Tag: Enrico Fermi

Categories
Analysis Science

The real story of ‘The Old Guard’

Spoiler alert: Don’t read this post if you intend to watch The Old Guard but haven’t done so yet.

The Old Guard, an action film starring Charlize Theron among others, released on Netflix on July 10. In a scene in the film, Copley (Chiwetel Ejiofor) delivers two undying men to the CEO of a pharmaceutical company (Harry Melling) only to watch the CEO, demanding that their proof of immortality be “indisputable”, stab them to death and then watch their wounds heal. After he’s had his fill, the CEO orders the men to be taken away to a lab for ‘tests’. Before he leaves the room, Copley walks up to the CEO and attempts to remind him that “this” – referring to their arrangement, pursuant to the CEO’s stated intention to mine the immortals’ genetic material for life-saving drugs – “is about science, not profits or sadism”.

The Old Guard has received good reviews, as you might know if you’ve already watched it, but perhaps the film’s entire story could have been non-existent were it not for Copley’s naïve beliefs, no?

At another point in the film, Copley talks about entering into his deal with Merrick, the CEO, because Copley’s wife’s death of ALS taught him that genetic gifts that could alleviate “needless suffering” should be shared with humanity, not hoarded by a few. A noble sentiment – and I almost fell for it until being jolted back by another character, who reminds Copley that the gift wasn’t his to give. In The Old Guard, it’s four white people who have been forced to give, but the argument is strengthened by the fact that it’s an apt metaphor for the real world, in which it’s often the people of the developing world, and in that world the most marginalised, doing the ‘giving’.

In effect, the film’s story is about Copley’s mistake and Copley fixing that mistake – except the mistake doesn’t seem defensible to me as much as it must have been born out of a long-standing ignorance of a bunch of issues, from self-determination to science’s need to be guided by politics. When Copley tells Merrick that “this is about science, not profits”, I laughed out loud, and my scalding hot tea poured out through my nose when he added “or sadism”. What kind of person arranges to violently capture four people who really don’t wish to be caught, puts them in chains, and brings them to a pharma company believing it’s neither for “profits” nor “sadism”?

Even more broadly, when has science ever not been for sadism or profits? Vast swathes of modern science as we know it – since the atomic bombings of Hiroshima and Nagasaki and the entry into consciousness in those moments of the science-military nexus, exemplified by the apoliticism of Enrico Fermi that, in the final analysis, had deeply political ramifications – have been for profits and power, if not directly sadism.

Modern medicine is not at all free of pain either. Even within the limited view of physical violence, drug trial protocols require a set of preclinical trials to be conducted in ‘animal models’, and many researchers who work with animals also grapple with mental health issues, for example in the form of compassion fatigue. Only in this decade or so have we begun to grow organs in the lab or virtual environments in computers to simulate the actions of different drugs, and even these solutions are eons away from entering regular practice. And then there’s the brutal history of medical and psychological experimentation that, at various points in time, overlapped disturbingly neatly with the day’s most significant human rights abuses.

If we considered violence of other forms as well – including but not limited to rationalists who wield ‘science’ to delegitimise non-scientific ways to organise and make sense of the world and to terrorise the followers of other traditions; to the West, which, “rather than improve conditions of work where necessary, or make a provision for proper career structures where they are lacking so as to attract local graduates, … has found it simpler and less expensive to import foreign doctors to work under conditions which locally trained doctors would not accept” (source); to even imperialist trade agreements that suppress local enterprise in favour of foreign imports – neither medicine nor the institutions responsible for its development are at all free of violence.

This said, I’m not railing against Copley here as much as his writers, Greg Rucka and Leandro Fernández. Even considered in toto, The Old Guard affords Copley the resolution of his moral crisis by facilitating the rescue of the ‘caged’ immortals – but in so doing legitimises the separation of scientific practice from cruelty and abuse. But as history has revealed on multiple occasions, science as so many of us would like it to be is so frequently not what it actually is. As a human enterprise, it’s dirty, fraught and contested. Most of all – likely to the chagrin of those who still believe there can be a functional line between science and politics that wouldn’t be to science’s detriment – it is negotiated. And the more we persist in our efforts to install the scientific enterprise on a pedestal, as being even if only in idea to be untainted by social and cultural considerations, the more we diminish its influence on society, the more we overlook its use unto oppressive ends and thus the more we empower those who do so.

