An Engineer In Wonderland – A day in the Science Museum

I never tire of the Science Museum in London.

exterior-of-museum-jpg.jpgI 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.


inductioncrop.jpgThe 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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  1. I did notice that the children’s exhibits had the allen-bolts-and-steel look that I normally associate with experimental pressure vessels.
    Maybe kid-proofing rather than electron flow explains the huge metal link between the slabs of copper on the floating magnet demo.

  2. Having visit this and other science parks over the years, I have come to the conclusion that there should be four grades of durability for switches:
    Domestic, industrial, military, childrens’ science park.

  3. Magnet/Copper – Isn’t it to do with Eddy Currents?

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