Since my Head of School is currently on his way to a boondoggle in Mexico I thought it might be safe to point out, as many have done to me, that he bears more than a passing resemblance to Swiss Tony from the Fast Show. Doing astronomy, you see, is very like making love to a beautiful woman…
Walter Gear
Swiss Tony
It’s been a busy day today, so I’ve decided to be lazy and plunder the online stack of juicy Herschel images for a pretty picture to show. This one has done the rounds in the popular media recently, which is not surprising given how strange it looks.
Image Credits: ESA / PACS & SPIRE Consortium, Dr. Annie Zavagno, LAM, HOBYS Key Programme Consortia
This image shows a Galactic bubble (technically an HII emission region) called RCW 120 that contains an embryonic star that looks set to turn into one of the brightest stars in the Galaxy. It lies about 4300 light-years away. The star is not visible at these infrared avelengths but its radiation pressure pushes on the surrounding dust and gas. In the approximately 2.5 million years the star has existed, it has raised the density of matter in the bubble wall by so much that the material trapped there can now collapse to form new stars.
The bright knot to the right of the base of the bubble is an unexpectedly large, embryonic star, triggered into formation by the power of the central star. Herschel’s observations have shown that it already contains between 8-10 times the mass of our Sun. The star can only get bigger because it is surrounded by a cloud containing an additional 2000 solar masses.
Not all of that will fall onto the star, because even the largest stars in the Galaxy do not exceed 150 solar masses. But the question of what stops the matter falling onto the star is an astrophysical puzzle. According to theory, stars should stop forming at about 8 solar masses. At that mass they should become so hot that they shine powerfully at ultraviolet wavelengths exerting so much radiation pressure that it should push the surrounding matter away, much as the central star did to form this bubble in the first place. But this mass limit is must be exceeded sometimes, otherwise there would be no giant stars in the Galaxy. So astronomers would like to know how some stars can seem to defy physics and grow so large. Is this newly discovered stellar embryo destined to grow into a stellar monster? At the moment, nobody knows but further analysis of this Herschel image could give us invaluable clues.
It also reminds me a little bit of the Starchild from 2001: A Space Odyssey…
An inconclusive general election, mass protests about electoral reform, another stock market crash – Britain’s got the jitters. I think it’s time for a bit of old-fashioned stoicism. In fact, yesterday, when I saw a lot of comments on the unprecedented politicial situation facing Britain, I changed my facebook image to the following poster dating from the Second World War.
I meant it as a bit of a joke but it got me thinking about parallels between the UK’s current situation and that of this month 70 years ago when we faced problems of an altogether different magnitude.
I’m no historian so I’ll just include an excerpt from Simon Schama‘s BBC TV series A History of Britain. The last programme of the series cleverly follows the story of the Second World War through the eyes of two very different Englishmen, George Orwell and Winston Churchill. Here Schama describes how close this nation came, in May 1940, to doing a deal with Hitler. Meeting after meeting behind closed doors in Whitehall took place until eventually Churchill held sway. There was no to be no surrender.
Of course the problems facing the nation in 1940 make those facing us now pale into insignificance, so I’m not going to push the parallel too far. Nevertheless, 70 years on, we once again have lengthy and no doubt heated secret negotiations whose outcome is still by no means certain, but which will probably alter the political landscape of this country for many years to come. This time it’s not so much a matter of danger, but one of opportunity. I think change is in the air, and I also think we need it.
Another parallel is that the war in Europe came to an end almost exactly five years after the installation of Churchill as Prime Minister. Victory in Europe (VE) Day, which marks the anniversary unconditional surrender of the Germans on May 8th 1945, was yesterday. In fact the leaders of all three political parties took time out from their haggling to take part in the commemoration ceremony. Soon after the end of the War, on July 5th 1945, a General Election was held that yielded a Labour landslide and booted Churchill out of office. I don’t think that people were ungrateful, just that their wartime experiences made them aspire to a more progressive vision of the future than the old guard could provide. Clement Attlee‘s government took over a country bankrupted by war, with most of its cities in ruins, and with terrible labour shortages. Not surprisingly given that it was beset by so many problems, the Attlee government struggled to deliver what it set out to do. Nevertheless, it gave us – amongst other things – a National Health Service and a Welfare State that, to me, are emblematic of the “real” Britain.
