|
||||||||||||||||
|
||||||||||||||||
|
|
|||||||||||||||
|
| ||||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||
Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 13
that
¡nd-
onts
THE PRESENT POSITION
new
IN GROUND-BASED ASTRONOI,TT
lmy
ìent
port
ents
ces-
It is clear that ground-based astronomy has spread before it a wealth of
inviting prospects. Questions of the most fundamental nature regarding
med
the structüe and evolutionary history of the universe can be asked with
DOt
reasonable hope of obtaining answers. But on one frontier after another
uch
the growth of knowledge is limited because we need far more extensive
oce.
obse¡vational data than we now have.
rbe
What new facilities are needed to exploit the opportunities? In arriving
refft
at a recommended program, the Panel has conside¡ed the existing facilities,
oce.
and has reviewed how they came into being and were brought to their
ugh
present state of operating eficíency. It has compared the technical capabil-
tds,
ities of existing proven telescopes with the requirements set by the observa-
)my
tional tasks now clearly foreseen, It has also considered a projection of
astronomical manpower over the next ten years, to keep the facilities and the
number of observing outlets ín step with the demands of a growing body of
researchers, and yet not outrun the expected supply of experienced instru-
mentalists and observers needed to build and operate t-he new major installa-
tions proposed. The Panel presents here its evaluations of tìe present posi-
tion as a background for the recommendations tÏat follow in Sections III
and IV.
EORET IC AL AST ROP HY SIC
TH S
Before éxtensive new facilities are recommended, it is necessary to ínquire
whether progress in understanding the universe is not as dependent on
interpretâtion of old observations in the light of known physical laws, and
on the new ideas that may thus come from theoretical astrophysicists, as
it is on accumulation of still more observations. In the earþ decades of the
20th century, when the highly successful mountain-top observatories in tle
western United States were exploring the virgin ffelds laid open by the
great new telescopes, it was perhaps tme that not enough time was spent
t3
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 14
on relating observaüons to theo¡etical lmowledge, The interpretations
were not long in coming, but they came mainly from elsewhere. The founda-
tions of modern theoretical ashophysics-theories of stellar atmospheres, the
internal constitution of tlle stars, and cosmolog¡ for example-wãe hid in
Europe, where cloudy skies anil small telescopes discouraged rapid develop-
ment of observational astronomy.
The Panel believes that any imbalance that may once have existed in
this coultry has long since been co¡¡ected. At many universities in the
United States tlere are groups of mature practitioners of theoretical astro-
physics. Graduate schools give every young astronomer ín training a basíc
grounding in the subiect, and at certain centers a number of studànts pre.
pare for caree¡s in that field. Physical scientists trained in neighboring
ûelds have become interested in astronomy and have made maior theoretica-i
conkibutions to problems of thermonuclear energy soutces, to stellar evolu-
tion, and to the radiation physics of radio sources, for example.
Another desirable development has been the near disappearance of t}re
separation between observationalists and theo¡ists. euite a number of U.S.
astronomers are adept in both roles, and a balance in the numbers of spè-
cialists of the two Çpes is maintained in most university graduate depart-
ments. Through Irequent visitation and extended sojoìlrns at maior centets,
the pure theoretical âshophysicists maintain fairly continuous contact with .
:,1
the latest observational results, and there is immediate feedback of their
ideas into proposed new observations.
The Panel concludes that progress in observational astronomy is not
idealimited. The limitation is still well on the side of obsewations, which
come much more slowly than the flashes of insight that may be their initial
ilspiration.
While the Panel has concentrated its attention on the facilities needed
to accelerate the acquisition of new observatíonal data about tÏe universe,
it also recognizes the great importance of a continuing buildup of strength
on the theo¡etical side.
OPTICAL ASTRONOMY
Present Domínant Position of the UníteiL States
The position of Ieadership that thd United States enjoys in optical astronomy
has been won as a direct result of its superior observing facilities. The event
of greatest hístoric signiffcance was the building of the S6-inch refractor
T4
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 15
at Lick Observatoïy on Mount Hamilton in the 1880's. This was the ffrst
rtions
permanently occupíed mountain observatory anywhere, anil quickly demon-
unda-
itt"ted t¡" advantages of such a site' The greât success of tle 36-inch
tìe
s,
Crossley reflector at Lick Observatory a few years later leil naturaþ to
ricl in
tle perfecting of the large modern reflecting telescope, with all its advan-
'elop- tages for askophysical research. The founding of the Mount Wilson Ob-
seivatory witl its 60-inch reflector, completed in 1908, and its 100-inch
in
:ed
in 1918, was perhaps the decisive step towaril achieving leatlership. It was
n the
not entirely a matter of size and superior atmospheric conditions, however.
astlo-
The insistence of tle builders of all these pioneering telescopes on the high-
basic
est sta¡dards of optical and mechanical performance also contributed to
¡ pre:
their spectacular success. The McDonald 82-inch telescope in West Texas
oring
in 1939, the giant 200-inch reflector on Palomar Mou¡rtain in 1949, and the
etical
120-inch reflàctor at Lick Observatory in 1959 complete tìe list of tle
rvolu-
telescopes that have continued ttre tradition. All save the last were private
grftr; th" 120-inch was ffnanced by tax monies of the State of California.
rf the
Íhese great telescopes are the peculiar American contribution to the devel-
: U.S.
opment of asbonomy. Inshuments like them are so essential to astronomers
I spe-
tlat nerv large telescopes are being planned in other parts of tÏe world.