Instead, what Copley should really have done after being contacted is deduce preemptively that Merrick is cruel and therefore Merrick’s practice of science is bound to be cruel, sign the contract (to keep the deal from going to someone else) and then stealthily undermine Merrick’s plans while also protecting the immortals. Then, once Merrick has been killed off (in order to make it a good action film), the immortals volunteer to have their genomes sequenced and the corresponding results uploaded onto a preprint server, and then recall all their time on this good Earth to write anecdotally well-supplied books about the real history of science.

Categories
Culture Science

To read or not a bad man’s book

Photo by Pouria Teymouri on Pexels.com

The Life of Science team uploaded the video of their webinar on July 10, about the construct of the genius in science, on YouTube on July 14. Please watch it if you haven’t already. I had also blogged about it. During the webinar, Gita Chadha – a sociologist of science and one of the two guests – answered a question I had posed, which in turn had arisen from contemplating whether I should read a soon to be published book authored by Lawrence M. Krauss.

Specifically, Krauss has been accused of being a predator and is also tainted by his association with and defence of Jeffrey Epstein. He will soon have a book published about the physics of climate change. I was and am inclined to boycott the book but this is an emotional response. More objectively speaking I didn’t/don’t know if my decision was/is as a matter of principle the right one. (More detailed deliberation, taking recourse through the stories of Geoffrey Marcy, Georges Lemaître, Enrico Fermi and Richard Feynman as well, here.)

So at the time of registering for the webinar, I had recorded this question: “How can we separate scholarship from the scholar when the latter are ‘geniuses’ who have been removed from pedestals for abusing power?” Chadha’s reply follows (from 36:45):

I got the question as – how can you separate scholarship from the scholar? This is an extremely complex question.

I find it extremely difficult to argue for the non-separation. For example, after the #MeToo movement, a lot of us faced the following situation. Suppose I know that some scientist or social scientist has been named a predator. What do I do with their work? Do I stop using or teaching the work, or something else? These are dilemmas. I would argue saying that it is impossible to keep the work away. But when we know they are capable of unethical or non-inclusive practices, it becomes inevitable to call them out. Because in calling them out, you will also call out the culture to which they belong, which will help you to restore the balance of justice, if I may say so.

But I would push the question further and say that we need to critically start engaging with how the social location of a scholar impacts the kind of work that they do. It’s very important, the kind of things Shalini Mahadev [the other panellist] has been talking about. Why do we privilege a certain kind of abstract work? Why do we privilege a certain kind of abstract testing of intellect? Why do we [pursue] work in [some areas over others]? Why is ‘glorified work’ in mathematics in number theory? How is knowledge constructed by the social location of caste in India, for example?

This question about the knowledge and the knowledge-maker is a deeper question. I would think it’s important to keep the connection between the two alive. Them being on pedestals is a different question. This is exactly what I was trying to say: There is no talent, there is only the struggle for eminence, awards… [these are] ways of wielding power. And that power you wield, because you are an eminent scientist, will always give you the clean chit: “He’s a genius, so it’s okay if he’s a wife-beater”, “it’s okay if he’s a predator,” etc. His genius and his work needs to be preserved. That is where the problem arises.

This is all insightful, and partly helpful. For example, a lot of people have called out Krauss and he also ‘retired’ shortly after. The effects of the #MeToo movement have prompted some reforms – or at least reformatory tendencies – in a variety of fields, as a result of which more than a few scientists have been ‘outed’ thus. More importantly, abusing the power imbalance between teachers and students is today widely understood to be an implicit bad, at least in quarters from which other scientists have been already removed. We have not restored the balance of justice but we have surely, even if imperfectly, started on this path.