I think Schama gets it exactly right in the clip when he talks about the War not just being about Britain as a physical entity but about much more abstract notions, such as freedom and democracy. We weren’t just fighting the Germans, we were fighting Nazism and the threat it posed to the liberties the British people had taken hundreds of years to win. The pricewas very heavy, but it was certainly worth paying. I too, would rather have died fighting than live under Fascism. My only worry would have been whether I had it in me to show the courage and resourcefulness needed to meet the challenge.
This all brings me to the question of what “Britain” actually represents in the modern age. The BNP present their views as a vision of Britishness, but most British people find their attitudes repugnant. Not only did they fail to win any seats at the General Election, they also lost all their council representation in Barking, previously thought to be a stronghold. The people of Barking clearly aren’t as mad as they’ve been portrayed.
We probably have very different views on many aspects of our national identity – or even if there is such a thing at all – but we can probably agree on, as Schama puts it in the clip, “freedom, democracy, and the rule of law”. Outside that core, people clearly differ. For myself, I would add a sense of social justice and compassion, which is why the Welfare State and NHS are so important to me.
To me, inclusiveness (whether cultural, religious, racial, or whatever) is also essential to what it means to be British, but that view clearly isn’t shared by everyone. Immigration is a hot potato in British politics these days, a fact that surprises given our existence as a mongrel nation that has been enriched over the centuries by people coming here from elsewhere. I suppose its natural that people are suspicious of strangers, and this can be exploited by unscrupulous people looking for scapegoats, but we should remember, for example, that sixty years ago we were desperate to persuade people from the West Indies to move here in order to deal with the post-war labour shortage. Nowadays we too need immigration to deal with shortages of skilled labour and to counteract the economic effects of our rapidly ageing population. I can’t imagine what state our universities would be in if it weren’t for the many excellent researchers who have come here from all round the world, and that also goes for the UK as a whole.I’m not trying to say that immigration is a non-issue, just that it’s neither new nor something we need to panic about. We can cope with it.
After all, we’re British.
It’s nice to be able to pass on some upbeat news for once.
The first thing is that, after a lot of delays and a bit of haggling, the School of Physics & Astronomy at Cardiff University has finally issued advertisements for a bunch of new Faculty positions in Experimental Physics. The positions, which are tenured, involve both Chair and Lecturer/Reader levels and there are several positions available. The School and University have put together a handsome start-up package for a new group and there’s plenty of spanking new experimental laboratory space to set up shop. Coupled with the fact that Cardiff is a great city to live in, with low costs and great sporting and cultural infrastructure, this should prove a tempting opportunity for someone to set up their own group.
It’s also a welcome vote of confidence from Cardiff University which, despite cuts in its overall budget, has decided to invest heavily in the School’s strategic plan. I hope and believe we’ll attract a strong field for these appointments and look forward to seeing what develops. We need a shot in the arm and this might just deliver it.
What’s particularly interesting about this clutch of new appointments is that they are open to people working in any area of physics, with the exception of astrophysics. Given the massive cuts in STFC’s budget, this is no time to be expanding in areas covered by its remit. I say that as an astrophysicist, with considerable regret but pragmatism in the face of the changing landscape of British science funding. In times of risk you have to broaden your portfolio. However, that’s not to say that astrophysics at Cardiff is downbeat. Far from it, in fact.
ESA held an international press conference to present exciting new results from the Herschel Observatory at the European Space Research and Technology Centre, Noordwijk, The Netherlands, on Thursday 6 May. A webcast of the press conference with Cardiff’s Professors Matt Griffin and Steve Eales taking part, can be seen at from http://www.esa.int/SPECIALS/Herschel. At the conference Steve Eales talked about the latest results from the Herschel ATLAS survey: an ATLAS of the Universe. ATLAS will cover one eightieth of the sky, four times larger than all the other Herschel surveys combined and is led by Professor Eales and Dr Loretta Dunne at Nottingham University.
