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The cost is one-half to one-third that of infrared instru- ments designed for more complex and demanding work. Despite this difference in price, P-E Infracords can handle most analytical problems a chemist in research and develop- ‘ment, process or quality control, must perform. This means you don’t pay for performance you don’t need ...nor for a high-salaried specialist, since a technician can operate the Infracord after a few minutes’ instruction.

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1586

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INSTRUMENT DIVISION

Perkin-Elmer Gyno NORWALK, CONNECTICUT SCIENCE, VOL. 134

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ords ples nore busy

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17 November 1961, Volume 134, Number 3490 SCIENCE:

Editorial

Articles

Science and the News

Book Reviews

Reports

Association Affairs

Departments

Cover

The Search and the End Product

Bae NE KAD ates aca eines Ate EE eee cS Pee ee 1591 reas ceciesInCiON:. WO, NE. PV OLmene ios oe eins 3. Si ea Sw oe we Se anew 1593

Stellar scintillation is shown to be a good indicator of the upper-air

winds near the tropopause. reriVe PACIIGROI Rr C DPMP cco. alk cc vie oo Ce Os cl we 1599

The exclusion principle is recast in the context of a generalized scheme

for interspecific interactions.

Money for Space: The Program’s Managers Fear the Public Does Not Understand

the Issue; Overhead Costs: Intangibles Make It Difficult To Compute Cost of

MEPEEVONGIEY | ROREHRGIE oe ee ae ee od 5 Ge IE ees 1602 Psychology’s Role in Economic Development: E. E. Hagen ...................... 1608

Is there an identifiable personality trait that promotes or retards.

economic progress in societies?

J. H. Young’s The Toadstool Millionaires, reviewed by G. Sonnedecker;

RRM RENO WE ec ees ae tart Oe Mora ity otae sehen Sy a OR ae Eee ee Depressant Agent from Walnut Hulls: B. A. Westfall, R. L. Russell, T. K. Auyong .... 1617 Proof of an Adaptive Linkage Association: M. Levitan .......0....... ccc cceees 1617 Effect of Verbalization on Reversal Shifts in Children:

Pee PREP ARM OS TREE es es sss ook ved os Rn as oa teen eee 1619 Electron Diffraction from Coals: S$. Ergun and J. T. McCartney ...............004. 1620 Accumulation of Potassium Anaerobically by Renal Medullary Slices:

Becca Cl Ble ST ERE ke oie DLR. Rect alec eee 1622 Effects of Context on the Subjective Equation of Auditory and Visual Intensities:

R. Smita ond A. H. Hardy.) 052... coal dk eae Se Er ae 1623 Coesite Discoveries Establish Cryptovolcanics as Fossil Meteorite Craters:

A.J. Cohen, T. E. Bunch, A. M. Reid oe Se te Sree eater nce 1624 Electroretinogram of the Visually Deprived Cat: B. L. Baxter and A. H. Riesen ....... 1626 Predictions of the Growth Model for Normal Chicken Growth: J. L. Kavanau ..... 1627 An Age-Dependent Change in the Response of Fern eo to Red Light:

dg. iieoiialler and DeR. Wrignt 5. oc nce ces. shy .. lnk 2 ge eee 1629 izcm Annual Meeting: Program: Sammary «25 ...:095..)<0.« sew ne sisthi nds + Sai ee ee 1630

Ruectronm Microscopy; Forthcoming: Hvents: . . 2 ie-.c.. sss. can TA A en te Wal 1636

Mold after a megashatter cone on a southeast face of McCray quarry at Kentland, Indiana. The megashatter cone has been blasted away by quarrying operations. The mold impression is partially covered with a thin coating of injected breccia. The exposed dimensions of this cone structure are 28 feet at the base and 160 feet high. See page 1624.

Said Svante Arrhenius: “The change of the logarithm of a chemical reaction rate constant with respect to temperature, is inversely proportional to the square of the absolute temperature.”

The aerospace industry is searching constantly for strong, light-weight, heat-resistant materials. Finely-spun glass fiber, bonded with a plastic binder, is beginning to exhibit superior properties. Until recently the glass fiber has been far more heat-resistant than any binder.

Scientists at Lockheed Missiles & Space Company, however, have developed a compatible binder. This now makes it necessary for the glass-producing industry to evolve a glass to match its superior heat-resistance.

Comparable successes are being achieved in dozens of disciplines in which Lockheed is engaged. As Systems Manager for the DISCOVERER, MIDAS, and other satellites, and the POLARIS FBM, Lockheed probes all areas of aerospace endeavor.

Lockheed Missiles & Space Company is located on the beautiful San Francisco Peninsula, in Sunnyvale and Palo Alto, California. Why not investigate future possibilities at Lockheed? Write Research and Development Staff, Dept. M-30D, 962 West El Camino Real, Sunnyvale, California. U.S. citizenship or existing Department of Defense industrial security clearance required. An Equal Opportunity Employer.

