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{{Short description|Dutch astronomer (1921–2021)}}
{{Use dmy dates|date=May 2021}}
{{family name hatnote|de Jager|Jager|lang=Dutch}}
{{Infobox scientist {{Infobox scientist
| name = Cornelis de Jager | name = Kees de Jager
| image = Kees-de-jager-1967.jpg | image = Kees-de-jager-1967.jpg
| image_size = | image_size =
| alt = | alt = Photograph of Kees de Jager taken in 1967
| caption = Kees de Jager in 1967 | caption = Kees de Jager in 1967
| birth_date = {{Birth date and age|1921|4|29|df=yes}} | birth_name = Cornelis de Jager
| birth_date = {{Birth date|1921|4|29|df=yes}}
| birth_place = ], ], ] | birth_place = ], ], Netherlands
| death_date = <!-- {{Death date and age|YYYY|MM|DD|YYYY|MM|DD}} (death date then birth date) --> | death_date = {{death date and age|2021|5|27|1921|4|29|df=yes}}
| death_place =
| residence = Den Burg | death_place = Den Burg, Texel, Netherlands
| citizenship = | citizenship =
| nationality = | nationality = Dutch
| fields = ], ] | fields = {{hlist|]|]}}
| workplaces = ] | workplaces = ]
| alma_mater = Utrecht University | alma_mater = Utrecht University
| doctoral_advisor = ] | doctoral_advisor = ]
| academic_advisors = | academic_advisors =
| doctoral_students = | doctoral_students =
| notable_students = | notable_students =
| known_for = | known_for =
| author_abbrev_bot = | author_abbrev_bot =
| author_abbrev_zoo = | author_abbrev_zoo =
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'''Cornelis "Kees" de Jager''' (born 29 April 1921) is a Dutch astronomer.


'''Cornelis''' "'''Kees'''" '''de Jager''' ({{IPA|nl|ˈkeːz də ˈjaːɣər|pron}}; 29 April 1921 – 27 May 2021) was a Dutch astronomer who specialized in predicting ] to assess the Sun's impact on future climate. He was the General Secretary of the ] from 1967 to 1973 and former director of the observatory at ]. He was a fellow with the ] and played an important role in the European ] as the first chairman of both ] and the ].
==Education==
Born in ], de Jager spent his school years in the ]. From 1939 to 1945 he studied ], ] and ] at ]. On 13 October 1952 he obtained his ] with a thesis called "The Hydrogen Spectrum of the Sun". His supervisor was ].


==Solar and stellar research== == Personal life and education ==
Born in ] on the Dutch island of ], de Jager spent his school years in the ].<ref name=":0">{{cite web|last=van den Heuvel|first=Ed|url=https://www.astronomie.nl/nieuws/in-memoriam-kees-de-jager-sterrenkundige-1921-2021-2832|title=In memoriam Kees de Jager, sterrenkundige (1921–2021)|publisher=Astronomie|website=astronomie.nl|date=28 May 2021|access-date=18 July 2021|language=Dutch}}</ref> In 1939, De Jager heard Professor Minnaert speak. De Jager said "I was so fascinated by what he said, that I decided right then and there to study Astronomy."<ref>{{cite web|title=Utrecht astronomer Kees de Jager turns 100 – News – Universiteit Utrecht|url=https://www.uu.nl/en/news/utrecht-astronomer-kees-de-jager-turns-100|website=www.uu.nl|date=29 April 2021|access-date=1 June 2021}}</ref> From 1939 to 1945, he studied ], ] and ] at ].<ref name=":0" /><ref name=":1">{{cite web|last=Welch|first=Faye|url=https://commentaryboxsports.com/digital-concert-special-magazine-for-astronomer-kiss-de-jagger-100/|title=Digital Concert & Special Magazine for astronomer Kiss de Jagger (100)|publisher=Commentary Box Sports|website=commentaryboxsports.com|date=April 2021|access-date=18 July 2021}}</ref><ref name=":2">{{cite web|last=Buiter|first=Rob|url=https://www.trouw.nl/wetenschap/astrofysicus-kees-de-jager-draaide-honderd-rondjes-om-zijn-zon~b44ea0ae/|title=Astrofysicus Kees de Jager draaide honderd rondjes om zijn zon|newspaper=]|date=1 May 2021|access-date=18 July 2021|language=Dutch}}</ref> On 13 October 1952, he obtained his ] with a thesis called "The Hydrogen Spectrum of the Sun".<ref name=":1" /> His supervisor was ].<ref name=":2" />
De Jager did work on stars and ], in relation to which he was a founding editor of the journal '']''.<ref></ref> In 1980 he was ] of the Hard X-ray Imaging Spectrometer (HXIS) on board the ] satellite.