Herschel ATLAS has measured the infrared light from thousands of galaxies, spread across billions of light-years. Each galaxy appears as just a pinprick but its brightness allows astronomers to determine how quickly it is forming stars. Roughly speaking, the brighter the galaxy the more stars it is forming. The Herschel images show that in the past there were many more galaxies forming stars much faster than our own Galaxy. But what triggered this frantic activity is not completely understood. Steve Eales said
every time astronomers have observed the universe in a new waveband, they have discovered something new. So as well as our regular science programmes, I am hoping for the unexpected.
I am hoping to get involved with the ATLAS data myself at some point as I am formally a member of the consortium, but I’ve been too busy doing other things to get involved in these initial stages so am not on any of the preliminary science papers. I hope I can get properly involved in this project sooner rather than later…
The ATLAS survey, image courtesy of ESA and the ATLAS consortium
The full press release also includes surprises on how stars are formed including work carried out by Cardiff’s Professor Derek Ward-Thompson. Herschel’s star formation surveys are beginning to reveal the mysteries behind how massive stars are created.
I wasn’t planning to stay up last night watching the General Election results come in, but in the end I stuck with it until about 3am, basically hoping to understand what was going on. Even by that hour there didn’t seem to be a particularly clear pattern emerging, so off I went. I had a revision lecture this morning as well as a lot of other things so I didn’t fancy an all night sitting.
Whenever there’s a General Election I always pay attention to constituencies I used to live in to see how things are changing. Broxtowe (the constituency that contains Beeston, where I used to live when I worked at Nottingham University) changed hands from Labour to the Conservatives. It had been a Conservative marginal in 1997 when it was won during the New Labour landslide. It seemed fairly typical for seats like that to revert to what they were pre-Blair. Brighton – remarkably – returned Britains first ever Green Party MP. Bethnal Green returned to the Labour fold after a flirtation with George Galloway’s Respect party.
Meanwhile here in Cardiff the results were as mixed as elsewhere. My own constituency, Cardiff West, stayed Labour, as did Cardiff South (and Penarth). The Vale of Glamorgan reverted to its pre-1997 Tory hue, unsurprisingly. The Labour candidate in Cardiff North was the wife of former Welsh Assembly leader Rhodri Morgan and it was a definite surprise to see that seat turn blue too. Cardiff Central remained Liberal Democrat.
As it has turned out the exit polls got it just about right, with the Conservative Party leading the popular vote (36%) and number of seats (306), but not enough to make an overall majority. Labour (28%, 258 seats) and Liberal Democrats (23%, 57 seats) between them have a majority of the votes cast but don’t have enough seats to form a coalition. It’s a well and truly hung Parliament and we look set for days of discussions to see what kind of agreement can be reached between which parties. Gordon Brown remains Prime Minister until some kind of resolution is reached. We live in interesting times.
Although the election results were extremely interesting by virtue of their puzzlingly inhomogeneous variation across the country, they really amount to little more than a sideshow compared with the spreading panic on international markets. The markets fell sharply, not because of the hung parliament but as part of a worldwide panic over the knock-on effect of the Greece and Portugal sovereign debt problems. The contagion could be very dangerous if Greece can’t convince traders that it’s not going to default and in an attempt to do so its government has put together a severe austerity package. Cue violent unrest. The Greeks live in even more interesting times than us.
I’m not going to pretend that I have the slightest clue how either of these things will pan out, but I’m not very optimistic about the forthcoming months. I hope I’m wrong. We’ll see.
The other thing that struck me was the story of people being unable to vote because of long queues at the polling stations near 10pm when they closed. At first I wasn’t at all sympathetic. Polls are open from 7am until 10pm, so there’s no need to turn up with only 5 minutes remaining. However, it then emerged that some polling stations couldn’t cope with the large turnout and people had been queuing for hours by the time the doors closed. The turnout was 65% nationally, higher than last time but by no means ridiculously high. In fact I think it’s a shame the usual turnout isn’t very much higher than this. However, turnout seems to have been much higher in certain wards and the staff unprepared for the demand, sometimes with insufficient ballot papers and sometimes with out-of-date copies of the electoral register. I don’t mind saying that I found this level of incompetence deeply shaming. We can’t afford to be so careless with our democratic system. It doesn’t matter if only a few hundred people were affected. It’s the principle that matters.