)part-
À 104-inch reflector at the Crimean Observatory in the U.S.S.R. is iust get-
nters,
ting its auxiliary instruments, and a 237-ínch for a mountain site in the
with
U.S.S.n. is being planned. A 150-inch reflector for the Southem Hemisphere
their
is beíng planned by a group of European countries, and anottrer one of
similar size for t}re Southern Hemisphere is being discussed by British
s not
Commonwealth nations. The momentum of the .{merican observatories will
vhich
not be quícHy overcome, but inevitable continuation of a position of leader-
¡itial
ship should not be assumedl,
leded
i¡else, Thø Limìting Fa.ctor for Future Success
rngth
\ryith these excellent instruments in thè good-climate areas of tÏe western
United States, what limits more rapid progress on the unsolved prob-
lems already opened up? The Panel believes that it is not a lack of a unifying
tleoretical concept or of new ideas, as explained earlier; not is it the lack
of a proper number of skilled and imaginative observational âstronomers,
It is not tÏe need to wait for crucial bits of data from space telescopes,
helpful as these may be in certain cases. Neither is it delay in the con-
nomy
struction of a larger telescope than any yet made to get pâst an all-important
event
threshold of information. The limíting factor is, rather, simply the ertremelg
actor
t5
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 16
smnll m.rmber ol telescopes of ad.equnte siza in d.ark-skg Incatians and, úrc
l
consequent slow accumulation of urgentþ needed observational data. Only
:
a handful of ast¡onomers can now be engaged in a sustaineil attack on fron-
tier problems at any one time.
This dilemma arises because astronomical soulces are so faint tlat tele-
scopes of the largest size are required for at least part of most problems.
If we compute tle output capacity of all telescopes with adequate light-
collecting area now in operation any'rvherg and compare this with the crucial
I
problems requiring certain numbers of photon-hours for their solution, we
immediately perceive that our present instrumental facilities are entirely
inadequate to meet the astronomical demand. Thus data precious to the
advance of astrophysics are presently denied us.
Only two existing telescopes are adequate for pushing current frontier
problems to the observational limit. These are the Lick 120-inch and the
Palomar 200-inch reflectors. (The 100-inch telescope on Mount Wilson
has lost efiectiveness because of the light from nearby metropolitan areas.)
These two telescopes do not begin to satisfy the requirements of mid-2Oth
century astronomy. Experience over the past 20 years at the McDonald,
Lick, Mount Wílson, and Palomar Observatories, shows that the most effi-
cient exploitation of large telescopes requires carrying on several programs at
once-work on faint obiects at the photomehic limit during the dark of tle
moon, and spectroscopic work during moonlight. There is, however, an
optimum number of perhaps 10 long-term problems that can be handled
at any one time-giving each of them about 35 nights a year. Even then,
such problems as t-he distance scale of the udverse, where cepheid variables
must be found and measured. in galaxies, require.two to four years to com-
plete at tlis rate, because of the large number of plates required. This
means that 10 to 15 stafi astlonomers per major telescope is all that can be
efiective. With onþ two major frontier telescopes operating, this means
that no more than two or th¡ee astronomers in tTe entire worlil now have
the opportunity to work on the most excitíng problems in any given ûeld.
Competition and the obviously needed opportunity to check results are
lacking. The problem, serious enough from the standpoint of progress,
is even more serious in another respect: it squeezes out of research life at
the frontier top-notch men who, by accident, are not among the fortunate
staff members of big observatoríes. This is an extremely unilesirable situa-
tion from many points of view.
The problem can be, and is, documented every month by the adminis-
trations of both Lick and Mount Wilson-Palomar, where meritorious projects
16
r-_
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 17
bv competent "outsicle" astronomers must be fumed down time after time
il the
fár hck of guest-investigator time at tbe telescopes'
Ooly
The establishment of the Kitt Peak National Observatory will begin to
fron-
ease the problem, but it is so acute that tÏe establishment
of only one more
50-inch) is ot a sufficient answer' This is partþ
-rio, t"i"r"op" (the 1be the only non-private instnment available to the
tele-
:
because Kitt Þeak will n
,lems.
more thnn 700 obsørcer canÅ,íilntes' ( Neither the Lick nor tle
Mount Wil-
IiCht-
instítutions, ancl
,on arrd Pulomar Observatories are federally supportetl
rucial
thei¡ instruments are not generally available' ) If the yearþ assigned observ-
n, we
ing ,i*" on any large telescope is cut below 15 niqhts p3r proiect, no real
tirely
mã¡or problem'can be completed successfully in less,than three or four
o the
.,""r.. *hi"h is extremeþ long by modern standarils' There will, of course,
L" i"* spectacular onå-shoi discoveries made with only a few nights, but
rntier
th" "follo*-ìp of these leads, so essential in the orclerly, progressive advance
tl the
of astronomy, will be missing.