However, Krauss continues to stand his ground, and soon he will have a book. If in this context I’m intent on keeping the connection between knowledge and the knowledge-maker alive, I can read his book. At the same time the act of purchasing his book will make this predator-in-denial richer, financially more powerful, and as a scholar more relevant and therefore more employable. Considering Chadha only said we must call out the culture to which such scientists belong, and nothing about whether the scientist in question should repent, I’m still confused.

If I’m wrong or have lost my train of thought in some obvious way even as I mull Chadha’s words, just as well. But if you know the way out of these woods, please don’t keep it to yourself!

Categories
Culture Science

Review: ‘Salam – The First ****** Nobel Laureate’ (2018)

A screenshot of Abdus Salam from 'Salam – The First ****** Nobel Laureate'. Source: Netflix
A screenshot of Abdus Salam from 'Salam – The First ****** Nobel Laureate'. Source: Netflix

Awards are elevated by their winners. For all of the Nobel Prizes’ flaws and shortcomings, they are redeemed by what its laureates choose to do with them. To this end, the Pakistani physicist and activist Abdus Salam (1926-1996) elevates the prize a great deal.

Salam – The First ****** Nobel Laureate is a documentary on Netflix about Salam’s life and work. The stars in the title stand for ‘Muslim’. The label has been censored because Salam belonged to the Ahmadiya sect, whose members are forbidden by law in Pakistan to call themselves Muslims.

After riots against this sect broke out in Lahore in 1953, Salam was forced to leave Pakistan, and he settled in the UK. His departure weighed heavily on him even though he could do very little to prevent it. He would return only in the early 1970s to assist Zulfiqar Ali Bhutto with building Pakistan’s first nuclear bomb. However, Bhutto would soon let the Pakistani government legislate against the Ahmadiya sect to appease his supporters. It’s not clear what surprised Salam more: the timing of India’s underground nuclear test or the loss of Bhutto’s support, both within months of each other, that had demoted him to a second-class citizen in his home country.

In response, Salam became more radical and reasserted his Muslim identity with more vehemence than he had before. He resigned from his position as scientific advisor to the president of Pakistan, took a break from physics and focused his efforts on protesting the construction of nuclear weapons everywhere.

It makes sense to think that he was involved. Someone will know. Whether we will ever get convincing evidence… who knows? If the Ahmadiyyas had not been declared a heretical sect, we might have found out by now. Now it is in no one’s interest to say he was involved – either his side or the government’s side. “We did it on our own, you know. We didn’t need him.”

Tariq Ali

Whether or not it makes sense, Salam himself believed he wouldn’t have solved the problems he did that won him the Nobel Prize if he hadn’t identified as Muslim.

If you’re a particle physicist, you would like to have just one fundamental force and not four. … If you’re a Muslim particle physicist, of course you’ll believe in this very, very strongly, because unity is an idea which is very attractive to you, culturally. I would never have started to work on the subject if I was not a Muslim.

Abdus Salam

This conviction unified at least in his mind the effects of the scientific, cultural and political forces acting on him: to use science as a means to inspire the Pakistani youth, and Muslim youth in general, to shed their inferiority complex, and his own longstanding desire to do something for Pakistan. His idea of success included the creation of more Muslim scientists and their presence in the ranks of the world’s best.

[Weinberg] How proud he was, he said, to be the first Muslim Nobel laureate. … [Isham] He was very aware of himself as coming from Pakistan, a Muslim. Salam was very ambitious. That’s why I think he worked so hard. You couldn’t really work for 15 hours a day unless you had something driving you, really. His work always hadn’t been appreciated, shall we say, by the Western world. He was different, he looked different. And maybe that also was the reason why he was so keen to get the Nobel Prize, to show them that … to be a Pakistani or a Muslim didn’t mean that you were inferior, that you were as good as anybody else.

The documentary isn’t much concerned with Salam’s work as a physicist, and for that I’m grateful because the film instead offers a view of his life that his identity as a figure of science often sidelines. By examining Pakistan’s choices through Salam’s eyes, we get a glimpse of a prominent scientist’s political and religious views as well – something that so many of us have become more reluctant to acknowledge.

