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.