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Sunday, January 31, 2010

Destiny and Exploration

The Dimming of Starlight

Ch. 2a

Supporters of space exploration are often perplexed by the failure of their fellow citizens to grasp the significance and fascination of exploring the heavens. In the words of Arthur C. Clarke: "The urge to explore, to discover, to follow knowledge like a sinking star" is its own justification.[1] This self-justification is presumably rooted in human nature or human destiny. As the Norwegian explorer Fridtjof Nansen once said, "The history of the human race is a continuous struggle from darkness to light. It is therefore of no purpose to discuss the use of knowledge - man wants to know and when he ceases to do so he is no longer man." [2]

For supporters of exploration such as these, the matter is quite simple. Since knowledge is of the essence for man, man cannot help wanting to explore. Thus it is destiny that propels us forward into the cosmos. Under such circumstances there is little point in bothering with a more extensive justification. We need only grab history by the tail and make it go where we wish to take it. Why should philosophy force us into reflection where action is so tempting?

One reason for reflection is that appeals to human nature and destiny are not convincing enough. In saying that it is in our nature to explore or that man's destiny is in the stars, we can mean several things, but some interpretations are more central than others. We can mean that

(1) We are going to explore space come what may,

(2) Because of our nature we have a strong tendency to explore space,

(3) Our nature is such that in some important sense we will not fulfill ourselves if we do not explore space.

Let us see how these interpretations fare in the task of making clear that space exploration is a worthwhile undertaking.

Interpretation (1)

From the mere fact that we are going to explore come what may it does not follow that exploring space is to be recommended. We are all going to die come what may, but many of us do not think highly of the prospect. That something is inevitable does not make it good.

Interpretation (2)

The claim that humans have a strong disposition or inclination to explore space does not fare much better. If the claim is true, and I suppose that it is, we may be interested to know why. But if we wish to know whether the exploration of space is wise, we have not yet moved from our starting point. After all, suppose that men had a strong disposition to rape. Should we condone rape then? Should we yield to it or, if no longer able, encourage its exercise by the strong of body and heart? Surely not!

Appeals to nature or evolution do not get us very far.[3] For it would be a mistake to think that any trait with which nature has endowed our species cannot fail to be commendable. The trait in question might be an adaptation to an environment that no longer exists, and thus it may no longer serve us well. The fate of most species that ever lived has been marked by the development of characteristics well suited to one environment but woefully inadequate when the environment changed. Hence they became extinct. Imagine for the sake of argument that our species has a disposition toward war. In these days of nuclear weapons, that is clearly a bad disposition to have. Thus, for the purposes of justification, it is not enough to show that a natural disposition exists: We must show that it is a good disposition.[4] Therefore, to justify space exploration, it does not suffice to learn that man's nature tempts him to the heavens.

Interpretation (3)

This third claim, that because of our nature we will go unfulfilled unless we explore, is perhaps more promising. It would have to specify, however, in what important ways space exploration might fulfill us.[5] To become convincing, it would have to go beyond slogans and platitudes: it would have to supply strong evidence for the conclusion. It would require, that is, a good argument after all. This result thus returns us to the problem the supporters of space exploration face.

If those supporters hope to win over their fellow citizens, they should pay greater attention to why their opponents resist their entreaties. True argumentation cannot take place in a vacuum: You may not always be able to convince open-minded people, but you improve your chances when you consider seriously what keeps these people from coming over to your side. This is why impatience tends to be rhetorically self-defeating. Supporters should start, then, with the objections critics offer against space exploration.

[1]. Arthur C. Clarke, "The Challenge of the Spaceship," Journal of the British Interplanetary Society, December 1946, p. 68. With great honesty he wrote: "Any ‘reasons’ we may give for wanting to cross space are afterthoughts, excuses tacked on because we feel we ought, rationally, to have them. They are true but superfluous - except for the practical value they may have when we try to enlist the support of those who may not share our particular enthusiasm for astronautics. . . . The search for knowledge, said a modern Chinese philosopher, is a form of play. Very well: we want to play with spaceships."

