LIFE IN SPACE: THE COMPLETE STORY?

Chapter 6L

LIFE IN SPACE: THE COMPLETE STORY?

Astrobiology and what I have called space biology proper do not exhaust the possibilities that space offers to the life sciences. Those possibilities extend to many areas in which our understanding of life may have profound consequences for our interaction with nature. I would like to conclude this chapter by considering briefly three novel areas of investigation.

The first may be called planetary biology, or perhaps global biology. So far I have discussed our attempts to understand micro-organisms, plants, and animals. But we also wish to understand the living environment as a whole and in relation to the other components of the global environment. Planetary biology attempts to achieve this by means of interdisciplinary research that makes extensive use of space techniques for atmospheric sampling and remote sensing. From the remarks made in Chapter 4 it is clear that the study of the role of bacteria and plants in the global environment fits in nicely with the aims of planetary science. Planetary biology expands the scope of investigation and makes the relationship to general planetary science all that more evident. One of its initial aims is to trace the flow of nitrogen and sulfur in the marine environment off the coast of California, and to determine the mechanisms by which different compounds of these elements are converted into others.[1] The eventual goal of this new field is quite ambitious. In Harold Klein's words, it is "to treat the planet as an ecosystem and try to understand the laws of this ecosystem."[2]

A second area of investigation involves the construction of closed environments in space. Until now we have not built any really closed environments up there -- natural wastes are thrown into space, not recycled as on the Earth, oxygen is lost to the vacuum, and so on.[3] Furthermore, the balance of those environments is maintained by artificial means. Whether we can ever built living closed environments in space is a matter of controversy. Indeed, at this time we cannot even determine the minimum size required for a naturally self-sustaining environment amenable to Earth life. But in trying to build one we may learn much. In fact, even artificially closed environments may teach us valuable lessons about terrestrial ecology.

There are several obstacles that limit severely the knowledge we can obtain about an ecological system. One of them is that the amount of variables involved, most of which are interrelated, is simply unmanageable. And even when this obstacle is overcome, the victory seldom lasts long. Normally, a model of a system accounts for changes in one part of the system by changing the amount of reaction in other parts. More sophisticated models may go as far as predicting the rate of such reaction. The problem is that, when confronted with different circumstances, organisms sometimes change not just the amount and rate but the modality of reaction. This problem is illustrated by two examples from a report of the National Academy of Sciences entitled Life Beyond the Earth's Environment: "...many bacteria will use available nitrogen if it is present but in its absence become fixers of nitrogen from the air. Brown hydra in competition with green hydra will, in the presence of abundant food, eat their competitors, and in the absence of abundant food, will float away to some new location leaving the area to the green hydra alone."[4]

Another problem is that a complete description of an ecosystem often requires that we count the numbers of each kind of organism in order to ascertain what it contributes to the flux of matter and energy of that ecosystem. But such counting, for example of worms in the soil, in many cases destroys the ecosystem we are merely trying to describe.

A suggestion for getting around these problems is that we test models of the system in closed versions of it. These models would not attempt to represent every element of the system -- which would be practically impossible -- but would be based instead on a list of the species present and on the roles played by the species presumed to dominate the system. The suggestion is that we build closed environments in accordance with one such model, and then partition them in a variety of ways. We can learn from the interruptions in the normal flows and cycles of the system what its crucial factors are. By disturbing or interrupting the cycle of nutrients, for example, many species may starve while their food accumulates elsewhere, and others may be poisoned by the concentration of toxic wastes that normally would have been washed away. Of course, these partitions do not only take away from the system, in some cases they add to it; just as a dam that interrupts the flow of a river creates a habitat favorable to a variety of organisms that would have been at a disadvantage otherwise.

Intelligent manipulation of this ecology of failure offers the prospect of many exciting questions and experiments. But on Earth there are two serious limitations. One is that the only completely closed system is the Earth itself, which, though open to energy, is relatively closed to matter. Partial closure is of course satisfactory for many investigations, but in some cases we may need greater experimental control. Another limitation is that some closures may be dangerous or undesirable (they may produce very toxic substances, for example). Space offers an opportunity to achieve perfect closure in many investigations that cry out for it; it also permits us to carry out some of the most dangerous experiments in capsules safely isolated from our home planet.

