Today I had a gate fitted to my orchard, replacing the scruffy bit of wire netting that had served as the only barrier between my property and the farm animals regularly herded down my road. I am sure my farming neighbours will be pleased. It has rained a lot in the Vendée over the last …
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Category:Physics
Slinky…
Two short videos from Australia… . . I would love to get a high-speed camera for the science department. If I do, what do you think we should film with it?
Clear Explanation…
It is lovely when something is explained in such a way that the ‘light bulb’ goes on inside and one suddenly realises the point of the subject being explained. I teach for a living, but it is still relatively rare that I am sure that such an event has occurred. I often get asked about E=mc2. …
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Transformers: Inductively Coupled Conductors In Disguise…
Oliver H asked me in class where the energy goes when mains electricity is stepped up or down inside a transformer. He correctly cited the first law of thermodynamics (or the law of conservation of energy) pointing out that when 240 volts from the mains is stepped down to 9 volts to run an electronic balance in …
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Curiosity…
As you will no doubt have noticed, the Curiosity rover has successfully landed on Mars. Its mission is to explore the planet’s surface, with a particular emphasis on searching for any signs that life once existed on Mars. There may be traces of bacteria or other simple organisms and if there are then the rover …
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That’s Deep…
This isn’t really a post – just an encouragement to view the BBC page all about some upcoming exploration of the Pacific Ocean’s Mariana Trench. As always, the BBC do it brilliantly with video clips and fancy graphics way beyond my ability to compete. It does link to my post about putting it all into perspective. …
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Shooting…
I went shooting in South Wales on Tuesday. I shared a peg with my father shooting driven pheasant, occasional woodcock and, on a couple of drives, mallard duck. We were sharing a shotgun that fires cartridges filled with shot. The diagram shows how they are constructed. When the primer is struck, it ignites the gunpowder …
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The Earth In Space
This video, from the absolutely fantastic YouTube collaboration called Sixty Symbols, explains why the 21st of June is the longest day, why we have seasons and how Eratosthenes used differences in shadow length to calculate the circumference of the world about 2000 years ago. Watch it – it’s really good.
2B’s Homopolar Motors…
The creative whizzes in 2B (2011) came up with several brilliant variations on the homopolar motor design I gave them. I filmed them with my Blackberry so you don’t really get a sense of how fast they were spinning. They have so little friction that they keep turning for several minutes after the current is switched …
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Local Knowledge…
There was not much snow in evidence from my balcony yesterday. Since I don’t ski very well I thought this was probably a good thing. The locals all seemed very confident that it was going to snow but I have little confidence in weather forecasts. It started to snow at about 8pm and it is still …
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