Archive for astronomy

The Necessity of Atheism

Posted in History, Literature, The Universe and Stuff with tags , , , , , , , , on February 15, 2011 by telescoper

In the course of doing a crossword at the weekend, I learnt that the poet Percy Bysse Shelley was sent down from (i.e. kicked out of) Oxford University 200 years ago this month for writing a pamphlet entitled The Necessity of Atheism. He was at University College, in fact. A bit of googling around led me to the full text, which is well worth reading whatever your religious beliefs as it is a fascinating document. I’ll just quote a few excerpts here.

The main body of the tract begins There is No God, but this is followed by

This negation must be understood solely to affect a creative Deity. The hypothesis of a pervading Spirit co-eternal with the universe remains unshaken.

That’s pretty close to my own view, for what that’s worth.

More interestingly, Shelley goes on later in the work to talk about science and how it impacts upon belief. A couple of sections struck me particularly strongly, given my own scientific interests.

In one he tackles arguments for the existence of God based on Reason:

It is urged that man knows that whatever is must either have had a beginning, or have existed from all eternity, he also knows that whatever is not eternal must have had a cause. When this reasoning is applied to the universe, it is necessary to prove that it was created: until that is clearly demonstrated we may reasonably suppose that it has endured from all eternity. We must prove design before we can infer a designer. The only idea which we can form of causation is derivable from the constant conjunction of objects, and the consequent inference of one from the other. In a base where two propositions are diametrically opposite, the mind believes that which is least incomprehensible; — it is easier to suppose that the universe has existed from all eternity than to conceive a being beyond its limits capable of creating it: if the mind sinks beneath the weight of one, is it an alleviation to increase the intolerability of the burthen?

The other argument, which is founded on a Man’s knowledge of his own existence, stands thus. A man knows not only that he now is, but that once he was not; consequently there must have been a cause. But our idea of causation is alone derivable from the constant conjunction of objects and the consequent Inference of one from the other; and, reasoning experimentally, we can only infer from effects caused adequate to those effects. But there certainly is a generative power which is effected by certain instruments: we cannot prove that it is inherent in these instruments” nor is the contrary hypothesis capable of demonstration: we admit that the generative power is incomprehensible; but to suppose that the same effect is produced by an eternal, omniscient, omnipotent being leaves the cause in the same obscurity, but renders it more incomprehensible.

He thus reveals himself as an empiricist, a position he later amplifies with a curiously worded double-negative:

I confess that I am one of those who am unable to refuse my assent to the conclusion of those philosophers who assert that nothing exists but as it is perceived.

This is a philosophy I can’t agree with, but his use of words clearly suggests the young Shelley has been reading David Hume‘s analysis of causation.

Later he turns to the mystery of life and the sense of wonder it inspires.

Life and the world, or whatever we call that which we are and feel, is an astonishing thing. The mist of familiarity obscures from us the wonder of our being. We are struck with admiration at some of its transient modifications, but it is itself the great miracle. What are changes of empires, the wreck of dynasties, with the opinions which support them; what is the birth and the extinction of religious and of political systems, to life? What are the revolutions of the globe which we inhabit, and the operations of the elements of which it is composed, compared with life? What is the universe of stars, and suns, of which this inhabited earth is one, and their motions, and their destiny, compared with life? Life, the great miracle, we admire not because it is so miraculous. It is well that we are thus shielded by the familiarity of what is at once so certain and so unfathomable, from an astonishment which would otherwise absorb and overawe the functions of that which is its object.

Finally, I picked the following paragraph for its mention of astronomy:

If any artist, I do not say had executed, but had merely conceived in his mind the system of the sun, and the stars, and planets, they not existing, and had painted to us in words, or upon canvas, the spectacle now afforded by the nightly cope of heaven, and illustrated it by the wisdom of astronomy, great would be our admiration. Or had he imagined the scenery of this earth, the mountains, the seas, and the rivers; the grass, and the flowers, and the variety of the forms and masses of the leaves of the woods, and the colors which attend the setting and the rising sun, and the hues of the atmosphere, turbid or serene, these things not before existing, truly we should have been astonished, and it would not have been a vain boast to have said of such a man, Non merita nome di creatore, se non Iddio ed il Poeta. But how these things are looked on with little wonder, and to be conscious of them with intense delight is esteemed to be the distinguishing mark of a refined and extraordinary person. The multitude of men care not for them.

I think the multitude care just as little 200 years on.

