I gave a talk to the Junior Naturalists in Hamilton last Friday. It had some similarity to the talks I gave in June to the Osborne Days (year 12 and 13 school students), but I needed to change a few things because 1. The audience was younger, and 2. I wasn’t prepared to cart voluminous apparatus across from the University to Hamilton Gardens and back on a dark night.
The mobile phone in foil experiment works pretty well, and is simpler to do than the mobile phone in water experiment, and this time I extended it to a radio in aluminium foil. (It shouldn’t receive anything – the foil reflects all the waves and the radio goes quiet.)Now, I tried to test this a couple of evenings previously at home (to avoid embarrassing situations where your experiment doesn’t work.) But we’d run out of foil at home, and I had to improvise by sticking my pocket radio in a saucepan and putting the lid on. This is when I got a bit of a startling result – on FM, the radio went silent as I expected. But on AM, it still continued to pick up stations while completely surrounded by metal.