Like with Srinivasa Ramanujan, one of whose theorems was incidentally the subject of Salam’s first paper, physicists saw a genius in Salam but couldn’t tell where he was getting his ideas from. Salam himself – like Ramanujan – attributed his prowess as a physicist to the almighty.

It’s possible the production was conceived to focus on the political and religious sides of a science Nobel laureate, but it puts itself at some risk of whitewashing his personality by consigning the opinions of most of the women and subordinates in his life to the very end of its 75-minute runtime. Perhaps it bears noting that Salam was known to be impatient and dismissive, sometimes even manipulative. He would get angry if he wasn’t being understood. His singular focus on his work forced his first wife to bear the burden of all household responsibilities, and he had difficulty apologising for his mistakes.

The physicist Chris Isham says in the documentary that Salam was always brimming with ideas, most of them bizarre, and that Salam could never tell the good ideas apart from the sillier ones. Michael Duff continues that being Salam’s student was a mixed blessing because 90% of his ideas were nonsensical and 10% were Nobel-Prize-class. Then, the producers show Salam onscreen talking about how physicists intend to understand the rules that all inanimate matter abides by:

To do this, what we shall most certainly need [is] a complete break from the past and a sort of new and audacious idea of the type which Einstein has had in the beginning of this century.

Abdus Salam
A screenshot from ‘Salam’ showing Abdus Salam’s gravestone. Source: Netflix

This echoes interesting but not uncommon themes in the reality of India since 2014: the insistence on certainty, the attacks on doubt and the declining freedom to be wrong. There are of course financial requirements that must be fulfilled (and Salam taught at Cambridge) but ultimately there must also be a political maturity to accommodate not just ‘unapplied’ research but also research that is unsure of itself.

With the exception of maybe North Korea, it would be safe to say no country has thus far stopped theoretical physicists from working on what they wished. (Benito Mussolini in fact setup a centre that supported such research in the late-1920s and Enrico Fermi worked there for a time.) However, notwithstanding an assurance I once received from a student at JNCASR that theoretical physicists need only a pen and paper to work, explicit prohibition may not be the way to go. Some scientists have expressed anxiety that the day will come if the Hindutvawadis have their way when even the fruits of honest, well-directed efforts are ridden with guilt, and non-applied research becomes implicitly disfavoured and discouraged.

Salam got his first shot at winning a Nobel Prize when he thought to question an idea that many physicists until then took for granted. He would eventually be vindicated but only after he had been rebuffed by Wolfgang Pauli, forcing him to drop his line of inquiry. It was then taken up and to its logical conclusion by two Chinese physicists, Tsung-Dao Lee and Chen-Ning Yang, who won the Nobel Prize for physics in 1957 for their efforts.

Whenever you have a good idea, don’t send it for approval to a big man. He may have more power to keep it back. If it’s a good idea, let it be published.

Abdus Salam

Salam would eventually win a Nobel Prize in 1979, together with Steven Weinberg and Sheldon Glashow – the same year in which Gen. Zia-ul-Haq had Bhutto hung to death after a controversial trial and set Pakistan on the road to Islamisation, hardening its stance against the Ahmadiya sect. Since the general was soon set to court the US against its conflict with the Russians in Afghanistan, he attempt to cast himself as a liberal figure by decorating Salam with the government’s Nishan-e-Imtiaz award.

Such political opportunism contrived until the end to keep Salam out of Pakistan even if, according to one of his sons, it “never stopped communicating with him”. This seems like an odd place to be in for a scientist of Salam’s stature, who – if not for the turmoil – could have been Pakistan’s Abdul Kalam, helping direct national efforts towards technological progress while also striving to be close to the needs of the people. Instead, as Pervez Hoodbhoy remarks in the documentary:

Salam is nowhere to be found in children’s books. There is no building named after him. There is no institution except for a small one in Lahore. Only a few have heard of his name.

Pervez Hoodbhoy

In fact, the most prominent institute named for him is the one he set up in Trieste, Italy, in 1964 (when he was 38): the Abdus Salam International Centre for Theoretical Physics. Salam had wished to create such an institution after the first time he had been forced to leave Pakistan because he wanted to support scientists from developing countries.

