The University of Waikato - Te Whare Wānanga o Waikato
Faculty of Science and Engineering - Te Mātauranga Pūtaiao me te Pūkaha
Waikato Home Waikato Home >Science & Engineering & gt; Physics Stop
Staff + Student Login

August 2009 Archives

I'm still working on the problem of why is the sky blue?  Now, I've already told you its because the short-wavelength blue light is scattered more than the long-wavelength red light, but why are short wavelengths scattered more than longer ones? In words suitable for a blog.

I could do some maths to show you that's the case, but that's really a cop-out. (Plus most of you wouldn't follow it.) I think if a physicist has to resort to maths to explain something, it means he doesn't understand it himself. (That said, you will struggle to do physics without being reasonably competent at maths - since maths provides the language in which physics is often best expressed.)

Help!

| | Comments (0) | TrackBacks (0)

This morning we had a school group visit us from Whakatane - about 30 year 10 students (14 and 15 year olds) - they carried out some activities in Chemistry, Earth Sciences and Physics. I led them (as two groups) in a physics activity involving catapults.

After doing the boring bit (talking about how energy is transferred from one form to another as the catapult is loaded and fired) we got to actually using the things. Our catapults have a metal arm, that can be bent back and locked in place. A projectile is placed on the arm, and then the arm is released. As it springs back into position, it throws the projectile about fifteen metres (if you get it right) across the room. Students can vary the release angle of the catapult, the mass of the projectile they put on it, and the effective length of the spring arm. They need to think through the best combination to get the projectile going the desired length.

| | Comments (0) | TrackBacks (0)

Last night our cat failed to live up to the reputation of his species for executing four-footed landings when he lept off a perch in hot pursuit of a piece of string, landed on his front paws with too much forward rotation, performed a graceful flick-flack and thuded head first into the CD rack. After a couple of seconds looking very dazed he got to his feet again and decided (to our relief) he was still fit enough to teach that bit of string a lesson.

 

| | Comments (0) | TrackBacks (0)

In the last few days I've had a couple of people ask what is happening with the Large Hadron Collider.

Well, if you want the latest news, you can grab the press releases from http://lhc.web.cern.ch/lhc/News.htm . In short, they are doing various tests, and finding and addressing various problems as they arise. It now looks like November before the collider is 'fired-up', (press release 16 July 2009) but initially it will only be running at a paltry 3.5 TeV energy (that's still a pretty mean machine) while the technicians gain practice with running it - it looks unlikely they'll take it up to its full 7 TeV until 2011 (press release 6 August 2009).

You'll see it hit the popular news again, I'm sure, as November approaches.

| | Comments (0) | TrackBacks (0)

So last Friday, after a hard week at the office, I went over to the Opus Bar on campus to enjoy some evening music.  And, because I wished to consume neither alcohol (I had to drive home) nor caffeine (I didn't want to stay up till midnight), I bought a hot chocolate.

| | Comments (0) | TrackBacks (0)

For those in easy reach of Hamilton Gardens, the NIWA Science Fair is well worth a visit. I spent a considerable portion of yesterday looking over the exhibits - which mostly consist of posters describing children's science projects.  It is wonderful to see that, despite the perpetual moanings in the media, there are children out there who are interested in science,  and are able to do some really good scientific investigations.

And I didn't see a single energy-saving lightbulb.

The exhibits are open for public viewing (Friday 21) and tomorrow. Well done to all who participated.

| | Comments (0) | TrackBacks (0)

This is doing the rounds at the moment. Modelling the spread of zombie-ism amongst the human population.   (E.g. report on BBC website.)

The original article is actually a bit physicsy - the methods used are pretty common ones for modelling physical processes with a computer, and the sort of thing I do a lot of in my research.  The authors just happen to have picked a rather different application to normal. This is the kind of modelling I was referring to when I made a comment a few months ago about swine flu  (though I think the swine flu  - sorry, Influenza A (H1N1) -  modelling is likely to be more advanced than this.)

Anyway, enjoy the report, and commetary for example on Orac, and, if you every come across a zombie, please don't rush over and tell me about it.

| | Comments (0) | TrackBacks (0)

One of the likely candidates for the recent explosion at the Sayano Shushenskaya hydro-electric plant in Russia is a transformer. But what is a transformer, and why might one explode?