De Jager died where he was born, in Den Burg (Texel), on 27 May 2021,<ref name=":3">{{cite news|last=van der Heijden|first=Margriet|url=https://www.nrc.nl/nieuws/2021/05/28/een-leven-gewijd-aan-de-zon-a4045233|title=Een leven gewijd aan de zon|newspaper=]|date=28 May 2021|access-date=18 July 2021|language=Dutch}}</ref> less than a month after he became a ].<ref>{{cite news|last=van den Ham|first=Hans|url=https://www.ad.nl/utrecht/utrechtse-astronoom-kees-de-jager-is-100-maar-de-sterrenhemel-kan-hij-niet-meer-zien~a1dde9b4/|title=Utrechtse astronoom Kees de Jager is 100, maar de sterrenhemel kan hij niet meer zien|newspaper=]|date=29 April 2021|access-date=1 May 2021|language=Dutch}}</ref><ref>{{cite web|url=https://www.texelsecourant.nl/nieuws/algemeen/205920/professor-kees-de-jager-overleden|title=Professor Kees de Jager overleden|website=www.texelsecourant.nl|date=28 May 2021|access-date=18 July 2021|language=Dutch}}</ref>
From 1978 onward de Jager did noted work on the most luminous stars, known as ]s.<ref></ref>


== Solar and stellar research ==
From 1960 to 1986 de Jager was a professor at Utrecht University. In 1969 he became member of the ].<ref>{{cite web|author= |url=https://www.knaw.nl/en/members/members/4303 |title=Kees de Jager |publisher=Royal Netherlands Academy of Arts and Sciences |date= |accessdate=28 July 2015}}</ref>
De Jager did work on stars and ], in relation to which he was a founding editor of the journal '']''.<ref>{{cite journal|title=SAO/NASA Astrophysics Data System (ADS)|url=http://adsabs.harvard.edu/full/1969SoPh...10..243.|journal=Solar Physics|year=1969 |volume=10 |page=243 |bibcode=1969SoPh...10..243D|last1=De Jager |first1=Cornelis |last2=Švestka |first2=Zdeněk |issue=2 |doi=10.1007/BF00145510 }}</ref> In 1980, he was ] of the Hard X-ray Imaging Spectrometer (HXIS) on board the ] satellite.<ref name=":3" /> His work on ]s was often done in collaboration with ].


From 1978 onward, de Jager did noted work on the most luminous stars, known as ]s.<ref>{{cite web|url=http://alobel.freeshell.org/festschrift.pdf|title=Two Decades of Hypergiant Research|website=festschrift|access-date=13 May 2016}}</ref> From 1960 to 1986, de Jager was a professor at Utrecht University.<ref>{{cite web|url=https://nos.nl/artikel/2382626-sterrenkundige-en-bedenker-woord-oerknal-kees-de-jager-overleden|title=Sterrenkundige en bedenker woord 'oerknal' Kees de Jager overleden|publisher=NOS|website=nos.nl|date=28 May 2021 |language=Dutch}}</ref><ref name=":4" />
==Sun-climate relations==
De Jager's current research focuses on predicting ] to assess the Sun's impact on future climate. Usually ] is defined in terms of the Sun's toroidal magnetic field, the field component parallel to the solar equator. Sunspots are one expression of this component. De Jager introduces the ] field of the Sun, which connects its two poles, as a factor of possibly similar importance. He uses ] for both components and takes 19-year ]s to eliminate all effects that last only one or two ]s. Next he plots both components in a diagram, thus creating an experimental ]. The track of the two components went from low to high activity around 1925. Around 2009 the same point has been passed in the opposite direction. Thus solar activity in the 21st century is expected to be lower than it was for most of the 20th century. A reduction in solar activity means less energy input to the Earth, thus counteracting ].


