{"id":6398,"date":"2018-09-19T13:44:30","date_gmt":"2018-09-19T13:44:30","guid":{"rendered":"http:\/\/uni.hi.is\/einar\/?p=6398"},"modified":"2018-09-19T13:44:30","modified_gmt":"2018-09-19T13:44:30","slug":"halastjornur-fyrr-og-nu-1-fra-midoldum-til-loka-sautjandu-aldar","status":"publish","type":"post","link":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/?p=6398","title":{"rendered":"Halastj\u00f6rnur fyrr og n\u00fa  &#8211;  1. Fr\u00e1 mi\u00f0\u00f6ldum til loka sautj\u00e1ndu aldar"},"content":{"rendered":"<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">Inngangur<\/span><\/h3>\n<p>\u00deessi f\u00e6rsla er s\u00fa fyrsta af fj\u00f3rum um halastj\u00f6rnur. Hinar eru:<\/p>\n<ul>\n<li>Halastj\u00f6rnur fyrr og n\u00fa &#8211; 2. \u00c1tj\u00e1nda og n\u00edtj\u00e1nda \u00f6ld.<\/li>\n<li>Halastj\u00f6rnur\u00a0fyrr og n\u00fa &#8211; 3. Tuttugasta \u00f6ld.<\/li>\n<li>Halastj\u00f6rnur\u00a0fyrr og n\u00fa &#8211; 4. Upphaf tuttugustu og fyrstu aldar.<\/li>\n<\/ul>\n<p>A\u00f0 stofni til er h\u00e9r um a\u00f0 r\u00e6\u00f0a <strong>heimildaskr\u00e1<\/strong> og <strong>safn minnispunkta<\/strong> h\u00f6fundar. Inn \u00e1 milli er og skoti\u00f0 myndum og fr\u00e1s\u00f6gnum af s\u00e9rlega \u00e1hugaver\u00f0um halastj\u00f6rnum, kenningum um e\u00f0li \u00feeirra og\u00a0 einstaklingum sem koma vi\u00f0 s\u00f6gu. Auk tilv\u00edsana \u00ed f\u00e6rslunum sj\u00e1lfum, m\u00e1 \u00ed lok fj\u00f3r\u00f0u f\u00e6rslu finna lista yfir \u00fdmsar a\u00f0rar gagnlegar vefs\u00ed\u00f0ur og ritsm\u00ed\u00f0ar.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-6795 aligncenter\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/08\/1681_latest-251x300.jpeg\" alt=\"\" width=\"396\" height=\"473\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/1681_latest-251x300.jpeg 251w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/1681_latest-858x1024.jpeg 858w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/1681_latest-768x917.jpeg 768w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/1681_latest-1286x1536.jpeg 1286w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/1681_latest.jpeg 1299w\" sizes=\"auto, (max-width: 396px) 100vw, 396px\" \/><\/p>\n<p>Umfj\u00f6llunin er langt fr\u00e1 \u00fev\u00ed a\u00f0 vera t\u00e6mandi og ver\u00f0ur n\u00fdjum uppl\u00fdsingum b\u00e6tt vi\u00f0 eftir \u00fe\u00f6rfum, b\u00e6\u00f0i \u00ed megintexta og me\u00f0 vi\u00f0aukum. Ef einhver lumar \u00e1 vitneskju um \u00e1hugavert efni, sem \u00e6tti heima h\u00e9r, \u00fe\u00e6tti m\u00e9r v\u00e6nt um a\u00f0 f\u00e1 fr\u00e9ttir af \u00fev\u00ed.<\/p>\n<p>\u00c1\u00f0ur en lengra er haldi\u00f0 er r\u00e9tt a\u00f0 benda \u00e1 nokkrar vefs\u00ed\u00f0ur \u00fear sem h\u00e6gt er a\u00f0 rifja upp fyrri kynni af halastj\u00f6rnum og mikilv\u00e6gi \u00feeirra \u00ed menningu og heimsmynd:<\/p>\n<ul>\n<li>ESA: <a href=\"http:\/\/sci.esa.int\/rosetta\/54198-harbingers-of-doom-windy-exhalations-or-icy-wanderers\/\">A history of comets<\/a>.<\/li>\n<li>Public Domain Review: <a href=\"https:\/\/publicdomainreview.org\/collections\/flowers-of-the-sky\/\">Flowers of the Sky<\/a>.<\/li>\n<li>Stj\u00f6rnufr\u00e6\u00f0ivefurinn: <a href=\"https:\/\/www.stjornufraedi.is\/solkerfid\/halastjornur\/\">Halastj\u00f6rnur<\/a>.<\/li>\n<li>Wikipedia: (a) <a href=\"https:\/\/en.wikipedia.org\/wiki\/Comet\">Comet<\/a> og (b) <a href=\"https:\/\/en.wikipedia.org\/wiki\/Observational_history_of_comets\">Observational history of comets.<\/a>\u00a0 Yfirlit yfir e\u00f0li og eiginleika halastjarna og s\u00f6gu ranns\u00f3kna \u00e1 \u00feeim, allt fr\u00e1 forn\u00f6ld til dagsins \u00ed dag.<\/li>\n<li>Wikipedia: <a href=\"https:\/\/en.wikipedia.org\/wiki\/Comets_in_fiction\">Comets in Fiction<\/a>.<\/li>\n<li>P. McCouat, 2014: <a href=\"http:\/\/www.artinsociety.com\/comets-in-art.html\">Comets in Art<\/a>.<\/li>\n<\/ul>\n<p>\u00de\u00f3tt umfj\u00f6llunin \u00ed f\u00e6rslunum fj\u00f3rum s\u00e9 frekar almenn, er l\u00f6g\u00f0 \u00e1hersla \u00e1 a\u00f0 tengja hana vi\u00f0 ritsm\u00ed\u00f0ar, m\u00e6lingar og hugmyndir \u00cdslendinga um halastj\u00f6rnur. Sl\u00edkt \u00e6tti me\u00f0al annars a\u00f0 gefa d\u00e1g\u00f3\u00f0a mynd af t\u00ed\u00f0arandanum hverju sinni.