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Really Big Science (and really small minds)

The universe is very flat and very smooth. By “flat” the physicist means that if you take regions whose dimensions are “small” (for a cosmologist, small is something like 108 lightyears, or 100 times the distance to the Andromeda galaxy)
Addendum 30 Jun: I just came across a page according to which “local” in discussions of dark energy, the cosmological constant, and so on means 10 billion (1010) light-years. See News of the Universe and search on “within about 10 billion”. The diameter of a proton is between
.8 and .9 femtometer (=10-15 meter).
One light-year is
9.5 · 1015 meters.
A light-year is proportionately about as much greater in length than a person as a person is greater than a proton. 10 billion is roughly the ratio between a person’s height and the diameter of a carbon atom (2.2 · 1010 meters).
, space looks like the Euclidean space of high-school geometry—the angles of a triangle add up to 180° and so forth. “Smooth” means that the distribution of matter is uniform except at very large scales; the universe near the beginning must be smooth enough to account for the distribution we now observe, but lumpy enough to allow for the formation of galaxies. The favored explanation for both flatness and smoothness is that at a very early period in its history the universe expanded enormously over a short period of time, and then slowed down to its present more sedate rate of expansion.
Present-day theories of inflation begin with a proposal by Alan Guth in 1979, and have since been incorporated into various Grand Unified Theories that attempt to give a single account of all the forces of nature (gravitational, strong, weak, electromagnetic). At first blush inflation looks like an ad hoc addition to the then standard history of the universe, beginning with the Big Bang. But its predictions concerning fluctuations in the omnipresent microwave background (the 3° K. “black-body” radiation, discovered in 1964–1965 by Arno Penzias and Robert Woodrow Wilson, that pervades the heavens) have been borne out by recent observations (see the Cosmic Background Explorer or the COBE page at NASA).
cmbanisotropy.jpg
Fluctuations in the microwave background from four years of observations by the Differential Microwave Radiometers on COBE. Source: CMB Astrophysics Research Program.
μK = microkelvins (10-6 °C)
As Guth says of the fluctuations, "I really never thought that anybody would ever actually measure these things … now they're measuring them with such high precision—it really is just fantastic" (Castelvecchi, “Growth”). The density fluctuations show up at a scale of 10-5 (by comparison the smallest or “just noticeable” difference in the human perception of brightness is roughly 10-2).
The 45% of Americans who agree that “God created human beings pretty much in their present form at one time within the last 10,000 years or so” are effectively casting aside most of the last two centuries of physics, observational and theoretical astronomy, and cosmology. Not just particular claims about the age of the universe, but the science behind them. We have got the basic features of the micro- and macrocosm basically right at what might be called the “middle” scale: from galaxies, say, to the nucleus of the atom. From that we can infer with great confidence that our instruments are reliable, and thus that the theories which explain results obtained by the use of those instruments are well-confirmed. Conversely, to engage in the kind of radical doubt—for that is what is required—according to which an error of six orders of magnitude in the age of the universe is possible (1010 years, according to the scientists, 104 according to 45% of Americans) would require giving up an enormous mass of middle-level theory.
The question “What is the composition of the Sun?” and the question “Why is the composition of the Sun what it now is?” (where a genetic answer is expected) are indeed logically distinct. I noted earlier that in the evangelical Christian universities there is a tendency to isolate the synchronic from the diachronic in biology: molecular biology but not evolution. A science that had very little notion of what in the nineteenth century came to be called “development” (not only in biology, but in geology, cosmology, and the human sciences, including the study of religion) is certainly possible. Until the seventeenth century, natural philosophy hardly concerned itself with development. The difference now is that science has pervasively taken up notions of development; to do away with that would require an enormous forgetting, not to mention outright suppression of inquiry. There are indications that some Christian groups are not averse to curtailing the discussion of “origins” in public school teaching: would they go so far as to forbid it in science generally?
  • Inflationary Cosmology
    Charles J. Peterson. A basic outline of the problems and their solution in Grand Unified Theories. Less technical and less nuanced than Watson.
  • An exposition on inflationary cosmology
    Gary Scott Watson. A detailed account, intended to be accessible to undergraduates (meaning, I think, undergraduate physics majors). Even if equations are Greek to you (make that Cherokee for the Greek readers), the last line of the summary ought to give you something to think about.
  • The growth of inflation
    Davide Castelvecchi. From Symmetry, Dec 2004–Jan 2005. A survey, written at New Scientist level, of recent experimental results pertinent to inflation. Symmetry is published by Fermilab and SLAC. It covers developments in high-energy physics, especially experimental. See, for example, Kurt Riesselmann, “The elusive neutrino”, on “neutrino oscillations”—spontaneous transformations of neutrinos from one to another of the three kinds now thought to exist.
    When I was growing up there was just one neutrino, not three, and so of course no oscillations. The neutrino (or rather a neutral particle at first not well distinguished from the neutron) was proposed by Wolfgang Pauli in 1930 to account for the apparent violation of the law of conservation of energy in the β-decay of certain radioactive atoms. The first “direct” observations of neutrinos were made in 1956 by Reines and Cowan (Franklin Are there…? ch. 5.2). By the 1990s, neutrinos were being used to “observe” the interior of the Sun. See Alain de Bellefon, “Le neutrino, particule fantôme”, Didier Verkindt “History of the neutrinos”, and especially Allan Franklin, Are there really neutrinos? An evidential history (Perseus Book Group, 2001) · 0738202657 at Best Book Buys, isbn.nu, Powells, ABE.
  • The Big Questions
    Phillip Adams and Paul Davies. Davies, a physicist and cosmologist, discusses a variety of fundamental questions concerning the origin of the universe and its fate long hence.
  • “[One-]Third of Americans Say…
    “…Evidence Has Supported Darwin's Evolution Theory/Almost half of Americans believe God created humans 10,000 years ago”. Frank Newport. Gallup Report 19 Nov 2004. (Also at Canadian Content.) Newport notes that the numbers haven’t changed much over the last few years, or even over the last thirty.
  • Creationists.org
    What the name implies. The “position statement” referred to above takes as its second choice the abandonment of any reference to origins. See also the Back to Genesis page at the Institute for Creation Research. On ICR and the accreditation of its graduate school, The Panda’s Thumb.

LinkJune 25, 2005 in Physics · Science