Over the next few days there’ll be a lot of discussion about electoral reform. Perhaps the fact that our current electoral system seems to be showing signs of neglect might generate some impetus for change, quite apart from the scandals of MPs fiddling their expenses. I’ve always been on the fence over proportional representation. Our system is absurd in some respects, delivering huge majorities in the Commons to parties with only a modest share of the popular vote. On the other hand our country is so divided that it’s not obvious what the short-term consequences of changing to PR would be. It seems likely, for one thing, that fringe parties such as the neo-fascist BNP would actually be represented in Westminster. I find that a repulsive prospect, but putting up with people you can’t abide is one of the consequences of democracy.
I have an open mind on electoral reform and I’d like to hear the arguments for and against different systems of PR aired properly. Presumably the Liberal Democrats will want a referendum on this as part of the price of their support in a coalition, so no doubt there’ll be a lot of chat about this.
At last we’ve reached General Election day and I’ve just been to cast my vote following the guidance I passed on a few days ago. I was going to go this morning but I had a meeting at 9.15am to go to (which went on until 1pm, in fact) and I didn’t get up in time to visit the polling station, even though it’s in a Church Hall only a few hundred yards from my house. When I eventually got there just after 7pm it was still quite busy and I had to queue to get my ballot paper. It was very different during last year’s European elections, where the turnout is always pretty low. I don’t know what the turnout is like this time, but I hope it’s good. I don’t think there’s really any excuse for not voting.
I’ve already explained why I’m not as caught up in the campaigning this time as I have been in previous years, so I doubt if I’ll stay up late to watch the results come in. Polls don’t close until 10pm and until then there’s a blackout of press coverage relating to the vote so there’s nothing to follow until quite late at night, when I’m usually tucked up in bed with my cocoa. The latest opinion polls suggest that the Conservative Party will get the biggest share of the vote, but it’s not clear if they’ll win a majority of the seats. Nor should they, in fact, even if they get as high a share as the polls suggest (37%) then that’s still far less than the number that didn’t vote for them. Labour and LibDems are together worth about 55%. The likelihood therefore is a hung parliament, at which point we’ll probably find all parties agreeing with each other to the implement massive spending cuts they’ve been carefully keeping from the electorate. It will still be interesting to see how the horse-trading works out over the next few days, but after three weeks of phoney war we’ll soon have to face up to reality. I’m not really looking forward to that.
Anyway, a comment by Keith Ashman on an item I posted a few days ago reminded me that no less than 13 years ago I was actually in Lawrence, Kansas, on polling day. Don’t ask me why. I’d arranged a postal vote, but had to watch the proceedings from afar on the TV. In fact, Keith and his partner decided to hold a party that night in their house and I went along to drink beer while the results came in. Watching a British election from the midwest USA is a bit strange, but it’s improved by the fact that the polls close in the UK at what is early evening Kansas-time and it’s all pretty much over by midnight.
That election I was swept up in the euphoria generated by the prospect of a New Labour government with its slogan “Things can only get better”. When they won a landslide majority we celebrated in grand style, singing Jerusalem in Keith’s back garden and then tottered not too soberly to a tattoo parlour to have a red rose put on my arm.
We had a great time that night, and the good vibes continued after I returned to London from my short stay at the University of Kansas. It didn’t take long, however, for my enthusiasm to wane. Instead of doing the really radical things their large majority would have allowed, they basically pratted about for four years. I’m not saying they didn’t do any good things, but they were so keen to tie everyone up in red tape that the good ideas often came to nothing except frustration. Then of course Blair took us into Iraq and I vowed never again to vote for the Labour Party until it renounced that decision, which I haven’t.
But I’ve still got the red rose tattoo.