<\/p>\n<p>&nbsp;<\/p>\n<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">Um halastj\u00f6rnur \u00ed R\u00edmbeglu og \u00f6\u00f0rum fornritum<\/span><\/h3>\n<p>\u00cdslenska mi\u00f0aldahandriti\u00f0 <a href=\"http:\/\/baekur.is\/bok\/000331679\/0\/7\/Rimbegla\">R\u00edmbegla<\/a> kom ekki \u00e1 prenti fyrr en sex \u00f6ldum eftir a\u00f0 \u00fea\u00f0 var upphaflega sett \u00e1 skinn. \u00dea\u00f0 var \u00e1ri\u00f0 1780 \u00ed fr\u00e6gri \u00fatg\u00e1fu <a href=\"http:\/\/uni.hi.is\/einar\/2017\/10\/18\/aflfraedi-i-verkum-stefans-bjornssonar\/\">Stef\u00e1ns Bj\u00f6rnssonar<\/a> reiknimeistara. \u00dear segir um halastj\u00f6rnur \u00e1 bla\u00f0s\u00ed\u00f0u 478:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-5674 aligncenter\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/07\/Rymbegla_478_Nytt-300x60.png\" alt=\"\" width=\"575\" height=\"115\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Rymbegla_478_Nytt-300x60.png 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Rymbegla_478_Nytt.png 607w\" sizes=\"auto, (max-width: 575px) 100vw, 575px\" \/><\/p>\n<p>Latneska or\u00f0i\u00f0 yfir halastj\u00f6rnu, <em> cometes,<\/em> er komi\u00f0 \u00far gr\u00edsku,<em> (\u1f00\u03c3\u03c4\u1f74\u03c1) \u03ba\u03bf\u03bc\u03ae\u03c4\u03b7\u03c2<\/em>, sem merkir s\u00ed\u00f0h\u00e6r\u00f0 (stjarna), og \u00feannig ber a\u00f0 skilja or\u00f0alagi\u00f0 \u201estj\u00f6rnur lokka\u00f0ar\u201c. Me\u00f0 \u201emj\u00f3lkhring\u201c er \u00e1tt vi\u00f0 Vetrarbrautina. \u00cd <a href=\"https:\/\/rafhladan.is\/handle\/10802\/4962\">Alfr\u00e6\u00f0i \u00edslenzk II<\/a>, \u00fatg\u00e1fu <a href=\"https:\/\/is.wikipedia.org\/wiki\/Kristian_Kaalund\">Kr. Kaalunds<\/a> og <a href=\"https:\/\/sv.wikipedia.org\/wiki\/Natanael_Beckman\">N. Beckmans<\/a> fr\u00e1 1914-16, segir Beckman (ne\u00f0anm\u00e1ls, bls. 119) a\u00f0 sennilega s\u00e9 \u00feessi umfj\u00f6llun um halastj\u00f6rnur a\u00f0 hluta s\u00f3tt \u00ed verki\u00f0 <em>De natura rerum<\/em>, sem Beda prestur samdi snemma \u00e1 \u00e1ttundu \u00f6ld. Svipa\u00f0a l\u00fdsingu megi einnig finna hj\u00e1 Honorius Augustodunensis \u00ed ritinu <em>Imago mundi <\/em>fr\u00e1 fyrri hluta t\u00f3lftu aldar. N\u00e1nar ver\u00f0ur viki\u00f0 a\u00f0 verkum \u00feessara fornu spekinga h\u00e9r \u00e1 eftir.<\/p>\n<p><span lang=\"IS\">Eins og n\u00e1nar kemur fram \u00ed n\u00e6sta kafla, er oft geti\u00f0 um halastj\u00f6rnur \u00ed \u00edslenskum ann\u00e1lum. Eina l\u00fdsingin \u00e1 halastj\u00f6rnu \u00ed \u00edslenskum fornritum mun hins vegar vera \u00ed <\/span><span lang=\"IS\"><a href=\"https:\/\/is.wikipedia.org\/wiki\/H%C3%A1konar_saga_H%C3%A1konarsonar\">H\u00e1konar s\u00f6gu H\u00e1konarsonar<\/a> eftir Sturlu \u00de\u00f3r\u00f0arson. \u00dear segir: <\/span><\/p>\n<blockquote><p><span lang=\"IS\">\u00deat var n\u00edu n\u00f3ttum eftir j\u00f3l er konungr gekk um kveldit \u00fat, ok var hei\u00f0vi\u00f0ri \u00e1. Hann s\u00e1 undarliga stj\u00f6rnu, miklu meiri en a\u00f0rar ok \u00f3gurligri ok af sem skaft v\u00e6ri. Konungr l\u00e9t kalla til s\u00edn meistara Vilhj\u00e1lm, ok er hann kom ok s\u00e1 stj\u00f6rnuna m\u00e6lti hann: \u201eGu\u00f0 g\u00e6ti v\u00e1r. \u00deetta er mikil s\u00fdn. \u00deessi stjarna heitir k\u00f3meta, ok s\u00fdnisk hon fyrir fr\u00e1falli \u00e1g\u00e6tra h\u00f6f\u00f0ingja ella fyrir st\u00f3rum bard\u00f6gum.\u201c \u00deessi stjarna var s\u00e9n \u00e1 m\u00f6rgum l\u00f6ndum um vetrinn. <\/span><\/p><\/blockquote>\n<p>Eftir \u00f6llum s\u00f3larmerkjum a\u00f0 d\u00e6ma er \u00feetta l\u00fdsing \u00e1 <a href=\"https:\/\/de.wikipedia.org\/wiki\/C\/1240_B1\">halastj\u00f6rnunni miklu \u00e1ri\u00f0 1240<\/a>, sem var \u00ed s\u00f3ln\u00e1nd 21. jan\u00faar \u00fea\u00f0 \u00e1r. Sj\u00e1 n\u00e1nari umfj\u00f6llun h\u00e9r:<\/p>\n<ul>\n<li>C. Andersson og N. Bj\u00f6rgo, 1986: <a href=\"https:\/\/notendur.hi.is\/~einar\/Kometen1240.pdf\">Kometen av \u00e5r 1240 i H\u00e5kon H\u00e5konssons saga<\/a>.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">Verk \u00c1rna Hjartarsonar um halastj\u00f6rnur og \u00edslenska ann\u00e1la<\/span><\/h3>\n<p>Fyrir um \u00fea\u00f0 bil \u00feremur \u00e1ratugum kanna\u00f0i <a href=\"http:\/\/www.isor.is\/starfsmenn\/arni-hjartarson\">\u00c1rni Hjartarson<\/a> jar\u00f0fr\u00e6\u00f0ingur umfj\u00f6llun \u00edslenskra ann\u00e1la um halastj\u00f6rnur. Ni\u00f0urst\u00f6\u00f0ur hans er a\u00f0 finna h\u00e9r:<\/p>\n<ul>\n<li>\u00c1rni Hjartarson, 1985: <a href=\"https:\/\/notendur.hi.is\/~einar\/AH1985.pdf\">Halastjarnan Halley \u00ed \u00edslenskum heimildum.<\/a><\/li>\n<li>\u00c1rni Hjartarson, 1989: <a class=\"external text\" href=\"http:\/\/timarit.is\/view_page_init.jsp?pageId=2056898\" rel=\"nofollow\">Halastj\u00f6rnur, s\u00f3lmyrkvar, eldgos og \u00e1rei\u00f0anleiki ann\u00e1la<\/a>.<\/li>\n<li>\u00c1rni Hjartarson (vefs\u00ed\u00f0a): <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522182557\/http:\/\/www.isor.is\/~ah\/comet\/hali1.htm\">Ann\u00e1la\u00f0ar k\u00f3metur<\/a>.