[2]. As quoted in The Impact of Space Science on Mankind, T. Greve, F. Lied, and E. Tandberg, eds., Plenum Press,1976., p 13.

[3]. Actually, if most men, let alone all men, had a disposition to rape, we might suspect that they had it by virtue of being (male) humans. This, of course, would not justify it.

[4]. Some philosophers may be disappointed by my failure to accuse these supporters of exploration of committing the "naturalistic fallacy." In saying that since exploring is part of our nature we need no further justification, the supporters might be thought to claim that "being in one's nature" is sufficient justification to show that exploration is a good thing. And this claim the philosophers would interpret as deducing values from facts (or prescriptions from descriptions, or an "ought" from an "is") – a deduction that presumably amounts to a fallacious inference: the naturalistic fallacy. Some ideological critics also can be thought to commit the fallacy when they charge that the practice of science disrupts the harmony of nature. I am not quick to make such accusations, however, because they fit only the most simplistic and often distorted version of the position under discussion. My impression is that most of the "classic" examples of the naturalistic fallacy are nothing but arguments that were taken out of context, oversimplified, and distorted so as to serve as illustrations of a neat "logical" point. A more detailed discussion of this claim belongs in a different kind of work (see my "Review of Peter Singer's The Expanding Circle," Explorations in Knowledge, Spring 1987, p.43; “Evolution and Justification,” The Monist, Vol. 71, No. 3, 1988; and especially “The Morality of Rational Ants,” Ch. 11 of my Evolution and the Naked Truth, Ashgate, 1998. At any rate, we can see in the text below that the supporters of exploration can, with some thought, express their insight in terms of fulfillment – a move that does not strike me as fallacious.

[5] I am sympathetic to this intuition, as will be seen throughout this book, although I am critical of some of the ideas involved in what some have called the “space imperative,” which is discussed by G. Genta and M. Rycroft in their book Space, the Final Frontier? Cambridge University Press, 2003. Indeed, some versions of the space imperative fall under the interpretations 1 and 2 criticized above.

Saturday, January 23, 2010

The Obligation of Philosophy

The Dimming of Starlight

Ch. 1D

It is actually surprising that professional philosophy has not taken up in earnest the question of whether space exploration can be justified. After all, it is part and parcel of philosophy to examine the justification of all significant human activities, including science and technology. Professional philosophers have examined, for example, what computers can and cannot do[1], whether human cloning should be permitted[2], and the extent to which even theoretical scientists are morally responsible for their research.[3] But the call of the “final frontier,” whose significance may well dwarf all other human adventures, has received only scant attention from philosophy. The lack of interest is due in part to the fact that fundamental research has the highest prestige in philosophy, and a field named “the philosophy of space exploration” probably sounds like applied philosophy to most practitioners. But the distinction between fundamental (or pure) and applied can be as misleading in philosophy as in science. This can be seen, for example, in the case of the philosophy of artificial intelligence, where it became clear that the mind is not at all like a digital computer – a fundamental finding in philosophy. I would argue that the deep practicality of science, found in the examination of space science, is also a fundamental finding. Whatever the reason professional philosophy has not concerned itself with the exploration of space, this book is an attempt to remedy that oversight.

Scientific textbook mythology would have us believe that Galileo’s opponents simply refused to believe their own eyes when looking through his telescope (or worse, refused to even look through it!). But the documents of that time indicate instead that many who looked through Galileo’s telescope saw double images or the disc of the Moon displaced to one side, and some people could see nothing at all where Galileo claimed the existence of Jupiter’s moons. This is not surprising. When we perceive we make use of many clues from the environment. We estimate at a glance, say, how large a new painting is, because we see that it takes up so much of a familiar wall. Without those clues, our vision is prey to all sorts of illusions. For example, a point of light on a dark background may appear to move around rapidly. That is why Jupiter shining through a fog in the early evening is often reported as a UFO. Consider also that Galileo’s telescope was primitive and built for his eyes (it lacked a focus mechanism). And to make matters worse, the testimony of the telescope often conflicted with that of the unaided eye.[4]

One of those conflicts involved the brightness of starlight, for in Galileo’s telescope the magnitude of the stars did not keep pace with that of the planets (planetary disks were enlarged, whereas stars remained points of light). Some observers even complained that his telescope made the stars look dimmer[5]. The dimming of starlight was then one of the illusions that threatened the new scientists' exploration of the cosmos. Four hundred years later, as we seek to launch human and machine alike to new worlds, there are those who recoil at the very thought. Where vision once undercut the exciting appeal of the new, today social and ideological misgivings would keep us from reaching for the heavens.

