March Weather in Sussex…

Posted in Uncategorized with tags , , , on March 14, 2013 by telescoper

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The Heat Death of Herschel

Posted in The Universe and Stuff with tags , , , , on March 13, 2013 by telescoper

Most of the astronomers who read this blog will have heard the news that the Herschel Space Observatory is running out of the Helium that it has been using to keep it cool enough (~1.4K) to be sensitive to the far-infra-red radiation emitted by very distant objects.

There’s a gallery of wonderful images obtained by Herschel since it was launched in 2009 at the news item linked to above, but my favourite is one of the least photogenic:

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Many of these fuzzy blobs correspond to immensely distant galaxies; what we see is starlight from very young stars absorbed by vast amounts of cosmic dust and then re-radiated in the infra-red. Understanding these sources is decidedly non-trivial and it will take many years to get all the information out that is hidden in images like this.

Anyway, one thing worth pointing out here is that what is going on now with Herschel is not some kind of failure. Quite the contrary, in fact. The original mission lifetime was planned to be three years, and Herschel has now been operating for nine months longer than that. The supply of Helium was always going to be the limiting factor as the spacecraft operates at the second Lagrange point of the Earth-Sun system, which is almost a million miles away and thus too far to be replenished. When the Helium does run out, Herschel will rapidly heat up to the point where its detectors are swamped. It will then be blind.

I was at this point going to make a cheap joke to the effect that after years on its own in the dark preoccupied with images of heavenly bodies, it was entirely predictable that Herschel would go blind. But I decided not to. I’ll save that kind of off-colour remark for Twitter…

ps. Coincidentally, on this day (March 13th) in 1781,  William Herschel  discovered the planet Uranus. The telescope is named in Herschel’s honour because he was also the first person to demonstrate the existence of infra-red radiation.

Snow, by Louis MacNeice

Posted in Poetry with tags , on March 13, 2013 by telescoper

I’ve posted this before, but it seems appropriate to post it again today…

The room was suddenly rich and the great bay-window was
Spawning snow and pink roses against it
Soundlessly collateral and incompatible:
World is suddener than we fancy it.

World is crazier and more of it than we think,
Incorrigibly plural. I peel and portion
A tangerine and spit the pips and feel
The drunkenness of things being various.

And the fire flames with a bubbling sound for world
Is more spiteful and gay than one supposes–
On the tongue on the eyes on the ears in the palms of your hands–
There is more than glass between the snow and the huge roses.

by Louis MacNeice (1907-1963).

Snowbound in Brighton

Posted in Biographical with tags , , on March 12, 2013 by telescoper

The last twenty-four hours in Brighton have been very strange. It started snowing yesterday morning. Not snowing very much, actually, but it was also very cold so not a very pleasant way to start the week. Nevertheless I had a trouble-free bus trip to the University of Sussex campus and got on with my business. It carried on snowing a bit, but not much. This is what it looked like outside my office at about 11.30.

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It kept on snowing a bit, but not much, all afternoon. By five o’clock I noticed that the Twitter feed for the Brighton & Hove Bus and Coach Company was announcing that some bus services were suspended. Then all of its bendy buses were withdrawn from service. Since most of the buses I get to and from campus are of the bendy variety I decided to head home. It was snowing a little heavier by then, and it took a long time to get home owing to heavy traffic, but I made it to my flat by about 6.30pm. Checking Twitter again I saw that all bus servives had been cancelled. The accumulated amount of snow in central Brighton was no more than a centimetre.

Buses remained suspended this morning. Owing to the transport difficulties facing its staff and students the University of Sussex decided to cancel teaching for the day and operate at a minimal level of service. I settled down to work a bit at home, with a view to travelling to campus as soon as the buses were running again. In fact the roads appeared very clear when I decided to make the most of my morning off, by doing some shopping and getting a haircut, but the bus service to Falmer was not reinstated until about two hours after I took this picture…

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When I did eventually get on a Number 25 bus, the roads were completely clear of snow. Not surprisingly, actually, because although it snowed for quite a long time it was really rather light.

What is staggering is that less than half an inch of snow could paralyse the transport system of entire Town the size of Brighton, especially when it was forecast days in advance. There may have been heavier snowfall elsewhere in the area of course. The town is also rather hilly which, in icy conditions could cause problems for buses. But Brighton & Hove Council’s preparations for this cold snap seem to have been woefully ineffective. It’s sobering to experience how vulnerable this town is to even slightly bad weather.

Anyway, I’m now on campus. It’s not snowing. The sun’s shining, in fact. All the roads are clear. But there are few students about because there’s no teaching going on. Time to get some work done…

..and then try to get home!

Oh what a tangled web we weave…

Posted in Bad Statistics with tags , , , , , , on March 11, 2013 by telescoper

..when first we practice frequentist statistics!

