I've had a few difficulties in some discussions with students recently. It comes down to this: "How do I explain something that is so blatantly obvious it doesn't need explanation?" The problem really is that a particular concept can be obvious to me, but not obvious to a student. The danger is then that, in […]
Continue readingYear: 2014
Apparent forces
A couple of weeks ago I had the misfortune to be on a bus which had an accident. I wasn't hurt, because I was safely seated, which is more than I can say for one unfortunate passenger who was still on his way to his seat at the time. It wasn't a high-speed event – […]
Continue readingDon’t moan about it if you haven’t actually taught it.
At a recent staff meeting here, the topic of students' writing ability came up (yet again)! Why are our engineering students and physics students just so bad at writing in whole sentences, using correction punctuation and using consistent tenses? Why can't they string four relevant sentences together to make a paragraph that actually makes a […]
Continue readingThe advantage of a transponder
So, as I said, it appears that it's awfully hard to hide a commercial airliner from military radar. But let's backtrack a bit. Why do aircraft carry transponders? (What is a transponder?) There are a couple of reasons here. First, we need to look at a big problem with radar. It has limited range. We […]
Continue readingA fun experiment to try at your desk
I received the latest PhysicsWorld magazine from the Institute of Physics yesterday. A quick flick through it reveals a fantastic demonstration you can do with kids (or grown-up kids) to show how strong friction can be. Take two telephone directories, and interleave the pages (so every page of book A has a page from book […]
Continue readingWhat makes something show on radar?
One of the questions on everyone's lips at the moment is "How does a large passenger jet simply disappear from radar without trace?" It is clearly very distressing for anyone with friends or relatives on board – not knowing what has happened. As I write this, there still seems to be a complete lack of […]
Continue readingIn cyberspace no one can hear you scream
So, you spend six days working frantically on a large project proposal in order to meet the ludicrous deadline (see previous post), and just as you think that the it's under control and the goal is in sight, someone walks onto the pitch, picks up the goal posts and deposits them in the vicinity of […]
Continue readingSorry I’ve blogged-off
Hello everyone. Are you still there? It's not much fun reading a blog that doesn't update for several days, is it? My excuse is two-fold. 1. That the University of Waikato Semester A has just started. Actually, that isn't a real excuse since I've known about it for a long time. It just acts to […]
Continue readingDem Cables
I've just been shifting around various bits of equipment and computers in our 2nd and 3rd year physics lab, to make way for an item that's shifting in there from a nearby lab. It's gone something like this…(rising in semitones, with apologies to the original performers) Da power socket is connected to da extension cord; […]
Continue readingA load of rubbish
I've been reading through a student's report of his summer work placement. He had a project on improving the performance of a heat exchanger used for getting rid of heat from a cryogenic cooler. The basic concept is that materials are being cooled to about 40 kelvin (that's 40 degrees above absolute zero, minus 233 […]
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