Marcus Wilson

Dr Marcus Wilson is a lecturer in the Engineering Department at Waikato University and author of the Physics Stop blog. His current research involves modelling of the electrical behaviour of the human brain during natural sleep, focussing particularly on the transitions between sleep states. Previous research interests include infra-red physics and signature control (stealth) and quantum Monte Carlo methods. He graduated from Cambridge University in 1992 (BA Hons) and completed his PhD at Bristol University in 1995.

How to cheat at university - Physics Stop

Nov 11, 2019

A couple of days ago I attended (and spoke at) the University of Waikato’s “LearnFest” event. There were lots of talks and sessions on very diverse aspects of teaching, mostly at tertiary level. One was by Myra Williamson from Te Piringa Faculty of Law here at Waikato, on Contract Cheating at Tertiary Institutions. Now, I was a very well-behaved undergraduate. I attended nearly ALL my lectures (in fact I missed just two in my three years, and those two because I was really sick), I did ALL my various assignments MYSELF, ON TIME, and even lending my lecture notes to a friend (who couldn’t be bothered to get out of bed and onto his bike for a 9am lecture on a minus 6 Celsius February morning) felt uncomfortable to me. The thought of getting someone else to write an … Read More

Twenty thousand leagues under the sea - Physics Stop

Oct 31, 2019

I’ve been reading Jules Verne’s novel Twenty thousand leagues under the sea, considered as one of the very earliest science fiction stories. In brief, Monsieur Aronnax and a couple of sidekicks are taken prisoner by Captain Nemo and his mysterious crew and treated to an underwater voyage around the world on the truly expansive submarine, Nautilus. They get to visit vast reefs, raid sunken galleons, speed through submarine tunnels, view underwater volcanoes and talk a walk (in full diving suit) through the lost city of Atlantis. Written in 1869, the novel gives an interesting picture of the state of scientific knowledge at the time, and how it might find an outworking in the future. One curious feature of the Nautilus is its power supply: Electricity. It’s worth pointing out that in 1869 thermodynamics was still young – only 25 years … Read More

Counting Barretts - Physics Stop

Oct 23, 2019

Just in case you don’t have a seven-year-old boy in your house (in which case this will be obvious) a well-known brand of breakfast cereal here in NZ is currently coming with All-Blacks stats cards. Perfect for finding out your favourite rugby player’s height, number of caps, and how much they can eat for breakfast. Buy a family pack and you get four cards. We now have way more whole wheat biscuits in our house than we are likely to get through before Christmas, much to the delight of the cereal company no doubt. What great advertising. Anyway, there are 40 different cards (current All Blacks plus some “all-time greats”) and an obvious question that sprung to the mind of my seven-year-old was “Wouldn’t it be amazing if I opened the pack and got all three Barretts (Jordie, Scott and … Read More

If you can’t measure it, does it exist? - Physics Stop

Oct 18, 2019

In the last couple of weeks, I’ve been busy preparing for our summer paper on Science Communication. Looking for something amusing about ‘risk’ in science, I came across this neat xkcd.com cartoon about why so many people come knocking on my door (or phoning me, or emailing me) desperately wanting me to spend hundreds of thousands of dollars proving their sensational, Nobel-prize winning, world revolutionizing, if-only-someone-would-fund-me, the-CIA-is-suppressing-it, utterly bizarre theory about quantum mechanics: Only this week I deleted an email along those lines that I just couldn’t face responding to.  Quantum Mechanics does, indeed, take a lot of maths to get to grips with in detail. In fact, it’s developed it’s own maths, in a sense. Try combining two particles of spin 1/2 and you get the result 0 and 1.  Half plus half = zero and one.  … Read More