== Sun–climate relations ==
==Other activities==
De Jager's later research focused on predicting ] to assess the Sun's impact on future climate. ] is usually defined by the Sun's toroidal magnetic field, the field component parallel to the solar equator. Sunspots are one expression of this component. De Jager introduced the ] field of the Sun, which connects its two poles, as a factor of possibly similar importance. He used ] for both components and took 19-year ]s to eliminate all effects that last only one or two ]s.<ref>Yaskell, S. H., ''Grand Phases On The Sun: The case for a mechanism responsible for extended solar minima and maxima'' (Trafford: 2013)</ref>{{Better source needed|date=May 2021|reason=Author refers to "climate alarmism", and lacks credentials, with only a B.A. in social sciences}} Next he plotted both components in a diagram, thus creating an experimental ]. The track of the two components went from low to high activity around 1923. Around 2006 the same point has been passed in the opposite direction.<ref name=":5">{{Cite journal|last=de Jager|first=Kees|date=1 April 2016|title=Solar activity and its influence on climate|url=https://www.cambridge.org/core/journals/netherlands-journal-of-geosciences/article/solar-activity-and-its-influence-on-climate/A6067FE54FCC7BB44E28E449BA260BD5|journal=Netherlands Journal of Geosciences|volume=87|issue=3|pages=7|via=]}}</ref> Thus solar activity in the 21st century is expected to be lower than it was for most of the 20th century. A reduction in solar activity means less energy input to the Earth as part of the ], partially countering ].<ref name=":6" />
]
He was the General Secretary of the ] from 1967 to 1973 and former director of the observatory at ].<ref></ref> He was the first chairman of ] from 1987 to 1998,<ref>{{Cite web |url=http://www.skepsis.nl/sn13.html |title=Randverschijnselen in de wetenschap – Liber amicorum voor Kees de Jager |work=Stichting Skepsis website |publisher=Stichting Skepsis |accessdate=28 October 2014}}</ref> the first chairman of the ] from 1994 to 2001,<ref>{{cite journal |last=Mahner |first=Martin |date=February 2002 |title=10th European Skeptics Congress: Rise and Development of Paranormal Beliefs in Eastern Europe |url=http://www.csicop.org/si/show/10th_european_skeptics_congress_rise_and_development_of_paranormal_beliefs_ |journal=] |publisher=] |volume=26 |issue=1 |pages= |doi= |accessdate=28 October 2014}}</ref> and is also a ] fellow.<ref></ref><ref></ref>


De Jager postulated that solar magnetic activity is the most significant contributor to ] temperatures, with polar activity also being significant, and that with the subtraction of these factors from temperatures recorded over the preceding 400 years, peaks and dips in temperature could be observed, accounting for recent increase in global warming.<ref name=":5" /> Similar theories have been rejected by other climate scientists as solar activity and global temperatures have diverged since 1975, with energy output from the Sun decreasing and Earth temperatures still increasing. Additionally, warming caused exclusively by the Sun would result in an even warming throughout the atmosphere, rather than the observed cooling in the ] and warming in the ] associated with ]es.<ref name=":6">{{cite book|last1=Thomas Farmer|first1=G.|title=Climate Change Science: A Modern Synthesis|last2=Cook|first2=John|publisher=]|year=2012|isbn=978-94-007-5756-1|pages=14, 475–476}}</ref>
== Awards ==