An apparent limitation of space is that larger and richer environments cannot be easily recreated. But there is a sense in which this limitation becomes an advantage. An increased manned presence in space means a greater complexity of man-made habitats, perhaps with a serious attempt to create space agriculture. But this would automatically require that as the ecosystem gets larger we learn more and more about what the crucial flows and cycles are and what it takes to maintain them. A lunar base, for example, can be viewed as an experiment to determine the degree to which environmental sufficiency can be achieved. And a Martian colony may be in a good position to experiment with a variety of environments for agriculture, since the red planet is rich in resources and the colonists may thus have many choices in the composition of such environments. Gerard O'Neill's space colonies may have an even greater potential.

A third area of promise is the invention of new tools to investigate the basic levels of organisms. This point seldom receives the attention it deserves. The absence of gravity permits the development of experimental techniques that are either very difficult or plain impossible on the surface of the planet. I will mention a few ideas that have been suggested over the years, just to catch the flavor of the possibilities.

The technique of electrophoresis, which was described in Chapter 2, can become a useful tool for the production of pure drugs. But its real potential may be found in research instead. For example, our metabolic processes are controlled by about 2,000 enzymes, of which as many as one hundred are mixtures of isozymes. With electrophoresis, we can separate and study those isozymes. If nothing else we can vastly improve our diagnostic skills in matters concerning imbalances and disorders of the human body.

And I think there is reason to believe that this use of electrophoresis in space may herald a new generation of analytical tools for biologists and medical researchers. And that reason is simply that by removing gravity we may not only gain much in purity but also take advantage of the fine operation of electric currents. Some of this fine operation already pays dividends on Earth. Using weak pulsed electric fields, for instance, it is possible to induce cells to fuse, a technique that leads to very unusual new cells. It can be used, among other things, to fuse tumor cells with the spleen cells that produce the specific antibodies that could destroy the tumor if there were only enough of them. The value of one of these fused cells (hybridomas) is that it will make many copies of itself (clones). And all of these copies will produce the same antibody of the original spleen cell, but now in large amounts, we hope, to get rid of the tumor once and for all. I do not know whether this very technique will prove feasible in space.[5] But others kindred to it may find in the advantages of space (purity, effective use of weak currents) the right spark to ignite a new explosion in biomedical research.

Many tools for medical research, and many new medical technologies may come from physics instead. According to an article by John Tierney:

The Russians invented an air scrubber using strong electric fields and cold-plasma chambers to prevent biological contamination of the air in the MIR space station. Now the French-based firm AirlnSpace, with support from the European Space Agency, have refined the Russian invention to create the portable “Inmunair.” According to the firm’s general manager, the system successfully screened anthrax and small-pox substitutes in laboratory tests.[6]

These three areas are mere examples. I have neither the expertise nor the imagination to evaluate all the promise of space biology. Suffice it to say, for now, that space biology is in a position to ask not only new questions but also new kinds of questions. In this, like the rest of space science, it fulfills the function of preserving the dynamic character of science. Some of space biology, the search for origins in particular, merits its pursuit as a main goal. Space biology proper, as I have called it, is in its theoretical and experimental infancy, and will probably have to ride as a passenger of other space undertakings. Nevertheless I have given reasons why it is worth supporting in its own right. For the time being, it can be considered as one of the benefits that come to us from the general exploration of space.

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[1] For example, to what extent is dymethyl sulfide produced by marine algae?

[2] Harold Klein, "The Biological Sciences and NASA," NASA Advisory Council Talk, May 1983, p.5 of the text.

[3] For a discussion of these issues see Life Beyond the Earth's Environment, a report of the Space Science Board of the National Academy of Sciences, 1979 (section in ecology, pp. 105-132); R.M. Mason, J.L. Carden, eds., Controlled Ecological Life Support System: Research and Development Guidelines, NASA CP-2232, 1982; B. Moore III and R.D. MacElroy, Controlled Ecological Life Support System: Biological Problems, NASA CP-2233, 1982; and B. Moore III, R.A. Wharton, R.D. MacElroy, eds., Controlled Ecological Life Support Systems: First Principal Investigators Meeting, NASA CP-2247, 1982.