When the power goes off - Physics Stop

Aug 20, 2019

This morning we woke up to discover  a power cut. This meant: No electric kettle. We do have a gas stove, however, which we could light with the help of matches (the automatic ignition relies on mains power.) So we did eventually get some hot drinks. No toaster. No microwave. No hot toast, no porridge. Back to the Weetbix. No hot water. The gas instant water heating relies on electricity for the ignition. So no shower. No heating. Obviously the heat pump and panel heaters don’t function, but neither did the gas fire. It needs electricity for ignition and control. No internet. The modem needs electricity. No landline phone. Ours is connected through the fibre network, which needs electricity. No mobile phone. Out of charge. No automatic garage door. and the list goes on… My point is that so much … Read More

The lying dashboard (part 2) - Physics Stop

Aug 14, 2019

Following-on from my suspicions as to the accuracy of my car’s reporting of my travel statistics, here’s another mystery. The length of my journey from home to work, as recorded by my odometer this morning, was 24.7 km.  The length as recorded by Google Maps is 25.2 km.  So, my odometer underreads. Or it did this morning, anyway.  But the car overreads my speed. If it gets the speed from revolutions-of-the-wheels data, one might expect that an overreading speedometer implies that the speed is being calculated based on a larger tyre circumference than actually exists. That makes sense with my current tyres, which are getting close to needing replacement. (Yes, they are still legal). But then, assuming the odometer also goes off wheel revolutions, I’d expect that to overread too. But it showed less than Google Maps. Now, also, … Read More

Student evaluations of teaching effectiveness tell us nothing about teaching effectiveness - Physics Stop

Aug 12, 2019

I thank my colleague Chris Lusk for bringing this paper by Uttl, White and Gonzalez to my attention. Many universities and polytechnics acquire Student Evaluation data on courses and teacher quality at the end of a course. There are different ways this can be done – here at The University of Waikato students are asked (online) a series of questions about the course and teaching of the course to which they can ‘Agree strongly’, ‘Agree’, ‘Disagree’, or ‘Disagree strongly’.  They can also provide free-response feedback on the course. It is the quality of these student evaluations that is the subject of the research of Uttl et al. They present a large meta-analysis (i.e. a combined analysis of lots of peoples’ data) on the extent to which the scores that university students give to their teachers in end-of-semester evaluations relate to … Read More

The lying dashboard - Physics Stop

Aug 07, 2019

How accurate are our car speedometers? That’s well discussed., e.g. on this AA question forum.  If the ‘expert’ here is correct, your car speedometer could over-read by as much as 10% + 4 km/h (which is quite a bit – if you are doing 45 km/h it might read 54.5 km/h, or if you are doing 90 km/h it might read 103 km/h). But it should never under-read speed. So, when I travel through the Tamahere roadworks  and the large “Your speed is…” sign tells me I am doing 48 km/h, I should not be surprised that my speedometer is reading 55 km/h. (OK, you ask, when can you ever travel through the Tamahere roadworks at 48 km/h? Fair point. Answer: about 9:15 am this morning. Child number two is sick today and I was rather late in to … Read More

Quantum cryptography - Physics Stop

Jul 30, 2019

I was reading last week a children’s book about “Secret codes”.  You probably know the kind of thing I’m talking about – substituting one letter for another, or a squiggly shape for a letter, rearranging letters, and so on. Fun things to do, but not the basis of modern cryptography. However, the book didn’t just stop at these codes, but went on to talk about some of the modern principles of cryptography, trying its best to keep it understandable to (say) a ten year-old. For example, there’s the box with two padlocks.  How do I send a secret message to my friend, keeping it secure? I can lock it in a box – that will keep it secure, but then I have the problem of how I send a copy of the key to the box to my friend. The … Read More

Language in physics teaching - Physics Stop

Jul 23, 2019

Hello everyone. It’s been a long while since I was blogging, but I am back again now. The second-half of the year is rather less hectic for me, so I have some time to get back to this. I’ve been considering recently the learning that students have achieved in our first year paper “Physics in Context”.  This is a paper designed for students who haven’t done a lot of physics. We have collected various bits of data from this paper, and one of the clear messages is the difficulty students find in expressing physical understanding in words. For example, “what do I write down in my lab notebook?” was a question that cropped-up time and time again throughout the course. It is really difficult for students to articulate their understanding. In some cases, this is because the vocabulary of physics … Read More