What’s small, brown, damp, disguisting, goes round in circles, and is still alive? Answer: A cockroach in a washing machine. Finding one in amongst the sheets as you haul them into the laundry basket isn’t very pleasant, I can tell you. Unfortunately, in the northern North Island, the Gisborne cockroach (an Aussie import) is rather […]
Continue readingTag: water
Another exponential decay example
In the last couple of weeks, my wife has been having a go at making sourdough bread. One of the defining characteristics of this bread is that it doesn’t use yeast – at least, not directly. The idea is, to start it off rising, you leave it outside for a while, and allow lots of […]
Continue readingResults of the mobile phone experiment
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 […]
Continue readingThings 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 readingFallstreak cloud
Those of you who check out the NZ metservice website frequently, may remember last week’s ‘photo-of-the-week’: It’s of fallstreak cloud, and this example was spotted by my mother-in-law, Barbara Seccombe, off the coast from New Plymouth recently. (Photo credit to my father-in-law, Wally Seccombe, used with permission). It’s not something you see everyday, so I asked my brother […]
Continue readingHeads I win, tails you lose
The comment on my previous entry raises a few issues with the way we feel heat. (NB for those who normally read this blog on http://www.sciblogs.co.nz , you’ll need to go onto physicsstop to see the comment – https://sci.waikato.ac.nz/physicsstop ) How hot we feel has more to do than just what the temperature is. Anyone who […]
Continue readingIce and the freezer
Last Saturday I got around to doing one of those long overdue jobs in the house – defrosting and clearing out the freezer. There are numerous reasons why this was a good idea – it’s not just about getting rid of the food that has been there rather too long, but also about making sure it […]
Continue readingBack to the long-neglected blog
Well, I’m back in at work now after three weeks and four and a half thousand kilometres. Pleased to discover that in my absence the house hadn’t burnt down, there had been no floods and Christmas presents hadn’t been stolen. So it’s now back to trawling through three weeks’ worth of emails, catching up with […]
Continue readingThe We(s)t Coast
Back online briefly – blogging is a bit tricky from campsites – not all of them have wireless broadband connections yet – particularly on the West Coast. For those non-New Zealanders, ‘West Coast’ refers to the west coast of the South Island, which I have now driven the length of. Or as much as is […]
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