/ilson
The inádeq-uacy of the existing large telescopes for the difficult prob-
:eas,)
lems involving fãínt sources would be even more acute if telescopes of lesser
i-20th
size could ,to-'t b" used to câlry the considerable fraction of the needed
rnald,
observations that do not demanil such geat light-gathering power' Tele-
t efi-
scopes of intermediate size can perforrn all the standard- observational tasks
ms at
ove-r most of the brightness range covered by obiects of a given class' For
,i thu
some types of measrirement, toãh ut the study of nebulae, there is almost
)f, an
no loss of efficiency in going to a quite motlest telescqpe'
ndled
of the most productive use of
Recent astronãmy it t"pl"t" *ith
then,
"*amples
telescopes of small and intermediate size. Examples are: (1) photoelectric
iables
photometry of hundreds of sta¡ clusters to iletermi¡e color-magnituile dia-
com-
g."-., (2j the study of the rotation of galaxies from- spectrographic r-adial
This
ielocities, (S) spectroscopic studies of physical conditions and abundance
an be
ratios in gàsåous nebdaã, (4) the study of intrinsic variablg stars a¡d
neans
eclipsing iinaries, ( 5 ) narrow-band ûlter photometry for determining
have
lumlnosity and chemical composition of stars, and (6J obiective prism
ûeld.
suruey, fó, the discovery of peculiar emission obÍects and t-he iilentiffcation
s are
of stars of a particular class.
gress,
Interest L these valuable lines of research has maintaineil a steady
ife at
pressure on telescopes of small ancl intermediate size, which has been
unate
ànly pa*ly relieved b'y the facilities alreacly completecl at the Kitt Peak
situa-
Ñ"íi-"t óbservatory. The inadequacy so strongly felt at the largest tele-
scopes is equally critical all along the line, and plans to bolster observing
ninis-
poiu, by U"lai"g new telescopeì must give attention to the whole range
oiects
t7
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 18
of sizes in order to provide an eficient set of observing tools tailored to
the varied obsewational needs of the astronomical community.
RADIO ASTRONOMY
PÍesent Posítiøn of the United States
The United States now has an impressive group of major radio telescopes;
contrary to the situation in optical astronomy, however, it can not be said
that the Àmerican position is dominant. The ûrst line of American tele-
scopes, all constructed in the recent past, includes three large telescopes:
the 1,000-foot ffxed-mirror irìstuument at .,{recibo, Puerto Rico, the 300-foot
paraboloid at the National Radio Astronomy Observatory (NRÀO), and
the 600-foot cylindrical paraboloid of the Universíty of lllinois; the latter two
are tuansit instruments. Then there are the two-element interfetometers
at the California Institute of Technology anil NRAO, and the soon-to-be-
completed, 140-foot, fuþ steerable radio telescope at NRAO. As power-
ful as these i¡strûments are, they are exceeded in capability (in ways to
be discussed later ) by such foreign instuuments âs the 2l0-foot telescope
in Australía, tÏe 22-meter millimeter-wave telescope near Moscow, and
ttre large cross-q4)e arrays nearing completion near Sydney and Moscow.
A {urther development that will outrank American telescopes in capability
is tlre proposed high-resolution instrument to be constructed by the Benelux
nations.
for Hàgþ Angulnr Resolutian
NaeiL
Even more important than the capabilities of U. S. railio telescopes rela-
tive to tlose in other parts of tlre world, however, is the capaciÇ of these
telescopes to provide the key data requirecl by the central problems now
confronting radio astronomers. In one ffeld of research after another,
existing and projected telescopes fall short in one all-important respect:
angular resolution. The reason for the exceedíngly |uzzy view o{ the radio
sþ given by these instruments is that they are not large enough, measured
in units of the wavelength of the receíved radiation, to narrow the instru-
mental diflraction patter:n to efiective levels. It must be remembe¡eil that
radio telescopes difier f¡om optical telescopes in their ability to resolve ûne
detail because the wavelengths of the radio waves are as much as a million
times longer tlian the wavelength of the optical railiation.
t8
t_ s
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 19
opes;
, said
tele-
opes:
)-foot
, and
r two
retels
o-be-
lwef-
ys to
scope
, ?nd
scow.
