Questioning the Millennium: A Rationalist's Guide to a Precisely Arbitrary Countdown
By Stephen Jay Gould, Harmony Books, 179 pages, $17.95, ISBN 0-609-60076-1
The hands of the clock of civilization strike a cosmic midnight, tolling the end of a thousand years and the beginning of a thousand more. Religions were formed around the fear of this passage, governmental systems crumbled under its weight, the very nature of time was questioned during the transition into the new millenium. From ancestral cave scratchings of the moon and sunrises, to the tapestries recounting the season's harvest, we have been driven to define and organize time, its passage capturing the essence of human thinking and creativity. Stephen Jay Gould's Questioning the Millenium engages the reader in a socio-scientific discussion on the origin and impact of this most majestic moment as it approaches the year 2000.
Gould asks three main questions: What is the millennium? When is it? Why does it carry such importance? From these questions emerge scientific debate and historical intrigue.
What is the millennium? Gould refuses to acknowledge that it is simply the tearing of a calendar page or a number of atomic oscillations. The passage of time comprises events that carry the momentum of humanity. Gould writes: "We need time's arrow to assure us that sequences of events tell meaningful stories and promise hope for improvement. We need time's cycle for an ordered rescue from the fear that history might feature no more than a random and senseless jumble of events without meaning or guidance--just one damn thing after another..." Without a meaningful organization of time, existence is schizophrenic: events seem fragmented and inaccessible to the needs of human introspection.
The construction of temporal intervals reflects a deep-seated human need to impose structure upon reality. In this section, Gould challenges the reader to cast off any notions of time as an absolute or objective quantity, leading the reader to wonder if time is a reflection of humanity, rather than of natural reality. He recounts past civilizations' attempts to construct time based on their exposure to the periodicity in nature. From the counting of days by the average time between sunrise and sunset to the change in seasons, time's divisions have been evolving with experience and technology, but remain inherently subjective. Atomic clocks which some may percieve as an objective measure, are based upon the observation of millions of oscillations of cesium atoms, which now define our second. This section is fascinating, since it delves into the fundamental subjectivity of time.
In light of the human origin of time, we turn to the second question: When is the millennium? The search for the answer began in the sixth century. At that point, Dionysus Exiguus (Dennis the Short) was asked to construct a chronology for Pope St. John I. Oddly enough, the beginning of time according to Exiguus was not Year Zero, but Year One when Rome was built, an obvious subjective construction. He divided time again by the circumcision date of Jesus, 753 years after the building of Rome. This choice of year led to a dramatic inconsistency with the Gospels since King Herod, who played a pivotal role in the early life of Jesus Christ, would have died before Jesus was born. Consequently, the calendar was revised and led to the B.C./ A.D. system starting at 1 B.C., not zero. Starting a calendar with Year One is not surprising since at the time, the Chinese did not have a zero, the Egyptians had rarely used it, the Mayans did not grasp zero's deep meaning, and Hindu and Arabic scholars did not invent zero for themselves until about the ninth century.
The error of starting at Year One instead of Year Zero propagates into the next question: When is the millennium? Do we celebrate on 1 January 2000 or on 1 January 2001? The answer to this question is more of a class-cultural issue than a scientific question. What Gould argues is that both celebration dates are correct, but have led to the dichotomization of an intellectual class and a primitive class, with the intellectuals using historical fact to define their celebrations and the primitives longing for the aesthetic appeal of round numbers. The ancient creators of the calendar we use today started at one, not zero, so the passage of 1000 years occurs when we move from year --00 to year --01. However, the passage from 1999 to 2000 has a more dramatic appearance than from 2000 to 2001. Through historical anecdotes, Gould argues that this sensually pleasing change leads many of us to don our New Year's hats a year earlier than an intellectual definition would allow.
Why celebrate at all? Gould's third question focuses on humanity's need to celebrate time's passage. Gould does not fully address the notion of why we care about the millennium at a sociological level and is perhaps the weakest point of the book. Recognizing Gould's pronounced scholarly approach from previous books, the reader is forced to conclude that there is little available research about this question, else Gould would have elaborated upon it in scholarly exuberance. In spite of this, Gould engages the reader on topics such as the history of the Jewish Calendar and hypotheses on the origins of our primordial notions of time. The book concludes with a personal account of Gould's experience with his son, who is autistic and capable of instantantly calculating the day of the week for any date in any century. This section is a personal look into the meaning of time and is warming to the soul.
As we approach the new millenium, it is appropriate to address the social and scientific impact that the construction of the passage of time has had on civilization. Stephen Jay Gould's book discusses this impact and its implications on time, a quantity that the scientific community takes as an objective given.
D. Elizabeth Pugel
126MRL, Loomis Physics Labs
Urbana, IL 61801
Articles from Science on Global Warming
Dieter H. Ehhalt, Science, 13 February 1998, 1002-1003.
Warmer and Wetter 6000 Years ago?
