I attended the final of the The3is in Three competition on Wednesday night. It was a really entertaining evening; compere Te Radar was in great form, as were the eight finalists (N.B. I know that those of you who are not from NZ won't have the slightest idea who Te Radar is, but I'm sure Google could solve that for you.) Each contestant had three minutes to present their PhD research, with the aid of one powerpoint slide and whatever over-exaggerated hand movements they wished to employ.
October 2009 Archives
I'm in the thick of marking exam papers. In physics, a lot of what a student does is mathematically based, so a fair bit of any exam is going to contain calculations of things. But don't think that it is compulsory to make your answer totally incomprehensible.
Many of the exam answers I see from students look like the result of a twisted experiment involving Sudoku and Scrabble. Letters and numbers are strewn around the page in a fairly random manner, occasionally with an equals sign that may or may not be in the right place. Units are always conspicous by their absence. Such a scrawl is really really hard to mark. Your reasoning, in your head, might be perfect, but unless you can get it down onto the paper in a comprehensible manner it might not be getting you much credit.
So please, put in a few well chosen words. For example, you can say 'taking moments about point O gives...', or 'using conservation of energy we have...' rather than launching straight into the equation. Remember, if the examiner can't work out what on earth you are doing, your chances of getting credit for it are on a par with those of New Zealand winning the rugby world cup.
There are some lovely physics demonstrations that get repeatedly wheeled-out for things like Open Day and visits from school groups. Things like holding a spinning bike wheel on a rotating chair (flip it over and you start rotating - conservation of angular momentum) and levitating a piece of superconductor above a magnet at liquid nitrogen temperatures. But one thing that I've yet to get my hands on to demonstrate is Cavorite.
I think it's an excellent suggestion, but, borrowing from Red Dwarf, with two minor drawbacks. One, it comes with significant health and safety concerns, and two, it is fictional.
Magnets attract iron. Yes? So what happens when you place a drop of ferrofluid (which is basically an oil whose molecules have been laced with iron atoms) on the surface of water and lower a maget towards it. The oil will flow on top of the water and accumulate under the magnet, since that is the closest it can get.
Well, no. As the picture shows, what happens is the fluid accumulates in a ring, which is devoid of fluid near the centre - the very place that is closest to the magnet.
If you want to know when not to expect annihilation of the earth following a second-big-bang in the Large Hadron Collider, I'm afraid the best I can offer you is a link to their press site.
They are being very coy about exactly when things will happen.
If you think it unfair that your children get to go on lots of exciting school trips that you never went on this is for you - virtual field trips throughout New Zealand on the LEARNZ website.
Sent to me by NZ Institute of Physics - thanks guys.
The alternate stretching and squashing casued by a gravitational wave is an example of a quadrupole oscillation. This is another word that probably means very little to most readers, and, unless you like maths, Wikipedia isn't going to help you, so I'll explain.
Let's start with a monopole. You get a monopole when you put 'stuff' somewhere. Here, 'stuff' can mean almost anything you like - mass, electric charge, nematodes...(cafe scientifique last night was about nematodes, or 'roundworms' - such is their world domination that they deserve to be used to illustrate these physics ideas...) So talking about the number of nematodes in a centimetre cubed of soil would be a describing their distribution in a monopole form.
One of my undergraduate students has been researching gravitational waves this year. Last Friday, he gave a nice presentation on the subject.
Gravitational waves are one of the many examples of waves in physics. We are perhaps more used to waves on the surface of water, or waves along a guitar string, or electromagnetic waves (such as radio waves and light), and, in many ways, gravitational waves aren't much different.
I reckon that every scientist should be able to explain his or her work to any audience, in any situation. Whether it is a 30 second conversation with a six year old with the aid of a pencil and paper, an oral presentation to the general public (a la cafe scientifique), or a detailed effort using all the functionality of Microsoft Powerpoint at a specialist conference, it should be possible to convey meaning to your audience. In fact, if I'm feeling brave, I would go as far as to suggest that if a scientist is unable to do this, it is an indication that he or she does not understand the topic him- or herself.
So, for those who want it in full, here is the joke I referred to earlier.
A geneticist, a physicist, and a statistician are all asked by a gambler to advise him on which horse to place his money in the Melbourne Cup.
There is nothing a physicist likes better than to get one up on a chemist. In a friendly way of course. Rather like New Zealand beating Australia at some sporting event.
So it is with great delight that I hear that the 2009 Nobel Prize in Chemistry has been awarded to a physicist. (See commentary by The Institute of Physics).
Activity is really hotting up (should that be 'cooling down'?) at CERN as the Large Hadron Collider is prepared again for proton-proton collisions, hopefully in November. Most of the beam tunnel is now at operating temperature (1.9 K), with the rest expected to be ready very soon. I would expect to see the collider hitting mainstream media again shortly. The latest CERN bulletins can be found on their website.
What does 'big' mean? How big does something have to be in order to reasonably carry that adjective? The answer, of course, is 'it depends'.
For example, I am pretty tall. But after standing next to someone much taller than me on a tram last week, I realise that maybe I am not so tall after all. I got to see what it was like for many people looking at me.
What gives NASA the right to hurl projectiles at 1.5 miles per second into the surface of the moon? Interesting, definitely. Useful, perhaps. Reasonable? I'm not so sure. Did this mission go through some kind of ethics approval?
Last year, according to the American Physical Society, there were over a hundred thousand articles published in physics journals
Physicists are notorious for making approximations. This character trait is the subject of many jokes - for example, one rather rambling one involving a physicist advising a punter on which horse to put his money ends with the line "Oh, didn't I tell you - my calculations assumed a spherical horse rolling through a vacuum."
But approximations are useful things. The general idea is that a physicist will want to consider something in all necessary detail, but no more. All necessary detail is obvious - for example it is very hard to adequately describe static electricity without talking about positive and negative charges. But physicists don't like going the other way either - for example the reason why the earth orbits the sun can be explained without invoking General Relativity. It just adds in extra complication that is not necessary.
I'm having an extra llllooonnnngggg weekend, so blogging may take a back seat for a few days, but I shall be back very soon.
Over the last week or so I have, amongst other things, been doing some preparation for two summer scholarship students that will be working with me from December to February. The summer scholarships are a great opportunity for undergraduate students to experience what research is like. The University of Waikato, like several other universities, offers this chance to several students every year.