*1974 ]
== Cyclosophy ==
*1984 ]
]
*1988 ] by the ] of the ]
Expanding on a 1990 paper presentation at the International Skeptics Conference, de Jager published an article for '']'' where he parodies ]. In ''Adventures in Science and Cyclosophy'', de Jager claims that many times pseudoscientific reasoning ignores coincidences dealing with the relationship between objects when there are unlimited data points. He states that measurements surrounding the ] have been used to show a relationship with astronomy. To do so, he explains, anyone can use the ]<ref>{{cite web|last=Lee|first=Adam|url=http://www.patheos.com/blogs/daylightatheism/2008/04/popular-delusions-ix/|title=Popular Delusions IX: Numerology|publisher=Patheos|website=Daylight Atheism|access-date=28 June 2016|date=7 April 2008}}</ref> to relate to anything one would want, to try and prove there is some connection. As an illustration, he uses the example of his ] and the cosmos.<ref>{{cite web|last=de Jager|first=Cornelis|url=http://www.geistigenahrung.org/ftopic2051.html|title=The Holy Bicycle|website=Geistige Nanrung Dein Forum|access-date=28 June 2016}}</ref><ref>{{cite book|last=Paulos|first=John Allen|author-link=John Allen Paulos|url=https://books.google.com/books?id=o0gmTPmlUjMC&q=Xa+Yb+Zc+Wd&pg=PA24|title=Irreligion: A Mathematician Explains Why the Arguments for God Just Don't Add Up|isbn=978-0-8090-5918-8|year= 2009|publisher=Macmillan |access-date=28 June 2016}}</ref> Enthusiasts in this formula have created a website that allows visitors to submit data to replicate de Jager's experiment.<ref>{{cite web|last=Hars|first=Florian|url=http://www.hars.de/misz/rado.html|title=Radosophie|website=Misz|access-date=28 June 2016}}</ref>

{{quotation|I measured the diameters of my bike's: -pedals, symbolizing the forward-going dynamics; -front wheel, which directs my ways into the unknown future; -lamp, enlightening my paths; -bell, through which I communicate with encounters. Thus I laid the building stones for a new holistic four-dimensional religion apt to the coming of the New Age of Aquarius: cyclosophy. The measurements were expressed in Holy Bike inches, being 17 mm. This is so since 1 is the first prime number and 17 the seventh, and because seven is the holy number. Calling P, W, L and B the four measured quantities, it turns out that P ^ 2 √ L x W <nowiki>=</nowiki> 1823 which is the ratio between the masses of the proton and the electron.... Coincidences occur regularly in numerical experiments, as in daily life ... are not rare ... Most people greatly underestimate the enormous amount of possible combinations between numbers. ''Adventures in Science and Cyclosophy''<ref name="Cyclosophy article">{{cite journal|last=de Jager|first=Cornelis|title=Adventures in Science and Cyclosophy|journal=Skeptical Inquirer|date=1992|volume=16|issue=2|pages=167–172}}</ref>}}

According to ], who attended the 1998 Second World Skeptics Congress in ], Germany, de Jager's "dead-pan" description of how he took measurements throughout his house showing the "absurdities of those who attach great mystical significance to measurements of the Great Pyramid" had the audience "in stitches". Apparently "his home is in an astronomical observatory, a location, he said, 'that may be very close to the cosmos and well receptive to its incredible powers.'"<ref>{{cite web|last=Kendrick|first=Frazier|author-link=Kendrick Frazier|url=http://www.csicop.org/si/show/science_and_reason_foibles_and_fallacies_and_doomsdays|title=Science and Reason, Foibles and Fallacies, and Doomsday|publisher=Center for Inquirys|website=CSI|date=November 1998|access-date=6 June 2016}}</ref>

