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University Physics Examinations, Vintage 1892

Posted in Education, History with tags , , on September 7, 2011 by telescoper

There recently came into my possession a book of very old school and university physics examinations, which are of interest because I’ve been posting slightly less ancient examples in recent weeks. These examinations were set by the University College of South Wales and Monmouthshire, which was founded in 1883,  an institution which eventually became Cardiff University. I find them absolutely fascinating.

The papers are rather fragile, as is the book containing them, so I daren’t risk trying to scan them systematically in case flattening them out causes damage. Here instead are a few random examples that I photographed on my desk, in the manner of an old-fashioned secret agent. Sorry they’re not all that clear, but you can see them blown up if you click on them.

The collection is fairly complete, covering most of classical physics, at all examination levels from university entry to final honours. For some reason, however, the papers on relativity and quantum physics appear to be missing….

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An A-level Physics Examination Paper, Vintage 1981

Posted in Education with tags , , , on September 1, 2011 by telescoper

At the risk of becoming one of the Great Bores of the Day on the subject of past examinations I thought I’d follow up  my old O-level Physics paper  with a Physics A-level examination paper to see what people think about it. It might add to the discussion over on another blog I read too.

I took this particular examination myself in 1981. Can it really be 30 years ago? Agh. Paper 1 comprised a collection of short questions of multiple-choice type from which I’ve already posted one example on this blog.  This one is Paper 2 and, as you’ll see, it consists of longer questions with a freer format.

One comment I’ll make is that Question 5 is remarkably similar to a coursework questions we have been using here in the School of Physics & Astronomy at Cardiff University in our First year Physics module on Electricity and Magnetism.

Any other comments from people who’ve done A-levels more recently would be very welcome through the Comments Box, e.g. is there anything  in this paper that you wouldn’t expect to see nowadays? Is it easier, harder, or about the same as current A-level physics papers?

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An O-level Physics Examination Paper, Vintage 1979

Posted in Education with tags , , , , on August 30, 2011 by telescoper

My recent post about the O-level Mathematics examination I took way back in 1979 seems to have generated quite a lot of comment, both here and elsewhere, so I thought I’d follow it up with a Physics examination paper to see what people think about that.

One complication with this is that I didn’t actually take Physics O-level; the School I went to preferred to offer Combined Science instead. This examination covered a general syllabus including Physics, Chemistry and Biology but was worth two O-levels rather than three. More or less, therefore, I did 2/3 of a Physics O-level.

I think the reason for choosing Combined Science rather than three separate subjects was to allow us kids the chance to take as broad a range of subjects as possible. In fact I did ten O-levels: Combined Science (2); Mathematics; Additional Mathematics; History; Geography; English Literature; English Language; French; and Latin. My best mark at O-level was in neither mathematics nor science subjects, actually, but in Latin…

Anyway, the examination for Combined Science consisted of four papers. Paper 1 was a general paper with a range of short questions in a booklet into which candidates had to write their answers in the space provided. Obviously I don’t have this paper because I handed it in. The three other papers were each on one of the main subjects and Paper 2, shown below, was the Physics paper.

This also gives me the opportunity to try out slideshare as a better way of displaying the paper than the clumsy method of photographing it on my desk I used for the Mathematics paper.  Unfortunately our temperamental scanner – which is rapidly becoming my arch enemy – seems to have missed some of the question numbers, so I put them in by hand.

The first thing that struck me about Question 5 is “During an experiment a boy obtained…”. Girls don’t do physics, obviously.

Any other comments or comparison with GCSE Physics papers should be written in the space provided.  Write clearly and legibly, and show clearly the reasoning by which you arrive at your conclusions. You may begin.

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More Cosmological Haiku

Posted in Poetry, The Universe and Stuff with tags , , , , on August 18, 2011 by telescoper

In view of my current rather hectic schedule – why else would I be up at this ungodly hour? – I thought I’d combine another bit of recycling with some audience participation. I’ve updated below the list of Haiku I posted some time ago with some new ones I’ve jotted down at random intervals over the intervening months.

