Isaac Newton's apple tree explained

Isaac Newton's apple tree
Species:Flower of Kent, Malus domestica
Location:Woolsthorpe-by-Colsterworth, near Grantham, Lincolnshire
Map:United Kingdom Lincolnshire
Felled:1816; years (original)
Label:2946
Custodian:National Trust
Seeded: (original)
(regrown)

Isaac Newton's apple tree at Woolsthorpe Manor[1] represents the inspiration behind Sir Isaac Newton's theory of gravity. While the precise details of Newton's reminiscence (reported by several witnesses to whom Newton allegedly told the story) are impossible to verify, the significance of the event lies in its explanation of Newton's scientific thinking. The apple tree in question, a member of the Flower of Kent variety, is a direct descendant of the one that stood in Newton's family's garden in 1666. Despite being blown down by a storm in 1820, the tree regrew from its original roots.

It's often referred to as the "gravity tree" because it's said to have inspired Newton's theory of gravity and It stands as a living connection to Newton's ground-breaking insights. The tree has become a cherished symbol, and its descendants and clones can be found in various locations worldwide.

The apple incident

It is known from his notebooks that Isaac Newton was grappling in the late 1660s with the idea that terrestrial gravity extends, in an inverse-square proportion, to the Moon; however, it took him two decades to develop the full-fledged theory.[2] The question was not whether gravity existed, but whether it extended so far from Earth that it could also be the force holding the Moon to its orbit. Newton showed that if the force decreased as the inverse square of the distance, one could indeed calculate the Moon's orbital period, and get good agreement. He guessed the same force was responsible for other orbital motions, and hence named it "universal gravitation".[3]

Newton himself often told the story that he was inspired to formulate his theory of gravitation by watching the fall of an apple from a tree.[4] [5] [6] The story is believed to have passed into popular knowledge after being related by Catherine Barton, Newton's niece, to Voltaire.[7] Voltaire then wrote in his Essay on Epic Poetry (1727), "Sir Isaac Newton walking in his gardens, had the first thought of his system of gravitation, upon seeing an apple falling from a tree."[8] [9] [10]

Some have argued that the apple story is a fiction and that he did not arrive at his theory of gravity at any single moment.[11] Acquaintances of Newton (such as William Stukeley) recorded Newton's version of the incident, though not the meritless version that the apple actually hit Newton's head.[12] [13] [14] Stukeley recorded in his Memoirs of Sir Isaac Newton's Life a conversation with Newton in Kensington on 15 April 1726 (50 years after the supposed event):[15]

John Conduitt, Newton's assistant at the Royal Mint and husband of Newton's niece, also described the event when he wrote about Newton's life:

British science writers Mary and John Gribbin assert that Newton simply made it up, because, in 1666, Newton's theory of the nature of gravity[16] would not have encompassed it. In their view, either the elderly Newton had forgotten that he had once posited it as an explanatory analogy or (more probably) because he would not admit that Robert Hooke had given him the concept of universal gravity in his [Hooke's] 1674 Gresham lecture, An Attempt to Prove the Motion of the Earth by Observations (published 1679), which explained that gravitation applied to "all celestial bodies".[17]

The tree

The actual story behind Newton's apple tree can be traced back to Newton's time at Woolsthorpe Manor, his family estate in Lincolnshire, England.[18] [19] During his stay at the manor in 1665 or 1666, it is believed that Newton observed an apple falling from a tree and began pondering the forces that govern such motion.[20] Dendrochronology, done by the Research Laboratory for Archaeology and the History of Art at the University of Oxford, confirms one of the trees in the orchard to be over 400 years old, having regrown from roots surviving from a tree which was blown over by a storm in 1816.[21] In 1820, part of the blown tree was also cultivated by Lord Brownlow at Belton Park into a tree that came to be known as the Belton tree.

Other various trees are claimed to be the apple tree which Newton describes. The King's School, Grantham, which Newton attended between 1655 and 1660, claims that the tree was purchased by the school, uprooted and transported to the headmaster's garden some years later.[22] The staff of the (now) National Trust-owned Woolsthorpe Manor dispute this claim.The apple tree is a culinary apple[23] of the Flower of Kent variety. The Flower of Kent is known for its large and flavourful, but mealy green apples, which were used for cooking and baking.[24] The apple tree still exists today at Woolsthorpe Manor, and it is attended by gardeners, secured with a fence, and cared for by National Trust for Places of Historic Interest or Natural Beauty.