[4] Life Beyond the Earth's Environment, ibid., p.111.

[5] There are three problems with this technique as a weapon against cancer. One is the difficulty in the formation of hybridomas. In this, weak currents offer some advantages over competing technologies. My guess is that these advantages would be even more apparent in microgravity. A second problem is the stability of the hybridomas. In this, the record of microgravity experimentation should offer some encouragement. The third problem is the selection of the appropriate spleen cell to fuse with the tumor. In this, space does not offer special advantages, unless we consider the possibility of refined techniques of separation and identification.

[6] John Tierney, “Outer Space on Earth: NASA Should Try It,” reprinted in Detroit Free Press, August 2, 2005, p. 7A. Tierney’s derogatory comments are limited to the Space Shuttle. He does believe that much worthwhile scientific exploration can be done otherwise.

Dark Problems

Chapter 5B

Dark Problems

AN EXAMPLE: THE DARK SIDE

It had been suspected for some time that galaxies had far more matter than we could determine from what was visible. Once we were able to look at galaxies in the full spectrum we realized that perhaps as much as 90% of some galaxies’ mass was unaccounted for (one main reason for this realization is that the outer stars in a galaxy are going so fast that without that much extra mass to keep them in, they would be flung into intergalactic space). But apparently most of that missing mass (now called “dark matter”) cannot be seen, for it does not interact with ordinary matter, except through gravity. In other words, most of the matter in the universe is completely different from anything we have known until now (it is not made up of protons, neutrons, electrons and the like). To study dark matter it is necessary to observe the universe with space telescopes, as will be explained below.

To make matters worse, it was discovered that the expansion of the universe is accelerating, in violation of the sensible belief that gravitational attraction should slow down and perhaps even reverse the expansion initiated in the most famous of all explosions, the Big Bang. A new form of energy, Dark Energy, which we understand even less than we understand Dark Matter, presumably accounts for that perplexing expansion. Since dark energy and dark matter take up most of the universe, our precious Standard Model tries to explain the entire universe on the basis of the less than ten percent of matter that it is acquainted with. Imagine that you come to a new place and get to know ten percent of it. All you know about the rest is that it is completely different from the small portion you know. How confident would you feel about explaining the whole on the basis of the one part you can handle? And then add the complication that Dark Energy make up two thirds of the universe!

Again, to study dark energy we need to go into space, sooner or later. Some of the work of surveying the universe can be done with terrestrial telescopes, but the findings of such surveys will have to be corroborated and supplemented by telescopes in orbit, as we will see below. This means that to have much of a chance to come up with a fundamental explanation of the universe we need to do space science. Some physicists still hope that in the new particle accelerators, which will produce very high energies, violent collisions will yield some dark matter particles. And, who knows, their hopes may perchance be realized, but since we do not know what dark matter is, those physicists sound a bit too optimistic. And even then we would still have the even bigger puzzle of dark energy.

To do away with the problem of Dark Energy, some physicists have proposed to replace the Theory of General Relativity with another theory in which gravity is not a constant. This hypothesis, which is rejected by most physicists, would of course represent a radical transformation of fundamental physics brought about by space astronomy and physics. Either way, space science should receive significant credit for the serendipity that will result from the soon-to-be new physics.

SPACE SCIENCE AND THE TRADITION OF FUNDAMENTAL PHYSICS

Let us begin our discussion of Claim (1) by remembering that the connection with astrophysics has been a trademark of modern physical science from its inception and throughout most of its history.

Although it is well known that Copernicus proposed that the sun and not the Earth was at the center of the universe, his motivation is not so well understood. It was not that his system could account for the position of the planets clearly better than the Ptolemaic system, for even Copernicus acknowledged that the matter was not settled. Nor was it obvious either, in spite of the claims by Pierre Duhem and others, that his system was vastly simpler. It is true that the Ptolemaic system employed a variety of mechanisms--epicycles, eccentrics, deferents, equants--to account for the paths of the planets, but with the exception of the equant so did the Copernican system. (See figures).[1] The difference was that the Ptolemaic system often had alternative combinations of such mechanisms for different aspects of the behavior of the same planet. This would seem outrageous to someone weaned on the notion that only one such mechanism could be correct. But the mere talk of correctness assumes that we can inquire about the real nature of the heavens.