.bility
7
¡elux The peculiar galary tr482 in hlJd,rogen light. Thø frLaments eúend,íng upøard and
Fíguîe
are composeð. ol nateîial tlxrolÙn oltt bg an erplosion in tlle nuclear regioñ of the
dotL;nuaard,
galaq about I milliþn geo.Ìs aga.
rela-
these
; now
other,
rpect:
radio
!sured
nsfuu-
I ttrat
'e ûne
lillion
É.
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 20
r
Fígure 2 The spiúL galaxg M31, uíth íts tüo compaìnioß,
as photogruphed þith øn optícøl telescope giDíng a rcsolu-
tion of 1 second, of arc-
iJ-
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 21
The galarg M31 øs ít u;ould, appeu to a lelesaope
4
¡esoluÍían ol 34' The gaünV M37
Fìgure seen tD¡th 12, resohttìon-
o.s
L íts tØo aompaníons,
,ope eíþíng ø rcsolu
5 galatg M31 as seen aith 3' resolut¡on- 6
Th.e The galary M37 as seen @ìth ft
Figurc rcsolutìon.
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 22
8 The spiîol golLxg M87 os seen Ðilh 7' rcsolutíon'
Fìs|iîe
galarg M87 as seen aíth an optícal
7 The l)71n, tio" tttot pott¡ble Øíth er'islìñg rcilìo relescopes
spìto¿
Fìeu¡e
telescope gioíng 7" tesolution
The uhbþool galary as seen 1þith 7' resohiìon'
The whi pool ¿alaxg,M51' as seen þith an optí'
9
Figure
gioìn! 7" resolulion'
cal telescope
i
I- l
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 23
seen tDíth 7'
xs
ting tad,io t el¿sc opes.
12 Thé bared spi¡al gala*g NGC 1300, a's seen
Th.e barred' spâ¡al' gala*E NCC 7300' as seen r-igute
11
of existirl! radío
Loith 7' lesolution, begond the cøpabi\ta
optícal telescope giDing 7" rcsolutìon
telescopes,
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 34
ïï
I
strongly supported small but active astronomy programs' These few schools
then ãevelopeil into the only graduate departments in the Unitetl States that
stressed observational astrophysics, and tley a¡e the schools from which
most graaluate astronomers have emerged' Not only thes-e schools, but also
schooli that wânt to stør, astronomy programs' face almost insurmount-
able problems in the present era with its increased pressure for excellence.
Except for a hantlful of radio telescopes, there have been very few major
adilitions to tÏe equipment of the existing graduate schools for mâny years.
Even mo¡e serious is the fact that most of tle newly created grailuate depart'
ments have virtually no instrumental legacy from the past.
This problem was recognized about ten years ago when the discussions
leading tJ setting up tÏe Kitt Peak National Observatory anil the National
Radio Astronomy Observatory were begun. If the Kitt Peak Obserwatory did
not exist, the situation in optical astronomy would now be almost intoler-
able. At present, some of tìe graduate-student pressure is relieved because
students from any institution in the courìtry can use the national facilþ at
Kitt Peak. But it is estimated that Kitt Peak can satisfy only 25 per cent of
the total demand that will develop in the near future.
Furthermore, there is a fundamental disadvantage in reþing solely on
the national facilities. Faculty members and students must travel from their
home institutions to distant places in order to collect material for their re-
search problems. They then return to their own graduate departments to
analyze t}'te data. It is usuaþ the case in all experimental science that, as
insight into a problem develops, difierent data are required or new tech-
niqies must be employed at intermediate stages in the research. It is dificult
.meet
this requirement unless the research facilities are constantþ at
to
hand at the home institution. The most efficient use of the telescopes at Kitt
Peak and NRAO would be in the Ênal push toward solution of problems,
after observational techniques had been thoroughly tested on nearby mod-
ern instruments. Thus, the necessariþ limitetl period with a larger telescope
and good skies for optical observers could be usecl far more productiveþ'
it is the opinion of this Panel that a number of graduate schools in tÏe
country should be supported in tlreir attempt to acquire moderate-size tele'
scopes so tåat such a icheme of operation could be adopted generally' There
a Iimit to tlie size of the optical telescope that can be iustiûed
i*, åf
"orrrse,
in parts of the country with low percentages of clear nights' In tlre opinio'l
of ihe Parrel, telescopås hrger than 48 inches should not be built in areas of
relatively poo, *""|h"r. Ho*"u"t, ít is abundantþ clear from results ob-
tainecl, íoiexample, at the Case Institute of Technology, the University of
!t
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 35
t,
Wisconsín, and the University of Michigan that telescopes of 24- to 4O-inch
size can anil have contributeil enormously to tle progress of observational
astronomy. The research of both faculty and students _at these institutions is
of high caliber, and exempliffes what can be done under relativeþ poor sþ
conditions.