<\/li>\n<\/ul>\n<p>\u00deegar vitna\u00f0 er \u00edslenska ann\u00e1la \u00ed eftirfarandi bloggf\u00e6rslum, er textinn yfirleitt fenginn a\u00f0 l\u00e1ni hj\u00e1 \u00c1rna.<\/p>\n<p>&nbsp;<\/p>\n<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">Halastj\u00f6rnur \u00ed jar\u00f0mi\u00f0juheimi Arist\u00f3telesar og Pt\u00f3lema\u00edosar<\/span><\/h3>\n<p>Elstu heimildir um halastj\u00f6rnur munu vera fr\u00e1 K\u00edna, en \u00fear var fylgst vel me\u00f0 \u00feessum fyrirb\u00e6rum vegna mikilv\u00e6gis \u00feeirra fyrir stj\u00f6rnusp\u00e1d\u00f3ma. \u00dea\u00f0 voru hins vegar kenningar <a href=\"https:\/\/en.wikipedia.org\/wiki\/Aristotle\">Arist\u00f3telesar<\/a> (384-322 f.Kr.), sem fyrst og fremst m\u00f3tu\u00f0u hugmyndir manna \u00e1 Vesturl\u00f6ndum um halastj\u00f6rnur, allt fram \u00e1 sautj\u00e1ndu \u00f6ld.<\/p>\n<p>\u00cd heimsmynd Arist\u00f3telesar tilheyra halastj\u00f6rnur \u00feeim hluta heimsins, sem er milli hvela jar\u00f0ar og tungls. Hann fjallar \u00fev\u00ed um \u00fe\u00e6r \u00ed riti s\u00ednu um fyrirb\u00e6ri ne\u00f0an tungls (<a href=\"https:\/\/en.wikipedia.org\/wiki\/Meteorology_(Aristotle)\">Meteorologica<\/a>), en ekki \u00ed b\u00f3kinni um hnetti himinsins og hvel \u00feeirra (<a href=\"https:\/\/en.wikipedia.org\/wiki\/On_the_Heavens\">De caelo<\/a>).<\/p>\n<figure id=\"attachment_5768\" aria-describedby=\"caption-attachment-5768\" style=\"width: 562px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-5768\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/07\/AM732b-copy-2-291x300.jpg\" alt=\"\" width=\"562\" height=\"580\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/AM732b-copy-2-291x300.jpg 291w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/AM732b-copy-2.jpg 573w\" sizes=\"auto, (max-width: 562px) 100vw, 562px\" \/><figcaption id=\"caption-attachment-5768\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Mynd \u00far \u00edslenska handritinu <a href=\"https:\/\/handrit.is\/en\/manuscript\/imaging\/en\/AM04-0732-b#page\/3v++(12+of+26)\/mode\/2up\">AM 732b 4to<\/a> (bls. 3v) fr\u00e1 fj\u00f3rt\u00e1ndu \u00f6ld. H\u00fan s\u00fdnir \u00feversni\u00f0 af hinum endanlega og afmarka\u00f0a jar\u00f0mi\u00f0juheimi Arist\u00f3telesar me\u00f0 \u00fer\u00edv\u00ed\u00f0um hvelum s\u00ednum. Fyrir ne\u00f0an tunglhveli\u00f0 er s\u00edbreytilegur og forgengilegur heimur <a href=\"https:\/\/en.wikipedia.org\/wiki\/Classical_element#Greece\">h\u00f6fu\u00f0skepnanna fj\u00f6gurra<\/a>: Innst er \u00feurr og k\u00f6ld j\u00f6r\u00f0in, \u00fe\u00e1 hi\u00f0 raka og kalda vatn, n\u00e6st rakt og heitt lofti\u00f0 og loks \u00feurr og heitur eldurinn (me\u00f0 eldi er h\u00e9r \u00e1tt vi\u00f0 eldfim efni). Fyrir ofan eldhveli\u00f0 er \u00f3breytanlegur heimur fimmtu h\u00f6fu\u00f0skepnunnar,\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Aether_(classical_element)\">eisunnar<\/a> (etersins), me\u00f0 hvelum f\u00f6ruhnattanna sj\u00f6. Tungli\u00f0 er \u00fear ne\u00f0st, \u00fe\u00e1 Merk\u00far\u00edus, Venus, s\u00f3lin, Mars, J\u00fap\u00edter og loks Sat\u00farnus, sem er efstur. Fyrir ofan (utan) hvel hans kom svo fastastj\u00f6rnuhveli\u00f0, sem af einhverjum \u00e1st\u00e6\u00f0um er ekki s\u00fdnt \u00e1 myndinni. Utan um \u00fea\u00f0 kom Pt\u00f3lema\u00edos s\u00ed\u00f0ar fyrir <a href=\"https:\/\/en.wikipedia.org\/wiki\/Primum_Mobile\">frumhreyfihvelinu<\/a> (primum mobile), sem mi\u00f0lar sn\u00faningshreyfingu til hvelanna fyrir ne\u00f0an (innan). \u00dear fyrir utan er\u00a0 ekkert, ekki einu sinni t\u00f3m. \u00dear fundu kristnir menn \u00e1 s\u00ednum t\u00edma sta\u00f0 fyrir himnar\u00edki.<br \/><\/span><\/figcaption><\/figure>\n<p>Kenning Arist\u00f3telesar var s\u00fa, a\u00f0 halast\u00f6rnur yr\u00f0u til vi\u00f0 \u00fea\u00f0 a\u00f0 \u00feurrar, heitar og sam\u00fejappa\u00f0ar gufur leitu\u00f0u fr\u00e1 j\u00f6r\u00f0u upp til eldhvelsins, \u00fear sem n\u00faningur vi\u00f0 hveli\u00f0 kveikti \u00ed \u00feeim. Eftir \u00fea\u00f0 snerust eldstj\u00f6rnurnar \u00f3reglulega um j\u00f6r\u00f0u vegna \u00e1hrifa fr\u00e1 hringhreyfingu tunglhvelsins. \u00deegar eldsneyti\u00f0 \u00feryti slokkna\u00f0i svo \u00e1 \u00feessum skamml\u00edfu fyrirb\u00e6rum.