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Wednesday, November 10, 2010

Space Physics and Astronomy

Chapter 5A

Space Physics and Astronomy

According to the journal Science, Rashid Sunyaev, a famous Russian astrophysicist, “once heard the chair of his department say that ‘astronomy was an absolutely useless science.’”[1]

After the spectacular successes of the space telescopes and the new generation of Earth-bound telescopes, the public may be surprised to learn that not long ago many scientists regarded space astronomy and space physics with some suspicion. Quite a few physicists, for example, felt that all those billions of dollars for space astronomy should have supported the construction of a new generation of particle accelerators instead – particle accelerators dealt with truly basic science. I presume that a good many of those physicists may now agree that the money spent in space telescopes has been money well spent. But it is important to see why they are right in having changed their minds.

The reason is that, in the pursuit of cosmological knowledge, physics and astronomy done in space affect the transformation of our views in a very important respect: They provide a framework within which to challenge our most fundamental terrestrial sciences. For to understand the formation and evolution of the universe we need to see how the basic laws of nature are expressed in it. At the same time, to have a good grasp of the basic laws of nature we need to see how well we can describe the universe by using them. In a second respect they affect that transformation in an even more radical way: astronomy and physics done in space allow us to discover phenomena that we could not have discovered otherwise and that will force us to develop a new physics.


As we recall from Chapter 3, a scientific critic might argue that, since these sciences examine far-away objects, the ensuing transformation of our views is unlikely to pay off for the inhabitants of the Earth. For example, space astronomy and physics constitute a prime example of attempting to satisfy our intellectual curiosity -- they aim to describe features of the universe that many people find interesting, sometimes fascinating. The problem for my thesis is precisely that these space sciences fit my points about curiosity so well while apparently failing to satisfy my expectation about practical results in the long run. Surely, the objection continues, it is by no means obvious that the transformation of our theories about black holes, quasars, and intergalactic gas will be of much application on the Earth.

There is, according to the objection, a great difference between Earth-bound physics and these space sciences. Consider anew the example of how Einstein’s revolution in physics led to lasers and their application in medicine: That revolution transformed our understanding of the basic principles of matter, of principles that apply down here. It is not surprising, then, that our panorama of problems and opportunities was bound to change as a result of the transformation of our thought. The principles of fundamental science (e.g. particle physics) apply down here because they apply everywhere. By contrast, space astronomy and space physics merely apply to stars, galaxies, and quasars the fundamental principles of matter discovered by Earth-bound physics -- thus they are derivative sciences. My thesis about serendipity would then apply only to fundamental science. Therefore, space astronomy and space physics cannot be justified by my general philosophical argument.

For almost a century now the most fundamental and empirically successful description of matter has been given by the so-called Standard Model, which explains the universe in terms of its building blocks (particles) and the fields (strong, weak, electromagnetic and gravitational) that allow those blocks to interact. The main experimental tools of the Standard Model have been giant particle accelerators that smash those particles at speeds close to that of light and then theorize from the resulting debris. When the choice came between spending billions to build even more powerful accelerators or spending billions to put up telescopes in orbit, the feeling among many physicists was that, interesting though astronomy may be, taking money away from the terrestrial tools that would allow us to advance the Standard Model further was tantamount to blunting fundamental science’s cutting edge.

My response will be as follows: (1) space physics and astronomy have distinct scientific advantages over terrestrially bound sciences; (2) these scientific advantages show that space physics and astronomy are fundamental science in the same sense that terrestrially bound physics is because (a) you cannot do terrestrial physics properly without doing space science, and (b) the theoretical and experimental articulation of physics needs challenge, a challenge that space science has provided and will continue to provide. Space science has made the Standard Model due for a change.

[1] “News Focus: In the Afterglow of the Big Bang.” Science, vol 327, January 1, 2010: 27.

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