I never tire of the Science Museum in London.
I can tramp the halls for hours without finding anything too dry to be of interest.
And I have spent a very long time in front of a cabinet in the locksmithing gallery getting more and more frustrated at failing to fathom one – or, to be honest, any – of the mechanisms behind the glass.
But this time I had a whole new experience there: Fun.
It turns out that all you need to do to have a giggle is take some children with you.
Because then you don’t feel such a fraud when you go into the all-hands-on Launchpad zone to play with the stuff in there.
And there is some amazing stuff.
For example, there is a magnet that is free to move in a gap between two slabs of copper.
The amazing bit is that the magnet takes more than a second to fall 20mm through free space.
I realise it is all induction, and I also know that bits of superconductor happily float over magnets, but it never occurred to me that copper was conductive enough to visibly slow the fall of a magnet. Particularly almost to a standstill.
I am still a little puzzled why the copper slabs are joined at one end – anyone know?
And take a look at this video – which plays on a continuous loop in Launchpad.
It was made for the Museum to show children examples of energy transfer by Engineered Arts in Cornwall.
And I had an uncontrollable urge to make a bridge out of blocks
and an arch
and… there was still enough time to go and see the first prototype of the Clock of the Long Now, the Merlin engine I seem always to gravitate to, and the Foucault Pendulum.
This last thing is a very long pendulum that – in ways that I also cannot fathom – demonstrates that the earth rotates.
I tried to work out how oscillation in the pendulum is maintained without corrupting its direction of oscillation and came up with a coaxial electromagnet mechanism under the mass.
If the link above is to believed, this turns out to be the way most people do it.
But it appears the Science Museum – care of The Cavendish labs (they really did bring in the big guns then) – has come up with a completely different drive mechanism.
It was indeed a great day out.
Even the children enjoyed it.
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