We feel entitled to make that assumption rather freely today. But that was not the case in Copernicus' day. From the time of Ptolemy (second century AD.), the inquiry about the reality of the heavens had been looked upon with suspicion. The reason was that whereas the progress of mathematical astronomy made it possible to calculate with increasing precision the positions of the planets, the accounts of why the planets moved as they did had broken down not long after Aristotle had proposed the interaction of concentric spheres made of his quintessence (about 350 BC.).

According to Ptolemy himself, mathematics can apply only to "changes in form: i.e. in trajectory, shape, quantity, size, position, time, and the rest."[2] As to the actual nature of things there is little that science can do because they either take "place far above us, among the highest things in the universe, far away from the objects we directly observe with our senses," or else, as the objects of (terrestrial) physics, those "material things...are so unstable and difficult to fathom that one can never hope to get philosophers to agree about them."[3] Questions about the nature of the heavenly objects must lead one back to the ultimate source of all change, and thus they can only be answered by theology. Therefore science gains little to profit from asking them. And they are also distinct in kind from the sorts of questions that physics tries to answer, whose underlying principles, if any, did not seem amenable to mathematical treatment.

In the long run the Copernican revolution accomplished several important changes in points of view. For one thing it insisted in investigating the nature of the behavior of the heavenly objects. And it did so by looking for mutual underlying mathematical principles for both the heavens and the Earth. The success of this gross violation of Ptolemy's methodological rules turned on Copernicus' belief that astrophysics was possible. Eventually Newton succeeded where Aristotle had failed, and astrophysics became the shining example that new branches of physics had to follow.

Confusions about Copernicus' motivation were created mainly by Osiander's preface to Copernicus' masterpiece, On the Revolutions. Fearing a confrontation with theological dogma, Osiander urged the readers to "permit these new hypotheses to become known together with the ancient hypotheses," and to do so because Copernicus' hypotheses are "admirable and also simple, and bring with them a huge treasure of skillful observations." But the Copernicus' reader, Osiander wrote, should not accept as the truth "ideas conceived for another purpose."[4] All these admonitions by Osiander contradict Copernicus' own words and belie his attempt to discover the truth about the heavens by rational means instead of revelation.

In the centuries following Copernicus, astrophysics continued as a driving force of fundamental theory. Newton is, of course, the most prominent example. His laws of dynamics applied equally to terrestrial and heavenly objects, and his law of gravitation was a striking statement of the discovery that the force that kept us glued to the surface of the Earth was the same that made the stars and planets keep their appointed rounds.

We begin to see why this view of science is distorted when we realize that fundamental questions often cannot be asked without the appropriate technology and will not be asked without the right kind of inspiration and motivation. But this realization leads to another: that a whole host of activities are potentially as crucial to scientific progress as work that aims to solve problems within the most prestigious field of the time. Researchers who create new technology or new opportunities may contribute just as much to keep intact the dynamic character of science. And inspiration has often come as much from the planets as from the stars.

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[1] T.S. Kuhn. (1957) The Copernican Revolution. Harvard University Press.

[2] S. Toulmin and J. Goodfield (196 ) The Fabric of the Heavens.

[3] Ibid.

[4] Ibid.

Challenges to the Argument

Chapter 3F

Challenges to the Argument

In a survey the journal Science did in 1964 by, only 16% of the science Ph.D.s who responded agreed with President Kennedy’s decision to go to the Moon, while an overwhelming 64% disagreed. It was generally felt then that the Apollo Program was undertaken mainly for political reasons.[1] Ever since, many scientific and other critics have questioned the scientific value of space exploration.

The point is that my serendipity argument depends on a close connection between space exploration and science. If this connection is brought into question, my argument is also brought into question.

