Saturday Science: What is it all about?

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Thanks for joining us here ! Press on the menu button with the triple ‘ = ‘ symbol above to get the menu/ navigation. There you will find sections about science projects and experiments you can make yourself.
Before diving into the dozens of projects on this website you might like to take a look at a video or two . The first one gives some answers to the question “Why do science projects”, while the second one shows some slightly crazy ways to literally launch a book. The third one is from the launch of my last book, The Ultimate Book of Saturday Science, which we made at Isaac Newton’s old house Woolsthorpe, where you can still see where he lived, and re-try some of his experiments in optics and mechanics.

As well as science projects, experiments and demonstrations there is a section called the Half-Bakery, where there a some half-baked projects – bright ideas that are half-tried, or worked but need further innovations. You’ll also find some tips and tricks on making things, and analysing what is going on. There is even a short section on innovation: brainstorming in teams and inventing new stuff. You might also find it interesting to take a look at the ‘blog’ below, at science and gadgets that are currently being worked on. As in the Half-Bakery section, though, you will find physics that is incomplete and projects that maybe don’t quite work – but maybe you can fix that !


Following a tip from Esther Redhouse White (thanks Esther !), Diane and I have been playing around with how hand blenders – those electric kitchen gadgets handy for making soup out of vegetables – can actually lift up cups /small bowls of water. Really ? you might think. It may be weird but it really happens. If you don’t believe us, grab a blender and just try it yourself.

But how, why does it happen ? What is the physics behind this ?

I thought that this might be down to some kind of Bernoulli effect, because Bernoulli is often causes weird surprising effects. But now I think it might be basically down to the blender working like a peculiar sort of ‘cut-away’ centrifugal pump.

A proper centrifugal pump produces a basic pressure P given by

P = ρv2 / r

where ρ is the density, v the speed of the blade tips, and r the radius. Now it turns out that if you put some numbers in, you get forces like 10N, or 1 kilogram lift force. Could this be right ?

Well Diane had a nice idea for how to prove it: she taped a length of plastic straw to the side of the blender, going down to the centre at the bottom. There are probably some other effects going on – I am not sure what – but I think that this is 80% of the explanation of how lifting blender works. Now watch the video to see how Di’s ingenious modification works.

When you block the pipe, the blender lifts, just like it ‘normally’ does. but when you let air into it, the cup just sits there ignoring the blender.
ri talk question

The most exciting phrase in science is not “Eureka !”  but ‘That’s funny” – Albert Einstein  Neil A Downie doing Saturday Science at the Royal Institution, London