Archive for astronomy

Posted in Science Politics with tags , , , on October 26, 2011 by telescoper

No time for a post of my own today – it’s our “Staff Away Day” (which owing to budget cuts is only half a day and is being held in Cardiff, at the Millennium Stadium). Anyway, I was going to pass on the same rumours that Andy Lawrence is writing about, and he knows more about this than I do, so over to him for the ongoing ramifications of JWST…

Baby Planet Pictures…

Posted in Astrohype, The Universe and Stuff with tags , , on October 20, 2011 by telescoper

My eye was caught this morning by this dramatic picture on the front page of the Guardian website, linked to a story about the discovery of a very young planet:

I wonder how many people looking at it thought that it was an actual picture of a planet actually forming? In fact the above graphic is just an “artist’s conception” of the view near the planet, which is called LkCa 15b. The real picture is considerably less dramatic:

What you see is (left) a disk of dust and gas surrounding a star cleverly made visible by masking out the light from the star, which is much brighter than the disk.  On the right you can see a blow up of the inner region of the system, which appears to show a Jupiter-like planet associated with an irregular blob of material, out of which it probably condensed and from which it may still be accreting.

The size of the picture on the right is worth noting. The angle indicated is 76 milli-arcseconds. This is the angle subtended by  the  width of a  human hair at distance of about 130 metres…

The Astronomy Career Problem – it starts with the PhD

Posted in Science Politics with tags , , , , , on October 14, 2011 by telescoper

Just time for a quickie today, as I’ve got to run an examples class before dashing off on the train to London to attend the annual George Darwin Lecture which, this year, is to be given by Michael Turner with the title From Quarks to the Cosmos. I expect it to be very enjoyable and may well write a report at the weekend.

Yesterday evening there was a discussion on twitter (#astrojc) about the astronomy careers problem. I didn’t take part – in fact I didn’t realise it was happening – as I was slaving over the Private Eye crossword at the time.

Anyway, it gives me the excuse to rehash an argument I have presented before, which is that most analyses of the problems facing young postdoctoral researchers in astronomy are looking at the issue from the wrong end. I think the crisis is essentially caused by the overproduction of PhDs in this field. To understand the magnitude of the problem, consider the following.

Assume that the number of permanent academic positions in a given field (e.g. astronomy) remains constant over time. If that is the case, each retirement (or other form of departure) from a permanent position will be replaced by one, presumably junior, scientist.

This means that over an academic career, on average, each academic will produce just one PhD who will get a permanent job in academia. This of course doesn’t count students coming in from abroad, or those getting faculty positions abroad, but in the case of the UK these are probably relatively small corrections.

Under the present supply of PhD studentships an academic can expect to get a PhD student at least once every three years or so. At a minimum, therefore, over a 30 year career one can expect to have ten PhD students. A great many supervisors have more PhD students than this, but this just makes the odds worse. The expectation is that only one of these will get a permanent job in the UK. The others (nine out of ten, according to my conservative estimate) above must either leave the field or the country to find permanent employment.

The arithmetic of this situation is a simple fact of life, but I’m not sure how many prospective PhD students are aware of it. There is still a reasonable chance of getting a first postdoctoral position, but thereafter the odds are stacked against them.

The upshot of this is we have a field of understandably disgruntled young people with PhDs but no realistic prospect of ever earning a settled living working in the field they have prepared for. This problem has worsened considerably in recent  years as the number of postdoctoral positions has almost halved since 2006. New PhDs have to battle it out with existing postdoctoral researchers for the meagre supply of suitable jobs. It’s a terrible situation.

Now the powers that be – in this case the Science and Technology Facilities Council – have consistently argued that the excess PhDs go out into the wider world and contribute to the economy with the skills they have learned. That may be true in a few cases. However, my argument is that the PhD is not the right way to do this because it is ridiculously inefficient.

What we should have is a system wherein we produce more and better trained Masters level students  and fewer PhDs. This is the system that exists throughout most of Europe, in fact, and the UK is actually committed to adopt it through the Bologna process.  Not that this commitment seems to mean anything, as precisely nothing has been done to harmonize UK higher education with the 3+2+3 Bachelors+Masters+Doctorate system Bologna advocates.

The training provided in a proper two-year Masters programme will improve the skills pool for the world outside academia, and also better prepare the minority of students who go on to take a PhD. The quality of the  PhD will also improve, as only the very best and most highly motivated researchers will take that path. This used to be what happened, of course, but I don’t think it is any longer the case.

The main problem with this suggestion is that it requires big changes to the way both research and teaching are funded. The research councils turned away from funding Masters training many years ago, so I doubt if they can be persuaded to to a U-turn now.

This won’t solve the existing careers crisis, of course, but in order to make things better you first have to stop them getting worse.

Wave your hands and think of Astronomy….