Significance

While there is debate regarding the precise details of the apple tree incident, the story has become deeply ingrained in scientific history and popular culture. The apple tree symbolizes the moment of inspiration that led Newton to develop his ground-breaking ideas. It serves as a powerful metaphor for the process of scientific discovery and the ability to perceive patterns in nature.[25] A statue of Isaac Newton, looking at an apple at his feet, can be seen at the Oxford University Museum of Natural History. A large bronze statue, Newton, after William Blake, by Eduardo Paolozzi, dated 1995 and inspired by Blake's etching, dominates the piazza of the British Library in London. A bronze statue of Newton was erected in 1858 in the centre of Grantham where he went to school, prominently standing in front of Grantham Guildhall.

The tree was ranked number five on the TIME TOP 10 Awesome Trees on Arbor Day in 2010,[26] and was chosen as one of the 50 Great British Trees in 2012, the year of Queen Elizabeth II's Diamond Jubilee.[27] Part of the tree was used in the state coach for Queen Elizabeth II's diamond jubilee.[28]

On 14 May 2010, British-born NASA astronaut Piers Sellers took a 10cm fragment of the Newton's apple tree into space as part of the celebrations for the 350th anniversary of the Royal Society, of which Newton was a former president. The tree sample, engraved with Newton's name, was originally taken from the Royal Society's archives and entrusted to Piers Sellers for his 12-day mission aboard the space shuttle Atlantis to the International Space Station (ISS).[29] [30] [31] After the mission, both the tree sample and the picture was returned to the Royal Society and became part of a historical exhibition.[32]

Seeds of the tree were sent by the European Space Agency into space to the International Space Station on the 2014-15 Principia mission with astronaut Tim Peake.[33] As part of the "Pips in Space" research, the seeds floated in microgravity for six months before returning to Earth in 2016 to be raised into young trees.[34] Winners of a competition to host one of the unique seedlings include the National Physical Laboratory,[35] Jodrell Bank Observatory, and the Eden Project. In 2023, 10 saplings from the tree were auctioned to support the upkeep of Woolsthorpe Manor.[36]

Clones

There are several genetically identical trees, or clones, of the original apple tree that have been planted around the world. Trinity College in Cambridge, Newton's alma mater, hosts a genetically identical tree, growing outside the main gate of the college below the room Newton lived in when he studied there.[37] [38] Woolsthorpe Manor gifted five cuttings from Newton's Apple Tree to Loughborough University, located near Newton's childhood home. These cuttings were planted at Loughborough University as part of an initiative to inspire students to think like Isaac Newton.[39] Cambridge University Botanic Garden had a clone of Newton's Apple Tree that stood at the Brookside entrance. Unfortunately, it fell during Storm Eunice.[40] Yet, the garden plans to plant a new clone elsewhere on the premises.[41] National Institute of Standards and Technology (NIST), Gaithersburg campus in the United States had a clone of Newton's Apple Tree planted.[42] But it fell over and died in June 2023 due to unknown reasons.[43] [44]

Grace Babson, the wife of Roger Babson, was able to pursue her collection, later amounting to over 1,000 editions of Newton materials, being the largest source in the United States.[45] [46] In 1995, the Babson College collection was placed on loan to MIT's Burndy Library, and in 2006, to the Huntington Library in San Marino, California, where it is available for scholarly research.[47] Between Sir Isaac Newton Library (now known as Tomasso Hall) and the Lunder Admission Center lay descendants of the original apple trees.[48] Grace also saved the parlour of Newton's last residence before its demolition and created a replica in Babson Park.[49]

From 1997 to 2007, at Inter-University Centre for Astronomy and Astrophysics three endeavors were undertaken to cultivate Newton's Apple Tree brought in by Jayant Narlikar. Some of the trees managed to thrive and produce apples. However, by 2007, the last remaining tree from those attempts had perished.[50]