P.S. The quotation is from the 16th Century Italian poet Torquato Tasso; in translation it reads “None deserve the name of Creator except God and the Poet”.


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We have all the Time in the World

Posted in Music, The Universe and Stuff with tags , , on February 14, 2011 by telescoper

I came across this on Youtube a while ago, but I’ve been saving it up because I thought it might make a nice St Valentine’s Day gift for all lovers of astronomy (and/or someone special). Enjoy!


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Our Place in the Universe

Posted in Television, The Universe and Stuff with tags , , , on February 9, 2011 by telescoper

I suspect I’m not the only person working in astronomy who found inspiration in Carl Sagan‘s epic TV series Cosmos, which was broadcast on British television when I was at Secondary School. Although the graphics are a bit dated now, and the language perhaps a bit florid for modern tastes, it has lost nothing of its splendour or profundity which is largely due to the charisma (and beautiful writing) of the presenter. It’s also in stark contrast to the simple-minded stuff served up by modern so-called science programmes. Here’s a little taster, which brought back happy memories to me, and I hope will do the same for fellow astronomers-of-a-certain-age.

We live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a Universe in which there are far more galaxies than people. We make our World significant by the courage of our questions, and by the depth of our answers.


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Decline and Fall

Posted in Education, Science Politics with tags , , , , , , , , on February 7, 2011 by telescoper

There’s an interesting discussion going on over at the e-Astronomer Andy Lawrence’s blog about truth, lies and astronomy grant funding.

The centrepiece of Andy’s post is the following graph, which is based on the most accurate available figures, showing how the number of postdoctoral research associate (postdoc) positions funded (first by SERC, then by PPARC, and then by STFC) in Astronomy has evolved over the last couple of decades, along with the number of permanent academic staff employed in UK universities.

To be precise it shows the number of new postdoc posts funded each year; since a postdoc position typically lasts 3 years, the total number of postdocs at ay time is roughly 3 times the number shown.

A few things are immediately clear. One is that both the number of academics and the number of postdocs grew steadily over the period covered by the graph, until 2006 after which there was a steep decline in the number of postdocs to a level substantially lower than the number funded in 2000. It’s not a coincidence that STFC was created in 2007.

The numerical growth of the UK astronomical community coincided with a  general expansion of the number of academics in the University resulting from the growth of funded student  numbers, but it also was also accompanied by improved access to large facilities. It also happened to be a time of high achievement by British astronomers, who played major roles in large projects that uncovered many deep secrets of the Universe, such as the existence of cosmological dark matter and dark energy.

Further details of the achievements of UK Astronomy over the last decade are given by our own Bill Frindall, Paul Crowther (see his page for references):

Astrophysics: UK space science (astrophysics) is ranked 2nd in citations (1999-2009), while UK physics ranks 5th internationally (1997-2007). According to Section 3 of the RCUK Review of Physics, combining these two categories places the UK 2nd to the USA overall – see bibliometric analysis. According to the IoP Survey of Academic Appointments in Physics, the UK astronomy academic community grew by 14 per cent in the 5 years leading up to 2008, compared with 12% for physics overall. From 2003/04 to 2007/08 physics departments expanded by 14%, equal to the wider UK average for all disciplines (see Sustainability of the UK research workforce report from RCUK. Undergraduate applications (admissions) to physics grew by 19% (11%) between 2002-2007 according to the DIUS Research Report 08-21. Astrophysics formed one of the case studies for a CSHE (UC Berkeley) science communication report from Jan 2010.

All this expansion didn’t come cheap, of course, but in my view  it was entirely justified on the grounds of scientific excellence. That used to count for something among the science policy makers, but those times seem to have gone. Not that the collateral benefits were negligible, as you can see from the above.

I’ll grant that it is not easy to establish what fraction of STFC’s budget should be spent on its “core” science and how much on managing facilities, but I think the balance has obviously gone way too far in one direction. I’m not the only one to think so. The probably deliberate decision to clobber astronomy grants flies in the face of the Institute of Physics Review of International Perceptions of UK Physics, carried out in 2005, which says

In summary, the state of astrophysics and solar system physics is relatively healthy at this time. Morale is good in the research community, particularly among the young, and wise investments seem to have been made since the 2000 review. Attention will need to be paid over the next five years to foster the astronomical observing community so as to recoup the investment in large telescope access.

STFC has done many things since its creation in 2007, but fostering the astronomical observing community is definitely not amongst them. Instead it has slashed the postdocs needed to collect, reduce and analyse the data coming from the facilities we paid so much to access.