Posted in The Universe and Stuff with tags on October 12, 2011 by telescoper

Here’s a short video presentation in which it is demonstrated that astronomers like to move their hands while talking. It’s frightfully amusing, but I can’t help thinking it would have been even better if the musical accompaniment had been, well, musical. Anyway, keep watching until 2:17 or thereabouts and you’ll see that I have a small part.

Telescoping

Posted in The Universe and Stuff with tags , , , , , on October 2, 2011 by telescoper

I stumbled upon the following cartoon on Youtube and, since it’s about a mad astronomer, I thought I’d post it here.

It strikes me how  comic depictions of astronomical observatories, such as the example on the left,  always seem to show the telescope pointing out of the dome like the barrel of a gun poking out of a turret, which they never do. I venture to suggest that a great many members of the general public think that’s how they work also. I wonder why?

Perhaps it’s connected with the origins of the verb form of telescope which the OED gives as

a. trans. To force or drive one into another (or into something else) after the manner of the sliding tubes of a hand-telescope: usually said in reference to railway carriages in a collision. Also fig. to combine, compress, or condense (a number of things) into a more compact or concise form; to combine or conflate (several things, or one thing with another); to shorten by compression.

b. intr. To slide, run, or be driven one into another (or into something else); to have its parts made to slide in this manner (see quot. 1882 for telescoping n. and adj. at Derivatives, s.v. telescoping below); to collapse so that its parts fall into one another (quot. 1905).

The inference being that large astronomical telescopes must extend in the same way as the much smaller hand-held variety. Anyway, this idea is taken to a ludicrious extreme in the cartoon, with hilarious consequences…

 

Back to the Drawing Board

Posted in Art, Education, The Universe and Stuff with tags , , , , , , , , , on August 30, 2011 by telescoper

I came across a press release this morning which contains the following

More should be done to encourage students to use their drawing skills in science education, researchers at The University of Nottingham say.

In a paper being published in Science this week, academics say that although producing visualisations is key to scientific thinking, pupils are often not encouraged to create their own drawings to develop and demonstrate their understanding.

In the paper the authors, led by Dr Shaaron Ainsworth in the University’s School of Psychology and Learning Sciences Research Institute, said: “Scientists do not use words only but rely on diagrams, graphs, videos, photographs and other images to make discoveries, explain findings, and excite public interest.

In the light of this I thought it would be topical to post an updated version of an old piece I wrote on the theme of sketching. This is quite a strange subject for me to have picked pick because drawing is something I’m completely useless at, but I hope you’ll bear with me and hopefully it will make some sense in the end. I always thought that drawing was an important and neglected aspect of education, but I hadn’t until today any solid research to back it up!

-0-

What  spurred me on to think about this subject was the exhibit I was  involved with for the  Architecture Biennale in Venice as part of a project called Beyond Entropy organized by the Architectural Association School of Architecture. In the course of researching this project I came across this image of the Moon as drawn by Galileo

This led to an interesting discussion about the role of drawings like this in science. Of course  the use of sketches for the scientific representation of images has been superseded by photographic techniques, initially using film and more recently by digital techniques. The advantage of these methods is that they are quicker and also more “objective”. However, there are still many amateur astronomers who make drawings of the Moon as well as objects such as Jupiter and Saturn (which Galileo also drew). Moreover there are other fields in which experienced practioners continue to use pencil drawings in preference to photographic techniques. Archaeology provides many good examples, e.g.

The reason sketching still has a role in such fields is not that it can compete with photography for accuracy or objectivity but that there’s something about the process of sketching that engages the sketcher’s brain in a  way that’s very different from taking a photograph. The connection between eye, brain and hand seems to involve a cognitive element that is extremely useful in interpreting notes at a later date. In fact it’s probably their very subjectivity that makes them useful.  A thicker stroke of the pencil, or deliberately enhanced shading, or leaving out seemingly irrelevant detail, can help pick out  features that seem to the observer to be of particular significance. Months later when you’re trying to write up what you saw from your notes, those deliberate interventions against objectivity will take you back to what you  saw with your mind, not just with your eyes.

It doesn’t even matter whether or not you can draw well. The point isn’t so much to explain to other people what you’ve seen, but to record your own interaction with the object you’ve sketched in a way that allows you to preserve something more than a surface recollection.

You might think this is an unscientific thing to do, but I don’t think it is. The scientific process involves an interplay between objective reality and theoretical interpretation and drawing can be a useful part of this discourse. It’s as if the pencil allows the observer to interact with what is observed, forming a closer bond and probably a deeper level of understanding patterns and textures. I’m not saying it replaces a purely passive recording method like photography, but it can definitely help it.