Salam sacrificed a lot of possible scientific productivity by taking on that responsibility. It’s a sacrifice I would not make.

Steven Weinberg

He also wanted the scientists to have access to such a centre because “USA, USSR, UK, France, Germany – all the rich countries of the world” couldn’t understand why such access was important, so refused to provide it.

When I was teaching in Pakistan, it became quite clear to me that either I must leave my country, or leave physics. And since then I resolved that if I could help it, I would try to make it possible for others in my situation that they are able to work in their own countries while still [having] access to the newest ideas. … What Trieste is trying to provide is the possibility that the man can still remain in his own country, work there the bulk of the year, come to Trieste for three months, attend one of the workshops or research sessions, meet the people in his subject. He had to go back charged with a mission to try to change the image of science and technology in his own country.

In India, almost everyone has heard of Rabindranath Tagore, C.V. Raman, Amartya Sen and Kailash Satyarthi. One reason our memories are so robust is that Jawaharlal Nehru – and “his insistence on scientific temper” – was independent India’s first prime minister. Another is that India has mostly had a stable government for the last seven decades. More pertinently, we keep remembering them because of what we think of the Nobel Prizes themselves. This perception is ill-founded at least as it currently stands: of the prizes as the ultimate purpose of human endeavour and as an institution in and of itself – when in fact it is just one recognition, a signifier of importance sustained by a bunch of Swedish men that has been as susceptible to bias and oversight as any other historically significant award has been.

However, as Salam (the documentary) so effectively reminds us, the Nobel Prize is also why we remember Abdus Salam, and not the many, many other Ahmadi Muslim scientists that Pakistan has disowned over the years, has never communicated with again and has never awarded the Nishan-e-Imtiaz to. If Salam hadn’t won the Nobel Prize, would we think to recall the work of any of these scientists? Or – to adopt a more cynical view – would we have focused so much of our attention on Salam instead of distributing it evenly between all disenfranchised Ahmadi Muslim scholars?

One way or another, I’m glad Salam won a Nobel Prize. And one way or another, the Nobel Committee should be glad it picked Salam, too, for he elevated it to a higher place than it could have been intended for.

Note: The headline originally indicated the documentary was released in 2019. It was actually released in 2018. I fixed the mistake on October 6, 2019, at 8.45 am.

Categories
Op-eds Science

Unseating Feynman, and Fermi

Photo by Pixabay on Pexels.com

Do physicists whitewash the legacy of Enrico Fermi the same way they do Richard Feynman?

Feynman disguised his sexism as pranks and jokes, and writers have spent thousands of pages offering his virtues as a great physicist and teacher as a counterweight against his misogyny. Even his autobiography doesn’t make any attempts to disguise his attitude, but to be fair, the attitude in question became visibly problematic only in the 21st century.

This doesn’t mean nobody exalts Feynman anymore but only that such exaltation is expected to be contextualised within his overall persona.

This in turn invites us to turn the spotlight on Fermi, who would at first glance appear to be Italy’s Feynman by reputation but on deeper study seems qualified to be called one of the greatest physicists of the 20th century.

Like Feynman, Fermi made important and fundamental contributions to physics and chemistry. Like Feynman, Fermi was part of the Manhattan Project to build the bombs that politicians would eventually drop on Hiroshima and Nagasaki. But unlike Feynman, Fermi’s participation in the latter extended to consultations on decisions about where to drop the bomb and when.

For us to acknowledge that we were being grossly unfair to all women when we overlooked Feynman’s transgressions, women needed to become more vocal about their rights in social and political society.

So it’s only fair to assume that at some point in the future, society’s engagement with and demands of scientists and scientific institutes to engage more actively with a country’s people and their leaders will show us how we’ve been whitewashing the legacy of Enrico Fermi – by offering his virtues as a physicist and teacher as a counterweight against his political indifference.

Many people who fled fascist regimes in 20th century Europe and came to the US, together with people who had relatives on the frontlines, supported the use of powerful weapons against the Axis powers because these people had seen firsthand what their enemies were capable of. Fermi was one such émigré – but here’s where it gets interesting.