<\/p>\n<p>Eins og \u00e1\u00f0ur sag\u00f0i, voru hugmyndir Arist\u00f3telesar um efnisheiminn r\u00e1\u00f0andi allt fram \u00e1 sautj\u00e1ndu \u00f6ld. Sem d\u00e6mi m\u00e1 nefna, a\u00f0 <a href=\"https:\/\/en.wikipedia.org\/wiki\/Ptolemy\">Pt\u00f3lema\u00edos<\/a> (100-170) minnist ekki \u00e1 halastj\u00f6rnur \u00ed hinu mikla stj\u00f6rnufr\u00e6\u00f0iriti s\u00ednu <a href=\"https:\/\/en.wikipedia.org\/wiki\/Almagest\">Almagest<\/a>. Aftur \u00e1 m\u00f3ti fjallar hann um \u00fe\u00e6r \u00ed fj\u00f3rb\u00f3k sinni um stj\u00f6rnusp\u00e1d\u00f3ma, <a href=\"https:\/\/en.wikipedia.org\/wiki\/Tetrabiblos\">Tetrabiblos<\/a>. S\u00fa sta\u00f0reynd, a\u00f0 \u00feessi v\u00ed\u00f0fr\u00e6gi stj\u00f6rnufr\u00e6\u00f0ingur kynnti halastj\u00f6rnur ekki sem himinhnetti, heldur sem fyrirbo\u00f0a (yfirleitt v\u00e1legra) t\u00ed\u00f0inda \u00ed mannheimum, hefur eflaust \u00e1tt sinn \u00fe\u00e1tt \u00ed a\u00f0 vi\u00f0halda fornri hj\u00e1tr\u00fa manna um halastj\u00f6rnur sem \u00f3heillakr\u00e1kur.<\/p>\n<p>Ekki voru \u00fe\u00f3 allir s\u00f6mu sko\u00f0unar og \u00feessir gr\u00edsku spekingar. <a href=\"https:\/\/en.wikipedia.org\/wiki\/Seneca_the_Younger\">Seneca hinn yngri<\/a> (4-65) var til d\u00e6mis \u00e1 \u00f6ndver\u00f0um mei\u00f0i vi\u00f0 Arist\u00f3teles og f\u00e6r\u00f0i fram sterk r\u00f6k fyrir \u00fev\u00ed, a\u00f0 halastj\u00f6rnur v\u00e6ru hluti af heimi f\u00f6ruhnattanna. \u00c6givald sko\u00f0ana Arist\u00f3telesar kom \u00fe\u00f3 \u00ed veg fyrir, a\u00f0 sl\u00edkar hugmyndir hlytu almennan hlj\u00f3mgrunn fyrr en \u00e1 seinni hluta sautj\u00e1ndu aldar.<\/p>\n<ul>\n<li>Arist\u00f3teles: Um halastj\u00f6rnur \u00ed <a href=\"https:\/\/archive.org\/details\/L397AristotleMeteorologica\">Meteorologica<\/a> (bls. 38-57).<\/li>\n<li>Pt\u00f3lema\u00edos: Um halastj\u00f6rnur \u00ed <a href=\"https:\/\/archive.org\/details\/ptolemystetrabib00ptol\">Tetrabiblos<\/a> (bls. 62-63 og 161).<\/li>\n<li>Seneca yngri: Um halastj\u00f6rnur \u00ed <a href=\"http:\/\/naturalesquaestiones.blogspot.com\/2009\/08\/book-vii-tr-john-clarke.html\">Naturales questiones VII<\/a> (kaflar 22 og 23).<\/li>\n<li>A. A. Barrett, 1978: <a href=\"http:\/\/adsbit.harvard.edu\/\/full\/1978JRASC..72...81B\/0000081.000.html\">Observations of Comets in Greek and Roman Sources Before A.D. 410.<\/a><\/li>\n<li>Wikipedia: <a href=\"https:\/\/en.wikipedia.org\/wiki\/Historical_comet_observations_in_China\">Historical comet observations in China.<\/a><\/li>\n<\/ul>\n<p>Eftir <a href=\"https:\/\/www.visindavefur.is\/svar.php?id=6071\">fall R\u00f3maveldis<\/a> \u00e1 fimmtu \u00f6ld m\u00e1 segja a\u00f0 v\u00edsindaleg \u00feekking hafi a\u00f0 mestu veri\u00f0 horfin \u00ed Vestur-Evr\u00f3pu. S\u00fa litla b\u00f3k\u00feekking, sem var\u00f0veist haf\u00f0i \u00e1 \u00feessu sv\u00e6\u00f0i, var einkum geymd \u00ed alfr\u00e6\u00f0iritum eftir kristna l\u00e6rd\u00f3msmenn eins og <a href=\"https:\/\/en.wikipedia.org\/wiki\/Boethius\">B\u00f6\u00fe\u00edus<\/a> (477-524), <a href=\"https:\/\/en.wikipedia.org\/wiki\/Cassiodorus\">Kass\u00edod\u00f3rus<\/a> (485-585) og <a href=\"https:\/\/en.wikipedia.org\/wiki\/Isidore_of_Seville\">\u00cdsid\u00f3r fr\u00e1 Sevilla<\/a> (560-636). \u00cd kristnum klaustrum var jafnframt reynt af veikum m\u00e6tti a\u00f0 vi\u00f0halda \u00feekkingunni me\u00f0 kennslu og uppskriftum handrita.<\/p>\n<p>H\u00f6fundar eins og <a href=\"https:\/\/en.wikipedia.org\/wiki\/Bede\">Beda prestur<\/a> (672\/3-735) og <a href=\"https:\/\/de.wikipedia.org\/wiki\/Honorius_Augustodunensis\">Honorius Augustodunensis<\/a> (1080-1150\/51), sem \u00e1\u00f0ur voru nefndir sem mikilv\u00e6gir heimildarmenn R\u00edmbeglu, vir\u00f0ast hafa s\u00f3tt talsvert af \u00feekkingu sinni um stj\u00f6rnur og lofthj\u00fap til \u00cdsid\u00f3rs. Hann mun aftur hafa leita\u00f0 talsvert \u00ed ruglingslegan \u00feekkingarsj\u00f3\u00f0\u00a0 <a href=\"https:\/\/en.wikipedia.org\/wiki\/Pliny_the_Elder\">Pl\u00edn\u00edusar eldra<\/a> (23-79) og ef til vill til fleiri <a href=\"https:\/\/en.wikipedia.org\/wiki\/Encyclopedism#Rome\">h\u00f6funda r\u00f3mverskra alfr\u00e6\u00f0irita<\/a>.<\/p>\n<ul>\n<li>Pl\u00edn\u00edus eldri: Um halastj\u00f6rnur \u00ed <a href=\"http:\/\/www.perseus.tufts.edu\/hopper\/text?doc=Perseus%3Atext%3A1999.02.0137%3Abook%3D2%3Achapter%3D22\">Naturalis historia<\/a>.<\/li>\n<li>\u00cdsid\u00f3r fr\u00e1 Sevilla: Um halastj\u00f6rnur \u00ed <a href=\"https:\/\/www.researchgate.net\/publication\/315663902_On_the_Nature_of_Things_De_Natura_Rerum_by_Isidore_of_Seville_ca_560-636_AD_Translated_by_Carolyn_Embach_1969\">De natura rerum<\/a> (bls. 36) og <a href=\"https:\/\/sfponline.org\/Uploads\/2002\/st%20isidore%20in%20english.pdf\">Etymologiae<\/a> (bls.105).<\/li>\n<li>Beda prestur: Um halastj\u00f6rnur \u00ed <a href=\"https:\/\/books.google.is\/books?id=6_VDAAAAYAAJ&amp;source=gbs_navlinks_s\">De natura rerum<\/a> (24. kafli, bls. 111).