A comment posted today on a previous item reminded me that this is supposed to be a science blog, so I thought it would be a good idea to put up a brief message about the status of Herschel.
Today is the first day of the Herschel First Results Symposium which is being held on the premises of ESTEC at Noordwijk in The Netherlands; you can see the poster below. There’s quite a strong Cardiff contingent there, and the meeting will go on until Friday, so it’s a going to be a bit quiet around here for the rest of the week.
The results being presented at this Symposium are covered by a strict ESA policy and most of them are embargoed, at least for the time being. However, you can keep up with the meeting to some extent on Twitter, as I’ve been doing from time to time. Just follow #eslab2010. There are also edited highlights on the Herschel Mission Blog. It’s a bit frustrating only getting the odd snippet, but it does at least give you an idea of what’s going on and a heads-up for things that will be released officially soon.
In fact pretty soon a load of Herschel images and other results will be made public and I’ll be spoilt for choice as to what to post on here. In fact, I think all the presentations at the Symposium will be put online after it’s finished. There’s also going to be a deluge of science papers on the arXiv, the result of a lot of hard work (not to say a total panic) by those directly involved in analysing the first data to come through from the telescope. I’m looking forward to that, although there’s no way I’ll have time to read them all!
It’s hard to believe that it’s just a little under a year since we gathered in a state of nervous tension (moderated by a steady intake of alcohol) to watch the launch of Planck and Herschel. I don’t think I’m giving away any secrets when I write that the mission has been an outstanding success so far, even exceeding its specified performance in some respects.
I’ll be posting some Herschel goodies from time to time once the embargo is lifted, but until that happens you’ll just have to wait. I could tell you more but if I did I’d have to kill you.
PS. To return to my first sentence, I’m not even sure I should call this a science blog. I think of it as a personal blog, written by a person who happens to be a scientist…
I had the misfortune a few weeks ago to see a bit of a terrible BBC TV show called Over the Rainbow, the main aim of which seems to be to use TV License payers’ money to provide free advertising for a forthcoming West End production of the Wizard of Oz. Anyway, when I was thinking yesterday about cover versions of tunes that turned out better than the original, the tune Over the Rainbow sprang to mind. Since I’ve been on holiday today – studiously avoiding doing very much at all – I thought I’d put up some interesting jazz versions of that particular song.
There are hardly any tunes ever written that some jazz musician somewhere hasn’t taken a fancy to and done their own original version, however unpromising the raw material. Louis Armstrong had a particularly amazing ability to turn base metal into solid gold, making glorious music out of tunes nobody else wanted to touch. I’ve picked three quite different versions of Over the Rainbow, all of which I think are brilliant despite the mawkish sentimentality of the original song.
The first is from a concert by Keith Jarrett in Tokyo in 1984. As well as being a brilliant jazz musician, Jarrett is an accomplished classical performer who, for example, made an exceptionally fine recording of Bach’s Goldberg Variations a few years ago. Quite a few people seem to get put off by watching his antics at the keyboard. I can see why. I think he sometimes looks like the piano is playing him, rather than the other way around. But if his contortions bother you, just listen to the music, which is just gorgeous…
When I was still at school back in 1980 or 81 I had the good fortune to get to see the great alto saxophonist Art Pepper playing live with a band led by pianist Milcho Leviev. He played so beautifully on that concert that I became an immediate fan and tried to get hold of as many of his records as I could. I was devastated to hear just a couple of years later that he had died. Like many jazz musicians of his generation, Art Pepper had a serious drugs problem and he spent long periods in jail as a consequence. He joked that San Quentin Prison had better musicians than any establishment on Earth.
His tender, lyrical sound and graceful improvisations are beautifully represented on this track recorded with George Cables (piano) and – I think – Charlie Haden (bass) and Billy Higgins on drums.
The last one up is by the great Bud Powell. He was another musician who struggled with narcotics, but he also had serious mental illness to deal with – he suffered numerous breakdowns and was heavily medicated in an attempt treat his schizophrenia. Although he moved to Paris in 1959 to make a fresh start, his self-destructive tendencies caught up with him. The quality of his playing deteriorated, his behaviour became erratic and he eventually died in 1966. Before leaving the States, however, Powell had made a number of recordings in which he demostrated the virtuousity and musical imagination that established him as one of the greatest jazz pianists of all time, and certainly the leading stylist of the bebop era.
