Friday, July 29, 2011

The reason why not

I just discovered that this book review I wrote recently for The National, a UAE newspaper, was published back in early June. It doesn’t seem to have altered much in the editing, but here it is anyway.

The Reason Why:
The Miracle of Life of Earth

by John Gribbin
Allen Lane, 2011; ISBN 978 1 846 14327 4
219 pages

In 1950 the Italian physicist Enrico Fermi was walking to lunch at the Los Alamos National Laboratory with his colleagues from the Manhattan Project. They were discussing a recent spate of UFO reports, and as they sat down to eat, Fermi challenged the company. If the cosmos is full of space-faring aliens, he said, “Where is everybody?”

In The Reason Why, veteran science writer John Gribbin answers Fermi’s ‘paradox’ by saying that we have seen no sign of aliens because they don’t exist. Not, at least, in our Milky Way Galaxy – and beyond that, the distances are so vast that it is hardly worth asking. “We are alone, and we had better get used to the idea”, he concludes.

The likelihood of intelligent life on other planets has been conditioned since the 1960s by the thinking of Cornell astronomer Frank Drake, whose eponymous equation divides the question into its component parts, the probabilities of each of which one might conceivably hope to quantify or at least estimate: how many stars have planets, how many are Earth-like, and so on.

Depending on your taste, the Drake equation is either a logical way of getting purchase on a profound question, or an attempt to manufacture knowledge from ignorance. In trying to get a meaningful number by multiplying very big ones, very small ones, and very uncertain ones, the Drake equation seems more like guesswork disguised as maths.

Gribbin, however, asserts that just about every one of the necessary conditions for intelligent life to emerge has a low, perhaps minuscule, probability. Their combination then makes it highly unlikely that we have any galactic neighbours eagerly trying to make contact. For instance, only a relatively small part of our galaxy is inhabitable – the crowded interior is bathed in sterilizing radiation from black holes and supernovae. Only stars of a certain age have enough heavy chemical elements to make Earth-like planets and dwellers thereon. Only a few such stars lack partners that pull planetary orbits into extreme shapes, making climate variations unendurably extreme.

The specialness of the Earth is particularly apparent in the make-up of our solar system. For example, we are protected from more frequent impacts of asteroids and comets, like the one that seems to have sent the dinosaurs to extinction 65 million years ago, by the immense size of Jupiter, more a failed star than a planet, whose gravity sucks up these stray objects. One such, comet Shoemaker-Levy 9, ploughed into the giant planet in 1994, leaving a scar the size of the Earth.

Gribbin is especially good on the benign effect of the Moon. The Earth is unusual in having a moon so large in relation to the planet itself, which is now believed to have been created when a proto-Earth stumbled into another planet-like object called Theia with which it shared an orbit 4.5 billion years ago. The rocky debris clumped to form the Moon, while the traumatized, molten Earth swallowed Theia’s iron core to give it an unusually large core today, the source of the strong geomagnetic field that deflects harmful particles streaming from the Sun. This impact probably left the Earth spinning fast (a Venusian day lasts the best part of an Earthly year) and tilted on its axis, from which our seasons ensue. What’s more, the Moon’s gravity stops this tilt from being righted by the influence of Jupiter. Before the debris coalesced into the lunar globe, its gravity created awesome tides on the more rapidly spinning Earth that rose and fell several kilometres every two hours or so. Even though the barren Moon was too light to hold an atmosphere of its own, life on Earth would be very different – perhaps impossible – without it.

This ‘rare Earth’ case has been made before, but Gribbin gives the arguments a fresh shine. Yet he assembles them in a legalistic rather than strictly scientific manner. That’s to say, he marshals (generally impeccable) science to argue his case rather than objectively to investigate the possibilities. For example, he predicates a discussion of the ‘habitable zone’ of the solar system – a crucial part of the argument – on the claim that “it is reasonable to assume that ‘life as we know it’ does require the presence of liquid water.” That Trekkie-inspired ‘as we know it’ is back-covering, and reminds me of a conference I once attended that was convened to ask if life in the cosmos could exist without water. Speaker after speaker insisted that it could not, since that never happens on Earth, which was of course merely a statement that life adapted to water can’t do without it. Now, there are arguments why water might be essential for life anywhere, but they are subtle and not the ones Gribbin casually gives. More to the point, they are still arm-waving and do nothing to dent a counter-claim that it is reasonable to suggest that non-aqueous life is possible.