Supporters of space exploration sometimes find favorable omens in the insights of long ago. They should be delighted by Ovid's account of the difference between man and beast: "God elevated man's face and ordered him to contemplate the stars." It is for us now to determine whether Kepler was right in thinking that we should go beyond contemplation and reach for the stars. If he was, we should not let their light dim again.

[1] The first classic work in this field was H. Dreyfus, What Computers Can’t Do: A Critique of Artificial Intelligence, Harper, 1972. For a work on the nature of mind that includes neural nets (and thus parallel as opposed to serial processing) see P. Churchland, The Engine of Reason, The Seat of the Soul, MIT Press, 1975. Part of the discussion in Chapter 8 will be based on insights derived from these works.

[2] See, for example, Inmaculada de Melo-Martín, Taking Biology Seriously: What Biology Can and Cannot Tell Us about Moral and Public Policy Issues, Rowman and Littlefield, forthcoming.

[3] See G. Munévar, "The Moral Autonomy of Science and the Recombinant DNA Controversy," Journal of Social and Biological Structures, 1979, 2, pp.235-243.

[4] P.K. Feyerabend, Against Method, Verso, 1993, Third Edition, Ch. 9.

[5] As described in Feyerabend’s Against Method, ibid, n26, pp. 92-93.

Coming up next: Why there is a need to justify the exploration of space.

Saturday, January 16, 2010

Long-term exploration, SETI, space war

Dimming of Starlight

Ch. 1C

Space scientists, who may be generally sympathetic to the main theses of this book, are nevertheless deeply divided on the question of how best to explore space. Some claim that exploring with humans is frightfully expensive and dangerous, that the Space Shuttle has set back the cause of exploration, and that continuing to favor astronauts over robot spacecraft will set it back even further. And they are indeed correct – in the short run. I argue in Chapter 7 that a measured increment of the human presence in space will eventually lead to even greater opportunities for all the space sciences. I also point out how the proposed colonization of other planets, the mining of the asteroids, and the expansion into the outer solar system, and perhaps the galaxy, may secure the survival of the human species. Of course, such fanciful proposals may be little more than far-fetched dreams, but those dreams begin to pull us away from our mother planet, and as they color our perception of space exploration they influence its direction. Even more fanciful, although of special scientific and philosophical interest, are the heated debates about relativistic starships and faster-than-light travel.

Perhaps no aspect of space exploration has been as controversial as the search for extraterrestrial intelligence (SETI). For some it has been a noble calling, for others the most ridiculous waste of money and effort. The critics won the day in Congress when NASA was forced to drop SETI altogether many years ago, although private donations and platoons of volunteers have kept the search going. As we will see in Chapter 8, many of the arguments for and against the existence of extraterrestrial intelligence are based on what Carl Sagan called the “Principle of Mediocrity” (that the Copernican revolution has taught that there is nothing special about the Earth or its place in the universe). But, as I will argue, such a principle does not stand up to criticism. We have no good reasons for optimism or pessimism on this matter: the most reasonable position is agnosticism.

This is not to say that SETI is a worthless enterprise. For example, the problem of how we might communicate with extraterrestrial civilizations, if there are any, teaches us a few things about how we understand the world and ourselves. It is often thought that advanced species will have discovered many of the fundamental laws of physics, chemistry, and so on; otherwise they could not make the attempt to communicate across the vastness of interstellar space. But since the laws of nature are (presumably) the same everywhere, and since they are expressed in mathematics, all advanced species will have things in common that can serve as the basis of communication. According to this conventional wisdom, then, there must be intellectual convergence between highly intelligent species, just as there is convergence of form between fishes and dolphins.