The existence of modern telescopes at individual graduate schools has
many advantages. À healthy ,"s""r"L atmosphere is almost automatically
f"culty and students alike. The equipment is available for
"r""i"d stronoirical pioblems that could not be solved on an expeditiola,ry
"*orrf
many a
basis at a nauonal fãciüty. Specíal work on novae' comets, planets, and the
moon at certain unprediótable times requires obsewations thât could not be
made at a national observatory huntlreds or even thousands of miles away'
Any problem requiring close iurveillarce, such as those posed by irregular
]rarialle stars, eJipsirig binaries, int¡insic variables, and tìre radio emission
of Jupiter, cannotie ãealt with away from home because the neecl is for
,"j"uiu,l obr"*"tions at selected tímes. Most importânt is the fact that most
uniiversity-connccted astronomeïs are engaged in teaching and hence a¡e on
students are'
t-he campus for three quarters of the year. A'nil this is where the
If maxiirum use is to be made of equipment, it must not be locateil hun-
dreds of miles away, but must be easiþ accessible, not more than one hour's
travel time awaY.
MANPOWER
We have now outlined the present position of optical and radio astlonomy
with respect to the facilitiei needeil for an aggressive attack on problems
awaitinj solution. There remains the important question of the balance l¡e-
t*e"o tie creation of facilities and tìe number of astronomers that wiII be
demanding observing time when the facilíties are completed'
The a-nswer to this question cannot be given in hard bookkeeping terms'
because the availability of facilities afiects the choice that young scientists
l, make on whether to g; into tÌìeoretical or into observational astronomy' The
for
evidence we have cit-ed earlier in this discussion-the unsatisûed demand
centeï and the desire of many univer-
the telescope time at maior observing
sity graduate departments for modern, locaþ based observing equipment-
poLis to tlte current severe limitations in facilities' Fine new instmments
^o.rdonbt"dly
do attract and inspire imaginative use by outstanding young
28
,i
tn
Þ
-,..
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 36
lr
ì
ì
LC
scientists. Without allowance for such intangibles, the Panel has examined
the growth rate in the number of asttonomels in recent years, anil has at-
tempteil to set upper and lower limits on tìle nunber of U. S. astronomers a
decade hence. The conclusion points to no less than a doubling in t}re next
ten years. If the current rapid growth in graduate enrollment continues, the
factor of increase may be as large as 2.4.
Truiníng of As'tronnmers Comparcd to Ttainíng
of Other Phgsical Scíenfists
Astronomy is one of the smallest disciplines among the engineering, mathe-
matical, and physical sciences. The annual proiluction of Ph.D.'s has been
widely used as an index of the growth rate in these Êelils, The following
studies contain material relevant to the present discussion:
Doctorate Productíon in tJni,teiJ Statas Uniqersitíes. Ofice of ScientiÊc
Personnel of the National Àcademy of Sciences-National Research Council,
Publication 1142. (See also Phgsics Toil'ag, 15:21, 1962 for ilata on physics
Ph.D.'s.)
Comparìson of Eørned Degrees Aaarded 7907-1962 ttsith Ptoiectioru
to 2000. Nàtional Science For:ndation Report NSF 64-2.
lnoestíng án Scíentìfic Progress. National Science Foundation Report
NSF 6l-27; also Report NSF 62-43.
Meating Manpouer Naeds in Science ønd' Technologg. Report No. 1,
Graduate Training in Engineering, Mathematical, and Physical Sciences, by
President's Science Àdvisory Committee, Dec.12, \962.
The semilogarithmie plot of Figure 17 shows the annual U' S. Ph.D.
proiluction in astronomy, physics, and all physical sciences (ûrst two refer-
ãnces above ) . It is apparent tha t ouer the long term +Áe country's astuonomy
education system has not consistentþ maintained tÏe smoothed growth rate
of about 7 per cent per year (doubling time, 10.2 years) that has prevailed
in related ,ãi"n""r. The decline in the period 1935-4I may have been causeil
by the paucity of ¡obs in astronomy at a time when the field ofiereil many
fáwer industrial and government openings than were available to physicists'
The Ph.D.-production rate is perhaps a less reliable basis for estimating
tÏe U. S. wolking force in astronomy than in othei physical sciences because
of the importani fraction of foreign-born, foreign-trained scientists in the
group. Môreot er, there is good evidence that an appreciable proportion of
ihe present astronomy force transfened into astronomy aftel Ph'D' training
in o-ther disciplines, such as physics and engineering. Yet Figure 17 shows
29
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 37
tl:l
'i
,l;l
il
rl
i,.
.t
r970
1960
1950
r940
1930
1920
Fígure 77
sciences ùt the fJnitect States'
Annual Ph.D, 11ro¿uctìott itu attÍonony and other Ttlrysical
t
i
&_
I
1,u..