<\/li>\n<li>Honorius Augustodunensis: Um halastj\u00f6rnur \u00ed <a href=\"https:\/\/pdxscholar.library.pdx.edu\/open_access_etds\/4090\/\">Imago mundi<\/a> (bls. 194).<\/li>\n<\/ul>\n<p>S\u00fa v\u00edsindalega \u00feekking, sem finna m\u00e1 hj\u00e1 \u00feessum h\u00f6fundum, var hverfandi mi\u00f0a\u00f0 vi\u00f0 \u00fea\u00f0, sem \u00e1\u00f0ur haf\u00f0i \u00feekkst, einkum \u00ed Grikklandi hinu forna. H\u00fan reyndist samt gagnleg undirsta\u00f0a, \u00feegar n\u00e6ringin \u00far fornum \u00feekkingarbrunnum t\u00f3k a\u00f0 fl\u00e6\u00f0a yfir Vestur-Evr\u00f3pu \u00ed \u00fe\u00fd\u00f0ingarbylgjunum miklu \u00e1 t\u00f3lftu og \u00ferett\u00e1ndu \u00f6ld. \u00c1 \u00feeim miklilv\u00e6gu endurn\u00fdjunart\u00edmum voru \u00f6ll helstu verk hinna gr\u00edsku spekinga \u00fe\u00fddd \u00e1 lat\u00ednu \u00far arab\u00edsku e\u00f0a gr\u00edsku.<\/p>\n<ul>\n<li>Wikipedia: <a href=\"https:\/\/en.wikipedia.org\/wiki\/European_science_in_the_Middle_Ages\">European science in the Middle Ages<\/a>.<\/li>\n<li>Wikipedia: <a href=\"https:\/\/en.wikipedia.org\/wiki\/Transmission_of_the_Greek_Classics\">Transmission of the Greek Classics<\/a>.<\/li>\n<li>Wikipedia: <a href=\"https:\/\/en.wikipedia.org\/wiki\/Latin_translations_of_the_12th_century\">Latin translations of the 12th century<\/a>.<\/li>\n<\/ul>\n<figure id=\"attachment_5710\" aria-describedby=\"caption-attachment-5710\" style=\"width: 573px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-5710\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/07\/Lubienietsky_Comet_Crisis-300x144.jpg\" alt=\"\" width=\"573\" height=\"275\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Lubienietsky_Comet_Crisis-300x144.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Lubienietsky_Comet_Crisis-1024x493.jpg 1024w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Lubienietsky_Comet_Crisis-768x370.jpg 768w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Lubienietsky_Comet_Crisis.jpg 1047w\" sizes=\"auto, (max-width: 573px) 100vw, 573px\" \/><figcaption id=\"caption-attachment-5710\" class=\"wp-caption-text\">Myndin \u00e1 a\u00f0 s\u00fdna skelfilega atbur\u00f0i, sem fylgdu \u00ed kj\u00f6lfar halastj\u00f6rnu \u00e1 fj\u00f3r\u00f0u \u00f6ld. \u00dar ritinu <a href=\"https:\/\/archive.org\/details\/ned-kbn-all-00001421-001\">Theatrum cometicum<\/a> fr\u00e1 1668.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">Nokkrar \u00edslenskar heimildir um halastj\u00f6rnur \u00e1 13. og 14. \u00f6ld<\/span><\/h3>\n<p>\u00c1\u00f0ur hefur veri\u00f0 sagt fr\u00e1 l\u00fdsingu Sturlu \u00de\u00f3r\u00f0arsonar \u00e1 halastj\u00f6rnunni 1240 \u00ed <em>H\u00e1konar s\u00f6gu H\u00e1konarsonar<\/em>. \u00cd <a href=\"https:\/\/is.wikipedia.org\/wiki\/%C3%8Dslendinga_saga\">\u00cdslendinga s\u00f6gu<\/a> minnist Sturla einnig \u00e1 heims\u00f3kn halastj\u00f6rnu, n\u00fa \u00e1ri\u00f0 1222, \u00e1n \u00feess \u00fe\u00f3 a\u00f0 l\u00fdsa henni n\u00e1nar:<\/p>\n<blockquote><p>\u00deetta sumar er n\u00e6st var og n\u00fa hefir fr\u00e1 veri\u00f0 sagt t\u00f3k s\u00f3tt S\u00e6mundur \u00ed Odda, og anda\u00f0ist inn sj\u00f6unda idus novembris. \u00dea\u00f0 sama haust og \u00f6ndver\u00f0an vetur s\u00e1st oft stjarna s\u00fa er k\u00f3meta heitir. \u00de\u00e1 s\u00fdndist og s\u00f3lin rau\u00f0 sem bl\u00f3\u00f0.<\/p><\/blockquote>\n<p>\u00dearna var a\u00f0 \u00f6llum l\u00edkindum um a\u00f0 r\u00e6\u00f0a <a href=\"https:\/\/en.wikipedia.org\/wiki\/Halley%27s_Comet\">halastj\u00f6rnuna<\/a>, sem s\u00ed\u00f0ar var kennd vi\u00f0 Edmond Halley.<\/p>\n<p>\u00c1ri\u00f0 1301 s\u00e1st \u00feessi <a href=\"https:\/\/en.wikipedia.org\/wiki\/Halley%27s_Comet\">sama stjarna<\/a> aftur h\u00e9r \u00e1 landi. <em>L\u00f6gmannsann\u00e1ll<\/em> l\u00fdsir henni svo:<\/p>\n<blockquote><p>Cometa var s\u00e9n af kaupm\u00f6nnum \u00ed hafi um Mikj\u00e1lsmessuskei\u00f0 <em>[29. sept]<\/em>. S\u00fdndist \u00feeim h\u00fan meiri og d\u00f6kkvari en a\u00f0rar stj\u00f6rnur og var kleppur ni\u00f0ur og f\u00f3r h\u00fan hvern aftan er \u00feeir s\u00e1u hana \u00f6fugt fr\u00e1 landnor\u00f0ri til nor\u00f0urs. Item fyrir sunnan land var s\u00e9n cometa h\u00e1lfan m\u00e1nu\u00f0 n\u00e6r veturn\u00e1ttum.<\/p><\/blockquote>\n<p>\u00cd <em>Gottsk\u00e1lksann\u00e1l<\/em> fyrir \u00e1ri\u00f0 1316 segir:<\/p>\n<blockquote><p>S\u00e1st cometa \u00e1 himni \u00e1 \u00cdslandi oftliga fr\u00e1 fyrstu j\u00f3lan\u00f3tt allt til purificationem beate Marie.<em> [\u00fe.e. fr\u00e1 25. des. 1315 til 2. feb. 1316].