Other clones can be found at Queens' College, Cambridge planted in 1948,[51] Bushy House part of the National Physical Laboratory planted in 1953, the Royal Astronomical Society,[52] [53] TRIUMF planted in 1968, University of York gifted in 1976,[54] the Massachusetts Institute of Technology (MIT) in the United States planted in 1977,[55] Centro Atómico Bariloche planted in 1981, Koishikawa Botanical Gardens in Japan planted in 1981,[56] York University, Toronto planted in 1999, the University of Wisconsin-Madison's Physics Department and Botanical Garden plant on 25 May 2001,[57] University of Nebraska–Lincoln in Nebraska planted in May 2015,[58] Brown University in Rhode Island planted on 29 March 2018,[59] King Edward's School in Birmingham planted in 2018,[60] and Argentina's Parque de las Ciencias planted in 2022.[61]

More clones can be found at the Parkes Observatory in Australia, the Observatory Science Center at Herstmonceux in East Sussex, Vanderbilt University in Tennessee, West Virginia University and College of William & Mary in Virginia, Case Western Reserve University in Ohio, Houghton University in New York, Babylonstoren in South Africa, Monash University in Melbourne, Tufts University in Massachusetts, the University of British Columbia in Canada, New York Botanical Garden in Bronx, Balseiro Institute in Rio Negro, Orange Agricultural Institute in New South Wales, Wuling Farm in Taiwan, Nankai University in Tianjin, Beihang University in Beijing, Korea Research Institute of Standards and Science (KRISS) in Daejeon, Keiwa College in Shibata, Saitama University in Saitama, Koishikawa Kōrakuen in Bunkyo, and Technical University of Applied Sciences Wildau in Brandenburg.

The East Malling Research Station in East Malling remains the primary supplier of clones of the tree since 1930, but crossing borders can be challenging and plant delivery may be delayed for inspections or possibly quarantine due to worries about invasive pests and plant diseases. Nevertheless, there appear to be two distinct apple trees, the Woolsthorpe or the Belton tree, that are now being cultivated as "Newton's apple tree", despite the fact that the numerous specimens of the tree appear to be fairly similar on the surface. Whether these are specific to the Woolsthorpe or the Belton tree is still up for debate. For example, in 2016, the tree planted at the National Research Council Canada (NRC-CNRC) in Ottawa was discovered to be a fake and not even a Flower of Kent.[62]