== Other activities ==
]]]
He was the General Secretary of the ] from 1967 to 1973 and former director of the observatory at ].<ref>{{cite book|url=https://books.google.com/books?id=KWrB1jPCa8AC&q=%223798+de+Jager%22&pg=PA321|title=Dictionary of Minor Planet Names|first=Lutz|last=Schmadel|year=2003|publisher=Springer Science & Business Media|isbn=978-3-540-00238-3|via=Google Books}}</ref> In 1981, de Jager became a founding member of the ].<ref>{{cite web|title=About Us|publisher=]|url=http://www.consejoculturalmundial.org/about-us/|access-date=8 November 2016}}</ref> He was the first chairman of ] from 1987 to 1998,<ref>{{cite web |url=http://skepsis.nl/boeken/sn13/|title=Randverschijnselen in de wetenschap – Liber amicorum voor Kees de Jager|work=Stichting Skepsis website|publisher=Stichting Skepsis|access-date=28 October 2014}}</ref> the first chairman of the ] from 1994 to 2001,<ref>{{cite journal|last=Mahner|first=Martin|url=http://www.csicop.org/si/show/10th_european_skeptics_congress_rise_and_development_of_paranormal_beliefs_|title=10th European Skeptics Congress: Rise and Development of Paranormal Beliefs in Eastern Europe|journal=]|publisher=]|volume=26|issue=1|date=February 2002|access-date=28 October 2014}}</ref> and was also a ] fellow.<ref>{{Cite web|url=https://skepticalinquirer.org/fellows-and-staff/|title=Fellows and Staff &#124; Skeptical Inquirer|first=Marc|last=Kreidler|date=3 April 2019}}</ref><ref>{{cite book|url=https://books.google.com/books?id=tzEdpR4gizsC&q=%22cornelis+de+jager%22+astronomer&pg=PA70|title=Paranormal Claims: A Critical Analysis|first=Bryan|last=Farha|year=2007|publisher=University Press of America|isbn=978-0-7618-3772-5|via=Google Books}}</ref>

De Jager joined his CSI peers by signing the "Deniers are not Skeptics" petition that asks the media to stop referring to ]s as skeptics, with the petition stating "proper skepticism promotes scientific inquiry, critical investigation, and the use of reason in examining controversial and extraordinary claims", not "rejection of ideas without objective consideration".<ref>{{cite web|url=http://www.csicop.org/news/show/deniers_are_not_skeptics|title=Deniers are not Skeptics|publisher=Center for Inquiry|website=CSI|date=5 December 2014|access-date=6 June 2016}}</ref>

He spoke on astrology at the World Skeptics Congress in 1996.<ref>{{cite web|last=Flynn|first=Tom|author-link=Tom Flynn (author)|url=http://www.csicop.org/sb/show/world_skeptics_congress_draws_over_1200_participants|title=World Skeptics Congress Draws Over 1200 Participants|publisher=Center for Inquiry|website=CSI|date=September 1996|access-date=6 June 2016}}</ref>

== Honours and awards ==
In 1969, he became a member of the ].<ref>{{cite web|url=https://www.knaw.nl/en/members/members/4303|archive-url=https://web.archive.org/web/20171019220319/https://www.knaw.nl/en/members/members/4303|title=Cornelis de Jager|publisher=]|archive-date=19 October 2017}}</ref> In 1990, he was elected a member of ].<ref>{{cite web|url=https://www.ae-info.org/ae/Member/Jager_Cornelis|archive-url=https://web.archive.org/web/20200515140245/https://www.ae-info.org/ae/Member/Jager_Cornelis|title=Cornelis de Jager|publisher=Academia Europaea|archive-date=15 May 2020}}</ref>
* 1974 ]<ref>{{cite web|title=Recipients of the Karl Schwarzschild Medal|url=http://www.astronomische-gesellschaft.org/en/die-ag/awards/recipients-of-the-karl-schwarzschild-medal|website=The AG|publisher=Astronomische Gesellschaft German Astronomical Society|access-date=13 May 2016|archive-url=https://web.archive.org/web/20160816172243/http://www.astronomische-gesellschaft.org/en/die-ag/awards/recipients-of-the-karl-schwarzschild-medal|archive-date=16 August 2016|url-status=dead}}</ref>
* 1984 ]<ref name=":4">{{cite web|url=https://www.nhnieuws.nl/nieuws/286451/sterrenkundige-kees-de-jager-100-overleden|title=Sterrenkundige Kees de Jager (100) overleden|publisher=NH Nieuws|website=nhnieuws.nl|via=Texelse Courant|date=28 May 2021|access-date=18 July 2021|language=Dutch}}</ref>
* 1988 ] for Astronomy<ref>{{cite web|url=http://www.cdejager.com/about/|title=Short cv of C. de Jager|publisher=Cornelis de Jager|access-date=1 October 2020|archive-date=26 February 2021|archive-url=https://web.archive.org/web/20210226100936/http://www.cdejager.com/about/|url-status=dead}}</ref>
* 1988 ] by the ] of the ]<ref>{{cite web|title=Previous winners of the George Ellery Hale Prize|url=http://spd.aas.org/halepc.html|website=Solar Physics Division|publisher=]|access-date=13 May 2016|url-status=dead|archive-url=https://web.archive.org/web/20130813092340/http://spd.aas.org/halepc.html|archive-date=13 August 2013}}</ref>
* 1990 ] ''In Praise of Reason'' Award presented to de Jager for his "notable contributions to science and his vigorous criticism of pseudoscience."<ref>{{cite journal|last=Kurtz|first=Paul|author-link=Paul Kurtz|title=Skepticism in Europe: Brussels Conference Tackles Diverse Issues|journal=Skeptical Inquirer|date=1990|volume=15|issue=2|page=221}}</ref>