How about a few Haiku of your own on themes connected to astronomy, cosmology or physics?

Don’t be worried about making the style of your contributions too authentic, just make sure they are 17 syllables in total, and split into three lines of 5, 7 and 5 syllables respectively.

Here are some of my own to get you started:

Quantum Gravity:
The troublesome double-act
Of Little and Large

Gravity’s waves are
Traceless; which does not mean they
Can never be found

The Big Bang wasn’t
So big, at least not when you
Think in decibels.

Cosmological
Constant and Dark Energy
Are vacuous names

Microwave Background
Photons remember a time
When they were hotter

Isotropic and
Homogeneous metric?
Robertson-Walker

Galaxies evolve
In a complicated way
We don’t understand

Acceleration:
Type Ia Supernovae
Gave us the first clue

Cosmic Inflation
Could have stretched the Universe
And made it flatter

Astrophysicist
Is what I’m told is my Job
Title. Whatever.

“Clusters look cool,”  said
Sunyaev and Zel’dovich,
“because they are hot”.

Gaussianity
is produced by inflation,
normally speaking.

Gravity waves are
a kind of perturbation;
they make you tensor

Bubble collisions
Leave marks in the C-M-B
To please A. Linde

This Haiku contains
“Baryon Oscillations”
in its middle line.

What should we build next:
S-K-A or E-L-T?
Or maybe neither…?

J W* S T,
(the James Webb Space Telescope);
long name, big budget

* “W” has to be pronounced “dubya” for this one to work!

Contributions welcome via the comments box. The best one gets a chance to win Bully’s star prize.

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Acting and Clearing

Posted in Education, Finance, Politics, Science Politics with tags , , , , , , on August 14, 2011 by telescoper

Now that I’m back from my trip to Copenhagen, it’s going to be back to work with a vengeance. To those of you who think academics have massively long summer breaks, I can tell you that mine ends on Monday when I will be doing a stint as Acting Head of School. That’s not usually a particularly onerous task during the summer months, but next week happens to be the week that A-level results come out and it promises to be a hectic and critical period. It’s obviously a sheer coincidence that all the other senior professors have decided to take their leave at this time…

There are several reasons for this being a particularly stressful time. First the  number of potential students applying to study Physics (and related subjects) this forthcoming academic year (2011/12) in the School of Physics & Astronomy at Cardiff University was up by a whopping 53% on last year. I blogged about this a few months ago when it became obvious that we were having a bumper year.

The second reason is that Cardiff’s  School of Physics & Astronomy has been given a big increase in funded student numbers  from HEFCW. In fact we’ve been given an extra 60 funded places (over two years), which is a significant uplift in our quota and a much-needed financial boost for the School. This has happened basically because of HECFW‘s desire to bolster STEM subjects as part of a range of measures related to the Welsh Assembly Government’s plans for the regions. Preparations have been made to accommodate the extra students in tutorial groups and we’re even modifying one of our larger lecture rooms to increase capacity.

Unfortunately the extra places were announced after the normal applications cycle was more-or-less completed, so the admissions team had been proceeding on the basis that demand would exceed supply for this year so has set our undergraduate offers rather high. In order to fill the extra places that have been given to us late in the day, even with our vastly increased application numbers, we will  almost certainly have to go into the clearing system to recruit some of the extra students.

In case you didn’t realise,  universities actually get a sneak preview of the A-level results a couple of days before the applicants receive them. This helps us plan our strategy, whether to accept “near-misses”, whether to go into clearing, etc.

On top of these local factors there is the sweeping change in tuition fees coming in next year (2012-13). Anxious to avoid the vastly increased cost of future university education many fewer students will be opting to defer entry than in previous years. Moreover, some English universities have had cuts in funded student places making entry highly competitive. As an article in today’s Observer makes clear, this all means that clearing is likely to be extremely frantic this year.

And once that’s out of the way I’ll be working more-or-less full time until late September on business connected with the STFC Astronomy Grants Panel, a task likely to be just as stressful as UCAS admissions for both panel members and applicants.