See also

References

  1. Web site: Visitors gravitate to Newton's apple tree in Grantham . 2023-06-07 . www.aljazeera.com . en . 2023-05-28 . https://web.archive.org/web/20230528105016/https://www.aljazeera.com/features/2018/4/4/visitors-gravitate-to-newtons-apple-tree-in-grantham . live.
  2. I. Bernard Cohen and George E. Smith, eds. The Cambridge Companion to Newton (2002) p. 6. Accessed 17 July 2023.
  3. Book: Brackenridge, J. Bruce . The Key to Newton's Dynamics: The Kepler Problem and the Principia . 1996-02-29 . University of California Press . 978-0-520-91685-2 . en . 2023-07-08 . 2023-07-08 . https://web.archive.org/web/20230708151312/https://books.google.com/books?id=ovOTK7X_mMkC&dq=%22Newton%27s+Apple+Tree%22+-wikipedia&pg=PA269 . live.
  4. Book: White . Michael . Isaac Newton: the last sorcerer . Newton . Isaac . 1997 . Fourth Estate . 978-1-85702-416-6 . London . 86.
  5. Book: Numbers . Ronald L. . Newton's Apple and Other Myths about Science . Kampourakis . Kostas . 2015-11-04 . Harvard University Press . 978-0-674-91547-3 . 46–52 . en . 2023-06-30 . 2023-07-08 . https://web.archive.org/web/20230708151321/https://books.google.com/books?id=pWouCwAAQBAJ . live.
  6. News: Staff . Times . 2023-06-27 . Gravity of damage facing Newton's tree prompts action . . en . 2023-06-27 . 0140-0460 . 2023-06-27 . https://web.archive.org/web/20230627125359/https://www.thetimes.co.uk/article/gravity-of-damage-facing-newtons-tree-prompts-action-xz5gmtv53gj . live.
  7. Book: Malament, David B. . Reading Natural Philosophy: Essays in the History and Philosophy of Science and Mathematics . 2002 . Open Court Publishing . 978-0-8126-9507-6 . 18 October 2020 . https://web.archive.org/web/20210414055334/https://books.google.com/books?id=TqcMQy-Ioc4C&q=catherine+barton+apple&pg=PA118 . 14 April 2021 . live.
  8. Book: Voltaire . An Essay upon the Civil Wars of France, extracted from curious Manuscripts and also upon the Epick Poetry of the European Nations, from Homer down to Milton . 1727 . Samuel Jallasson . London, England . 104 . 14 June 2021 . https://web.archive.org/web/20210614182518/https://books.google.com/books?id=0o5bAAAAQAAJ&pg=PA104 . 14 June 2021 . live. From p. 104: 'In the like Manner Pythagoras ow'd the Invention of Musik to the noise of the Hammer of a Blacksmith. And thus in our Days Sir Isaak Newton walking in his Garden had the first Thought of his System of Gravitation, upon seeing an apple falling from a Tree.'
  9. Voltaire (1786) heard the story of Newton and the apple tree from Newton's niece, Catherine Conduit (née Barton) (1679–1740): Book: Voltaire . Oeuvres completes de Voltaire . 1786 . Jean-Jacques Tourneisen . 31 . Basel, Switzerland . 175 . French . The complete works of Voltaire . 15 June 2021 . https://web.archive.org/web/20210709192112/https://books.google.com/books?id=NKWTGHiZSm4C&pg=PA175 . 9 July 2021 . live. From p. 175: "Un jour en l'année 1666, Newton retiré à la campagne, et voyant tomber des fruits d'un arbre, à ce que m'a conté sa nièce, (Mme Conduit) se laissa aller à une méditation profonde sur la cause qui entraine ainsi tous les corps dans une ligne, qui, si elle était prolongée, passerait à peu près par le centre de la terre." (One day in the year 1666 Newton withdrew to the country, and seeing the fruits of a tree fall, according to what his niece (Madame Conduit) told me, he entered into a deep meditation on the cause that draws all bodies in a [straight] line, which, if it were extended, would pass very near to the center of the Earth.)
  10. McKie . D. . de Beer . G. R. . 1952 . Newton's Apple: An Addendum . Notes and Records of the Royal Society of London . 9 . 2 . 333–335 . 10.1098/rsnr.1952.0020 . 3087221 . 144544715 . 0035-9149 . free .
  11. Book: Out of the shadow of a giant: Hooke, Halley and the birth of British science . Gribbin . Gribbin . John . Mary . 978-0-00-822059-4 . London . 966239842 . 2017 . William Collins . John Gribbin . 165175.
  12. Web site: newtons-apple-tree . 3 October 2021 . Royal Society . 3 October 2021 . https://web.archive.org/web/20211003133759/https://royalsociety.org/blog/2012/02/newtons-apple-tree/ . live.