Such solipsism pervades the book, and is implicit in Fermi’s paradox to begin with. It supposes that intelligent life will think as we do now, with a determination to find and populate other inhabited worlds – and moreover, will have already done so in a way that leaves a mark so prominent that we’ll find it within the first 50 years (a comically short span in cosmic terms) of looking. Are even we so determined? If it would be unwise to conclude from the parlous state of human space exploration that this is just a phase civilizations quickly grow out of, the current situation is nonetheless even less suggestive of the opposite. Worse, since spaceflight seems increasingly likely to be a private enterprise, Gribbin implies that mega-rich philanthropists with a penchant for spaceflight like Virgin’s Richard Branson and Microsoft’s Paul Allen follow inexorably from the laws of physics.

The same historical determinism colours his belief that space-faring civilizations are a one-shot affair on inhabitable planets. If we foul up after having used all of the surface deposits of fossil fuels, he says, we’ll never again be able to claw our way out of a state of barbarism. But this assumes that apocalypse comes only after the oil and coal are exhausted, and moreover that a re-emergent civilization would stall not at the Stone Age but at the pre-industrial enlightenment. In this definition, a civilization capable of producing Aristotle, let alone Newton, doesn’t qualify as intelligent. The challenge of getting from Newton to Neil Armstrong without plentiful oil is a good pretext for a science-fiction novel, but it hardly proves anything else.

Gribbin’s account of the chance events that allowed humans to evolve from slime is particularly unpersuasive of any broader conclusions. It sounds increasingly like the kind of enumeration of contingency and coincidence that invites us to marvel at how ‘unlikely’ it is that we ever met our spouses. Once Gribbin starts invoking a highly speculative cometary impact on Venus to explain the Cambrian explosion in which complex life diversified about 540 million years ago, one senses that he is determinedly picking out a precarious path to a foregone conclusion.

None of this is to say that The Reason Why is a bad book. On the contrary, it is as lucid, well researched and enjoyable as Gribbin always is, and supplies a peerless guide to the way stars and planets are formed. And as a polemic, it is entirely justified in being selective with the evidence. Besides, many of Gribbin’s astrophysical arguments for the rarity of life are robust, and as such they make a convincing case that the Galaxy is not teeming with life that is loftily or mischievously ignoring us.

Yet the book fails to offer any philosophical perspective. The specialness of humanity has in history been asserted almost always as a theological issue, whether to counter Copernicus or Darwin. If Gribbin is right and we just got phenomenally lucky – that the laws of physics are so miserly about allowing matter to become self-aware – this is sufficiently peculiar to warrant more comment. Even atheists might then forgive theologians from taking an interest, just as they do in the ‘fine-tuning’ that seemingly makes physical laws exquisitely geared to support matter and life in the first place. Gribbin can suggest only that, if we’re alone in the galaxy, we have an even greater responsibility to our planet. It would be nice to think so, but see how far that gets you at the next climate summit.

Wednesday, July 20, 2011

No fit state

I’ve got a piece in the latest issue of Prospect (not yet online) about the recent report on the state of the oceans from the IPSO project. Here’s what the full draft looked like.

“Unprecedented… shocking… what we face is a globally significant extinction event.” These judgements on the state of the global oceans, pronounced by the scientists who attended a recent workshop of the International Programme on the State of the Ocean (IPSO), sound truly scary. The future of the ocean’s ecosystem look “far worse than we had realised”, says IPSO’s director, Oxford zoologist Alex Rogers. “If the ocean goes down, it’s game over.”

