rolling every year… http://www.cheese-rolling.co.uk/index1.htm. Even my primary school teacher wrote a book on the topic. (However, it is not focused on the Physics!)
So now you have the idea think about a man who lifts a cheese and himself up to the top of a hill. His muscles have to do work as he is moving himself and a cheese to a point further away from the surface of the Earth. This is because the man and cheese are in the influence of a “gravitational field” which causes anything with mass to feel weight or acceleration towards the centre of the object.
So the formulae we employ to work out the work done in climbing the hill is the change in height x distance moved against the field x mass. #
We often write this as…
Ep = mgh or sometimes as mgΔh to show “a change in height”.
So where has the energy come from…. well simple the muscles in the body of the man have contracted and converted chemical energy to movement energy to push the man away from the field.
So what happens to the energy as you release the cheese? Well we think of another idea of “kinetic energy”. As you roll down the hill and gain in velocity you exchange your gained Ep to Ek so then most of the energy is coverted according to the rule ½ mv2 .
Often we write that mgΔh = ½ mv2 so if it was a 100% transfer we could work out the maximum velocity of a cheese falling down the hill!
Try out these animations in flash to help you out…
Permanent link to this article: http://www.animatedscience.co.uk/2014/cheese-rolling-gravitational-potential-energy-to-kinetic
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May 18 2014
A true sea shanty: the story behind the Longitude prize
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May 16 2014
Why an octopus’s suckers don’t stick its arms together
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Apr 25 2014
Five secrets to revising that can improve your grades
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Apr 25 2014
Dazzling supernova mystery solved http://www.bbc.co.uk/news/science-environment-27118405
Permanent link to this article: http://www.animatedscience.co.uk/2014/dazzling-supernova-mystery-solved