Table Of ContentAstrophysics and Space Science Library 459
Pieter C. van der Kruit
Jan Hendrik Oort
Master of the Galactic System
Astrophysics and Space Science Library
Volume 459
Series Editor
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Pisa, Italy
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Pieter C. van der Kruit
Jan Hendrik Oort
Master of the Galactic System
123
Pieter C. vanderKruit
Kapteyn Astronomical Institute
University of Groningen
Groningen,The Netherlands
ISSN 0067-0057 ISSN 2214-7985 (electronic)
Astrophysics andSpace Science Library
ISBN978-3-030-17800-0 ISBN978-3-030-17801-7 (eBook)
https://doi.org/10.1007/978-3-030-17801-7
©SpringerNatureSwitzerlandAG2019
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JanHendrikOortin1973.FromtheOortArchives
This book is dedicated to
the memory of
Jacobus Cornelius Kapteyn (1851–1922),
whom Oort described as
‘mijn inspireerenden leermeester’,1
and to
my wife Corry
for her love, understanding and support.
1Myinspiringmentor,Oort(1936b,p.4).
From a Letter from British Astronomer Roger John Taylor (1929–1997) to Jet
Katgert-Merkelijn:
‘…thisarosethrougha‘Balloondebate’.Theseastronomersweresupposedtobe
inaballoon—Hoyle,LovellandOort—buttherewasonlyenoughgastocarryone,
sotwohadtobethrownout.Speakersonbehalfofeacharguedtheircaseandthen
theaudience(theUniversityastronomysociety)voted.ItookthepartofOort.Iam
gladtosaythathestayedintheballoon!
Thishappenedin1984.’
1 MynamesirisJanHendrikOort. 6 Superclustersareformedathighz(ed).
I’mwellknownwhereastronomy’staught. Beforequasarsappeartheylookdead.
I’veaspecialnotation AlthoughIsuggested
ForGalacticrotation. Hmaybedetected,
ThoseAandBconstantsofOort. Inapaperthatyou’venotyetread.
2 Thechangedmotionofstarswithdischeight 7 IfacometgoesclosetotheSun,
Hasshownthatthere’smasswithoutlight. Thatorbitmaybeitslastone.
Whetherfaintstarorplanet Butdonotdespair,
Orblackholeorgranite Thereisplentymorethere
TheOortlimitiscertainlyright. IntheOortcloudsofarfromtheSun.
3 Aballoonrequiresplentyofgas 8 ThenightskiesinEuropearegrey,
Muchofwhichusedtobehiddenmass, Butradiowavescomeallday.
UntilvandeHulstshowed SoIurgedthecreation
ThattheGalaxyglowed Inoursealevelnation
Witharadiolinefromthecoldgas. OfWesterbork’smightyarray.
4 Hisresearchesontheradioline 9 Atthesametimeforworkingwithlight,
Wereinspiredbyanideaofmine. Itisclearthatamountainisright.
Nowwhenstudiedwithcare SoFrenchmenandDutchmen
Ingalaxiesfar,their AndGermansandsuchmen
Rotationitservestodefine. PutourtelescopesonChileanheight.
5 Itisgenerallycountedariddle 10 Thoughmydecadesnownumbereight,
WhatoccursinourGalaxy’smiddle. Myknowledgeisnotoutofdate.
ButmyAnn.Rev.review Istillworkwithrelish
Istopreadingforyou, Forit’spublishorperish.
Ifyouhopetodeciphertheriddle. Inyourhandsdearsirismyfate.
Preface
Itriedtoimaginethesituationofahistorianofnatural
sciences,workingsometimeinthetwenty-firstcentury
onamonographdescribingJanOort’sscientificimportance.
Ifsuccessful,thishistorianwouldhavecoveredinhis
monographaverysubstantialportionofthehistoryof
astronomyinourcentury.
BengtGeorgDanielStrömgren(1908–1987)2
During 2015, when my biography of Jacobus C. Kapteyn had appeared in the
AstrophysicsandSpaceScienceLibrary,colleaguesaskedmewhatmynextproject
wasgoingtobe.Oftenthesuggestionwasmadethatthiswouldhavetobeasimilar
biographyofJanHendrikOort.IwashesitantsinceIhadknownOortwell.Butthe
idea gradually became more and more appealingand late in2015 I started to form
an idea of what would be involved; the task seemed overwhelming.
