At a laboratory in California, in what is called the National Ignition Facility, is the largest collection of giant lasers in the world. Their aim is to produce sustainable nuclear fusion similar to that happening in the Sun. The nuclear power stations we currently have split large atoms (such as Uranium) in a process called …
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Category:Physics
Words, Words, Words (Phys. Ed.)…
Some physics words with links to relevant Twig World videos. You will need to be logged into your Twig World account to be able to view the videos but you only need to log in once then you should be fine. Force – a force is a push or a pull gravity/weight – the force …
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Raindrops Keep Falling…
In the rain, is it better to walk or run if you want to get the least wet possible? This is such an obvious sounding question. Surely you need to run to spend as little time in the rain as possible? It is not quite that simple although most physicists do agree that if it …
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Osmosis…
One of my favourite SF classroom moments was when discussing density. I said that osmium was the densest metal, and therefore the densest material that one would be likely to meet on Earth, at 22.59 g/cm3 (with iridium as a close second on 22.56 g/cm3). A voice chimed up from the front asking whether osmium …
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Phase Transition…
. The graph shows how the temperature (in this case of some ice) changes over time when left out on a laboratory bench at 20 °C. The ice changes from being in a solid state to a liquid state. This change of state is a phase transition. There are five distinct regions of the graph …
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The Dzhanibekov Effect…
Also known as the Tennis Racket Theorem. Or intermediate axis theorem. When a gyroscope spins it stays upright because the spinning weight at its core resists any attempts to knock it off its access. This is called rotational inertia. Inertia refers to the tendency for moving objects to remain moving or stationary ones to remain …
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Various Reagents…
There are numerous chemicals that are used in science practical work but which only get the briefest of mentions. I thought it might be useful to make a list of some here so that you can learn what they all do. Solvents We use various solvents (to dissolve things) with water being the most obvious. …
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Standard Form…
This is especially relevant to those of you doing Radley Physics Papers. Joking aside, knowing a little mathematical notation can be very helpful. Often a “back-of-the-envelope calculation” is enough to use as a guide to the sort of answer you might expect. Standard form is a way of expressing numbers as multiples of ten. It …
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Coloured Compounds….
Although I have written about chromatography, and how it can be used to separate mixtures of coloured compounds, it occurs to me that I have not really talked about why certain chemicals are a particular colour or even what colour really is. I shall try to address this omission here. Our experience of colour is …
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Balthazar…
NB – if you have posted comments, I often include follow up questions in my replies so do check back and read my responses. A standard wine bottle holds 750 ml (cm3) of liquid. That is ¾ of a litre, sometimes called 75 cl. We almost always use units derived from the litre to measure …
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