When the IPSO report was released in June, it made apocalyptic headlines. But such is the prevailing public mood on climate and environmental change that strong words may do little to alter opinions. Sceptics will dismiss them as scaremongering in a bid for research funding, while they will fuel righteous indignation among those already convinced of impending catastrophe. And if you haven’t already made up your mind, this seems an invitation to paralysing despair.

So how seriously should we take the IPSO report? According to Hugh Ducklow, director of the Ecosystems Center at Woods Hole, Massachusetts, one of the US’s most prestigious marine biology laboratories, it isn’t exaggerating. “If anything”, says Ducklow (who is not a part of IPSO), “the true state of the ocean is likely worse than the report indicates.”

The IPSO workshop, held in Oxford in April, brought together leading marine scientists, legal experts and NGO representatives. They considered threats to ocean ecosystems ranging from over-exploitation of fish stocks to acidification of the waters, caused by increased amounts of dissolved carbon dioxide (CO2) as atmospheric levels of this greenhouse gas rise. Many fish populations have been literally decimated – even since the report was released, a paper in Science says that the state of some species of high commercial value, such as bluefin tuna, is worse than thought. Almost half of the world’s coral reefs, the most diverse ecosystems on the planet, have disappeared in the past 50 years, and the rest are now under severe threat because of overfishing, global warming and ocean acidification. But perhaps the greatest concern rests with the unglamorous plankton on which the entire the food chain depends. The microscopic plants (phytoplankton) that bloom seasonally in the upper ocean dictate the cycling of carbon, particularly CO2, between the ocean and atmosphere. But some phytoplankton are toxic, and when their growth is artificially stimulated by nutrients in fertilizers and sewage (a process called eutrophication), they can poison their environment. Worse, bacteria feeding on the decaying phytoplankton may use up all the available oxygen in the water, turning it into a dead zone for other life. In the longer term oxygen depletion (hypoxia or, if total, anoxia) is also caused in deep water by warming of the upper ocean, which suppresses the circulation of oxygen-rich surface water to the depths.

It’s not just marine biology that stands at risk. The melting of Arctic sea ice has been far faster than expected – summer at the North Pole could be essentially ice-free within 30-40 years. This doesn’t affect sea level, but is disastrous for Arctic life and the influx of fresh water could change patterns of ocean circulation. The melting of grounded ice from Antarctica and Greenland, however, is also proceeding apace – at least as quickly as the worst-case predictions of climate models. Coupled to expansion of water caused by warming, this means that sea-level rise is also tracking worst-case models: it could reach four feet or so by 2100, which will redraw the map of many coastlines.

Perhaps most troubling of all, the IPSO group concluded that these individual processes seem to exacerbate one another. For example, coral reefs damaged by ocean warming are further weakened by pollution and the overfishing of reef populations, making them even more fragile. The worry is that the combination of stresses could push ecosystems to a tipping point at which they collapse catastrophically.

Such things have happened naturally several times in the distant past. The geological record clearly shows at least five global mass extinctions, in which most species all around the planet vanished, as well as many more minor extinction events. The reasons for them are still not fully understood, but the prevailing ocean conditions in which they occurred are similar in some ways – warming, anoxia and acidification – to those we are seeing now. “We now face losing marine species and entire marine ecosystems, such as coral reefs, in a single generation”, the IPSO report avers. “Unless action is taken now, the consequences of our activities are at high risk of causing the next globally significant extinction event in the ocean.”

Sounds bad? Ducklow thinks that feedbacks and synergies could make things even worse. “Working in Antarctica, we’re seeing profound changes rippling through the food chain and affecting biogeochemical processes such as CO2 uptake.” Ducklow admits that any conclusions he and his colleagues have drawn so far, like those of the IPSO team, are based on inadequate observations – over too small a spatial scale, and for too short a time. But his informed hunch is that this merely means we’re not seeing the worst of it. “I expect that as we pass through another decade, with increased concern and surveillance, we will discover things are worse, not better, than we think.”