But how can we support this assumption of convergence? Evolutionary history is made up of millions of contingencies. It would be practically impossible for life to evolve in other worlds along the same paths it has followed on Earth. We thus face an unpleasant consequence: a different evolutionary history may produce different brains – different ways, that is, of perceiving the environment and of putting those perceptions together. And those are the brains that will one day develop science. It is thus plausible to suggest that those brains will operate with mental categories different from ours, and that alien science and mathematics may also differ from ours. Discussing the assumption of convergence will thus involve us in the philosophical problem of whether we discover or invent science.

Another idea whose discussion leads to a better understanding of living beings is the suggestion by Freeman Dyson and others that we should use von Neumann self-reproducing machines to colonize the galaxy. I argue, also in Chapter 8, that the very idea of such technology is based on the mistaken metaphor of the genome as a computer program. The speculations by Robert Zubrin that nanotechnology will allow us to get around the overwhelming obstacles to self-reproducing machines do not get very far either, for some of the most fanciful claims made about nanotechnology are also without justification.[i]

Many interesting issues come up in the details of practically all the fields of exploration discussed in this book. In Chapter 4, for example, I note that an argument against the possibility that Venus once had oceans has the same structure as an argument for the end of the world (or more precisely, of humankind) advanced by the philosopher John Leslie and inspired by the physicist Brandon Carter’s account of the anthropic principle. In my opinion, both the objection to Venusian oceans and Leslie’s argument assume an untenable view of probability.

Whatever the benefits of space exploration, it also involves a variety of risks. One danger, in particular, seems to be of great importance: the unavoidable connection between space technology and war. This connection is presumably made quite obvious by the terror inflicted upon London in World War II by Wernher von Braun’s V2 rockets, and strengthened by Ronald Reagan’s proposal for a Star Wars defense against the Soviets’ intercontinental ballistic missiles, themselves strong evidence of the evils men fall prey to when reaching for the heavens. We will see in Chapter 9, however, that the connection between space technology and war is not quite that obvious. Its apparent plausibility comes from popular historical interpretations of the relevant episodes, but a closer look fails to support the claim that the connection is unavoidable. Moreover, space technology may prove to be key to the long-term survival of terrestrial life, as Zubrin and others have claimed.

By Chapter 10, it will be clear that the profound practicality of science, via the serendipity that is its natural consequence, provides an adequate response to the social critics. Our new understanding of science in light of space exploration will also set aside the concerns of the ideological critics. Most ideological criticisms stem from purported insights about the relationship between human beings and the environment of the Earth – insights such as the balance of nature, the wisdom of non-interference with natural processes, and so on. But as we will see, such insights do not withstand scrutiny. Moreover, to offer a strong argument, the ideological critics need a global understanding of the Earth’s environment. But as I explain again in this final chapter, that global understanding requires the assistance of comparative planetology and space technology. To meet their ultimate goals, and our obligation to future generations, they would do well to ally themselves with the “big science” they so often deride.

[i] Robert Zubrin’s seminal ideas about exploration will be discussed in several other chapters, particularly in Chapter 7.

Saturday, January 9, 2010

Value of space science

The Dimming of Starlight: The Philosophy of Space Exploration

Ch. 1b

The notion that science and space exploration go hand in hand may seem obvious to a casual observer, but it has been bitterly contested over the years. Many scientists, perhaps the majority of scientists, were opposed to the Apollo program, to put a man on the Moon, on the grounds that it was political showbiz and not science. And just about every important field of space science has been denigrated, at one time or another, in the most prestigious and established quarters of science. Some of those fields still are.[i] And if we pay attention we may still hear rumblings that all that money should go for truly important research. Indeed, a common complaint, particularly in the physical sciences, has been that space science is merely applied science, and thus it would follow that, if we wish to forge changes to our fundamental views of the world, we should concentrate on putting our money and effort into fundamental science, not into space science.