I have not a shred of psychological evidence to back this up, but I’d also assert that sketching is very good for the learning process too.  Nowadays we tend to give out handouts of diagrams involved in physics, whether they relate to the design of apparatus or the geometrical configuration of a physical system. There’s a reason for doing this – they take a long time to draw and there’s a likelihood students will make mistakes copying them down. However, I’ve always  found that the only way to really take in what a diagram is saying is to try to draw it again myself. Even if the level of draftsmanship is worse, the level of understanding is undoubtedly better.Merely looking at someone else’s representation of something won’t give your brain as a good a feeling for what it is trying to say  as you would get if you tried to draw it yourself.

Perhaps what happens is that simply looking at a diagram only involves the connection between eye and brain. Drawing a copy requires also the connection between brain and hand. Maybe  this additional connection brings in additional levels of brain functionality. Sketching iinvolves your brain in an interaction that is different from merely looking.

The problem with excessive use of handouts – and this applies not only to figures  but also to lecture notes – is that they turn teaching into a very passive process. Taking notes in your own hand, and supplementing them with your own sketches – however scribbly and incomprehensible they may appear to other people – is  a much more active way to learn than collecting a stack of printed notes and meticulously accurate diagrams. And if it was good enough for Galileo, it should good enough for most of us!

It’s not a planet. It’s a white dwarf. (via Matt Burleigh’s Blog)

Posted in Astrohype, The Universe and Stuff with tags , , , , on August 27, 2011 by telescoper

When is a planet made of diamond not a planet made of diamond?

Perhaps when it’s a White Dwarf?

Perhaps when there’s not a shred of evidence that it’s actually made of diamond?

Yesterday Science announced the amazing discovery of an incredibly dense object that appears to be made of a crystalline form of carbon: possibly, ultra-dense diamond (Bailes et al. 2011, Science, DOI: 10.1126/science.1208890). The object orbits a recently-discovered pulsar, PSR J1719-1438, every two hours and ten minutes. It has a slightly higher mass than Jupiter (technically, its minimum mass), but the lack of evidence for direct interaction w … Read More

via Matt Burleigh’s Blog

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.

Best Evidence Yet for Flowing Water on Mars (via Well-Bred Insolence)

Posted in Astrohype, The Universe and Stuff with tags , , , on August 5, 2011 by telescoper

A nice blog on the evidence (such as it is) for water on Mars, which is good because it means I don’t have to try writing about it!

I’m not sure it is water. That dark colour suggests to me it might be Guinness…

Best Evidence Yet for Flowing Water on Mars NASA's Mars Reconnaissance Orbiter has discovered what amounts to the best evidence yet for liquid water on Mars.  Let's be clear though, it's not exactly a flowing spring, and you're unlikely to be drinking this stuff fresh out of the ground, but the odds are now much better for extremophilic bacteria surviving on the Red Planet. The results were reported in Science today (I was able to access through University subscriptions, but I am afraid th … Read More

via Well-Bred Insolence

The Curious Case of the Twisted Ring

Posted in The Universe and Stuff with tags , , , , , , , on July 21, 2011 by telescoper

Just time for a quickie this morning, prompted by the appearance of our own Professor Matt Griffin on the Today programme on BBC Radio 4 earlier on talking about newly published results from the Herschel Space Observatory. I didn’t hear it live as I’m strictly a Radio 3 person, but it must have made a pleasant change from stories about the imminent collapse of the euro and continuing extraordinay revelations about widespread corruption involving the British media, police force and political establishment. Among all this doom and gloom it’s nice to hear news of something that’s actually successful.

Anyway, the news from Herschel is that it has unveiled a ring structure in the centre of our Milky Way galaxy. The ribbon of gas and dust is more than 600 light years across and appears to be twisted, for reasons which have yet to be explained. The origin of the ring could yield important clues about the history of the Milky Way.

Warmer gas and dust from the Centre of our Galaxy is shown in blue in the  image below, while the colder material appears red. The ring, in yellow, is made of gas and dust at a temperature of just 15 degrees above absolute zero. The bright regions are denser, and include some of the most massive and active sites of star formation in our Galaxy.

and here it is with the curious ring drawn on with crayons:

The central region of our Galaxy is dominated by an elongated structure, rather like a bar, which stirs up the material in the outer galaxy as it rotates over millions of years and is probably connected with the spiral structure seen in the disk of the Milky Way. The ring seen by Herschel lies right in the middle of this bar, encircling the region which harbours a super-massive black hole at the centre of our galaxy. The ring of gas is twisted, so we see two loops which appear to meet in the middle. These are seen in yellow in the image above, tilted slightly such that they run from top-left to bottom-right. Secondly, it seems to be slightly offset from the very centre of our Galaxy. The reason for the ring’s twist and offset are unknown, but understanding their origin may help explain the origin of the ring itself. Computer simulations indicate that bars and rings such as those we see in the centre of our Galaxy can be formed by gravitational interactions, either within the Milky Way itself or between it and the nearby Andromeda galaxy, M31.

For the experts, and others interested, the scientific paper containing these results can be found here.