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 38
steady growth at about 3.8 per cent a year ( l9-year doubling time) through
all the lostwar years, including the I950's, when physics-Ph.D. proiluction
was onã plateau. Since 1956, there have been signs of an upsurge that may
lead to a much higher growth rate. Before exploring the implications and
making a projection based on the best cu¡rent data, it ís of interest to con-
sider alnother'index of research activity in astronomy to see if corroborative
evidence exists.
rdÀIt
89í PER
Fígøe 78
the lntemational Astrononúcal Uniotu 7921-1963'
Crouth of U,5. membetship ¡tu
proiecte¿ to f972.
tlw Infernatianal Astronomical Union
(J. S. Membershâp ín
Figure 18 shows the number of U. S' members in the International Astro-
nomical Union (IAU) from 1923 to 1961. Membership in the IAU is univer-
sal enough among established professional astronomers so that weighting in
favor of [he intemational-minded is negligible. Yet the standards of member-
ship are such that, at any one time, a number of young and productive
,"rã"."h"r* who make heavy demanils on facilities are not being counted'
The membership ffgure is tìerefore lower than the actual force, presumably
by a constant percentage in a period of stable growth. The enumeration is
insensitive to fôreign birth and training, anil to transfer into asEonomy from
initial training in another ûeld'
The plot in Figure 18 shows a steady growth rate of-4'5 per cent per
year ( iloubling Umã, fO years) from 1923 to 1955. The-tlree points {rom
(The
íSSS ìo fSO¿ Jrow a sharp ltptorn to a doubling time of nine years
1964 point is an estimate from the U. S. National Committee of the IAU,
31
lì
-t
þ
B'-
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 39
tle impression gainedJrom the glowÌb
based on nominations. ) This conffrms
tìe American Astronomical Society, and from the rapid
in membership of
swelling of the astronomy graduate student population' Since the latter gives
the most up-to-tlate irformation, it has been made tl-re subiect of a special
study. .
Graduate Stuiønt Populntion in Astrotwmg Depattments
The current survey gïew out of a census made by W. E. Howard III for the
1962 Conference on Graduate Education in Astronomy, held at Bìoomington,
Indiana. Material for this study was gathered by inquiries to the 28 clepart-
ments listed in the brochure entitled "Careers in Astronomy," published in
1962 by the Committee on Education in Astronomy of the American AStro-
nomicál Society, plus four new departments known to the committee' The
replies on tìe .t,rmbets of students in the falls of 1957, 1960, and 1963, plus
eaich deparunent's estimate of the 1966 enrollment, are listeil in Table 1' The
totals, plotted in Figure 19, establish a growth rate within the graduate
schools of 19 per cent a year (a doubling time of 4.0 years )' This is near-þ
twice the rate attained or projectecl in related sciences A simple extrapola-
tion predicts 2,590 graduate students in astronomy ín 1973 The ffrst efiect
of this surge was a Þh.D. output of 30 in 1962, considerably higher than ìn
any previJus year, but a figure consistent with the assumption that the
ph.O.t should'be at least 10 per cent of the student population, with a three-
year lag to allow for the fact that rapid growth means a hígher proportion of
ginning graduate students.
be
- What it the source of this boom and how long will it continue? In the
opinion of the Panel, some o{ it was a natural growth, stimulated by general
among science-inclined undergraduates of the exciting derrelop-
"i"."rr"r,astronomy of the postwar years, and fostereil by wise supplemen-
ments in
tary support of resåarch and instïumentation in many universities by federal
A new anil strong influence came with the ffrst Sputnik in 1957 ancl
"gá.t"iår.
tÈe widespread interest in space that followed. Since a good part of the
university-based space efiort is in special institutes separate from astronomy
departments-often dominated by physicists, geophysicists, and engineers-
thJ rapidly growing student population in the departmental tâbülation of
Table ì reprãsents a broad spectrum o{ interests, and something like the tra-
ditional pioportion of tlre students may be expecteil to go ínto ground-based
observational astronomy.
The new astronomy students irndoubtedly lepresent a shift in interest
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 40
7 THE NUMBER OF CA.NU ATE STUDENTS IN ASTRONOMI
TABLE
BY INSTITUTION
1966
1960
1957 1963
. (nxrncrao)
22835
Untuersitu ol Arízona O
19
22
CaliÍorûia. In'stítute of Tealnolagg 35
16
35
23
tlnÍaeîsítv of CøInÍoîrìa, BØkelea 65
20
28
20
Unìoeßitg oÍ Ca.UÍomùt, Los Angelzs 40
3
51720
Case htstitute of Techrølogv 1
71420
Uítueîsftv of Chí'cago 6
641
Unioeß¿tg of Chûìnnati 0
42
I5
Uflioeßìtg oÍ Colþru¿o 50
7
5412
Columbíø UûbeßìtlJ 5
Uníoeßítg 2
Conell
01220
Florìdø
Unbetsìtg of 0
40
31
Georgetoün Un oeßtfg 45
22
40
28
Haroard Uníoeßìta 55
24
813
Utuloeßìtu oî lllítuois 17
2
25
23 30
Indí.anafJnìaersítE 16
0610
Iotþ4.