In my reply I will show how every main branch of space science leads to new perspectives of immense value. I will argue in Chapter 4 that several of the main problems that our planet confronts now (e.g., the depletion of the ozone layer and global warming), as well as those it will probably confront in the next few centuries, are far more likely to be solved thanks to space exploration in two ways. The first is that such problems tend to be global problems and space technology is particularly well suited to study the Earth as a global system. The second is that as we explore other worlds we gain a broader and deeper understanding of our own planet.
From comparative planetology we will move on to space physics and astronomy, two fields ripe with the promise of radical changes to our scientific points of view. Such changes will in turn yield an extraordinary new harvest of serendipitous consequences for technology and for our way of life. The reason these two fields are ripe with promise is simple. The Earth’s atmosphere limits drastically the information we receive about the universe because it blocks much of the radiation that comes in our direction. This shielding is, of course, a good thing, for otherwise life could not exist on our planet. But to make even reasonable guesses about the nature of the universe, we need that information. That is why we need telescopes in orbit and eventually on the Moon and other sectors of the solar system. Until the day when space telescopes began to operate, many physicists thought of space physical science as applied science, mere application, that is, of the very successful “standard model” that explained matter in term of its constituting particles and the forces between them.

But, as I discuss in Chapter 5, physicists had been trying to explain a limited universe – a universe based on what we could observe through a few peepholes in the walls that protected us from cosmic dangers. It had already been known for some time, though not widely, that the visible mass in galaxies did not exert enough gravitational force to keep their outer rims of stars from being flung into intergalactic space. Astronomers presumed that eventually the missing mass would be found, but when space telescopes gave us the whole electromagnetic spectrum to look for that mass, we still could not find enough of it. According to some high estimates, up to 90% of the mass needed to account for the behavior of galaxies is undetectable (“dark matter”), apparently unlike the matter explained by the “standard model.”

To make a bad situation worse, in the late 1990s space astronomers discovered that the expansion of the universe was accelerating, even though we should expect that, after the Big Bang, gravity would slow down the rate of expansion. A new form of energy (“dark energy”) is supposed to explain this bewildering state of affairs, once we determine what its properties are.

Fundamental physics, which uses the “standard model” to think about the universe, explains familiar matter and energy. But most of the universe seems to be made up of unfamiliar dark matter and energy, perhaps even upwards of 90% when you combine those two. This means that thanks to space science we found out the extraordinary extent of our ignorance, and that space science is a necessary tool for developing a new physics.

Space exploration is also ripe with promise for biology. This promise is particularly interesting in the case of the astrobiologists’ attempt to search for life in other worlds. For example, when a NASA team announced in 1996 that a Martian meteorite contained organic carbon and structures that looked like fossils of bacteria, meteorite experts adduced that inorganic processes could account for all the substances and structures found in the meteorite. Therefore, these experts claimed, by Occam’s razor, we should reject the (ancient) Martian-life hypothesis (Occam’s razor is a principle that favors the simpler hypothesis; it is named after William of Occam, a medieval philosopher). Other scientists pointed out, in addition, that the presumed fossils were about one hundred times smaller than any known bacteria, too small in fact to be able to function as living organisms. But as we will see in Chapter 6, Occam’s razor would, if anything, favor the Martian-life hypothesis; and, ironically enough, the claim about the minimum size of living things spurred a search that, according to some, yielded many species of extremely small bacteria, nanobacteria, some even smaller than the purported Martian fossils![ii] Space biology proper (doing biological experiments in space) has not yet produced such spectacular and significant discoveries, but, as we will also see in Chapter 6, the main objections against its scientific value are based on misguided distinctions between fundamental and applied science not unlike those advanced some years ago against the space physical sciences. Some of these objections are also based on mistaken assumptions about genetics, and particularly about the relationship between genotype and phenotype.

[i] These points will be discussed in detail in Chapters 3-7. Stephen G. Brush has aptly illustrated the significance of the space sciences to the development of physics, as will be seen particularly in Chapter 5.
[ii] This is a controversial matter, but I will argue in Chapter 6 that this particular controversy is beneficial for biology.

Next Posting: brief summary of the additional controversies about space exploration to be explored in this book: humans vs. machines in exploration; space colonization; terraforming; travel at relativistic speeds; travel faster than light; SETI; space and war.