Fermi was known to be closed-off, to be the sort of man who wouldn’t say much and kept his feelings to himself. This meant that during meetings where military leaders and scientists together assessed a potential threat from the Germans, Fermi would maintain his dispassionate visage and steer clear of embellishments. If the threat was actually severe, Fermi wouldn’t be the person of choice to convey its seriousness, at least not beyond simply laying down the facts.

This also meant that Fermi didn’t have the sort of public, emotional response people commonly associate with J. Robert Oppenheimer, Karl Darrow or Leo Szilard after the bomb was first tested. In fact, according to one very-flattering biography – by Bettina Hoerlin and Gino Segrè published in 2016 – Fermi was only interested in his experiments and was “not eager to deal with the extra complications of political or military involvement”. Gen. Leslie Groves, the leader of the Manhattan Project, reportedly said Fermi “just went along his even way, thinking of science and science only.”

But at the same time, Fermi would also advocate – against the spirit of Szilard’s famous petition – for the bomb to be dropped without prior warning on a non-military target in Japan to force the latter to surrender. How does this square with his oft-expressed belief that scientists weren’t the best people to judge how and when the bomb would have to be used to bring a swift end to the war?

Fermi’s legacy currently basks in the shadow of the persistent conviction that the conducts of science and politics are separate and that they should be kept that way. The first part of the claim is false, an untruth fabricated to keep upper-class/caste science workers from instituting reforms that would make research a more equitable enterprise; the second part is becoming more untenable but it’s taking its time.

Ultimately, the fight for a scientific enterprise founded on a more enlightened view of its place within, not adjacent to, society should also provide us a clearer view of our heroes as well as help us discover others.

Categories
Science

What life on Earth tells us about life ‘elsewhere’

Plumes of water seen erupting form the surface of Saturn's moon Enceladus. NASA/JPL-Caltech and Space Science Institute
Plumes of water seen erupting form the surface of Saturn’s moon Enceladus. NASA/JPL-Caltech and Space Science Institute

In 1950, the physicist Enrico Fermi asked a question not many could forget for a long time: “Where is everybody?” He was referring to the notion that, given the age and size of the universe, advanced civilizations ought to have arisen in many parts of it. But if they had, then where are their space probes and radio signals? In the 60 years since, we haven’t come any closer to answering Fermi, although many interesting explanations have cropped up. In this time, the the search for “Where” has encouraged with it a search for “What” as well.

What is life?

Humankind’s search for extra-terrestrial life is centered on the assumption – rather hope – that life can exist in a variety of conditions, and displays a justified humility in acknowledging we really have no idea what those conditions could be or where. Based on what we’ve found on Earth, water seems pretty important. As @UrbanAstroNYC tweeted,

And apart from water, pretty much everything else can vary. Temperatures could drop below the freezing point or cross to beyond the boiling point of water, the environment can be doused in ionizing radiation, the amount of light could dip to quasi-absolute darkness levels, acids and bases can run amok, and the concentration of gases may vary. We have reason to afford such existential glibness: consider this Wikipedia list of extremophiles, the living things that have adapted to extreme environments.

Nonetheless, we can’t help but wonder if the qualities of life on Earth can tell us something about what life anywhere else needs to take root- even if that means extrapolating based on the assumption that we’re looking for something carbon-based, and dependent on liquid water, some light, and oxygen and nitrogen in the atmosphere. Interestingly, even such a leashed approach can throw open a variety of possibilities.

“If liquid water and biologically available nitrogen are present, then phosphorus, potassium, sodium, sulfur and calcium might come next on a requirements list, as these are the next most abundant elements in bacteria,” writes Christopher McKay of the NASA Ames Research Center, California, in his new paper ‘Requirements and limits for life in the context of exoplanets’. It was published in Proceedings of the National Academy of Sciences on June 9.

Stuff of stars

McKay, an astro-geophysicist, takes a stepped approach to understanding the conditions life needs to exist. He bases his argument on one inescapable fact: that we know little to nothing about how life originated, but a lot about how, once it exists, it can or can’t thrive on Earth. Starting from that, the first step he devotes to understanding the requirements for life. In the second step, he analyzes the various extreme conditions life can then adapt to. Finally, he extrapolates his findings to arrive at some guidelines.

