Alison has drawn my attention to this video showing a cat lapping milk in slow motion. The professor explains that the cat doesn’t scoop up the liquid like a dog would, but uses the tip of its tongue – the liquid adheres to the tongue and is drawn up in a thin column. The cat […]
Continue readingYear: 2010
Wallpaper lattice confusion
I got home from work last night to discover the decorator still hard at work, putting up the ‘feature’ wallpaper on one fairly small section of wall. He said he’d been struggling for the last hour trying to find the repeat in the pattern. It’s a dark paper, with detailed but low-contrast outlines of flowers in […]
Continue readingSymmetry, groups, and wallpaper
There is new wallpaper going up in our house. Since my DIY skills are marginally better than my cat’s, we’ve employed a decorator to do it. (I fixed a dripping tap once – that was the high point of my DIY activity.) Looking at the new wallpaper has reminded me that I studied it in my […]
Continue readingLearning outcomes
This week I’ve had three fairly lively discussions about learning outcomes in our university papers. (It’s well blogged already – e.g. here, but I’ll add some things to the mix). The concept is hardly new, but it is only just being given a really wide profile here at Waikato. Although many individual teachers, and many […]
Continue readingNegative Resistance
I was having a conversation last week with a student about negative resistances (in an electronics context). These are just as they sound – to send a current from terminal A to terminal B you have to apply a higher potential to terminal B than terminal A. Sounds backwards? Yes – it is. That’s why […]
Continue readingMouse-be-gone (-be-gone)
Here’s some interesting stuff courtesy of the mighty google on yesterday’s post. http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1033&context=nwrcrepellants It’s an old (1997) report on ‘electronic’ pest control devices. On ‘electromagnetic’ devices, it comments "Laboratory efficacy tests on the control of Norway rats … indicated definitively that such devices have no effect on feeding, drinking, mating or infestation patterns." Hmmm. […]
Continue readingElectromagnetic Pest Repellent
I saw in the newspaper yesterday an advert for an ‘ultrasonic and electromagnetic’ mouse and rat repeller. That got me interested. The ultrasonic bit seems to be plausible enough – I don’t know much about rodent ear physiology, but I’m willing to believe they can hear sounds at higher frequency to us and to dogs […]
Continue readingPipes and water pressure
The warm sunny weather has led to a discovery under the front lawn. The clue was the fact that the ground was squelchy after three weeks with no rain. Either a new hot spring was in the process of popping up out of the lawn, or our water pipe had sprung a leak. It’s not […]
Continue readingThe3is in Three final
The final of The3is in Three was a couple of weeks ago now – so I thought I’d better mention it before it becomes too out of date. As was the case last year, it was a great evening of entertainment, compered wonderfully by Te Radar. There were ten stunning three-minute presentations, covering all areas […]
Continue readingSo you think you’re good at mechanics?
Calculate the stress in the pole that crosses the picture nearest to you in the upper right corner. And calculate the frequencies of the lowest twenty modes of vibration of the structure. (It’s the temporary stand at Lake Karapiro put up for the World Rowing Championships. Had a very enjoyable day there on Thursday.)
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