Bud Powell’s version of Over the Rainbow is one of my all-time favourite pieces of music. He puts so much variation into the way he plays it, alternating a lush romantic style with jagged boppy lines and dark undertones introducing a strong element of parody juxtaposed with a more orthodox treatment of the melody. As much as I love the other two versions, this is my a favourite. By any standards, it is a masterpiece.
It being a rainy bank holiday weekend, I’ve been working, although I didn’t start until I’d done the Sunday crosswords and watched the football on the telly. Now it’s too late to post anything substantial, so I’ll resort to something from my back catalogue of bookmarked masterpieces from Youtube. This is a wonderful bluesy gospelly piece by the late great Nina Simone, a rare example in my opinion of a cover version being better than the original (in this case by Blind Willie Johnson).
Incidentally, I wonder if either of my regular readers can think of cover versions better than the original? Jeff Buckley’s intensely moving version of Leonard Cohen’s great song Hallelujah springs to mind, but I’d be interested to hear other suggestions…
This past week was the final week of proper teaching at Cardiff University, so I’ve done my last full lectures, tutorials and exercise classes of the academic year. Yesterday I assessed a bunch of 3rd-year project talks, and soon those students will be handing in their written reports for marking. Next week will be a revision week, shortly after that the examinations begin. And so the cycle of academic life continues, in a curious parallel to the football league season – the other routine that provides me with important markers for the passage of the year.
Anyway, this week I gave the last lecture to my first-year class on Astrophysical Concepts. This is a beginning-level course that tries to introduce some of the theory behind astronomy, focussing on the role of gravity. I cover orbits in newtonian gravity, gravity and hydrostatic equilibrium in extended bodies, a bit about stellar structure, gravitational collapse, and so on. In the last part I do a bit of cosmology. I decided to end this time with a lecture about dark energy as, according to the standard model, this accounts for about 75% of the energy budget of the Universe. It’s also something we don’t understand very well at all.
To make a point, I usually show the following picture (credit to the High-z supernova search team).
What is plotted is the redshift of each supernova (along the x-axis), which relates to the factor by which the universe has expanded since light set out from it. A redshift of 0.5 means the universe was compressed by a factor 1.5 in all dimensions at the time when that particular supernova went bang. The y-axis shows the really hard bit to get right. It’s the estimated distance (in terms of distance modulus) of the supernovae. In effect, this is a measure of how faint the sources are. The theoretical curves show the faintness expected of a standard source observed at a given redshift in various cosmological models. The bottom panel shows these plotted with a reference curve taken out so the trend is easier to see.
The argument from this data is that the high redshift supernovae are fainter than one would expect in models without dark energy (represented by the 
This plot contains the principal evidence that has led to most cosmologists accepting that the Universe is accelerating. However, when I show it to first-year undergraduates (or even to members of the public at popular talks), they tend to stare in disbelief. The errors are huge, they say, and there are so few data points. It just doesn’t look all that convincing. Moreover, there are other possible explanations. Maybe supernovae were different beasties back when the universe was young. Maybe something has absorbed their light making them look fainter rather than being further away. Maybe we’ve got the cosmological models wrong.
The reason I show this diagram is precisely because it isn’t superficially convincing. When they see it, students probably form the opinion that all cosmologists are gullible idiots. I’m actually pleased by that. In fact, it’s the responsibility of scientists to be skeptical about new discoveries. However, it’s not good enough just to say “it’s not convincing so I think it’s rubbish”. What you have to do is test it, combine it with other evidence, seek alternative explanations and test those. In short you subject it to rigorous scrutiny and debate. It’s called the scientific method.
Some of my colleagues express doubts about me talking about dark energy in first-year lectures when the students haven’t learned general relativity. But I stick to my guns. Too many people think science has to be taught as great stacks of received wisdom, of theories that are unquestionably “right”. Frontier sciences such as cosmology give us the chance to demonstrate the process by which we find out about the answers to big questions, not by believing everything we’re told but by questioning it.