<\/em><\/p><\/blockquote>\n<p>B\u00e6\u00f0i k\u00ednverskir og evr\u00f3pskir ann\u00e1lar geta um \u00feessa stj\u00f6rnu, sem fer\u00f0a\u00f0ist h\u00e1tt upp\u00e1 nor\u00f0urhimininn. \u00cd K\u00edna s\u00e1st h\u00fan fr\u00e1 28. n\u00f3vember 1315 til 12. mars 1316. Hennar er v\u00ed\u00f0a geti\u00f0 \u00ed tengslum vi\u00f0 <a href=\"https:\/\/en.wikipedia.org\/wiki\/Great_Famine_of_1315%E2%80%9317\">hungursney\u00f0ina miklu<\/a> \u00e1 \u00e1runum 1315-1317.<\/p>\n<ul>\n<li>\u00c1rni Hjartarson: Halastj\u00f6rnur \u00e1 <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522183913\/http:\/\/www.isor.is\/~ah\/comet\/hali5.htm\">\u00ferett\u00e1ndu<\/a> og <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522183920\/http:\/\/www.isor.is\/~ah\/comet\/hali6.htm\">fj\u00f3rt\u00e1ndu<\/a> \u00f6ld.<\/li>\n<li>L. Thorndyke, 1950: <a href=\"https:\/\/catalog.hathitrust.org\/Record\/001991474\">Latin treatises on comets between 1238 and 1368 A. D.<\/a> \u00dearna m\u00e1 me\u00f0al annars finna enskar \u00fe\u00fd\u00f0ingar \u00e1 verkum <a href=\"https:\/\/en.wikipedia.org\/wiki\/Albertus_Magnus\">Alberts mikla<\/a> (1200-1280) og <a href=\"https:\/\/en.wikipedia.org\/wiki\/Thomas_Aquinas\">T\u00f3masar af Aquino<\/a> (1225-1274) um halastj\u00f6rnur.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">Endurreisnin<\/span><\/h3>\n<p>Me\u00f0 <a href=\"https:\/\/en.wikipedia.org\/wiki\/Renaissance\">endurreisninni<\/a> h\u00f3fst sm\u00e1m saman n\u00fdtt skei\u00f0 \u00ed n\u00e1tt\u00faruv\u00edsindum. \u00dea\u00f0 l\u00fdsti s\u00e9r me\u00f0al annars \u00ed tilraunum l\u00e6rd\u00f3msmanna til a\u00f0 framkv\u00e6ma s\u00edfellt betri athuganir og n\u00e1kv\u00e6mari m\u00e6lingar \u00e1 n\u00e1tt\u00farfyrirb\u00e6rum. \u00cd stj\u00f6rnufr\u00e6\u00f0i voru \u00fea\u00f0 st\u00e6r\u00f0fr\u00e6\u00f0ilegu l\u00e6rd\u00f3msmennirnir <a href=\"https:\/\/en.wikipedia.org\/wiki\/Georg_von_Peuerbach\">G. Peuerback<\/a> (1423-1461) \u00ed V\u00ednarborg og nemandi hans og eftirma\u00f0ur Johannes M\u00fcller, betur \u00feekktur undir nafninu <a href=\"https:\/\/en.wikipedia.org\/wiki\/Regiomontanus\">Regiomontanus<\/a> (1436-1476), sem ri\u00f0u \u00e1 va\u00f0i\u00f0.<\/p>\n<p>Eitt af \u00fev\u00ed, sem \u00feessir frumkv\u00f6\u00f0lar ger\u00f0u, var a\u00f0 beita <a href=\"https:\/\/en.wikipedia.org\/wiki\/Parallax\">hli\u00f0runarm\u00e6lingum<\/a> til \u00feess a\u00f0 \u00e1kvar\u00f0a fjarl\u00e6g\u00f0 halastjana fr\u00e1 mi\u00f0ju jar\u00f0ar. \u00dea\u00f0 gekk reyndar fremur illa vegna\u00a0 \u00f3fullkomins t\u00e6kjab\u00fana\u00f0ar. Ni\u00f0ursta\u00f0a \u00feeirra var\u00f0 a\u00f0 lokum s\u00fa, a\u00f0 halastj\u00f6rnur v\u00e6ru n\u00e6r j\u00f6r\u00f0inni en tungli\u00f0, \u00ed samr\u00e6mi vi\u00f0 kenningar Arist\u00f3telesar.<\/p>\n<p>Regiomontaus var me\u00f0 fyrstu m\u00f6nnum til a\u00f0 n\u00fdta s\u00e9r hina n\u00fdju <a href=\"https:\/\/en.wikipedia.org\/wiki\/Printing_press\">prentt\u00e6kni<\/a>\u00a0 og \u00e1ri\u00f0 1473 gaf hann \u00fat fyrstu prentu\u00f0u kennslub\u00f3kina \u00ed stj\u00f6rnufr\u00e6\u00f0i (<a href=\"https:\/\/www.univie.ac.at\/hwastro\/books\/theoBWLow.pdf\">Theoricae novae planetarum<\/a> eftir Peuerback). Hann prenta\u00f0i einnig b\u00e6kur eftir sj\u00e1lfan sig, en b\u00e6klingur hans um <a href=\"https:\/\/books.google.is\/books?id=LdumByZ31xUC&amp;source=gbs_navlinks_s\">stjarnfr\u00e6\u00f0ilegar m\u00e6lingar \u00e1 halastj\u00f6rnum<\/a> kom af einhverjum \u00e1st\u00e6\u00f0um ekki \u00fat fyrr en 1531.<\/p>\n<p><strong>\u25ca <\/strong><a href=\"https:\/\/en.wikipedia.org\/wiki\/Comet_of_1472\"><strong>Halastjarnan 1472:<\/strong><\/a><\/p>\n<p>\u00deessarar halastj\u00f6rnu er n\u00fa einkum minnst vegna \u00feeirra m\u00e6linga, sem Regiomontanus ger\u00f0i \u00e1 henni. Ekki er til \u00feess vita\u00f0 a\u00f0 h\u00fan hafi s\u00e9st h\u00e9r \u00e1 landi.<\/p>\n<figure id=\"attachment_6609\" aria-describedby=\"caption-attachment-6609\" style=\"width: 421px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-6609\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/08\/RegiomontanusHalley1472-300x183.jpg\" alt=\"\" width=\"421\" height=\"257\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/RegiomontanusHalley1472-300x183.