LOCKHEED mISsILES & SPACE COMPANY

A GROUP DIVISION OF LOCKHEED AIRCRAFT CORPORATION

Systems Manager for the Navy POLARIS FBM and the Air Force AGENA Satellite in the DISCOVERER and MIDAS programs. Other current programs include SAINT, ADVENT and such NASA projects as OGO, OAO, ECHO, and NIMBUS.

SUNNYVALE, PALO ALTO, VAN NUYS, SANTA CRUZ, SANTA MARIA, CALIFORNIA e CAPE CANAVERAL, FLORIDA e HAWAII

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1590 SCIENCE, VOL, 134

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17 November 1961, Volume 134, Number 3490

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

Board of Directors

CHAUNCEY D. LEAKE, Retiring President, Chairman THOMAS Park, President Paut M. Gross, President Elect

HaRRISON BROWN Don K. PRICE HENRY EYRING ALFRED S. ROMER H. BENTLEY GLAss WILLIAM W. RUBEY MARGARET MEAD ALAN T. WATERMAN PauL A. SCHERER, Treasurer DaeEL WoLFLe, Executive Officer

Editorial Board

KonraD B. KrauskopF H. Burr STEINBACH Epwin M. LERNER WILLIAM L. Straus, Jr. Puitip M. Morse Epwarp L. TaTtuM

Editorial Staff

DaEL WOLFLE Hans NussBauM

Publisher Business . Manager GrRaHAM DvuSHANE Editor JOSEPH TURNER. RosBert V. ORMES

Associate Editor Managing Editor ELLEN E.° MurPuy, Assistant Editor

Nancy TEIMOURIAN, Assistant to the Editor

News: Howarp Marco.ts, DaNnriEL S. GREEN- BERG, PATRICIA D. Pappock

Book Reviews: Sarau S. DEES

Editorial Assistants: Suet E. BERKE, Nancy S. HAMILTON, OLIVER W. HEATWOLE, EpcarR C. RicH, JoHN E. RINGLE, ConraD YuUNG-Kwal

Staff Assistants: LiLLiAN Hsu, GENEVIEVE M. QUADA

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SCIENCE, now combined with THE SCIENTIF- IC MONTHLY, is published each Friday by the American Association for the Advancement of Science at National Publishing Company, Wash- ington, D.C. SCIENCE is indexed in the Reader’s Guide to Periodical Literature.

Editorial correspondence should be addressed to SCIENCE, 1515 Massachusetts Ave., NW, Washington 5, D.C. Manuscripts should be typed with double spacing and submitted in duplicate. The AAAS assumes no responsibility for the safety of manuscripts. Opinions expressed by authors are their own and do not necessarily reflect the opinions of the AAAS or the institutions with which the authors are affiliated. For detailed Suggestions on the preparation of manuscripts, see Science 125, 16 &@ Jan. 1957).

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hool year subscriptions: 9 months, $7.00; 10 Geen” $7.50. Cable address: Advancesci, Wash- ington.

SCIENCE

The Search and the End Product

Human groups that admit of a multiplicity of values and purposes are inevitably confronted by two perplexing tasks: they must assign relative weights to individual goals and allocate priorities in the use of their group’s resources. A democratic society assumes that ordinary citizens as well as policy makers are, at least on an intuitive level, capable of making such evaluations in a rational and commensurable fashion and that they do so not wholly on the basis of individual self-interest. What are the most suitable common measures on which a society can base its decisions? Specifically, what are appropriate indices for comparison when we deal with science and its possible applications?

Support for the broad spectrum of scientific research now greatly exceeds a just-noticeable fraction of our national budget. Thus it becomes necessary to decide each year what fraction of a finite amount of re- sources is to be allocated to the search itself, to research facilities, and to the communication and application of research results already available, and how much is to be set aside for the education of the young. One must also decide how much is to be allocated to the various component parts of the total scientific effort, and it is here that groups who are interested in different end products make themselves heard.

Most scientists are notably and justifiably reluctant to extrapolate from their laboratory experience to the benefits that society may eventual- ly derive from their search. They would feel uneasy were they asked to prescribe an ideal “mix” of physical, life, and behavioral sciences. On the other hand, they are also aware that easily measurable quantities are not always the most useful ones. They are, therefore, not overly impressed by the fact that it is obviously easier to assess the cost of research, of an education—or for that matter of human well-being and freedom—than to estimate the value of these commodities; accurate ledger entries do not necessarily constitute correct bases for decision making.

This state of affairs threatens to leave us without a common language —we might almost say without a common currency other than the dollar. We can, of course, take the view that the values involved are intangible and imponderable and that only a nation adequately trained in science might get more than a vague impression in terms of attitudes, expecta- tions, and hopes. Can we really do no better job of translating what science has wrought than to refer to megatons or appliances on a per capita basis? Here is a challenge to the ingenuity of our scientific ad- visory boards and science administrators. Here also is a challenge to social scientists and humanists. Let us look for new significant indicators of scientific and technological progress. Let us try to convey how the search for scientific knowledge constitutes, in modern. societies, one of the most basic commitments to a better future for mankind. There is little chance that we shall find an all-encompassing index or formula, but we need to experiment with a variety of partially valid yet broadly comprehensible measures.