According to a second objection, it is not enough to show that the scientific exploration of space is serendipitous. We are still required to show that such exploration is likely to produce greater serendipity than competing activities, including other types of scientific exploration.

Let me describe these objections in greater detail.

1. Space exploration does not involve fundamental science in a significant way.

The first objection goes something like this: what my argument shows, strictly speaking, is that changes in fundamental science lead to a different panorama of problems, solutions and opportunities, hence the serendipity of science. Such changes have the desired effect because fundamental science gives us a way of viewing the universe and of interacting with it.

It is not clear, however, that applied or peripheral science would have similar effects. And to these critics it seems that the science done in the pursuit of space exploration is for the most part applied or peripheral.[2] This is not to say that space exploration is not likely to produce serendipity of some sort, for obviously it already has. The point is rather that the significance of what space exploration will accomplish is much less than I have made it out to be. Yes, we will have some interesting though marginal science and lots of gadgets, but no radical transformations of our main points of view.

Two considerations may tempt us to dismiss this objection summarily. The first is that it assumes too regal a status for fundamental or pure science as compared to applied science and technology. A moment’s thought makes us realize that “gadgets” have often driven revolutionary developments in fundamental or pure science: lasers are pivotal instruments in the study of fusion; personal computers have enabled the launching of hitherto undreamed-of theoretical work in many scientific disciplines, from mathematical physics to neuropsychology; and let us not forget the most famous influential gadget in the history of science, Galileo’s telescope, which was invented as a toy in Holland. It is clear, then, that transformations in technology and “applied science” can create a new panorama of problems and opportunities for the practice of fundamental science.

Nevertheless, I will not take the easy way out offered by this consideration. The science done in space exploration runs the gamut from the most applied to the most fundamental, as I hope to show in the rest of the book, and thus it brings out the deep practicality of science in its fullest sense.

The second consideration is that the critic who belittles the scientific value of space exploration is perhaps a bit of a straw man: space science is far more respectable now than in the days of President Kennedy. Three reasons, however, should keep us from deriving much reassurance from this consideration.

The first reason is that not all space science is now respectable, as we will see shortly. In any event, it is important to understand why that shift of perception took place in the fields of space science where it did.^[3] The second reason is the need to address the nagging suspicion that some space research has gained prominence purely because the Government has thrown big money to support it. If this suspicion is correct, society's quest for space exploration has distorted the practice of science. The third reason is that even if, contrary to fact, most scientists did have a high opinion of most space science today, it would still be useful to state as bluntly as possible why someone might not agree. For in replying we stand to explain better why we ought to go into space.

Space science covers many fields, but for the purpose of this essay they can be subsumed under three main categories: planetary science, space physics and astronomy, and space biology. Let us see why their serendipity might seem questionable.

Take planetary science (under this rubric I am including comparative planetology and the scientific exploration of the solar system in general)[4]. Granted that by going into Earth orbit and looking down we can learn much about our own planet; but what can we learn about the Earth from looking at another planet? It would seem, as an early Greek might say, that if the other planet is different we are not learning about the Earth, and if it is like the Earth we should not waste effort going there when we might as well look at the Earth itself.^[5]

As for space physics and space astronomy, how can they change our lives down here? It may be fascinating to find out what makes quasars burn; but, fascination aside, will that knowledge feed hungry children or at least make automobiles run more efficiently? We need to see how space physics and astronomy can come to be in a position similar to that of the revolution in physics that led to the laser and its use in medicine.

A critic might argue that lasers are built on fundamental principles of matter; on principles, furthermore, that apply right here on Earth. So there is no mystery why a revolution that gave us those principles had terrestrial applications. By going into deep space, by placing telescopes in orbit and all that, we might challenge our points of view and force them to change. But they are points of view about what is up there, not about what is down here. Or are they?