My attitude to dark energy is that, given our limited understanding of the constituents of the universe and the laws of matter, it’s the best explanation we have of what’s going on. There is corroborating evidence of missing energy, from the cosmic microwave background and measurements of galaxy clustering, so it does have explanatory power. I’d say it was quite reasonable to believe in dark energy on the basis of what we know (or think we know) about the Universe. In other words, as a good Bayesian, I’d say it was the most probable explanation. However, just because it’s the best explanation we have now doesn’t mean it’s a fact. It’s a credible hypothesis that deserves further work, but I wouldn’t bet much against it turning out to be wrong when we learn more.
I have to say that too many cosmologists seem to accept the reality of dark energy with the unquestioning fervour of a religious zealot. Influential gurus have turned the dark energy business into an industrial-sized bandwagon that sometimes makes it difficult, especially for younger scientists, to develop independent theories. On the other hand, it is clearly a question of fundamental importance to physics, so I’m not arguing that such projects should be axed. I just wish the culture of skepticism ran a little deeper.
Another context in which the word “skeptic” crops up frequently nowadays is in connection with climate change although it has come to mean “denier” rather than “doubter”. I’m not an expert on climate change, so I’m not going to pretend that I understand all the details. However, there is an interesting point to be made in comparing climate change with cosmology. To make the point, here’s another figure.
There’s obviously a lot of noise and it’s only the relatively few points at the far right that show a clear increase (just as in the first Figure, in fact). However, looking at the graph I’d say that, assuming the historical data points are accurate, it looks very convincing that the global mean temperature is rising with alarming rapidity. Modelling the Earth’s climate is very difficult and we have to leave it to the experts to assess the effects of human activity on this curve. There is a strong consensus from scientific experts, as monitored by the Intergovernmental Panel on Climate Change, that it is “very likely” that the increasing temperatures are due to increased atmospheric concentrations of greenhouse gas emissions.
There is, of course, a bandwagon effect going on in the field of climatology, just as there is in cosmology. This tends to stifle debate, make things difficult for dissenting views to be heard and evaluated rationally, and generally hinders the proper progress of science. It also leads to accusations of – and no doubt temptations leading to – fiddling of the data to fit the prevailing paradigm. In both fields, though, the general consensus has been established by an honest and rational evaluation of data and theory.
I would say that any scientist worthy of the name should be skeptical about the human-based interpretation of these data and that, as in cosmology (or any scientific discipline), alternative theories should be developed and additional measurements made. However, this situation in climatology is very different to cosmology in one important respect. The Universe will still be here in 100 years time. We might not.
The big issue relating to climate change is not just whether we understand what’s going on in the Earth’s atmosphere, it’s the risk to our civilisation of not doing anything about it. This is a great example where the probability of being right isn’t the sole factor in making a decision. Sure, there’s a chance that humans aren’t responsible for global warming. But if we carry on as we are for decades until we prove conclusively that we are, then it will be too late. The penalty for being wrong will be unbearable. On the other hand, if we tackle climate change by adopting greener technologies, burning less fossil fuels, wasting less energy and so on, these changes may cost us a bit of money in the short term but frankly we’ll be better off anyway whether we did it for the right reasons or not. Of course those whose personal livelihoods depend on the status quo are the ones who challenge the scientific consensus most vociferously. They would, wouldn’t they? Moreover, as Andy Lawrence pointed out on his blog recently, the oil is going to run out soon anyway…
This is a good example of a decision that can be made on the basis of a judgement of the probability of being right. In that respect , the issue of how likely it is that the scientists are correct on this one is almost irrelevant. Even if you’re a complete disbeliever in science you should know how to respond to this issue, following the logic of Blaise Pascal. He argued that there’s no rational argument for the existence or non-existence of God but that the consequences of not believing if God does exist (eternal damnation) were much worse than those of behaving as if you believe in God when he doesn’t. For “God” read “climate change” and let Pascal’s wager be your guide….
In the Dark 