Not really magic – it is science but optical illusions so magic-adjacent. I thought about this because of a question on a Winchester Election paper about strobe lighting. They are two quite long videos but I thought they were worth sharing, particularly for those who like optical illusions. They left me baffled but delighted. . .. If you …
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Author:SFScience
Retired Schoolmaster living in Wiltshire and Vendee France
Gold Part One…
Pure gold is yellow, which makes it quite unlike other metals, but in every other way it is a typical metal. Like other metals it is… Gold is the most malleable and ductile metal of the lot, which means it can be rolled into incredibly thin sheets (called gold leaf). This is usually about 0.1 …
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ROYGBIV…
White light is a mixture of electromagnetic radiation at different wavelengths. The human eye is sensitive to wavelengths between roughly 380 nanometres (nm) and 750 nm with its maximum sensitivity being at about 555 nm. Other species, such as certain insects, are sensitive to different wavelengths of light e.g. ultraviolet (a short video worth watching!) The …
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Hoppy Hollydogs!
I hope you have a very Happy Christmas – or as they say in Wales, Nadolig Llawen. I will publish an article or two each day and they will always have a few questions at the end. The idea is that you can answer those questions using the comments section. They are always fairly simple …
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Density Of Gas…
Density means the mass of 1 cm3 of a substance. For example, 1 cm3 of water has a mass of 1 g – its density is 1 g/cm3. Lead, on the other hand is much denser than water. 1 cm3 of lead has a mass of 11.3 g ∴ lead has a density of 11.3 g/cm3. The …
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The Super Cow Is Lowing…
Cattle are selectively bred to encourage characteristics that the breeder wants to enhance. These might include greater muscle mass, thicker fur for survival in colder conditions or higher milk production. In the case of the Belgian Blue cattle in the following video the breeder is trying to enhance ‘double muscle’ to produce cattle for showing …
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Making Gas…
I am sure you are familiar with the processes involved in making and collecting gases in the laboratory. The two most common ones we encounter are carbon dioxide and hydrogen. You will know that carbon dioxide is produced when carbon combusts and when carbonates are heated, but we tend to use the action of an …
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Big Load Of Nothing…
Your weight is determined by your mass and the pull of gravity. On Earth, gravity is about 9.8 N/kg (usually rounded off as 10 N/kg). The force of gravity causes objects to accelerate towards the centre of the Earth at 9.8 m/s/s (m/s/s is sometimes written as m/s2 or ms-2). In a vacuum, two objects …
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Oily Fish…
I have eaten a lot of tinned sardines this week. Call me crazy but a warm baguette filled with good cheese and four oily sardines makes a great lunchtime snack. I prefer the ones packed in oil to the ones packed in tomato sauce but I am prepared to be open-minded on the issue. As …
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Where There’s Muck There’s Brass…
This was originally posted in March 2015. The title is a phrase meaning that where there are dirty or unappealing jobs to do, money can be made. Brass (an alloy of copper and zinc) is used to make coins – the pound coin being a good example. Several news outlets (BBC, Guardian) today reported that some …
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