यदिहास्ति तदन्यत्र। यन्नेहास्ति न तत्क्वचित्॥
Yadihāsti tad anyatra. Yannehāsti na tat kvacit.
What is here is elsewhere.
What is not here is nowhere.
In the late 16th century, Giordano Bruno told a surprised Europe that Earth was far from being the only place with living things on it.
Bruno (born 1548, died 1600) was a natural philosopher — a seeker of wisdom about nature. He was influenced by the ideas of Copernicus (1473 - 1543) and Nicholas of Cusa (1401 - 1464). He arrived at the idea that the object we call the Sun is but one of innumerable suns. The other suns, Bruno argued, are so far away that they appear to us as mere fixed stars. Around the other suns, other earths revolve. And the other worlds are inhabited: even if "not exactly as our own", still "no less nobly". 2
Bruno was burned at the stake for heresy in February 1600. There is some historical debate about whether the inquisitors condemned him because of what he said about stars and planets, or whether it was because of other opinions he had expressed — his alleged pantheism, and his views about Mary and Jesus…
In any case, he was right about other suns with planets going round them. Today planets of other suns are called "extra-solar planets" or "exoplanets". It is not known whether every star has them, but many have been detected and catalogued in the last 20 years. 3
Was he also right about the universe being full of life?
Why did Bruno think other solar systems existed? It was not because he actually saw any. Because of their size and distance, exo-planets are extremely difficult to observe from Earth, even with modern equipment — it is out of the question that the sixteenth century philosopher could have observed them.
Bruno's conception of the universe was based on the principle of consistency — he believed that comparatively distant bits of it were similar in character to the bits nearer home. This principle of consistency has been called the "Copernican principle" or "mediocrity principle". But it is based on a sense of the unity of nature which is older than Copernicus, though the work of Copernicus is indeed a powerful example. And it has little to do with "mediocrity" in the everyday sense.
Natural philosophy, east and west, has for thousands of years been based on the view that its subject matter, nature, is a coherent whole, based on relatively simple underlying principles. And even though modern science has rejected many tenets of earlier natural philosophy, it has continued to look for simple general principles underlying the complexity and diversity of the world we see.
Consider the work of Copernicus… To those who live on it, the Earth does not look much like those bright objects in the sky which the ancients called "wandering stars". "Wandering star" in Greek is planetes aster, a term that got shortened to "planet". However, Copernicus argued that the way the planets seem to wander, is caused by the fact that they go around the Sun, while the Earth itself does the same. The Earth not only moves, it moves in a way consistent with the movement of other planets. We are living on a wandering star.
What then of Giordano Bruno's thesis that life is abundant in the universe? That thesis, too, is based on the principle of consistency…
Despite considerable discussion between Bruno's time and today, the scientific community remains uncertain about life beyond Earth.
Some once-serious arguments, both for and against the prevalence of life, now seem ridiculous.
Later in the twentieth century, by using better instruments and by making comparisons with other galaxies, scientists learned more about the structure of the Milky Way, and established that our Solar System is nowhere near its centre. It turns out we are in a spiral arm. If living things can only function close to the centre of a galaxy, we earthlings are in serious trouble…
Compared to just a couple of decades ago, the tide of well-informed opinion today is running in Giordano Bruno's favor. The scientific world is going through a paradigm shift, 5 due in part to new data from the Solar System and beyond, and in part to new ways of thinking about the way life works.
The paradigm shift is opening up fields of research which did not seem to exist in the nineteen eighties.
In the 1980s, Earth, as a life-bearing planet, was considered unique in the Solar System. At that time no planet outside this Solar System had been detected. Although life elsewhere in the Milky Way Galaxy (and other galaxies) had not been ruled out, the prospects of actually finding it seemed remote.
Norman Horowitz, a biologist associated with the Viking mission, made the following statement in 1986:
Since Mars offered by far the most promising habitat for extraterrestrial life in the solar system, it now virtually certain that the earth is the only life-bearing planet in our region of the galaxy. We have awakened from a dream. We are alone, we and the other species, actually our relatives, with whom we share the earth.10
It was a strong statement. But there is such as thing as a false awakening — emerging from one dream into another…
As I write this article (in August 2011), life beyond Earth, yet within reach of Earth science, is again a wide open question. Life on Earth's neighbors — the other worlds of our Solar System — hasn't been proven to exist, but the arguments against its existence now look a lot less persuasive than they did in the nineteen eighties. Another thing that has changed is that planets of other stars are now known to be common, and information about them continues to increase.
Free oxygen (O2) is rare in the solar system. This does not rule out living things, but does suggest they would have to make do with less energy.
Even here on Earth — there are many single-celled organisms (known as anaerobes) that are quite happy without O2, as are a few species of the multicelled (but tiny) loricifera. 23 On the other hand, using free oxygen to burn sugars is a more productive way of getting energy than, for instance, reacting hydrogen with carbon dioxide (as some Earth anaerobes do), or reacting hydrogen and acetylene (as may be happening on Titan). Life seems to be able to do more with oxygen than without it. Lack of free oxygen on Mars and Titan may mean that organisms there have a size and a complexity comparable to bacteria or loricifera.
One place free oxygen does exist is in the thin atmosphere of Europa. Some of the oxygen may possibly find its way into Europa's subsurface ocean; if so, the dissolved oxygen could provide energy for multicelled living things as large and lively as fish. 24
There is a theory that cells on Titan, with cytoplasm based on liquid methane instead of water, would be larger than most cells on Earth, but would have a slower rate of metabolism. 25
Chemical building blocks of life, such as amino acids, are known to be fairly common in the universe. However, even simple forms of life are extremely complex compared to these building blocks.