Ho hum.

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Hold your breath (via viXra log)

Posted in The Universe and Stuff with tags , , on July 16, 2011 by telescoper

Some of you might think this is just ridiculous hype, but I couldn’t possibly comment…

Hold your breath I don’t think there has ever been a moment quite like this in physics before. Within the next few months, weeks or even days we will learn something new about the universe that will change our thinking forever. I don’t mean something like a little CP asymmetry or a new observation of neutrino physics. These things are great but they just pose questions that we can’t answer yet. What we are about to learn is going to generate so many new ideas in … Read More

via viXra log

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The Perils of Modern Living

Posted in Poetry, The Universe and Stuff with tags , , , on July 15, 2011 by telescoper

Well up above the tropostrata
There is a region stark and stellar
Where, on a streak of anti-matter
Lived Dr. Edward Anti-Teller.

Remote from Fusion’s origin,
He lived unguessed and unawares
With all his antikith and kin,
And kept macassars on his chairs.

One morning, idling by the sea,
He spied a tin of monstrous girth
That bore three letters: A. E. C.
Out stepped a visitor from Earth.

Then, shouting gladly o’er the sands,
Met two who in their alien ways
Were like as lentils. Their right hands
Clasped, and the rest was gamma rays.

by Prof. Harold P. Furth (1930-2002)

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A Simple Problem in Statistical Physics

Posted in Cute Problems with tags , , , , on July 11, 2011 by telescoper

In physics we often have to resort to computer simulations in which continuously varying quantities are modelled on a discrete lattice. We also have recourse from time to time to model physical properties of a system as random quantities with some associated probability distribution. The following problem came up in a conversation recently, and I think it’s rather cute so thought I’d post it here.

Consider a regular three-dimensional Cartesian grid, at each vertex of which is defined a continuous variable x which varies from site to site with the same probability distribution function F(x) at each location. The value of x at any vertex can be assumed to be statistically independent of the others.

Now define a local maximum of the fluctuating field defined on the lattice to be a point at which the value of x is higher than the value at all surrounding points, defined so that in D dimensions there are 3^{D}-1 neighbours.

What is the probability that an arbitrarily-chosen point is a local maximum?

Solution

Well, the most popular answer is in fact the correct one but I’m quite surprised that a majority got it wrong! Like many probability-based questions there are quick ways of solving this, but I’m going to give the laborious way because I think it’s quite instructive (and because I’m a bit slow).

Pick a point arbitrarily. The probability that the associated value lies between x and x+dx is f(x)dx, where f(x)=dF(x)/dx is the probability density function. According to the question there are 3^3-1=26 neighbours of this point. The probability that all of these are less than x isF(x)\times F(x)\times \ldots F(x) 26 times, i.e. [F(x)]^{26}  becauses they are independent. Note that this is a continuous variable so the probability of any two values being equal is zero. The probability of the chosen point being a local maximum with a given value of x is therefore f(x)dx\times [F(x)]^{26}. The probability of it being a local maximum with any value of x is obtained by integrating this expression over all allowed values of x, i.e. \int f(x) dx [F(x)]^{26} . But the integrand can be re-written

\int f(x) dx [F(x)]^{26} = \int dF \times F^{26} = \frac{1}{27} \int d\left(F^{27}\right) = \frac{1}{27},

because  F=1 at the upper limit of integration and F=0  at the bottom.

So you don’t need to know the form of F(x) – but the calculation does rely on it being a continuous distribution.

This long-winded method demonstrates the applicability of the product rule and the process of marginalising over variables, but the answer should tell you a much quicker way of getting there.  The central point and the 26 neighbours constitute a set of 27 points. The probability that any particular one is the largest of the set is just 1/27, as each is equally likely to be the largest. This goes for the central value too, hence the answer.

 

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LHC Hasn’t Destroyed Earth Yet (via Today’s New Reason to Believe)

Posted in The Universe and Stuff with tags , , , , , , on June 19, 2011 by telescoper

I thought I’d reblog this as it relates to the pronouncements about the LHC by Otto Rössler I mentioned yesterday.

