Well, I have now done themobile phone experiment in a lecture. The question was, is a bucket of water enough to shield the electromagnetic communication between a cellphone and the nearest mast? So, I wrapped my phone in glad wrap (or cling film, for those who don’t live in NZ), put it in a sealable […]
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Things that don’t like water
So, my class of students (well, at least one of them) have done the calculations and think that a centimetre of water is enough to shield a mobile phone from communicating with the nearest mast. Only one way to find out. I’ll bring along a bucket, lots of glad wrap and waterproofing materials to tomorrow’s […]
Continue readingMobile phone physics
Just occasionally, I have a crazy thought regarding a physics demonstration. This is one that I’m thinking about inflicting on my third year electromagnetism class. We’ve been discussing the way electromagnetic waves travel (or rather, do not travel) through electrical conductors. Basically, conductors allow electric currents to flow in response to an applied electric field (in simple terms […]
Continue readingHeat transfer within edible objects
The veggie-juicer in our kitchen will happily take fruit, such as apples and oranges. Apparently, in the case of the orange, it works best if the fruit is cold (but not frozen) throughout. So here’s the question my wife asked me last week: If I have an orange at room temperature, and want to cool it […]
Continue readingJust what did Rutherford get up to?
This story, reported by Hamish Johnston, is interesting. Did Rutherford leave something nasty lurking in his lab in Manchester? What mutant lifeforms are slowly evolving at the back of his old filing cabinet? Is Coronation Street safe? What hideous organism is about to eat its way out of the building and destroy half of North West England? […]
Continue readingInteresting but useless fact
According to the fount of all knowledge – Wikipedia 😉 – the only three countries not to have adopted the System Internationale units are Burma/Myanmar, Liberia and the United States of America. I can’t help thinking that there is something deeply significant about those three countries falling into the same group, but I can’t quite […]
Continue readingRemember your units
As any physics student knows (or should know), units are important things. By ‘unit’ I mean a measure of the kind of quantity you are dealing with. So if it’s mass, then a kilogram, a gram, an ounce, etc are all units; if it’s distance, then kilometres, light-years, feet are all units. Units are essential […]
Continue readingSay goodbye to the drill…
Here’s a nice piece of applied physics research that will excite a significant minority of the population – specifically those who dread going to the dentist. Personally, I have never had any issues with drills (needles are a different story), but I know lots of people who do. The proposed method uses cold plasmas to […]
Continue readingUseful origami (and wine bottles)
Here’s something silly and not-quite-entirely-useless for a Monday morning. Think of a deformable material (something solid but something you can squeeze, stretch, dent, etc). Maybe a bean bag, lump of plasticine, football etc. It might or might not return to its original position after you let go of it, but that doesn’t matter. Think what […]
Continue readingDark Matter and statistics

While I was on holiday, news broke (e.g. see the piece in The Guardian) about the possible detection of WIMPs. Weakly Interacting Massive Particles are what many physicists think makes up ‘dark matter’. (What is dark matter? – basically, if you analyse the way galaxies move, you discover that the amount of matter you can ‘see’ […]
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