  13. Web site: Memoirs of Sir Isaac Newton's Life by William Stukeley, page 15 . 3 October 2021 . Royal Society, "Turning the pages" . 3 October 2021 . https://web.archive.org/web/20211003135412/https://ttp.royalsociety.org//ttp/ttp.html?id=1807da00-909a-4abf-b9c1-0279a08e4bf2&type=book/ . live.
  14. Web site: Newton's apple tree Royal Society . 2023-06-27 . royalsociety.org . 2023-07-02 . https://web.archive.org/web/20230702064646/https://royalsociety.org/blog/2012/02/newtons-apple-tree/ . live.
  15. Web site: Revised Memoir of Newton (Normalized Version) . live . https://web.archive.org/web/20170314064817/http://www.newtonproject.ox.ac.uk/view/texts/normalized/OTHE00001 . 14 March 2017 . 13 March 2017 . The Newton Project.
  16. Book: Turnbull . H W . 1960 . Correspondence of Isaac Newton . 1 (1661-1675) . Cambridge University Press . 769886773 . 150 Newton to Oldenberg . https://archive.org/details/correspondenceof0001hwtu/page/404/mode/2up.
  17. Book: Hooke, Robert . 1679 . Lectiones Cutlerianae, or A collection of lectures, physical, mechanical, geographical & astronomical : made before the Royal Society on several occasions at Gresham Colledge [i.e. College] : to which are added divers miscellaneous discourses ]. An Attempt to prove the Annual Motion of the Earth . https://archive.org/details/LectionesCutler00Hook/page/n23/mode/2up . 2, 3.
  18. Web site: 2018-06-26 . How Isaac Newton's Apple Tree Spread Across the World . 2023-06-07 . Atlas Obscura . en . 2023-02-07 . https://web.archive.org/web/20230207213246/https://www.atlasobscura.com/articles/newton-apple-tree . live.
  19. Keesing . R. G. . 1998-05-01 . The history of Newton's apple tree . Contemporary Physics . 39 . 5 . 377–391 . 1998ConPh..39..377K . 10.1080/001075198181874 . 0010-7514 . 2023-06-07 . 2023-07-08 . https://web.archive.org/web/20230708151817/https://ui.adsabs.harvard.edu/abs/1998ConPh..39..377K . live.
  20. Web site: Gefter . Amanda Gefter . 2010-01-18 . Newton's apple: The real story . 2023-06-07 . New Scientist . en-US . 2023-05-30 . https://web.archive.org/web/20230530190519/https://www.newscientist.com/article/2170052-newtons-apple-the-real-story/ . live.
  21. Web site: the-most-famous-apple-tree-in-the-world . 3 October 2021 . The National Trust . 3 October 2021 . https://web.archive.org/web/20211003130446/https://www.nationaltrust.org.uk/woolsthorpe-manor/features/the-most-famous-apple-tree-in-the-world . live.
  22. Book: Martínez, Alberto A. . Science secrets: the truth about Darwin's finches, Einstein's wife, and other myths . 2011 . University of Pittsburgh press . 978-0-8229-4407-2 . Pittsburgh . 69.
  23. Web site: Isaac Newton's Tree . 2023-06-30 . National Fruit Collection . 2023-07-08 . https://web.archive.org/web/20230708151843/http://www.nationalfruitcollection.org.uk/full2.php?id=2946 . live.
  24. Web site: 2017-09-24 . Newton's Tree – The Apple Tree that Sparked an Epiphany . 2023-06-07 . The Treeographer . en . 2023-05-01 . https://web.archive.org/web/20230501031234/https://thetreeographer.com/2017/09/24/newtons-tree/ . live.
  25. Web site: Conocimiento . Ventana al . 2021-03-18 . The Legend of Newton's Apple Tree OpenMind's Puzzles . 2023-06-30 . OpenMind . en-US . 2023-06-30 . https://web.archive.org/web/20230630153414/https://www.bbvaopenmind.com/en/science/physics/legend-of-newtons-apple-tree/ . live.
  26. Romero . Frances . 2010-04-30 . Happy Arbor Day: Top 10 Awesome Trees - TIME . en-US . Time . 2023-06-07 . 0040-781X.
  27. Web site: 2022-11-15 . Newton's apple tree has descendants and clones all over the world . 2023-06-07 . Big Think . en-US . 2023-07-02 . https://web.archive.org/web/20230702064645/https://bigthink.com/strange-maps/newton-gravity-trees/ . live.
  28. Queen rides new carriage made from Isaac Newton's apple tree . 2014-06-04 . The Royal Family Channel.
  29. News: Luscombe . Richard . 2010-05-09 . Isaac Newton's apple tree to experience zero gravity – in space . en-GB . The Guardian . 2023-06-30 . 0261-3077 . 2023-06-30 . https://web.archive.org/web/20230630153413/https://www.theguardian.com/science/2010/may/09/isaac-newton-apple-tree-space . live.