Ducklow isn’t alone in confirming that the IPSO report’s warnings are not exaggerated. “I agree that the oceans have been greatly impacted by human activity”, says Andrew Watson at the University of East Anglia, one of the foremost UK experts on the interactions of oceans and climate. “They have changed enormously and alarmingly fast over the past 100 years or so.” In Watson’s view, analogies with past mass extinctions are appropriate. “We suspect that at past crises, the real killer was widespread ocean anoxia. This is something that eventually the changes brought about by humans, particularly increased eutrophication and global warming, could bring on.”

But has IPSO pitched its warning wisely? The team seems to have sided with the view of some climatologists, such as NASA scientist James Hansen, that concerns will be heeded only if voiced forcefully, even stridently. Watson isn’t convinced. “In human terms such a change to the life-support systems of the Earth is still a long way in the future. Such disasters unfold over very long time scales compared to a human life: thousands or tens of thousands of years.” So while Watson feels that “the report authors state their case that way with the best of intentions” and agrees on the urgent need for action, he feels uncomfortable with some of the alarming statements. “We create a false impression if we say that we have to act tomorrow to save the Earth or ‘it will be game over’. I don’t find that kind of environmental catastrophism very helpful because it simply fuels a bad-tempered ideological and political argument instead of a well-informed scientific one.”

It’s an irresolvable dilemma forced on the scientists by manufactured controversy and political inaction: risk either being ignored or damned as alarmists. However, the tone of the report is a side issue; all agree on the necessary response. “What’s really needed is a long-term plan to reduce our impact on the oceans,” says Watson. Ducklow insists that this must include not just serious and immediate regulation of fishing, pollution and carbon emissions, but “a comprehensive, global ocean observation system, including ecological and biogeochemical measurements, to determine the current and evolving state of the ocean’s health.” Any suggestion that this is merely a gambit for more research funds now deserves nothing but scorn.

Monday, July 18, 2011

Body shock

Earlier this month I went to a discussion about SciArt – more specifically, BioArt – at the GV Art gallery in London. Debates about science and art can all too readily become exercises in navel gazing, but this one wasn’t, thanks to the interesting folks involved. I’ve written a piece about it for the Prospect blog, and since it is available essentially unedited and for free, I won’t copy the text here.

Thursday, July 14, 2011

Arsenic and old wallpaper

Here’s my Crucible column for the July issue of Chemistry World. We haven’t heard the end of this story, I’m sure.

Was William Morris, socialist and utopian prophet of environmentalism, a hypocrite? That uncomfortable possibility was raised in 2003 by biochemist Andrew Meharg of the University of Aberdeen [1]. Meharg described chemical analysis of one of the famous floral wallpapers produced by Morris’s company in the mid-nineteenth century, which showed the foliage to be printed using an arsenic-containing green pigment - either Scheele’s Green (copper arsenite) or Emerald Green (copper acetoarsenite). A rather more incriminating fact was that the arsenic surely came from the Devon Great Consols mines (originally copper mines) owned by Morris’s family in a business of which Morris himself was a director until 1876. Morris’s immense wealth came partly from these mines, whose operations polluted the surrounding land and left derelict flues that are still hazardous today.

The clincher seemed to be that Morris knew of the claims by physicians that arsenic was toxic, but casually dismissed them. “As to the arsenic scare”, he wrote to the dyer Thomas Wardle in 1885, “a greater folly it is hardly possible to imagine… My belief about it all is that the doctors find their patients ailing, don’t know what’s the matter with them, and in despair put it down to the wall papers.”

Once Meharg expanded on this story in a book [2], it seemed that Morris’s reputation was tarnished irreparably. But now the accusations have been challenged by Patrick O’Sullivan of the William Morris Society, who asserts that the situation is by no means so clear-cut [3].

You might wonder if the William Morris Society offers an unbiased voice. But who else would be sufficiently motivated, not to mention well placed, to re-examine what is now widely assumed to be a cut-and-dried conviction? In any event, let’s consider the facts. O’Sullivan points out that the ‘arsenic scare’ of the nineteenth century by no means reflected the consensus of the medical community. Not until 1892 was the odour of arsenic wallpapers linked to the formation of a volatile arsenic compound by the action of a mould that grows in damp conditions. The gas was correctly identified as trimethylarsine only in the 1930s. And a recent review states that this gas is not highly toxic if inhaled, and is unlikely to be produced in significant quantities by the mould anyway [4]. So it isn’t clear that poisoning from arsenic-printed wallpapers was at all common in the nineteenth century – Morris may have been right to suggest that this was a convenient explanation for the multitude of ailments that afflicted people, especially children, during that age.