I couldn’t resist a quick post directing you to a short paper on the arXiv with the following abstract:

I use archival data to measure the mass of the central black hole in NGC 4526, M = (4.70 +- 0.14) X 10^8 Msun. This 3% error bar is the most precise for an extra-galactic black hole and is close to the precision obtained for Sgr A* in the Milky Way. The factor 7 improvement over the previous measurement is entirely due to correction of a mathematical error, an error that I suggest may be common among astronomers.

The “mathematical error” quoted in the abstract involves using chi-squared-per-degree-of-freedom instead of chi-squared instead of the full likelihood function instead of the proper, Bayesian, posterior probability. The best way to avoid such confusion is to do things properly in the first place. That way you can also fold in errors on the distance to the black hole, etc etc…

Always seeking greater silence

Posted in Poetry with tags , , , on March 11, 2013 by telescoper

Just a quick plug for a fascinating programme I heard on BBC Radio 3 last night about the great Welsh poet R.S. Thomas. It’s called Always Seeking Greater Silence and it is available on iPlayer for your listening pleasure.

Here’s an excerpt from the published description of the programme:

RS Thomas was a man full of contradictions, but one constant was his passion for birdwatching. Towards the end of his life he said that ‘the deity has chosen to reveal himself to me via the world of nature’. He also declared that he preferred to be alone with nature than be with human beings. Bird imagery in particular provided him with a means of symbolising renewal, nourishment and femininity in his poetry, but also of exploring his faith in God. Increasingly towards the end of his life, his bird poems explored the space between faith and doubt. In ‘Sea-watching,’ he directly associates bird-watching with prayer: ‘Ah, but a rare bird is/ rare. It is when one is not looking/ at times one is not there/ that it comes’.

I have the utmost admiration for R.S. Thomas as a poet, but I do wonder how effective he was as a priest looking after his flock when he could come out with statements like the following:

I’ve had more pleasure from being alone with the natural creation than I have with human beings. Human beings are responsible for so much unhappiness and cruelty and failure that one is not terribly enthusiastic about them.

This rather bleak view of humanity explains to some extent why so many of his poems are about the natural world rather than people, but he is unlike many other “nature poets” in that his voice is unflinching and devoid of sentimentality. Although not religious myself, I also deeply respect his openness about his struggle with faith and doubt – he seems to me to have been a man who was deeply allergic to superficiality, a trait which also manifests itself in his verse.

It is the centenary of the birth of R.S. Thomas on 29th March 2013. I hope I remember to mark the occasion with an appropriate poem.

Your PhD Questions Answered (?)

Posted in Education, The Universe and Stuff with tags , , , , , , on March 10, 2013 by telescoper

As I mentioned last week, one of the main items on the agenda at the moment is recruitment of new PhD students. As usual, this finds me having to operate on both sides of the fence,  playing a role in selecting students whilst also trying to advise students on how to target their applications, prepare for interview, and choose between offers (for those who manage to get a place).

In my field (astrophysics), the primary route for funding a PhD comes through the Science and Technology Facilities Council (STFC) which operates a national deadline (31st March) before which candidates can not be required to make a decision. This deadline sets the timescale for departments to decide too, as we clearly want to make sure all our first choice applicants get their offers before the cutoff date.

The national deadline prevents students from being pressured into making decisions before they have heard back from all the institutions to which they have applied, so in that sense it’s a good idea. On the other hand, it does mean that there’s often frantic activity on deadline day as offers are accepted or declined. Reserves have to be contacted quickly when a favoured candidate withdraws to go somewhere else and not all of them may still be available. A student who has been waiting anxiously without a first-choice offer may suddenly receive a lifeline on deadline day.

Getting offers is one thing, but deciding between them is quite another. There are many things to take into account, and the criteria are by no means clear. I’m not the only person to have been thinking about this. There are personal matters, of course. Is it a nice place? Are the people friendly? Do you think you can get on with your potential supervisor? That sort of thing. But there’s also the actual research. Is the project really what you want to do? Is is likely to open up a future career in research, or just be a dead end? Is the mixture of theory and experiment (or observation) what you would like?

One of the issues that often arises when I discuss research with potential PhD students is how structured the project  is. Some projects are  mapped out by the supervisor in great detail, with specific things to be done in a specific order with well-defined milestones against which progress can be measured. Others, especially but not exclusively theoretical ones, are much more of the nature of “here’s an interesting idea – let’s study it and see where it leads”. Most PhDs are somewhere between these two extremes, but it’s probably true that experimental PhDs are more like the former, whereas theoretical ones are more like the latter. Mine, in theoretical astrophysics, ended up evolving quite considerably from its starting point.