  30. Web site: updated . Tariq Malik last . 2010-05-10 . Piece of Newton's Apple Tree to Escape Gravity on Space Shuttle . 2023-06-30 . Space.com . en . 2023-05-09 . https://web.archive.org/web/20230509185004/https://www.space.com/8368-piece-newton-apple-tree-escape-gravity-space-shuttle.html . live.
  31. Web site: Newton's famous apple tree to experience zero gravity Royal Society . 2023-06-30 . royalsociety.org . 2023-06-02 . https://web.archive.org/web/20230602045618/https://royalsociety.org/news/2010/apple-tree-gravity/ . live.
  32. News: 2010-05-10 . Newton tree sample set for space . en-GB . BBC . 2023-06-07 . 2023-06-16 . https://web.archive.org/web/20230616103256/http://news.bbc.co.uk/2/hi/8671627.stm . live.
  33. Web site: Blenkin . Max . 2020-01-13 . Newton's apple tree seeds from space propagated into saplings . 2023-06-07 . www.spaceconnectonline.com.au . en-gb . 2023-03-15 . https://web.archive.org/web/20230315020730/https://www.spaceconnectonline.com.au/industry/4067-newton-s-apple-tree-seeds-from-space-propagated-into-saplings . live.
  34. Web site: Trees planted grown from seeds that went into space . 2023-06-26 . GOV.UK . en . 2023-06-26 . https://web.archive.org/web/20230626185018/https://www.gov.uk/government/news/trees-planted-grown-from-seeds-that-went-into-space . live.
  35. Web site: 2020-01-13 . One of Newton . 2023-06-26 . NPLWebsite . en . 2023-01-15 . https://web.archive.org/web/20230115093242/https://www.npl.co.uk/news/one-of-newton-s-space-saplings-lands-at-npl . live.
  36. News: 2023-09-04 . Isaac Newton apple tree saplings auctioned in UK first . en-GB . BBC News . 2023-09-10.
  37. Book: Boyd, Stephanie . The Story of Cambridge . 2023-05-25 . Cambridge University Press . 978-1-107-42888-1 . en . 2023-07-08 . 2023-07-08 . https://web.archive.org/web/20230708152328/https://books.google.com/books?id=YHa3EAAAQBAJ&dq=%22Newton%27s+Apple+Tree%22+-wikipedia&pg=PA90 . live.
  38. Web site: Dann . Niamh . 2023-03-05 . Tale of Newton's apple tree at Cambs college may not be as true as first thought . 2023-06-07 . CambridgeshireLive . en . 2023-03-22 . https://web.archive.org/web/20230322202600/https://www.cambridge-news.co.uk/news/history/tale-newtons-apple-tree-trinity-26341772 . live.
  39. News: 2018-03-13 . Sir Isaac Newton tree 'clones' to inspire Loughborough students . en-GB . BBC News . 2023-06-07 . 2022-02-21 . https://web.archive.org/web/20220221153928/https://www.bbc.com/news/uk-england-leicestershire-43385897 . live.
  40. Web site: Storm Eunice blows down 'Newton's apple tree' . 2023-06-07 . Varsity Online . en . 2022-05-22 . https://web.archive.org/web/20220522101219/https://www.varsity.co.uk/news/23172 . live.
  41. News: 2022-02-21 . Cambridge University Botanic Garden's 'Newton's apple tree' falls in storm . en-GB . BBC News . 2023-06-07 . 2023-07-02 . https://web.archive.org/web/20230702064646/https://www.bbc.com/news/uk-england-cambridgeshire-60453267 . live.
  42. Gould . Richard G. . 2002 . Isaac Newton's Apple Trees . Journal of the Washington Academy of Sciences . 88 . 3/4 . 103–112 . 24531138 . 0043-0439 . 2023-06-07 . 2020-06-07 . https://web.archive.org/web/20200607005639/https://www.jstor.org/stable/24531138 . live.
  43. Esser . Mark . 2018-06-26 . The Tangled Tale of NIST's Newton Apple Tree . NIST . en . 2023-06-07 . 2023-06-03 . https://web.archive.org/web/20230603063814/https://www.nist.gov/blogs/taking-measure/tangled-tale-nists-newton-apple-tree . live.
  44. Web site: A Tree So Important, It Allegedly Has Its Own Guards . 2023-06-07 . Atlas Obscura . en . 2023-07-02 . https://web.archive.org/web/20230702064644/https://www.atlasobscura.com/places/nist-newton-apple-tree . live.
  45. Web site: College . Babson . Grace K. Babson Collection . 2021-12-01 . www.babson.edu . en . 2021-11-29 . https://web.archive.org/web/20211129012411/https://www.babson.edu/about/news-events/babson-centennial/babsons-history/archives-and-collections/grace-k-babson-collection/ . live.
  46. News: Johnson . George . 2014-06-25 . The Man Who Hated Gravity, Part 2 . en-US . The New York Times . 2023-06-07 . 0362-4331 . 2020-11-12 . https://web.archive.org/web/20201112020644/http://www.nytimes.com/2014/06/25/science/space/the-man-who-hated-gravity-part-2.html . live.