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/RegiomontanusHalley1472.jpg 599w\" sizes=\"auto, (max-width: 421px) 100vw, 421px\" \/><figcaption id=\"caption-attachment-6609\" class=\"wp-caption-text\">Til vinstri m\u00e1 sj\u00e1 Regiomontanus halda \u00e1 <a href=\"https:\/\/en.wikipedia.org\/wiki\/Astrolabe\">stj\u00f6rnusk\u00edfu<\/a>, sem e.t.v. var notu\u00f0 til a\u00f0 \u00e1kvar\u00f0a hli\u00f0run halastjarna. Til h\u00e6gri er t\u00e1knr\u00e6n mynd af halastj\u00f6rnunni 1472. Myndirnar eru b\u00e1\u00f0ar \u00far ritinu <a href=\"https:\/\/en.wikipedia.org\/wiki\/Nuremberg_Chronicle\">Liber chronicarum<\/a> fr\u00e1 1493. Sj\u00e1 n\u00e1nari umfj\u00f6llun <a href=\"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0252921100012914\">h\u00e9r<\/a>.<\/figcaption><\/figure>\n<ul>\n<li>J. L. Jervis, 1985: <a href=\"https:\/\/books.google.is\/books?id=LgkCTA5T8e8C&amp;source=gbs_navlinks_s\">Cometary Theory in Fifteenth-Century Europe<\/a>.<\/li>\n<li>\u00c1rni Hjartarson: <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522183827\/http:\/\/www.isor.is\/~ah\/comet\/hali7.htm\">Myrkar aldir<\/a>.\u00a0 Um halastj\u00f6rnur \u00ed \u00edslenskum ann\u00e1lum\u00a0 \u00e1 fimmt\u00e1ndu og sext\u00e1ndu \u00f6ld.<\/li>\n<\/ul>\n<hr \/>\n<p><strong>\u25ca Halastjarnan 1531:<\/strong><\/p>\n<p>\u00dearna var \u00ed enn eitt skipti\u00f0 \u00e1 fer\u00f0inni <a href=\"https:\/\/en.wikipedia.org\/wiki\/Halley%27s_Comet\">s\u00fa halastjarna<\/a>, sem s\u00ed\u00f0ar var kennd vi\u00f0 Halley. \u00deessarar heims\u00f3knar er n\u00fa einkum minnst vegna teikninganna, sem <a href=\"https:\/\/en.wikipedia.org\/wiki\/Petrus_Apianus\">P. Apian<\/a> (1495-1552) birti af stj\u00f6rnunni sk\u00f6mmu s\u00ed\u00f0ar. \u00dear m\u00e1 greinilega sj\u00e1, a\u00f0 halinn beinist \u00e1vallt fr\u00e1 s\u00f3linni.<\/p>\n<figure id=\"attachment_6631\" aria-describedby=\"caption-attachment-6631\" style=\"width: 432px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-6631\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/08\/Halley_Comet_1531-300x289.jpg\" alt=\"\" width=\"432\" height=\"416\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Halley_Comet_1531-300x289.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Halley_Comet_1531.jpg 530w\" sizes=\"auto, (max-width: 432px) 100vw, 432px\" \/><figcaption id=\"caption-attachment-6631\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Litu\u00f0 \u00fatg\u00e1fa af fors\u00ed\u00f0umynd b\u00f3kar Apians, <em>Practica<\/em>, fr\u00e1 1531. S\u00f3lin er \u00ed <a href=\"https:\/\/www.stjornufraedi.is\/stjornuskodun\/stjornumerkin\/ljonid\/\">Lj\u00f3nsmerki<\/a>, en b\u00e6\u00f0i h\u00fan og halastjarnan fyrir ofan f\u00e6rast sm\u00e1m saman til mi\u00f0a\u00f0 vi\u00f0 bakgrunn fastastjarnanna.\u00a0<\/span><\/figcaption><\/figure>\n<p>Ni\u00f0ursta\u00f0an \u00fe\u00f3tti fur\u00f0uleg, \u00fev\u00ed kenning Arist\u00f3telesar um halastj\u00f6rnur sem brennandi gufur \u00ed lofthj\u00fapnum \u00e1tti enga sannf\u00e6randi sk\u00fdringu \u00e1 \u00feessu. Einnig m\u00e1 geta, a\u00f0 samt\u00edmama\u00f0ur Apians, <a href=\"https:\/\/thonyc.wordpress.com\/2009\/08\/13\/syphilis-and-comets\/\">G. Fracastoro<\/a> (1478-1553), t\u00f3k eftir \u00feessu einkenni halastjarna \u00e1 svipu\u00f0um t\u00edma.\u00a0Hvorugur \u00feeirra Apians h\u00f6f\u00f0u hugmynd um, a\u00f0 K\u00ednverjar h\u00f6f\u00f0u uppg\u00f6tva\u00f0 \u00feetta sj\u00f6 \u00f6ldum fyrr.<\/p>\n<p>Apian reyndi a\u00f0 \u00fatsk\u00fdra heg\u00f0un halans me\u00f0 \u00fev\u00ed, a\u00f0 h\u00f6fu\u00f0 halastjarna v\u00e6ru gagns\u00e6jar k\u00falur og verku\u00f0u eins og linsur. Halinn v\u00e6ri mynda\u00f0ur vi\u00f0 lj\u00f3sbrot s\u00f3largeisla \u00ed k\u00falunni og beindust \u00fev\u00ed \u00e1vallt fr\u00e1 s\u00f3linni. \u00deessa hugmynd notu\u00f0u fleiri s\u00ed\u00f0ar, oftast \u00fe\u00f3 \u00ed breyttu formi. \u00dear m\u00e1 til d\u00e6mis nefna <a href=\"https:\/\/en.wikipedia.org\/wiki\/Gemma_Frisius\">G. Frisius<\/a> (1508-1555), <a href=\"https:\/\/en.wikipedia.org\/wiki\/Gerolamo_Cardano\">G. Cardano<\/a> (1501-1576) og fleiri.<\/p>\n<ul>\n<li>P. Apian, 1531: <a href=\"https:\/\/books.google.is\/books?id=kMBZAAAAcAAJ&amp;source=gbs_navlinks_s\">Practica auff dz. 1532. Jar.<\/a><\/li>\n<li>G. Fracastoro, 1538: <a href=\"https:\/\/books.google.is\/books?id=stLnVvFizA0C&amp;source=gbs_navlinks_s\">Homocentrica.<\/a><\/li>\n<li>P. Apian, 1540: <a href=\"https:\/\/books.google.is\/books?id=oL_zx_oMYMYC&amp;source=gbs_navlinks_s\">Astronomicum Caesareum.<\/a><\/li>\n<\/ul>\n<hr \/>\n<p><strong>\u25ca\u00a0 <a href=\"https:\/\/de.wikipedia.org\/wiki\/C\/1533_M1\">Halastjarnan 1533:<\/a><\/strong><\/p>\n<p>\u00deessi stjarna er a\u00f0eins h\u00f6f\u00f0 me\u00f0 \u00ed \u00feessari upptalningu vegna \u00feess a\u00f0 hinn fr\u00e6gi\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Nicolaus_Copernicus\">K\u00f3pern\u00edkus<\/a> (1473-1543) fylgdist me\u00f0 henni \u00e1 s\u00ednum t\u00edma og skrifa\u00f0i stuttlega um \u00fe\u00e6r athuganir. S\u00fa ritsm\u00ed\u00f0 mun \u00fev\u00ed mi\u00f0ur gl\u00f6tu\u00f0.