State Uníaeßitg oÍ 0
026
Un¿aeßitg O
Louí9íøna Sta.te
22555
Ilntuersüg of Marllønd 0
32
28
Untuersttl! of Mtch¡'gan 76 40
011
NorthØestern uníoeßìtg 15
1
71425
Ohio St tte Unheîsìtu 5
81520
unìoeÍsifv ol Pennsgh)ania 3
6710
Pr¿ncehn Aníþeßíig 6
r8-13
RensselnetPolgtechn¿clnstitlûe 0
228
tJniÐeÌsitg oî Roch¿ster I
É712
Stanford Unloeß¡tg 5
51225
' Unioersitg of Terns 0
026
Vand.erbilt Uû¡þeßítg 0
o2L6
l
Uniþersítg oÍ V¿rginial
2610
Wesl.egafl Uníoersitg 0
19
14
Uníoersitv of Wbconsín 30
2
62840
Yalþ Uníoeßíta 5
Totals
within the 25 per cent fraction of the physical-science doctorates thai have
been going into astronomy, physics, and geo-scien ces (Doctorate Production
ín Uãitel ffiates Uníoersitíes, see p. 30). This percentage has remained
stable over many years, as has the over-all fractíon of abdut one sixth of total
doctorate production going into all the physical sciences' The shift diil not
need to b; a hrge one to produce the drastic increase in astronomy alone,
since astronomy plt.¡.t irr the years 1957-62 were only 3 per cent o{ t'hose
in physics, rising to just over 4 per cent in 1962. An íncrease of the astronomy
Ph.D.'s to 8 pei cent of the physics production, as was the case in the pre-
nuclear decaãe of the 1920t, or even to 10 or 12 per cent, woulil not be
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 41
UNIFORÀ{ CROWTI¡
/
, :¡ÀPERED GROWTII
NUIIIER OF ASTRONOI4ENS
GB¡.DUATE
STI'DE\TTS
I]NIFOR}I CNOWTII
, 19ø PER YE,lû
TÀPERED GÂOWTII
7 ¡¡n va¿¡ n¡ 1973
Fígurc 19
Ninnbet of gra.Iuate st¿(lents í'n asftonontg, the number of PhD"s 1954-1962, and Prcìecte¿
Ph.D. prcductíon an¿ total nuñl)et of \stronomeß to 7973'
I
l
I
I
I
L-"-
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 42
emphasis among the physical -sci-
tantamount to a drastic redístribution of when
o{ astronomers is stilitlisproportionately small
,¡"
;ö;ä ;the"*¡er manpower in physics' geophysics' and
" total
"î"ärï"" astronomv
combined.
"""^îîãrå"r be support for increas-
a" tustain a high growth rate there must
National Defense Education Act is
t-.,;;;; of øraduate ,úraÉots' The
in a1l the phvsical sciences' and the efiect
Ïiäil"ff;.'"i;"ì"pìr"'i""itt maximumpáint' The new National Aero-
;ililåå;;"i vet '"""h"d supportetl
Administratiãn iN¡'s¿') i"16ç5hip- ^program
and 886 fel-
iäöä.ii;;r;ãJ. i" il n"1'{' ii" r0 institutions tur1s62-63' sources' to
"",îu"r- ""Jóp"""'
to nsease' according to- NASÀ
it is expected
lows in 1963-64;
rn view of the announced pur-
;îi;;;*'t; as 4,00ô graduate students'
fraction of the recþients could be assumed'
:::ili1Ë;s;;;;*i" *ho *ot'Id otherwise have go, e into some other
;;;il;r*¿"""
í""il this influence could accel-
;hy"*üì;;;;. ,{ltho'tghnitis conceivable that high ffgure' it is probably
p'"'"nt very
erate the growth late even "yoJ th"
Ñns¡' fellowships mav be
not safe to attempt such " p;;ñ;ti"";*' rhe cur-
o"" ofthå sources of support that will sustain the
;;;ã,;";"d ", of inte¡est in astronomv in the universities'
;';;;";;;;n""sion
A Ten-Iear Proiectíon
in the Uniteil States will be
Two projections of the number of astronomers growth rate in
It may be assumed that the 19 per cent a;ear long enough to
"aì"nñ,"d. truduáte-st.'ilent pàpuìation- has-bee¡ in efiect
äsiffi;; long as the growth rate is sustainetl'
achieve a new equilibtitt"',
"íã'tttui, "s at u 19 p"t cent a year rate' starting
Aä ph.li. ptàa"Ë,íon will also increase
f he production' it mav
il;;ouap* of 30 in 1962' For a high estimate on tP-h.D. procluction.will
rate i
further be assumed th"t th;';;r""t g:rowth
1SOS-1SZS Since it is difficult to
iä*"i" ""¿""ged in the tetþ' p"t"iod
can be sustaineil over a long
maintain that such u pft""o-áouily high rate
on some assumption as
;;i;ã, ; t""t" conser-vatíve ostimate rÀust be baseclFor the low estimate' a
e
i" ift"'ait"i"g of a tapering fi of the growth rate'
t"i tfte ûrst year' decreasing uniformly
19 per cent $owth rate ¡
""""ft tU" Z per cent lóng-term growth rate char-
tt"t*ã
by 1.2 per cent per year to t ten-year period'
**õiah; i aì" nf..i"¡ *ià""át i" genåral by the enil oI theSociety on Janu-
"ä".tråã " r,36^0 itmbets ãf the Ãmerican'Astronomical
hold doctorates or professorships'
"-, I laR4 620 have U. S' "iådt"1t"t santl fringe asrronomers and persons
"a"a"s ome
ü,J'",,mI)-J;"d""u*a(
35
i
I
á-...
