Magic Cups
SciCast film goes here
If you're reading this text, try visiting http://scicast.org.uk/films/2008/01/magic-cups.html directly. If you're already there you probably need to update Flash
Magic Cups
Helston Science
Download film (right-click)Chemistry , Demonstration , Secondary
A simple trick using a hydrogel.
Director's Notes:
This is a simple trick using a hydrogel. Water retaining crystals from garden centres or crystals from nappies can be used.
We have developed this demonstration and put it onto our website, Helston Science, where you can also find instructions.
SciCast Notes:
This is the same experiment as featured in an earlier SciCast film, ‘Magic Teaparty’; it’s good to compare the two.
Helston’s version gives much more detail about what’s going on and is a good effort, though sadly the sound is a little indistinct in places. My guess is the microphone cable is rather long, and it’s acting as an aerial, picking up the 50Hz mains frequency — hence the buzzing noise.
The microphone is also of the sort that’s designed to be used quite close to the mouth — ideally it should be hand-held. Using it at range, as here, forces the camera to add more gain, which amplifies the buzzing.
But that’s all technical rubbish, and hard to fix. The film itself is clear and informative. I’d have liked to have seen some close-ups showing detail of what’s going on, and of the model, but that’s me being picky rather than anything dreadfully wrong.
Good work, folks!
— Jonathan.