I still don’t know what UK astronomy did to deserve the kick in the teeth it received in 2006 which precipitated the steep decline shown in the graph. Remember that this was before the credit crunch, which really took hold in 2008, so the cuts imposed STFC were clearly not in response to that. The message consistently being put out by the STFC Executive at the time was that it was spending “too much on science exploitation”, i.e. on doing science, and that a larger slice of the cake needed to be devoted to facilities and operations.

I suspect that the backlash against astronomy was led by senior figures in the Treasury who did not, still do not, and probably never will, see science as worth doing for its own sake rather than as a way of subsidising industry. I suspect also some senior figures in  UK Physics were not sorry to see the astronomical arrivistes get their comeuppance. I have encountered a number of distinguished physicists – usually of the condensed matter persuasion – who clearly resented the new wave of astronomers arriving in their departments. As long as they bring in more students, take on heavy teaching loads and don’t ask for expensive equipment then astronomers are fine, but what they do isn’t really proper physics is it?

But precisely who it was that was behind the strange demise of British astronomy is now not the main issue. The real question is what can be done about it starting from where we are now.

As things stand under the current STFC leadership, the grant line will stay roughly level in cash terms for the next three years. Adding in the effect of inflation that means the number of postdoc grants will slowly dwindle. Better than the last few years, but hardly grounds for celebration. The steady attrition of grant funding will eventually push many excellent university research groups over the edge and prematurely terminate many promising scientific careers.

STFC will be looking for a new Chief Executive very soon, and that raises at  the admittedly faint hope that some things might change for the better. What we need is a someone  who is prepared to champion fundamental research because he or she actually believes in it;  the  bedgrudging attempts of the current Chief Executive simply don’t convince in this regard.

Whether we get someone who fits the bill remains to be seen. If we don’t the future for UK astronomy looks very bleak.


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Astronomy Grant History (via The e-Astronomer)

Posted in Finance, Science Politics with tags , , , on February 4, 2011 by telescoper

Interesting view of astronomy grant funding versus time from AGP Chair Andy Lawrence.

Before commenting, I’m first going to calculate the Fourier Transform of Andy’s graph and analyse it in reciprocal space.

Astronomy Grant History Time for me to break a rule. As many of you will know, I am currently chairperson of STFC’s Astronomy Grants Panel. I have steered clear of discussing AGP business on this blog, for obvious reasons. However, the current round is now complete, so I can relax that rule somewhat. I wrote a chairman’s report which went out yesterday on the astrocommunity email list. Paul Crowther has put it on his website, so you can read it if you haven’t already. T … Read More

via The e-Astronomer


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Astronomy Grants: Past, Present, and Future

Posted in Finance, Science Politics with tags , , , , on February 3, 2011 by telescoper

Just time to put my community service hat briefly in order draw the attention of all friendly astronomers to the report on the 2010 STFC Astronomy grant round that has been circulated by the AGP Chair, Andy Lawrence (aka the e-Astronomer).

There is a lot of important information in this report, not only about the statistics of the last round but also about the new grants system that will be in operation from this year onwards so you really should read it carefully, especially if you’re planning to submit a grant application in 2011.

The report has been circulated to the astrocommunity mailing list, so most of you out there will have seen it but for those of you who haven’t you can find it on Paul Crowther’s website here.

I haven’t got time today to add detailed comments of my own – it’s a UCAS day in Cardiff today (among other things) – but I may do so in future. However, please feel free to comment/react/moan but please remember not to shoot the messenger!


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Scale

Posted in The Universe and Stuff with tags , , , , , on January 31, 2011 by telescoper

A number of people drew my attention to this today. It’s definitely worth passing on to those of you who haven’t seen it already. Have a look at this  blog post too!


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“Astrology is rubbish”, but… (via Whewell’s Ghost)

Posted in The Universe and Stuff with tags , on January 26, 2011 by telescoper

Here’s a very nicely reasoned and invective-free blog post, on the subject of the decision by the Astrological Association of Great Britain to petition the BBC in complaint about its “unfair representation of astrology”.

"Astrology is rubbish", but... Over the past week or two I've seen a steady trickle of tweets from astronomers, science writers and journalists having a good laugh about astrology. Fair enough, perhaps, except that this all began with a story on NBC News (and video here), reporting on the comments of one Parke Kunkle, an astronomy instructor linked with the Minnesota Planetarium Society and Minnesota Community and Technical College (where, it appears from Rate My Professor, he … Read More

via Whewell's Ghost


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NAM 2011

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

Just a quick post to plug this year’s forthcoming Royal Astronomical Society National Astronomy Meeting, incorporating the MIST and UKSP meetings, which will be taking place at the splendid Venue Cymru conference centre, Llandudno, North Wales, from Sunday 17 April to Thursday 21 April.