One of the first things I did was to have a talk with Jet Katgert-Merkelijn, who
had made an extensive inventory of Oort’s archives and next I had some initial
email exchanges with Marc Oort, who is a grandson of Oort and holds a Ph.D. in
astronomy.Idecided toproceed;Iestimatedtheprojectwouldtake four years and
that 90 days were required at the University Library Leiden, where the Oort
Archivesarekept.Iwentontosecuresomefundingthatwouldberequiredtomake
the many visits and quickly obtained approval or positive response. The Kapteyn
Astronomical Institute in Groningen, which is my home base, also supported the
project. Marc Oort consulted his uncle Abraham Hans Oort, younger son of Jan
Hendrik Oort, and arranged permission for me on behalf of the Oort family to
consult the confidential parts of the Oort Archives.
I was at that time six years into retirement and had only few time-consuming
duties or commitments left. I wrote the first draft of the first sentences of the first
chapter at home on 5 January 2016, when the northern Netherlands were hit by a
severecaseoffreezingrainandglazedfrostthatdisruptedalltrafficandforcedthe
University to completely shut down. People skated in the streets. I was unable to
2IntheLiberAmicorumwrittenforOort’seightiethbirthday(LibAm80[2]).
ix
x Preface
leavemyhouseforthreedaysandthatmadeforagoodstart.Whentheweatherhad
improved, I made my first visit to the Oort Archives in Leiden. In the end I spent
about 75 days in the University Library in Leiden. This was facilitated by having
supporttospendasimilarnumberofnightsinthevandeValkhotelLeiden,where
I—andmywifewhoaccompaniedmeonabouttwo-thirdsofthevisits—becamea
regular customer. To my surprise it took me only three years to complete the
manuscript. A major factor is the excellent inventory of the Archives that Jet
Katgert has provided.
I was fortunate to be able to visit the Carnegie Observatories in Pasadena,
California,in2018,foraperiodofmorethanfiveweeks,duringwhichIexamined
the archives of various astronomers Oort corresponded with at the Huntington
Library and at the California Institute of Technology, and had a enlightening
interview with Maarten Schmidt. I also visited the Oort Archives at the European
Southern Observatory in Garching, Germany.
Sources. Publications on Oort frequently referred to or matters closely related to
him have been given a special designation to be used throughout this book. For
example, Jet Katgert’s inventory of the Oort Archives is designated as the
JKM-Inventory[1],andmyKapteynbiographyastheJCKbiog.InAppendixC.1.,
these have been listed with reference to the complete bibliographical information.
There are two types of diaries in Oort’s private archives. One type has the size
of notebooks (on the order of 20 by 15 cm). These are catalogue number 9.3.1 in
the JKM-Inventory [1], running from 1915 to 1960, with 1946 missing (but
sometimesthereareverylongintervalsbetweenentries).Iwillrefertotheseasthe
diary notebooks. The other type consists of small appointment books that in
additiontoappointmentsoftencontaindetailednotesonactivitiesandimpressions.
These run from 1923 to 1991, again with some years missing, and are catalogue
number 9.3.2 in the JKM-Inventory [1]. I will designate these as pocket diaries.
Like for the Kapteyn volume, this book is also accompanied by a dedicated
Website:www.astro.rug.nl/JHOort.Thisnotonlyprovideslinkstopublicationsby
Oort, but also to publications about him. In addition, I give access to much of the
public material I used. Mymodus operandi atthe Oort Archives has been tomake
photographs on my tablet (an iPad) of all things I judged to be useful to have
available.Thesearehigh-resolutionpictures,andthereareoforder30,000ofthem.
IcollectedtheseinseparatedirectoriesforeachitemnumberintheJKM-Inventory
[1]. I compressed all pictures by a factor 2 by 2, ending up with four times fewer
pixels,andthenturnedtheresultintopdffiles,againbyitemnumber.Thesearealso
made available on the website, with permission of the Leiden University Library.
Of course, this does not include the private archives.
JetKatgert-MerkelijnhasprovidedawebpageatthesiteofLeidenObservatory,
which shows a number of high-quality scans of (mostly group-) photographs in
which Oort appears: www.strw.leidenuniv.nl/oortfotos/.
The audience I had in mind while writing this book broadly speaking includes
thoseinterestedinthehistoryofastronomythathaveabackgroundinnaturalscience
(so not necessarily astronomers) or historians specialized in astronomical history.