I’ve always been grateful to my supervisor for allowing me the freedom to follow my own curiosity. But I think it was essential to be given an initial focus, in the form of a specific project to cut my teeth on. Getting a calculation finished, written up and published gave me the confidence to start out on my own, but I did need a lot of guidance during that initial phase. We a;ll need to learn how to walk before we can run.

Another aspect of this is what the final thesis should look like. Should it be a monolithic work, focussed on one very specific topic, or can it be an anthology of contributions across a wider area?  Again, it’s a question of balance. I think that a PhD thesis should be seen as a kind of brochure advertising the skills and knowledge of the student that produced it. Versatility is a good quality, so if you can do lots of different things then your thesis should represent that. On the other hand, you also need to demonstrate the ability to carry out a sustained and coherent piece of research. Someone who flits around knocking out lots of cutesy “ideas papers” may get a reputation for being a bit of a dabbler who is unable or unwilling to tackle problems in depth. The opposite extreme would be a person who is incapable of generating new ideas, but excellent once pointed in a specific direction. The best scientists, in my opinion, have creative imagination as well as technical skill and stamina.  It’s a matter of balance, and some scientists are more balanced than others. There are some (scary) individuals who are brilliant at everything, of course., but us mere mortals have to make the most of our limited potential.

The postdoc market that lies beyond your PhD is extremely tough. To survive you need to maximize the chances of getting a job, and that means being able to demonstrate a suitability for as many opportunities as possible that come up. So if you want to do theory, make sure that you know at least something about observations and data analysis. Even if you prefer analytic work, don’t be too proud to use a computer occasionally. Research problems often require  you to learn new things before you can tackle them. Get into the habit of doing that while you’re a student, and you’re set to continue for the rest of your career. But you have to do all this without spreading yourself too thin, so don’t shy away from the chunky calculations that keep you at your desk for days on end. It’s the hard yards that win you the match.

When it comes to choosing supervisors, my advice would be to look for one who has a reputation for supporting their students, but avoid those who want to exert excessive control. I think it’s a supervisor’s duty to ensure that PhD student becomes as independent as possible as quickly as possible, but to be there with help and advice if things go wrong. Sadly there are some who treat PhD students simply as assistants, and give little thought to their career development.

But if all this sounds a bit scary, I’ll add just one thing. A PhD offers a unique challenge. It’s hard work, but stimulating and highly rewarding. If you find a project that appeals to you, go for it. You won’t regret it.

The UK’s first female professor

Posted in History, Uncategorized on March 9, 2013 by telescoper

admin's avatarWe Are Cardiff

Hello friends. Happy International Womens Day! To celebrate, our friend Kelly Page has written us a We Are Cardiff about the first female professor to be appointed to the (at the time) Cardiff University. Go! Go!

First Female Professor Appointed in the Largest Coal Port in the World

Imagine it is 1904.

You are living and working in Cardiff, the largest coal port in the world.
You are a woman, 40 years young, working as the head of women’s teacher training in the town’s new university.

The university, University College of South Wales and Monmouthshire (now Cardiff University) is only 20 years old. It was founded with 13 staff and 151 students, 15 of who were women (1883).

You are working at one of the first universities in Britain to open its doors to female students and with a residence specifically for women, Aberdare Hall (1885). A hall that is…

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London to Brighton in 4 Minutes

Posted in Television with tags , , on March 7, 2013 by telescoper

Since I’m going to be away from base for a while I thought I’d post this classic film to cover the interruption to normal blogging service. Here’s a description from the Youtube entry.

London to Brighton in Four Minutes, made by the BBC Film Unit in 1952, was a favourite of many viewers during the 1950s. In those days one never knew when it would be screened, but it often popped up when there was an unscheduled gap between programmes. Apparently the journey on the Brighton Belle was filmed at 2 frames per second, thus at the normal projection speed of 24fps a speed of 60 mph becomes 720 mph. The cameraman was sitting in the cab with the train driver and hand cranking the film camera. Each reel of film was only 1000ft and so the camerman had to change the film during the journey. When editing the film these “gaps” were filled with a shot of the train driver.

This film footage is from the Archive Collection held by the Alexandra Palace Television Society.

Modern trains still follow the same route, but there are many new developments either side of the line, including Gatwick Airport…

Updated Guidelines for Open Access from RCUK

Posted in Open Access with tags , on March 6, 2013 by telescoper

I’m about to head off on a short trip, so only have time for the briefest of brief blog posts today. However, at least I have a timely topic. In yesterday’s post about the RCUK Open Access Policy, I mentioned that they were revising their guidelines. Well, today the new guidelines have been published. That qualifies as timely in my book!

You can find the new policy here (PDF file).

I haven’t had time to read them carefully yet, so please feel free to do so on my behalf. Then someone can tell me through the comments box if the suggestion I made yesterday – to donate all the RCUK open access funding to the arXiv instead of handing it out to profiteering publishers – would be allowed under the new guidelines…