  47. Web site: The Newton You Didn't Know . 2021-12-01 . The Huntington . en . 2021-12-01 . https://web.archive.org/web/20211201043907/https://www.huntington.org/verso/2020/01/newton-you-didnt-know . live.
  48. Web site: 2019-07-23 . Isaac Newton papers returning home to Babson . 2021-12-01 . The Swellesley Report . en-US . 2021-11-29 . https://web.archive.org/web/20211129012411/https://theswellesleyreport.com/2019/07/isaac-newton-papers-returning-home-to-babson/ . live.
  49. Andrade . E. . 1950 . A Notable Newton Collection . Nature . 166 . 4216 . 284–285 . 1950Natur.166..284A . 10.1038/166284A0 . 4288538 . free.
  50. Web site: 2018-07-15 . Newton's apple tree may soon take 'root' in India . 2023-06-07 . Deccan Herald . en . 2018-07-16 . https://web.archive.org/web/20180716174717/https://www.deccanherald.com/national/newtons-apple-tree-may-soon-681353.html . live.
  51. Web site: Newton's Apple Tree Queens' College . 2023-06-07 . www.queens.cam.ac.uk . en . 2023-05-30 . https://web.archive.org/web/20230530124845/https://www.queens.cam.ac.uk/visiting-the-college/history/college-facts/the-buildings/newtons-apple-tree . live.
  52. Book: Pasachoff . Jay M. . The Cosmos: Astronomy in the New Millennium . Filippenko . Alex . 2014 . Cambridge University Press . 978-1-107-68756-1 . en . 2023-07-08 . 2023-07-08 . https://web.archive.org/web/20230708152326/https://books.google.com/books?id=tZsoAAAAQBAJ&dq=%22Newton%27s+Apple+Tree%22+-wikipedia&pg=PA111 . live.
  53. Book: The Observatory . 1912 . Editors of the Observatory . en . 2023-07-08 . 2023-07-08 . https://web.archive.org/web/20230708152328/https://books.google.com/books?id=ji5RAAAAYAAJ&dq=%22Newton%27s+Apple+Tree%22+-wikipedia&pg=PA126 . live.
  54. Web site: York . University of . Isaac Newton's apple tree . 2023-06-26 . University of York . en . 2023-06-20 . https://web.archive.org/web/20230620114740/https://www.york.ac.uk/physics-engineering-technology/about/newtons-apple-tree/ . live.
  55. Web site: 2006-10-04 . Newton's apple tree bears fruit at MIT . 2023-06-07 . MIT News Massachusetts Institute of Technology . en . 2023-04-02 . https://web.archive.org/web/20230402115408/https://news.mit.edu/2006/newtons-apple-tree-bears-fruit-mit . live.
  56. Web site: Newton's Apple Tree - School of Science, the University of Tokyo . 2023-06-07 . www.s.u-tokyo.ac.jp . 2023-04-02 . https://web.archive.org/web/20230402054944/https://www.s.u-tokyo.ac.jp/en/topics/2010/05.html . live.
  57. Web site: Newton's Apple Tree . 2023-06-07 . Department of Physics . en-US . 2023-02-03 . https://web.archive.org/web/20230203124745/https://www.physics.wisc.edu/newtons-apple-tree/ . live.
  58. Web site: Newton's Apple Tree Department of Physics and Astronomy . 2023-06-07 . www.unl.edu . 2023-04-01 . https://web.archive.org/web/20230401161628/https://www.unl.edu/physics/newtons-apple-tree . live.
  59. Web site: Newton's Apple Tree transplanted to new physics location Physics Brown University . 2023-06-07 . www.brown.edu . 2019-01-26 . https://web.archive.org/web/20190126220610/https://www.brown.edu/academics/physics/news/2018/04/newtons-apple-tree-transplanted-new-physics-location . live.
  60. Web site: Ben . 2018-05-23 . Newton's apple tree plants inspiration for pupils . 2023-06-07 . King Edwards School . en-GB . 2021-03-04 . https://web.archive.org/web/20210304130055/https://kes.org.uk/newtons-apple-tree-plants-inspiration-for-pupils/ . live.
  61. Web site: Argentine scientists plant sapling of Newton's tree to celebrate Researcher's Day . 2023-06-07 . MercoPress . en . 2023-03-24 . https://web.archive.org/web/20230324163005/https://en.mercopress.com/2022/04/12/argentine-scientists-plant-sapling-of-newton-s-tree-to-celebrate-researcher-s-day . live.
  62. News: 2016-09-21 . NRC trees thought to be descendants of Newton's apple tree may be imposters . en-CA . The Globe and Mail . 2023-06-07 . 2023-03-27 . https://web.archive.org/web/20230327115351/https://www.theglobeandmail.com/news/national/nrc-trees-thought-to-be-descendants-of-newtons-apple-tree-may-be-imposters/article31995511/ . live.

Further reading