Transformers are an ubiquitous part of our electricity generation and distribution network. Their job is essentially to transform an electricity supply from one voltage to another.  (Why would we want to do that? - to transmit power long distances without losing much of it on the way, we need to work at high voltage - but high voltage isn't always what's easy to generate, and isn't what you want to feed into your home. So there needs to be a method of changing it).

| | Comments (0) | TrackBacks (0)

Did anyone see Saturday's 'Country Calendar' on TVOne? In case you didn't, it followed a group of long-line tuna fishermen on their fishing trip North of North Cape. They were testing out a method for detering albatross from trying to take the bait (squid) from the hooks - a decision often fatal for the albatross. The method seemed to have two parts to it - first ensuring the hooks submerged themselves very quickly, and secondly dyeing the squid blue.

| | Comments (1) | TrackBacks (0)

With reference to my entry last week, here is the bit in Jostein Gaarder's Sophie's World about gravity. Spot the misconception. Sophie is talking to Alberto:

'Well, if the moon was drawn to the earth with the same foce that causes the apple to fall, one day the moon would come crashing to earth instead of going round and round it forever.'

'Which brings us to Newton's law on planetary orbits. In the case of how the earth attracts the moon, you are fify percent right but fifty percent wrong. Why doesn't the moon fall to earth? Because it really is true that the earth's gravitational force attracting the moon is tremendous...'

| | Comments (0) | TrackBacks (0)

I came across this article on the BBC website yesterday. It talked about how parents feel that they are being routinely baffled by science questions their children asked. Apparently, the top three questions that parents don't like to hear are: "Where do babies come from?", "What makes a rainbow?" and "Why is the sky blue?" (The article refers to the website Science: [So what? - so everything] which is great reading.)

| | Comments (0) | TrackBacks (0)

You may have seen the article in the NZ Herald on Saturday about our use of fossil fuels (The Carbon Party's Over, Chris Barton, NZ Herald 8 August 2009). The bit I loved about this article was translating a barrel of oil (159 litres) into more everyday terms - namely the energy in it is equivalent to 3500 cyclists giving it their all for an hour. I guess that is the fundamental problem - oil contains a lot of energy that's really easy, and really cheap (even at 149 dollars a barrel) to get at.

| | Comments (1) | TrackBacks (0)

My wife and I stayed at a lovely Bed and Breakfast on the Coromandel Peninsula over the weekend. Here's a snippet of conversation with the hosts over breakfast.

Host: What do you do for a living?

Me: I lecture physics at Waikato University

Host: Really? I used to lecture physics in the US - I'm a secondary school teacher now.

Wife: Wow - when he tells people what he does they usually just say "oh" and change the subject.

Well, finally I have proof that I am not the only physicist  in New Zealand. There then followed a very interesting conversation about solid state physics and how to calculate structures of solids with a computer, but I shan't relate that to you.

| | Comments (0) | TrackBacks (0)

This week I've been talking to my third year mechanical engineering class about the Lagrangian approach to solving dynamical problems. OK, please don't close your browser now, rest assured that you don't need to know what the Lagrangian approach is to follow this post. (if you do, then click here.)

I reckon there are two ways of dealing with this with a class of students. One (my favourite, as a physicist) is to go into gory detail about the principle of least action and calculus of variations (again, don't worry what these are, because the chances are that you will never ever need to know them). The other is to say 'here is the formula that makes it all work' and leave it at that.

| | Comments (0) | TrackBacks (0)

A few people have expressed surprise when they've learnt that that the university doesn't block access to websites like YouTube and Twitter. I mean, how many hours are wasted by employees gazing at silly video clips of buildings being blown up in Turkey rather than concentrating on their work?

| | Comments (0) | TrackBacks (0)

This question comes from a final year school student, trying to answer a question about astronauts in spacestations.

Well, having seen numerous videos of astronauts, the answer would seem to be no. They float around quite happily, scientists refer to them as being in a zero gravity environment, their leg muscles don't get enough exercise, and so on.

| | Comments (0) | TrackBacks (0)

I was on data-projector duty at church yesterday. That meant I had to press the buttons that made sure the correct verse of the song was showing at the correct time, a job that requires more concentration and co-ordination than you might think. When I'm sitting close to a projector, I find the way that dust particles light up and darken again as they drift through the beam quite hypnotic. It reminded me yesterday of the occasions many years ago (I guess it would have been about 30!) when Dad used to set up his slide projector in the lounge and we'd look excitedly at his pictures from our last summer holiday. What technology!

But something about the slide projector really confused me, for a fair while. (And I don't think I ever asked Dad about this.) And the blame lies squarely at the feet of Roald Dahl. Yes, Roald Dahl, as in Charlie and the Chocolate Factory, the BFG, James and the Giant Peach, etc.

| | Comments (1) | TrackBacks (0)