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 43
IN THE
PREDICTED ASTRONOMICAL MANPOWER
TABLE 2
UNITED STATES
uNrFoRM cRowrr¡ RÀTE (79% a gea¡ or 4-gear d,oubling perlod)
1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973
43 59 71 83 98 118 I38 162
50 I95
Neø Ph.D.'s
663 703 751 8-tr 882 967 7071 7193 1337 1512
SubJotal .
11 14 16 18 20
10 11 12 13
l-54 23
Loss
653 692 740 799 869 953 1055 1175 1317 1489
Total 620
ø geaî ín first geaL d,eøeasíng to 7% ø geøÌ at eñd)
cRowûr R.41æ (791¿
TÀPERED
1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973
42 49 56 72 8_t 90 98 106 113
64
Neu: Ph.D,'s
662 701 747 800 860 928 7004 1087 717',/ 7272
Sub-totøI
10 10 77 13 14 15 16 18 19
t2
1,5% Loss
652 691 736 788 847 914 989 1071 1159 1253
t: Total 620
,il
with primary interests in other ûelds, but there is probably approximate
compensatíon by the active astronomers in the other 54 per cent of the mem-
,,1
bership who do not hold doctorates or professorships. The National Register
,i
'j.
of Scientific and Technical Pe¡sonnel lists 483 full-time astronomers in the
ii
United States in 1962. (W. L. Koltun of the National Science Foundation,
,tl,ì
il
:t,l which maintains tle Register, estimates that tÏe listing, basecl on responses
ii
to a questionnairg is only 80 per cent complete. If allowance is made for
)
l
incompleteness and for about 40 Ph.D.'s added since 1962, and also for the
standard loss of 1.5 per cent a year by death or retirement, found by the
l
ll National Science Foundation to apply generaþ ín scientiffc-manpower srü-
veys, the corrected total becomes 626 full-time astronomers at the beginning
:, of 1964. This is a confirrnation of the previous ffgure of 620, and that number
i
may be adopted as a base for the prolection.
l
Two projections are worked out in Table 2 and plotted in Figure 19.
l|1
The high estimate shows an increase in total ashonomical manpower by a
l
l' ; / lactor o12.4in ten years. The low estimate proiects an increase by a factor
of 2.0. Thís tabulation does not attempt to classify astronomers by categoties
ì,,' of inte¡est-theoretical or observational, optical or radio, ground-based or
ili space-oriented. Since shifts in emphasis occur quite slowly, no complete
:'
lrl
overturn ín percentages would be expecteil in a decade. A prediction would
I
l
,i
be hazardous, but the proportion of tlle student population in graduate de-
i
tLl
partments that place emphasis on ground-based astronomy, compared with
I
.;
')' 36
l:
Copyright © National Academy of Sciences. All rights reserved.
OCR for page 44
ì
the proportion in departments that have taken up space-orienteil astronomy,
*orild årgo" againsf any immediate drift away from the present division of
interest.
Conclusían
The surge of students into the graduate departments of astronomy has fol-
no sign
lowed aiteaily upward course for at least six years, and as yet shows
from the cur-rent enrollment are
àf ,ou.rding oif. If only the Ph.D.'s expecteil
in the
countetl, a"sharp increase in growth rate of the number of ast¡onomers
in the
count yis ioevitable. Arry reasonable assumptíon about a ¡ounding-ofi
*o*tí t"t* of graduate enrollment leads to not less than a iloubling of the
iumber of astrolnomers in the United States in the next ilecade'
--'
iin"" grounil-baseil astronomy has been shown Jo be uncler-instru-
program of new facilities that
menæd forïe demand already
""ittittg, " to work efiectively at moilern
*ilt p"t-it roughly twice ", -åoy obseivets
i"lããop", *orrãt úe consiclered rash. There will sureþ be more than enough
astronomers waiting to use the new instruments'
Copyright © National Academy of Sciences. All rights reserved.