This, however, does not really absolve Morris. One might expect a man of his espoused principles to have taken seriously any suggestion that his company was making poisonous products, especially considering that the toxicity of arsenic itself was well established – Carl Wilhelm Scheele had felt obliged to reveal this ingredient of his green pigment in the 1770s for that very reason. O’Sullivan points out that Morris resigned as director of Devon Great Consols and sold his shares in the business two years before becoming politically active and six years before putting forward his socialist views. Perhaps, then, he was no hypocrite but realised that his position was no longer consistent with his new ideals?

But that remains a generous interpretation. That Morris was still so confidently denying the dangers of arsenic greens in 1885, without any sound scientific basis either way, somewhat suggests a determination to deny responsibility. And while Morris seems to have treated his workers well, the letter O’Sullivan quotes to justify why he did not make the company a socialist collective is an all-too-familiar refrain from hard-line socialists and Marxists: that such ‘palliatives’ merely delay the revolution. Quite aside from the conditions of workers in the wallpaper works, those in the mines (where arsenic was collected as the white trioxide, condensed from vapour) were undoubtedly awful: the safety precautions were crude in the extreme, and arsenic poisoning in copper mines had been known since at least the Middle Ages.

Most troubling of all is Morris’s silence on the matter. If he changed his mind about his business activities, should one not expect some sign of, if not remorse, then at least reflection? O’Sullivan has made a good argument for re-opening the case, but the suspicion lingers that Morris was no more scrupulous than most of us in examining his conscience.


1. A. Meharg, Nature 423, 688 (2003).
2. A. Meharg, Venomous Earth (Macmillan, London, 2005).
3. P. O’Sullivan, William Morris Society Newsletter, Spring 2011. Available here.
4. W. R. Cullen & R. Bentley, J. Envir. Monit. 7, 11-15 (2005).

Tuesday, July 05, 2011

The (digital) art of chemistry

Here’s a bit of naked advertising, because it’s for a good cause. The competition below, organized by ASCI in New York, should be fun if it can draw the right caliber of entries. And since I am a judge, that’s clearly what I hope. ASCI has been described to me by a very reliable witness in the following terms: “they are the largest and most active group of SciArt people and have been doing wonderful work for 20 or so years now.” So go on: give it a shot, and/or spread the word.

Announcing the Open Call for...

"DIGITAL2011: The Alchemy of Change"
An international digital print competition/exhibition to be held at the New York Hall of Science, September 3, 2011 - February 5, 2012

Organized by Art & Science Collaborations, Inc. (ASCI)

DEADLINE: July 17, 2011

Robert Devcic, owner-director of GV Art London gallery
Philip Ball, writer and noted author of popular science books

Humans, animals, insects, trees, plants, oceans, and air -- indeed, all that we see, taste, smell, touch, and breathe, contain molecular processes of physical transformation; a dynamic dance of change. This magic of transition, called alchemy by our earliest scientists, became the science of chemistry. It describes both the physical structure and characteristic actions of matter. It allows for all organic and inorganic change to take place -- brain synapses to fire, oxygen to be formed from carbon dioxide and water during photosynthesis; the transformation of gases in our solar system; along with the ability of proteins to turn our genes on/off. If you extend your imagination beyond the epithelial surface of your body, or into the ether that carries cosmic dust, or even into your kitchen, chemistry can inspire wonder. Like a fabulous menu of concocted primordial soups, when exposed to changes in temperature, pressure, or speed, chemistry can create a stick of dynamite or a magnificent soufflé!

For this exhibition, we celebrate the International Year of Chemistry by inviting artists and scientists to show us their vision of this deeply fundamental, magical enabler of life called chemistry.