According to the biologist Lynn Margulis: "To go from a bacterium to people is less of a step than to go from a mixture of amino acids to a bacterium." 26
There are different theories about how that step was taken, whether it was a stroke of luck or an inevitability, and how likely it is to have happened elsewhere. (See our page Clockmaker, casino, or crystallization?)
If nature elsewhere in our own solar system has taken the giant step from chemistry to microbes... it has to increase our hope — or fear? — that, on planets of other stars, life has taken what Margulis considers a lesser step, and gone from microbes to beings as complex and adaptable as we humans are... or perhaps just a bit more complex, more adaptable…
People who raise the question of life beyond Earth are sometimes charged with romanticism, wishful thinking. 27 The idea of abundant life in the universe is certainly one that speaks to our emotions, as well as to our reason.
But perhaps there is wishful thinking on both sides of the discussion.
The claim that our Earth is a world in a class all of its own — this claim, too, has its emotional appeal, as suggested by the popularity of the "Lonely Planet" brand of travel books.
A century ago, Alfred Russel Wallace complained that the existence of many inhabited worlds "would imply that man is... of no importance". 28 By Wallace's logic, the idea that only our world has life gives us earthlings more importance. It appeals to our collective pride.
Michael Medved, a conservative American intellectual, has drawn attention to polls suggesting that US citizens on the political right are less likely to think there is intelligent life beyond Earth, than are those on the left. Medved concludes that "an impassioned affirmation of American exceptionalism naturally connects to comparable assumptions of earthly exceptionalism". 29
If you believe the USA is a country like no other, it is easier to believe that the Earth is a world like no other. If you believe Earth is a world like no other, it is easier to believe that the USA is a country like no other.
If the thought of life beyond Earth can weaken national pride, that may be an excellent reason for thinking about this topic more.
A Christian scholastic, Benjamin Wiker, has compared the notion of extraterrestrial life to stories about elves. 30
I would compare them instead to the fauna of Australia — animals such as the kangaroo and the platypus. Not in the sense that I expect an extraterrestrial life-form to look anything like a platypus or a kangaroo. Simply in the sense that the platypus and the kangaroo…
Conversely, the knowledge-holders of Australian Aboriginal communities, who did know about the kangaroo and the platypus, knew nothing about the animals of other continents, such as the deer and the horse.
Why is it, that until the late eighteenth century, the natural scientists of the northern hemisphere knew nothing of the distinctive animals of Australia? Was it because Australia itself was unknown to them?
In fact that wasn't the reason: the continent of Australia had been visited by sailing ships since 1606. It was simply because the seafarers who did visit Australia hadn't investigated it sufficiently to find the kangaroo and the platypus.
Until we explore worlds such as Mars and Titan more thoroughly than we have, we can't expect to know what is there.
I began this article with a quote from the Tantraśāstra. I will close with one from the New Testament:
Seek and you will find.
Matthew 7: 7
1 Viśvasāra Tantra, cited in Arthur Avalon; Shakti and Shākta; Dover, NY, 1978; p 277.
4 Alfred Russel Wallace; Man's Place in the Universe; New York, McClure, Phillips and Co, 1903; Chapter XVI.
6 Steven J. Dick; The Biological Universe; Cambridge Universe Press, 1996; p 153.
7 Based on Lynn Margulis' description of Martian atmosphere in Stewart Brand; Space Colonies; Penguin 1977; p 124.
9 Steven J. Dick; The Biological Universe; Cambridge Universe Press, 1996; chapter 8.
10 cited in Steven J. Dick; The Biological Universe; Cambridge Universe Press, 1996; p 157.
12 Dauna Coulter, "A Fizzy Ocean on Enceladus", NASA Science, 26 Jan 2011 (accessed 7 Sept 2011)
16 Clara Moskowitz, "Scientists: Potential Mars water find a 'big deal' ", CBS News, 10 Aug 2011. (accessed 7 Sept 2011)
17 Guy Webster, "Missing Piece Inspires New Look at Mars Puzzle", NASA Jet Propulsion Laboratory, 3 Sept 2010, (accessed 3 Sept 2011)
19 Committee on the Limits of Organic Life in Planetary Systems, Committee on the Origins and Evolution of Life, National Research Council (USA); The Limits of Organic Life in Planetary Systems; The National Academies Press, 2007.
21 See the Wikipedia article "Mars Science Laboratory" where a list of references is given.
23 Janet Fang, "Animals thrive without oxygen at sea bottom", Nature News 6 April 2010 (accessed 10 Sept 2011)
24 Irene Klotz; "Europa, Jupiter's moon, could support complex life"; Discovery News, 8 Oct 2009, (accessed 3 Sept 2011)
25 Dirk Schulze-Makuch and David H. Grinspoon; "Biologically Enhanced Energy and Carbon Cycling on Titan?", arxiv.org, page 4 (accessed 3 Sept 2011)
27 See for instance the final chapter of Paul Davies; The Origin of Life; Penguin 2006
28 Alfred Russel Wallace; Man's Place in the Universe; New York, McClure, Phillips and Co, 1903; p 317.
29 Michael Medved; "Extraterrestrials, American Exceptionalism and the Left-Right Gap"; Townhall, 29 Dec 2010 (accessed 5 Sept 2011)
30 Benjamin Wiker, "Alien Ideas Christianity and the Search for Extraterrestrial Life", Crisis Magazine, November 2002. (accessed 5 Sept 2011)
© Colin Robinson 2011
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