The asteroid ] was named for him.<ref>{{cite book|last=Lutz|first=Schmadel|url=https://books.google.com/books?id=VoJ5nUyIzCsC&q=%223798+de+Jager%22&pg=PA321|title=Dictionary of Minor Planet Names, Volume 1|publisher=Springer|isbn=978-3-540-00238-3|year= 2003|access-date=28 June 2016}}</ref>

In 2021, Springer Nature established the ''Kees de Jager Prize'' in honor of the founding editor of the journals '']'' and '']'' as well as the book series ''Astrophysics and Space Science Library''. The prize will be awarded annually to the best article in the journal ''Solar Physics''.<ref>{{cite web|url=https://www.springer.com/journal/11207/updates/19650756/|title=2021 Kees de Jager Prize|publisher=Springer Nature|access-date=20 September 2021}}</ref>


The asteroid ] is named for him.
{{clear}}
== References == == References ==
{{Reflist}} {{Reflist|2}}


== External links == == External links ==
* *

{{Founding members of the World Cultural Council}}


{{Authority control}} {{Authority control}}


{{DEFAULTSORT:Jager, Cornelis de}} {{DEFAULTSORT:De Jager, Kees}}
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Latest revision as of 15:25, 8 January 2025

Dutch astronomer (1921–2021)

In this Dutch name, the surname is de Jager, not Jager.
Kees de Jager
Photograph of Kees de Jager taken in 1967Kees de Jager in 1967
BornCornelis de Jager
(1921-04-29)29 April 1921
Den Burg, Texel, Netherlands
Died27 May 2021(2021-05-27) (aged 100)
Den Burg, Texel, Netherlands
NationalityDutch
Alma materUtrecht University
SpouseDoetie Rienks
Scientific career
Fields
InstitutionsUtrecht University
Doctoral advisorMarcel Minnaert

Cornelis "Kees" de Jager (pronounced [ˈkeːz də ˈjaːɣər]; 29 April 1921 – 27 May 2021) was a Dutch astronomer who specialized in predicting solar variation to assess the Sun's impact on future climate. He was the General Secretary of the IAU from 1967 to 1973 and former director of the observatory at Utrecht. He was a fellow with the Committee for Skeptical Inquiry and played an important role in the European skeptical movement as the first chairman of both Stichting Skepsis and the European Council of Skeptical Organisations.

Personal life and education

Born in Den Burg on the Dutch island of Texel, de Jager spent his school years in the Dutch East Indies. In 1939, De Jager heard Professor Minnaert speak. De Jager said "I was so fascinated by what he said, that I decided right then and there to study Astronomy." From 1939 to 1945, he studied mathematics, physics and astronomy at Utrecht University. On 13 October 1952, he obtained his PhD with a thesis called "The Hydrogen Spectrum of the Sun". His supervisor was Marcel Minnaert.

De Jager died where he was born, in Den Burg (Texel), on 27 May 2021, less than a month after he became a centenarian.

Solar and stellar research

De Jager did work on stars and solar physics, in relation to which he was a founding editor of the journal Solar Physics. In 1980, he was principal investigator of the Hard X-ray Imaging Spectrometer (HXIS) on board the Solar Maximum Mission satellite. His work on solar flares was often done in collaboration with Zdeněk Švestka.

From 1978 onward, de Jager did noted work on the most luminous stars, known as hypergiants. From 1960 to 1986, de Jager was a professor at Utrecht University.

