We have a problem brewing in the lab. Recently, we (by which I mean a PhD student or two and a researcher) moved into a new lab. As part of our research we are recording electrophysiological signals (electricity produced by living cells). These are pretty small, often in the microvolt region (a millionth of a […]
Continue readingTag: electron
Momentum conservation
It’s mid-semester break here at Waikato so I have time to breathe and get back to things other than teaching, such as seeing what the PhD students are up to. Yay. But, here’s a comment about what I was talking about last week with the first year students: conservation of momentum. If you look in […]
Continue readingNatural units
Physics is all about describing physical quantities. Whether it’s length, velocity, force, electric current or heat flux, it takes physics to describe what it is and what it does. Central to this is our system of units. The three really common base units (in the S.I. system) are the metre (unit of length), the second […]
Continue readingThe Faraday Suit
Annette Taylor has sent me this link. Rather than turning off a high-voltage power line when you work on it, you just wear one of these special anti-electricity suits. Of course, there’s nothing hi-tech about them (at least, not conceptually). If you put one of these on, you are in your personal Faraday Cage, and […]
Continue readingDiode Flavours
A week or so ago, I had an exciting poster session with my second year solid-state physics class. Their main assignment for the term was to prepare, in small groups, a poster on a particular flavour of diode. My intention here was to get the students to learn about the underlying physics of a solid-state […]
Continue readingThe physics of slugs
At Tuesday night’s Cafe Scientifique, we had a very entertaining discussion, led by Mike Wilson from AgResearch, on that most cute and cuddly animal, the slug. Let’s face it, in terms of looks and popularity, the slug doesn’t have a lot going for it, but it’s certainly a very interesting creature. I learnt a fair bit […]
Continue readingThree heads are better than one
It’s often surprising how different people can bring different approaches to the same problem, but in a way that gets you moving forward. I experienced a good example last week. A PhD student has been tangled in a nasty net of circuit analysis, trying to understand how a particular circuit does what it does. I’ve […]
Continue readingSuperconductivity turns one hundred
There’s a fair bit in the physics magazines at the moment on superconductivity. http://Physicsworld.com has some interesting articles, for example this one by Ted Forgan and an interview with Frank Wilczek. Superconductivity has its hundreth birthday this year. In 1911, in Leiden, Netherlands, Heike Onnes and Gilles Holst discovered that mercury lost its electrical resistance […]
Continue readingElecmystery
I’m beginning to wonder how I’ve ever found time to do the nearly 400 entries that this blog has accumulated over the last two and a half years. It’s Friday already and I’ve only done one entry this week, on top of not much last week either. One of the highlights of electricity is the […]
Continue readingCorrelation or no correlation?
Here’s an example of how easy it is to see things that don’t exist. It’s from a real piece of research (mine). As way of background, I’ve been doing some work with computer models of neurons in the cortex (NB this isn’t artificial neural networks, which were all the rage in the 1980/90s). Broadly speaking, I’ve […]
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