It’s undeniable that these guidelines will be insular or play a limited role in our search for extraterrestrial life. But such criticism can be partly ablated if you consider Carl Sagan’s famous words from his 1980 book Cosmos: “The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.”

In 1991, RH Koch and RE Davies published a paper (titled ‘All the observed universe has contributed to life’) presenting evidence that “a standard 70 kg human  is always making about 7 3He, 600 40Ca, and 3,000 14N nuclei every second by radioactive decay of 3H, 40K, and 14C, respectively”. In other words, we’re not just made of starstuff, we’re also releasing starstuff! So it’s entirely plausible other forms of life out there – if they exist – could boast some if not many similarities to life on Earth.

To this end, McKay postulates a ‘checklist for habitability’on an exoplanet based on what we’ve found back home.

  • Temperature and state of water – Between -15° C and 122° C (at pressure greater than 0.01 atm)
  • Water availability – Few days per year of rain, fog or snow, or relative humidity more than 80%
  • Light and chemical energy sources
  • Ionizing radiation – As much as the bacterium Deinococcus radiodurans can withstand (this microbe is the world’s toughest extremophile according to the Guinness Book of World Records)
  • Nitrogen – Enough for fixation
  • Oxygen (as the molecule O2) – Over 0.01 atm needed to support complex life

McKay calls this list “a reasonable starting point in the search for life”. Its items show that together they make possible environmental conditions that sustain some forms of chemical bonding – and such a conclusion could inform our search for ‘exo-life’. Because we’re pretty clueless about the origins of life, it doesn’t mean we’ve to look for just these items on exoplanets but the sort of environment that these items’ counterparts could make possible. For example, despite the abundance of life-friendly ecosystems on Earth today, one way life could have originated in the first place is by meteorites having seeded the crust with the first microbes. And once seeded, the items on the checklist could have taken care of the rest.

Are you sure water is life?

Such otherworldly influences present yet more possibilities; all you need is another interstellar smuggler of life to crash into a conducive laboratory. Consider the saturnine moon Titan. While hydrocarbons – the principal constituents of terran life – on Earth are thought to have gassed up and out from the mantle since its formative years, Titan already boasts entire lakes of methane (CH4), a simple hydrocarbon. A 2004 paper by Steven Benner et al discusses the implications of this in detail, arguing that liquid methane could actually be a better medium than water for certain simple chemical reactions that are the precursors of life to occur in.

Another Solar System candidate that shows signs of habitability is Titan’s peer Enceladus. In April this year, teams of scientists studying data from the Cassini space probe said there was evidence that Enceladus hosts a giant reservoir of liquid water 10 km deep under an extensive ice shell some 30-40 km thick. Moreover, Cassini flybys since 2005 had shown that the moon had an atmosphere of 91% water vapor, 3-4% each of nitrogen and carbon dioxide, and the rest of methane.

These examples in our Solar System reveal how the conditions necessary for life are possible not just in the Goldilocks zone because life can occur in a variety of environments as long some simpler conditions are met. The abstract of the paper by Benner et al sums this up nicely:

A review of organic chemistry suggests that life, a chemical system capable of Darwinian evolution, may exist in a wide range of environments. These include non-aqueous solvent systems at low temperatures, or even supercritical dihydrogen– helium mixtures. The only absolute requirements may be a thermodynamic disequilibrium and temperatures consistent with chemical bonding.

As humans, we enjoy the benefits of some or many of these conditions – although we know what we do only on the basis of what we’ve observed in nature, not because some theory or formula tells us what’s possible or not. Such is the amount of diversity of life on Earth, and that should tell us something about how far from clued-in we are to understanding what other forms of life could be out there. In the meantime, as the search for extra-terrestrial life and intelligence goes on, let’s not fixate on the pessimism of Fermi’s words and instead remember the hope in Sagan’s (and keep an eye on McKay’s checklist).