We can scarcely hope to achieve voluntary planning for the benefit of: both a free science and a free society as long as we have so few tools for convincing our fellow citizens that without search today there may be no end products tomorrow.—WaALTER A. ROSENBLITH, Massa- chusetts Institute of Technology.

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Ex venir suffe: earth requi atmo plane form by th it en is sa of a notec form from the i goes the wave in Sf the | flucti the mete also and

Th by 1 from scope to be movi often The image upon select instat sity i when samp

17 NC

INSTRUMENTS AND TECHNIQUES

Except for dilution by the inter- vening space, the light from a star suffers little until it impinges upon the earth’s atmosphere. In the short time required for the light to traverse the atmosphere, what was originally a plane-parallel wavefront becomes trans- formed into a corrugated wavefront by the refractive inhomogeneities which it encounters. When such a wavefront is sampled through the finite aperture of a telescope, several effects can be noted. The quality of the image formed by the telescope deteriorates from that predicted by physical optics; the image becomes enlarged and under- goes changes in size and position, since the direction of the normal of the wavefront is no longer constant, either in space or time. Furthermore, when the turbulence causing the refractive fluctuations is at a great distance from the telescope, of the order of kilo- meters, the intensity of the wavefront also becomes variable in both space and time.

This latter effect can be observed by viewing the illumination . pattern from a bright star directly at the tele- scope aperture. The pattern appears to be crossed by a system of rapidly moving shadows and consequently is often called the shadow-band pattern. The total intensity of the telescopic image becomes variable; depending upon the sample of the shadow pattern selected by the telescope instant by instant. This variation in total inten- sity is called scintillation—or twinkling When the shadow pattern of a star is sampled directly with the eye. In the

17 NOVEMBER 1961

17 November 1961, Volume 134, Number 3490

Stellar Scintillation

Stellar scintillation is shown to be a good indicator of the upper-air winds near the tropopause.

W. M. Protheroe

latter instance, the effective frequency of variation is cut off near 16 cycles per second, due to the time response of the eye. Scintillation may be studied either by measuring the fluctuations in image intensity for a given telescope aperture (J, 2) or by measuring the shadow-band pattern directly (3-5). The results of both types of measure- ment are discussed here.

General Characteristics of

Stellar Scintillation

While the observational charac- teristics of stellar scintillation have been discussed in detail elsewhere (J, 2), it may be of interest to summarize some of these briefly. The more quanti- tative measurements have _ generally been made by means of photoelectric photometers. The fluctuating portion of the output current from the photo- cell, when corrected for shot noise, is directly proportional to the intensity variations of the shadow pattern in- tegrated over the telescope aperture. This output signal is readily analyzed, with regard both to amplitude and to frequency distribution, by the tech- niques commonly applied to noise measurements.

The amplitude of the scintillation signal varies greatly from night to night and is strongly dependent upon both the size of the aperture and the altitude of the star above the horizon. For small apertures, say 1 to 3 inches, the peak-to-peak fluctuations of the signal as compared to the mean light

SCIENCE

level are of the order of 50 to 150 percent for stars near the zenith and can increase to several hundred per- cent for stars near the horizon. As larger apertures are used, the inherent fluctuations in the shadow pattern tend to average out; thus, the peak- to-peak amplitude for stars near the zenith may decrease to the order of 10 to 20 percent for apertures of 10 to 20 inches. The root mean square devia- tions of the signal are of the order of 30 percent for small apertures and fall off to the order of 5 to 10 percent for apertures measured in tens of inches. The strength of the scintillation also tends to increase whenever the wind field in the vicinity of the tropopause is strong, and hence, on the average, for mid-latitudes in the Northern Hemisphere, winter scintillation is stronger than summer scintillation.

The distribution of the scintillation signal with respect to frequency—that is, its Fourier spectrum—is another interesting parameter. This is likewise strongly influenced by size of aperture and by altitude and is even more strongly influenced by the wind field than is the total amplitude, or strength, of the scintillation signal. In general, for stars near the zenith, where small apertures are used the Fourier spec- tra tend to have a constant strength at frequencies from zero to around 100 cy/sec, with a decreasing strength from there to about 500 to 1000 cy/sec, where the amplitude becomes zero. On the other hand, when large apertures are used, the flat part of the spectrum extends to only 10 to 50 cy/sec, and the zero point is reached at anywhere from 100 to 500 cy/sec. The decrease in high-frequency components with in- crease in aperture size is readily ex- plained as an aperture-smoothing ef- fect.

As stars at lower altitudes are ob- served, the low-frequency components increase rapidly as the high-frequency components decline, and although the total bandwidth of the noise signal is quickly reduced, the low-frequency

The author is vice dean of the Graduate School of Arts and Sciences and associate pro- fessor of astronomy, University of Pennsylvania, Philadelphia.

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