LHC Hasn’t Destroyed Earth Yet As I predicted nearly two-and-a-half years ago, it looks like the Earth will survive the most powerful accelerator ever built. A recent article validates my prediction. On September 8, 2008, I recorded a Science News Flash podcast addressing concerns that the Large Hadron Collider (LHC) would produce a shower of black holes that would, in turn, consume Earth from the inside out. I predicted that Earth would not only survive the experiments perfor … Read More

via Today's New Reason to Believe

You might also want to read this older blog post about the kerfuffle when the LHC was switched on. I quote:

Rössler turns out to be quite a strange fellow. He is an MD who stayed in academia, moved into biochemistry, and then made a name in the relatively new field of chaos theory. He seems to think of himself as a visionary, having founded a new field of physics called “endophysics,” which is supposed to take into account the observer’s inner state. Or something like that. Have you heard of it? Neither had I.

Recently, at the age of sixty-eight, Rössler, despite having no particle physics or blackhole physics credentials, announced that he had found important new results, alarmingly relevant to the destructive potential of microscopic black holes in LHC proton-proton collisions. Rössler variously estimates the likelihood of such blackhole production by LHC as being from 10% to 50% though he appears to have pulled these numbers out of a hat.

And there’s also this most excellent video that John Butterworth told me about because he’s in it…

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The Final Analysis

Posted in Education with tags , , , , on June 14, 2011 by telescoper

It’s that time of year again. The annual meeting of the Board of Examiners of the School of Physics & Astronomy at Cardiff University met this afternoon to consider the marks for students due to graduate this year and to draw up recommendations for the final degree classifications.

This year’s meeting was actually quite interesting and, at just over two hours, somewhat shorter than some we’ve had in previous years.  A group of students has already gathered in the foyer waiting for the dreaded list to be posted, and many will no doubt be celebrating or drowning their sorrows in local hostelries shortly after their fate is revealed.

Cardiff is a little old-fashioned in the way the final examiners’ meetings are conducted. For a start we still have a system of viva voce examinations for borderline candidates; they happened yesterday, in fact. Many universities have dispensed with this aspect of the process, but I still think they’re worthwhile. The Board of Examiners, including the two External Examiners,  also still has some discretion in how it arrives at the degree boundaries (which are nominally at 70% for a first, 60% for a 2.1, 50% for a 2.2, and 40% for a 3rd).

The tide is turning against this very traditional approach, however, and there are moves here to dispense with the viva examinations and with academic discretion. I’m not sure when this will happen, but it’s likely to be sooner rather than later. I think the main reason for this is to make the system more automatic so there’s less chance of legal challenge. In any case there doesn’t seem to me that there can be any educational reason for it.

The one thing that strikes me about the system we have is that it’s the whole business of classifying degrees into broad categories which is where the problem lies.  It was suggested some time ago that we should dispense with, e.g., the “Desmond” (2.2) and the “Thora Hird” (3rd) and instead simply give each student a transcript containing details of the entire spectrum of their academic performance. It’s been suggested again just recently too. That would seem to me to make much more sense than the current system of classifying degrees which involves (a) trying to condense a huge amout of information – examination marks, coursework, project assignments and the like – into a single number and then (b) drawing boundaries based on this number precisely where the distribution is most densely peaked. However, years have passed and nothing concrete has happened. The academic world is good at inertia.

Anyway, this isn’t the time or the place for a lengthy diatribe about the ins-and-outs of degree classifications. I’ve got to go back to marking my 1st year examination papers shortly in fact; these are considered by a separate meeting of the Board of Examiners.

It is time, however, for me to congratulate all our graduating students on their success. It’s the first group of Cardiff MPhys students that I’ve seen all the way through from entry  to graduation. I’ll be sad to see them go, but wish them all the best as they venture forth into the real world. At least I hope to see them back next month for graduation.  Until then, however, all I’ll  say is

Congratulations!

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