Physics Stop

Lenz’s law – at 3 tesla

Marcus Wilson • May 20, 2015

When I was at school, and introduced to magnetic fields in a quantitative sense (that is, with a strength attached to it), I remember being told that the S.I. unit of magnetic flux density (B-field) is the tesla, and that 1 tesla is an extremely high B-field indeed. Ha! Not any more. Last Friday night  I got to see … Read More

Special relativity – not so easy to grasp

Marcus Wilson • May 18, 2015

I've just given a couple of lectures on special relativity to a class of first years. It's clear that grasping the key ideas is going to take some time. The results are so far removed from everyday experience that there is a certain air of bewilderment in the classroom. Here's an example of what I mean.  Suppose two … Read More

Developing assessment literacy

Marcus Wilson • May 12, 2015

I just love the word 'obfuscate'. It means (in my words) to take something that is perfectly clear, and render it incomprehensible. As in "Using the word 'obfuscate' in a sentence will obfuscate its meaning".  I say this because I've just been reading an article on which (clearly) a statistician has been let loose - thus rendering an … Read More

Messing up the test: the next installment

Marcus Wilson • Apr 29, 2015

In the last few years I've been experimenting with the way I test our 3rd year mechanical engineering students in their 'Dynamics and Mechanisms' paper. I've chosen this paper because (a) it has more than a handful of students, and (b) I am in charge of it. When  I've suggested to my peers that I do something similar with … Read More

A lot of huffing and puffing

Marcus Wilson • Apr 15, 2015

While there is some great fiction out there, one really shouldn't try to learn much physics from it. One case in point, which I am forced to listen to over and over by the youngest member of our house, is the story of the Three Little Pigs.  I'm not talking here about the relative merits of various building … Read More

How high is a winning cricket score?

Marcus Wilson • Mar 24, 2015

I can't help thinking that the West Indies team got their run chase strategy wrong on Sunday night. They had a tricky task ahead of them. One might say the problem was one of their own making, judging from the rubbish that they served up to Guptill to hit at the end of tne New Zealand innings, but that … Read More

Why does time go forwards?

Marcus Wilson • Mar 10, 2015

Further to my last post, here's a very accessible discussion on some of the physics related to 'the arrow of time'. Maybe, just maybe, Benjamin has the right idea after all... http://www.bbc.com/earth/story/20150309-why-does-time-only-run-forwards   … Read More