Sun–climate relations

De Jager's later research focused on predicting solar variation to assess the Sun's impact on future climate. Solar activity is usually defined by the Sun's toroidal magnetic field, the field component parallel to the solar equator. Sunspots are one expression of this component. De Jager introduced the poloidal field of the Sun, which connects its two poles, as a factor of possibly similar importance. He used proxies for both components and took 19-year running averages to eliminate all effects that last only one or two solar cycles. Next he plotted both components in a diagram, thus creating an experimental phase portrait. The track of the two components went from low to high activity around 1923. Around 2006 the same point has been passed in the opposite direction. Thus solar activity in the 21st century is expected to be lower than it was for most of the 20th century. A reduction in solar activity means less energy input to the Earth as part of the Earth's energy budget, partially countering climate change.

De Jager postulated that solar magnetic activity is the most significant contributor to tropospheric temperatures, with polar activity also being significant, and that with the subtraction of these factors from temperatures recorded over the preceding 400 years, peaks and dips in temperature could be observed, accounting for recent increase in global warming. Similar theories have been rejected by other climate scientists as solar activity and global temperatures have diverged since 1975, with energy output from the Sun decreasing and Earth temperatures still increasing. Additionally, warming caused exclusively by the Sun would result in an even warming throughout the atmosphere, rather than the observed cooling in the upper atmosphere and warming in the lower atmosphere associated with greenhouse gases.

Cyclosophy

Kees de Jager in 2011

Expanding on a 1990 paper presentation at the International Skeptics Conference, de Jager published an article for Skeptical Inquirer where he parodies numerology. In Adventures in Science and Cyclosophy, de Jager claims that many times pseudoscientific reasoning ignores coincidences dealing with the relationship between objects when there are unlimited data points. He states that measurements surrounding the Great Pyramids have been used to show a relationship with astronomy. To do so, he explains, anyone can use the law of large numbers to relate to anything one would want, to try and prove there is some connection. As an illustration, he uses the example of his bicycle and the cosmos. Enthusiasts in this formula have created a website that allows visitors to submit data to replicate de Jager's experiment.

I measured the diameters of my bike's: -pedals, symbolizing the forward-going dynamics; -front wheel, which directs my ways into the unknown future; -lamp, enlightening my paths; -bell, through which I communicate with encounters. Thus I laid the building stones for a new holistic four-dimensional religion apt to the coming of the New Age of Aquarius: cyclosophy. The measurements were expressed in Holy Bike inches, being 17 mm. This is so since 1 is the first prime number and 17 the seventh, and because seven is the holy number. Calling P, W, L and B the four measured quantities, it turns out that P ^ 2 √ L x W = 1823 which is the ratio between the masses of the proton and the electron.... Coincidences occur regularly in numerical experiments, as in daily life ... are not rare ... Most people greatly underestimate the enormous amount of possible combinations between numbers. Adventures in Science and Cyclosophy

According to Kendrick Frazier, who attended the 1998 Second World Skeptics Congress in Heidelberg, Germany, de Jager's "dead-pan" description of how he took measurements throughout his house showing the "absurdities of those who attach great mystical significance to measurements of the Great Pyramid" had the audience "in stitches". Apparently "his home is in an astronomical observatory, a location, he said, 'that may be very close to the cosmos and well receptive to its incredible powers.'"

Other activities

Stichting Skepsis

He was the General Secretary of the IAU from 1967 to 1973 and former director of the observatory at Utrecht. In 1981, de Jager became a founding member of the World Cultural Council. He was the first chairman of Stichting Skepsis from 1987 to 1998, the first chairman of the European Council of Skeptical Organisations from 1994 to 2001, and was also a Committee for Skeptical Inquiry fellow.

De Jager joined his CSI peers by signing the "Deniers are not Skeptics" petition that asks the media to stop referring to climate change deniers as skeptics, with the petition stating "proper skepticism promotes scientific inquiry, critical investigation, and the use of reason in examining controversial and extraordinary claims", not "rejection of ideas without objective consideration".

He spoke on astrology at the World Skeptics Congress in 1996.

Honours and awards

In 1969, he became a member of the Royal Netherlands Academy of Arts and Sciences. In 1990, he was elected a member of Academia Europaea.