Space biology fares even worse, for many space scientists themselves see little value in it beyond the need to keep astronauts healthy. And since many of those scientists would prefer unmanned exploration, even this conditional value of space biology is in question. Such is a common verdict regarding the branch of space biology that investigates the behavior of terrestrial life in outer space. Another branch of space biology named exobiology (or “astrobiology”) presumably investigates extraterrestrial life. Under this rather cryptic description, exobiology became a target for critics who derided it, until the recent Mars meteorite controversy, on the grounds that, since we have never found extraterrestrial life, exobiology investigates nothing at all.^[6]

I will provide replies in the next three chapters, one per field. It will become evident, however, that this division of space science is largely a matter of convenience, for there exist strong connections between the three fields. Indeed, the seeds for the answers to some of the questions pertaining to astronomy and biology will be planted in the discussion of planetary science.

2. The serendipity of space exploration need not be greater than that of other scientific enterprises.

If we are to support scientific exploration because its serendipity will reward us with the tools to improve life on Earth, are there no better candidates than space exploration? Consider oceanography, for example.^[7] It is clear that the oceans play a crucial role in our climate and in the planet’s ability to sustain life. The benefits of understanding the oceans better thus seem quite direct. Shouldn’t oceanography then have greater priority than space exploration?

I offer two replies. The first is that I have never argued that space is the only stage for scientific exploration. In a well-run world, space exploration would be one of the important tasks human beings undertake, and perhaps some other scientific tasks should have even greater priority.

The second reply is that the priority of space is likely to be very high anyway. Consider the example of oceanography again. Clearly, obtaining knowledge of the oceans is very important to us. But as we will see in the following chapter, success in securing that sort of knowledge will require, at least in part, a global approach to the study of the oceans and the other systems with which they interact – a global approach for which space technology is exceptionally well suited. My suggestion is, then, that the majority of serious “competitors” to space exploration will actually be more successful if done in conjunction with space exploration.

Of course, I do not wish to claim that all space exploration is scientific. As space activities become routine, more and more of them turn into industrial enterprises or financial investments (e.g., satellite communications). The aim of this chapter was to provide a philosophical case, via serendipity, to justify the heart of space exploration.

In overcoming the objections, supporters of space exploration will be able to appropriate Descartes' words when claiming, for example, that space biology will contribute to medicine and thus bring about "the preservation of health, which is without doubt the chief blessing and the foundation of all other blessings in this life."^[8] And in addition they may proudly look forward to the new mastery of nature with which space science will reward their efforts. For that mastery will lead to "the invention of an infinity of arts and crafts which [will] enable us to enjoy without any trouble the fruits of the earth and all the good things which are to be found there."^[9] To the fruits of the earth, the supporters will say, space exploration promises to add the bounty of the universe.

NOTES

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[1] Even some supporters of exploration agree. Ben Bova from the National Space Society writes in a letter to Science (Vol. 233, August 8, 1986, p. 610) that “The U.S. space program’s primary motivations are, and always have been, political and economic.” He also thinks that it is a myth “that the space program exists mainly for the purpose of scientific research.” I will have more to say on these views in Chapter 7.

[2] For an account of this attitude against space science, see my “Pecking Orders and the Rhetoric of Science,” Explorations in Knowledge, Vol. III, No. 2, 1986, reprinted in my Evolution and the Naked Truth, op. cit.

[3]. This attitude within science, as well as negative attitudes about science in the larger society, plays an important role in our evaluation of space policy and of specific proposals for funding space undertakings. This role is, however, seldom made explicit. We often have little more than a gut feeling about how priorities should be allocated. But would not a different idea of the nature of science – and of the nature of space science – influence our gut feeling?

[4] For an account of the low status the planetary sciences suffered until rather recently, see Stephen G. Brush, “Planetary Science: From Underground to Underdog,” Scientia, 1978, Vol. 113, p. 771. Brush demonstrates how the prejudice against planetary science was blind to the history of physics.

[5]. This might be the approach taken by a student of Xenophanes.

[6]. This popular opinion of the field has changed considerably since David McKay’s team’s analysis of a now famous Martian meteorite (ALH84001) suggested that there were traces of fossil life inside of it. NASA has capitalized on the public enthusiasm, even though most meteorite experts have been hostile to the hypothesis. This issue will be discussed in Chapter 6.

[7]. This point was suggested to me by Terry Parsons.

[8]. Descartes, Discourse on Method, Haldane and Ross, trans., op. cit., p. 120.

[9]. Ibid., p. 119.