Registration is now open, and you can now also submit abstracts of either oral or poster presentations to be considered for inclusion in the various sessions described in the science programme.

I’ve been asked to organise a small part of this meeting, namely a session on Recent Developments in Astro-statistics, so if you’d like to give a talk in that session please register and upload an abstract to the website. You can’t do the latter until you have done the former. Astro-statistics will be interpreted widely, so I hope to have a varied programme including as many applications of statistics to astronomy and astrophysics as I can get!

NAM is a particularly good opportunity for younger researchers – PhD students and postdocs – to present their work to a big audience so I particularly encourage such persons to submit abstracts. Would more senior readers please pass this message on to anyone they think might want to give a talk?

If you have any questions please feel free to use the comments box (or contact me privately).


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What is a Galaxy?

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

An interesting little paper by Duncan Forbes and  Pavel Kroupa appeared today on the arXiv today. It asks what you would have thought was the rather basic question “What is a Galaxy?”. Like many basic questions, however, it turns out to be much  more complicated than you imagined.

Ask most people what they think a galaxy is and they’ll think of something like Andromeda (or M31), shown on the left, with its lovely spiral arms. But galaxies exist in many different types, which have quite different morphologies, dynamical properties and stellar populations.

The paper by Forbes and Kroupa lists examples of definitions from technical articles and elsewhere. The Oxford English Dictionary, for instance, gives

Any of the numerous large groups of stars and other
matter that exist in space as independent systems.

I suppose that is OK, but isn’t very  precise. How do you define “independent”, for example? Two galaxies orbiting in a binary system aren’t independent, but you would still want to count them as two galaxies rather than one. A group or cluster of galaxies is likewise not a single large galaxy, at least not by any useful definition. At the other extreme, what about a cluster of stars or even a binary star system? Why aren’t they regarded as gaaxies too? They are (or can be) gravitationally bound..

Clearly we have a particular size in mind, but even if we restrict ourselves to “galaxy-sized” objects we still have problems. Why is a globular cluster not a small galaxy while a dwarf galaxy is?

To be perfectly honest, I don’t really care very much about nomenclature. A rose by any other name would smell as sweet, and a galaxy by any other name would be just as luminous. What really counts are the physical properties of the various astronomical systems we find because these are what have to be explained by astrophysicists.

Perhaps it would be better to adopt Judge Potter Stewart‘s approach. Asked to rule on an obscenity case, he wrote that hard-core pornography was difficult to define, but ” I know it when I see it”….

As a cosmologist I tend to think that there’s only one system that really counts – the Universe, and galaxies are just bits of the Universe where stars seemed to have formed and organised themselves into interesting shapes. Galaxies may be photogenic, nice showy things for impressing people, but they aren’t really in themselves all that important in the cosmic scheme of things. They’re just the Big Bang’s bits of bling.

I’m not saying that galaxies aren’t extremely useful for telling us about the Universe; they clearly are. They shed light (literally) on a great many things that we wouldn’t otherwise have any clue about. Without them we couldn’t even have begun to do cosmology, and they still provide some of the most important evidence in the ongoing investigation of the the nature of the Universe. However, I think what goes on in between the shiny bits is actually much more interesting from the point of view of fundamental physics than the shiny things themselves.

Anyway, I’m rambling again and I can hear the observational astronomers swearing at me through their screens, so let me move on to the fun bit of the paper I was discussing, which is that the authors list a number of possible definitions of a galaxy and invite readers to vote.

For your information, the options (discussed in more detail in the paper) for the minimum criteria to define a galaxy are:

  • The relaxation time is greater than the age of the Universe
  • The half-light radius is greater than 10 parsecs
  • The presence of complex stellar systems
  • The presence of dark matter
  • Hosts a satellite stellar system

I won’t comment on the grammatical inconsistency of these statements. Or perhaps I just did. I’m not sure these would have been my choices either, but there you are. There’s an option to add your own criteria anyway.

The poll can be found here.

Get voting!

UPDATE: In view of the reaction some of my comments have generated from galactic astronomers I’ve decided to add a poll of my own, so that readers of this blog can express their opinions in a completely fair and unbiased way:


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