The asteroid 3798 de Jager was named for him.

In 2021, Springer Nature established the Kees de Jager Prize in honor of the founding editor of the journals Solar Physics and Space Science Reviews as well as the book series Astrophysics and Space Science Library. The prize will be awarded annually to the best article in the journal Solar Physics.

References

  1. ^ van den Heuvel, Ed (28 May 2021). "In memoriam Kees de Jager, sterrenkundige (1921–2021)". astronomie.nl (in Dutch). Astronomie. Retrieved 18 July 2021.
  2. "Utrecht astronomer Kees de Jager turns 100 – News – Universiteit Utrecht". www.uu.nl. 29 April 2021. Retrieved 1 June 2021.
  3. ^ Welch, Faye (April 2021). "Digital Concert & Special Magazine for astronomer Kiss de Jagger (100)". commentaryboxsports.com. Commentary Box Sports. Retrieved 18 July 2021.
  4. ^ Buiter, Rob (1 May 2021). "Astrofysicus Kees de Jager draaide honderd rondjes om zijn zon". Trouw (in Dutch). Retrieved 18 July 2021.
  5. ^ van der Heijden, Margriet (28 May 2021). "Een leven gewijd aan de zon". NRC (in Dutch). Retrieved 18 July 2021.
  6. van den Ham, Hans (29 April 2021). "Utrechtse astronoom Kees de Jager is 100, maar de sterrenhemel kan hij niet meer zien". Algemeen Dagblad (in Dutch). Retrieved 1 May 2021.
  7. "Professor Kees de Jager overleden". www.texelsecourant.nl (in Dutch). 28 May 2021. Retrieved 18 July 2021.
  8. De Jager, Cornelis; Švestka, Zdeněk (1969). "SAO/NASA Astrophysics Data System (ADS)". Solar Physics. 10 (2): 243. Bibcode:1969SoPh...10..243D. doi:10.1007/BF00145510.
  9. "Two Decades of Hypergiant Research" (PDF). festschrift. Retrieved 13 May 2016.
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  11. ^ "Sterrenkundige Kees de Jager (100) overleden". nhnieuws.nl (in Dutch). NH Nieuws. 28 May 2021. Retrieved 18 July 2021 – via Texelse Courant.
  12. Yaskell, S. H., Grand Phases On The Sun: The case for a mechanism responsible for extended solar minima and maxima (Trafford: 2013)
  13. ^ de Jager, Kees (1 April 2016). "Solar activity and its influence on climate". Netherlands Journal of Geosciences. 87 (3): 7 – via Cambridge University Press.
  14. ^ Thomas Farmer, G.; Cook, John (2012). Climate Change Science: A Modern Synthesis. Springer Publishing. pp. 14, 475–476. ISBN 978-94-007-5756-1.
  15. Lee, Adam (7 April 2008). "Popular Delusions IX: Numerology". Daylight Atheism. Patheos. Retrieved 28 June 2016.
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  17. Paulos, John Allen (2009). Irreligion: A Mathematician Explains Why the Arguments for God Just Don't Add Up. Macmillan. ISBN 978-0-8090-5918-8. Retrieved 28 June 2016.
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  19. de Jager, Cornelis (1992). "Adventures in Science and Cyclosophy". Skeptical Inquirer. 16 (2): 167–172.
  20. Kendrick, Frazier (November 1998). "Science and Reason, Foibles and Fallacies, and Doomsday". CSI. Center for Inquirys. Retrieved 6 June 2016.
  21. Schmadel, Lutz (2003). Dictionary of Minor Planet Names. Springer Science & Business Media. ISBN 978-3-540-00238-3 – via Google Books.
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  33. "Previous winners of the George Ellery Hale Prize". Solar Physics Division. American Astronomical Society. Archived from the original on 13 August 2013. Retrieved 13 May 2016.
  34. Kurtz, Paul (1990). "Skepticism in Europe: Brussels Conference Tackles Diverse Issues". Skeptical Inquirer. 15 (2): 221.
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  36. "2021 Kees de Jager Prize". Springer Nature. Retrieved 20 September 2021.

External links

Founding members of the World Cultural Council
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