Warren Beck, Science, 13 February 1998, 1003-1004
These two brief articles focus on the reactivity of the OH radical, and on oxygen isotope ratio dynamics, respectively, in the Earth's atmosphere. They provide, for the general reader, some of the understanding of atmospheric analysis required to understand, evaluate, and criticize the continually emergent literature--and folklore--of global warming.
Temperature and Surface-Ocean Water Balance of the Mid-Holocene Tropical Western Pacific
Michael K. Gagan, et al, Science, 13 February 1998, 1014-1018.
This report resolves some of the discrepancy between alkaline-earth metal isotope ratios in coral, and certain foraminiferal oxygen isotope ratios, in estimating sea water surface temperature (SST) during the holocene period of about 6000 years ago. Previously, the coral measurements of strontium versus calcium isotopes were in doubt, because they seemed to reveal a holocene-glacial temperature difference which was too great. The eight authors measured 18O vs 16O isotope ratios in the discrepant coral and in the foraminifera deposits of the relevant holocene time periods. A new discrepancy in oxygen ratios was found, and it covaried with the coral alkaline earth metal discrepancies. The authors conclude that atmospheric transport of 18O-enriched water was greater than previously thought; this implied higher SSTs than thought, based on the previously accepted foraminiferal ratios viewed in isolation. Thus, the old foraminiferal SSTs were too low. The authors estimate the full holocene-glacial temperature difference to have been about 6oC. Consideration of atmospheric transport may explain other discrepancies known in the prehistoric SST record.
Simulated Increase of Hurricane Intensities in a CO2 Warmed Climate
T. R. Knutson, R. E. Tuleya, and Y. Kurihara, Science, 13 February 1998, 1018-1020
The authors used weather simulation software to study the effect of sea surface warming on characteristics of hurricanes. Such warming would be predicted if average atmospheric CO2 levels were to rise sufficiently. For a Western Pacific temperature increase of 2.2oC, the peak wind speed of hurricanes was predicted to increase by 5-12%, consistent with theoretical predictions. Several different approaches were used to initiate and sustain the simulated storms.
Ozone Loss, Greenhouse Gasses Linked
Richard A. Kerr, Science, 10 April 1998, 202.
The author reports on a recent article in Nature by D. Shindell, D. Rind, and P. Lonergan. These NASA-Goddard researchers ran a computer simulation of Earth's upper atmosphere which for the first time included the interaction of temperature and ozone-chlorine chemistry. Their model, at least in its first, preliminary form, not only accounted well for observations of the past decade, but it also predicted a greater future attenuation of ozone over the Arctic than previously expected. The author points out that, unexpectedly, ozone loss over the Arctic this Spring has been about zero, for unknown but presumably relevant reasons.
Abrupt Climate Events 500,000 to 340,000 Years Ago: Evidence from Subpolar North Atlantic Sediments
D. W. Oppo, J. F. McManus, and J. L. Cullen, Science, 27 February 1998, 1335-1338.
By studying a restricted spatial extent (the Bjorn Drift) of North Atlantic oceanic foraminferal ooze, the authors were able to select for stratigraphy of higher temporal resolution than had been possible in past studies. The finding of apparent sea-surface temperature oscillations of period around 600-1500 yr, previously invisible because of undersampling, was pursued by comparing samples of ooze from glacial and interglacial epochs. Based on their sampling method, the authors conclude that such abrupt oscillations, of order a few oC, have been of smaller amplitude during interglacial times than during (a) glacial times, (b) epochs of deglaciation, or (c) epochs of ice growth. The authors attribute the amplitude differences to deep ocean circulation changes of global scope. See also the related news article, "Sea Floor Records Reveal Interglacial Climate Cycles", by R. A. Kerr, pages 1304-1305.
Time Scales in Atmospheric Chemistry: Coupled Perturbations to N2O, NOx, and O3
M. J. Prather, Science, 27 February 1998, 1339-1341.
The author uses a linear transform matrix method to show that greenhouse gas reactions can't very well be studied in photochemical reaction-product pairs; but, that availability of products from one reaction should be studied as coupled with all others. Eigenvalue analysis reveals that, in general, the actual atmospheric multiplicity of reactions makes the longer-lived products available to other action; so the average effect is to shorten residence time of any one reaction product. For the triplet of most interest in this study, the author concludes that the coupling has led to a 10-15% overestimation in previous simple, one-reaction analyses of N2O residence in the stratosphere and troposphere.
The Role of Ocean-Atmosphere Interactions in Tropical Cooling During the Last Glacial Maximum
A. B. G. Bush and S. G. H. Philander. Science, 27 February 1998 , 1341-1344.
The computer simulation reported here was enhanced by adding coupled, three-dimensional oceanic circulation parameters to previous atmosphere-only climate models. The result was a glacial-period sea-surface temperature which would be about 6oC cooler in the tropics than shown in previous simulations. The result obtained is in accordance with recent ice-core and other evidence showing tropical regions cooler than had been estimated in publications as recent as a few years ago.
John Michael Williams
P.O Bos 2697, Redwood City, CA 94064