<\/p>\n<p>Jafnframt er \u00e1st\u00e6\u00f0a til a\u00f0 nefna, a\u00f0 K\u00f3pern\u00edkus minnist a\u00f0eins einu sinni \u00e1 halastj\u00f6rnur \u00ed t\u00edmasm\u00f3taverki s\u00ednu <a href=\"https:\/\/en.wikipedia.org\/wiki\/De_revolutionibus_orbium_coelestium\">De revolutionibus<\/a> fr\u00e1 1543. \u00dear segir hann fullum fetum \u00ed 8. kafla fyrstu b\u00f3kar, a\u00f0 halastj\u00f6rnur s\u00e9u lofthj\u00fapsfyrirb\u00e6ri.<\/p>\n<ul>\n<li>W. Kokott, 1981: <a href=\"http:\/\/adsbit.harvard.edu\/\/full\/1981JHA....12...95K\/0000095.000.html\">The Comet of 1533.<\/a><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">Halastjarnan 1577 og Tycho Brahe<br \/>\n<\/span><\/h3>\n<p><a href=\"https:\/\/en.wikipedia.org\/wiki\/Great_Comet_of_1577\">Halastjarnan mikla \u00e1ri\u00f0 1577<\/a> skipar s\u00e9rstakan sess \u00ed v\u00edsindas\u00f6gunni. Me\u00f0 m\u00e6lingum \u00e1 henni t\u00f3kst st\u00e6r\u00f0fr\u00e6\u00f0ilegum l\u00e6rd\u00f3msm\u00f6nnum \u00ed fyrsta sinn a\u00f0 s\u00fdna fram \u00e1, a\u00f0 halastjarna v\u00e6ri mun lengra \u00ed burtu en tungli\u00f0. H\u00fan \u00e6tti \u00fev\u00ed heima me\u00f0al f\u00f6ruhnatta, en ekki \u00ed forgengilegum heimi h\u00f6fu\u00f0skepnanna fj\u00f6gurra, eins og gert var r\u00e1\u00f0 fyrir \u00ed hinum g\u00f6mlu og gr\u00f3nu kenningum Arist\u00f3telesar.<\/p>\n<figure id=\"attachment_7470\" aria-describedby=\"caption-attachment-7470\" style=\"width: 613px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-7470\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/08\/Comet1577-300x208.jpg\" alt=\"\" width=\"613\" height=\"425\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Comet1577-300x208.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Comet1577-768x533.jpg 768w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Comet1577.jpg 900w\" sizes=\"auto, (max-width: 613px) 100vw, 613px\" \/><figcaption id=\"caption-attachment-7470\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Halastjarnan yfir N\u00fcrnberg \u00ed n\u00f3vember 1577. Endurger\u00f0 samt\u00edmamyndar eftir G. <\/span><span style=\"font-size: 10pt\">Mack eldri.<\/span><\/figcaption><\/figure>\n<p>\u00deessar \u00e1hugaver\u00f0u fr\u00e9ttir b\u00e1rust \u00fe\u00f3 ekki hinga\u00f0 fyrr en l\u00f6ngu s\u00ed\u00f0ar og \u00ed \u00edslenskum ann\u00e1lum var umfj\u00f6llunin um stj\u00f6rnuna svipu\u00f0 og um fyrri halastj\u00f6rnur, og reyndar einnig \u00fe\u00e6r sem \u00e1 eftir komu. G\u00edsli Oddsson, biskup \u00ed Sk\u00e1lholti, fjallar til d\u00e6mis um \u00feessa stj\u00f6rnu \u00ed <em>\u00cdslenskum ann\u00e1labrotum<\/em> \u00e1 eftirfarandi h\u00e1tt:<\/p>\n<blockquote><p>Fr\u00e1 allraheilagramessu <em>[1. n\u00f3v.]<\/em> s\u00e1st \u00f3venjulega st\u00f3r stjarna samfleytt \u00ed 66 daga; st\u00f3\u00f0 h\u00fan ekki \u00f6\u00f0rum stj\u00f6rnum a\u00f0 baki a\u00f0 lj\u00f3ma, en eldgeislar hennar, er h\u00fan varpa\u00f0i aftur af s\u00e9r, l\u00edktust staf miklum og dreif\u00f0um yfir st\u00f3rt sv\u00e6\u00f0i.<\/p><\/blockquote>\n<p>\u00cd <em>Biskupaann\u00e1lum<\/em> J\u00f3ns Egilssonar er l\u00fdsingin heldur \u00edtarlegri:<\/p>\n<blockquote><p>Anno 1577 s\u00e1st ein stjarna \u00e1 himnum, s\u00e1st h\u00fan fyrst um allraheilagra-messu, \u00e1 mi\u00f0vikudaginn eptir hana, og var \u00e1 himnum 66 daga, fram til sunnudagsins eptir \u00ferett\u00e1nda; s\u00e1st h\u00fan \u00e1 kv\u00f6ldin \u00ed mi\u00f0ju lopti, n\u00e6rri svo sem \u00fe\u00e1 s\u00f3lin er h\u00e1 og hefir mi\u00f0jan g\u00e1ng sinn \u00e1 haust \u00e1 millum mi\u00f0munda og h\u00e1degis, en gekk undir \u00ed mi\u00f0saptans sta\u00f0. H\u00fan var svo sk\u00e6r, sem s\u00fa gla\u00f0asta stjarna ver\u00f0a m\u00e1, en aptur af henni var sem brennandi eldslogi, og vildi loginn nokku\u00f0 \u00ed lopt upp, og breiddist \u00ed sundur, eins sem \u00fe\u00e1 v\u00ed\u00f0ur v\u00f6ndur e\u00f0a mikill s\u00f3fl er.\u00a0 &#8211;\u00a0 \u00d6nnur stjarna s\u00e1st \u00e1 einu e\u00f0ur tveimur \u00e1rum seinna, en \u00fe\u00f3 hvergi n\u00e6rri \u00feessari l\u00edk, \u00fev\u00ed hvorki var h\u00fan svo bj\u00f6rt, n\u00e9 heldur miki\u00f0 skin af henni. \u00deessum b\u00e1\u00f0um stj\u00f6rnum, \u00fe\u00f3 heldur \u00feeirri fyrri, eptir (fylg\u00f0i) pen\u00edngafall og grasleysi <em>[&#8230;]<\/em> \u00deri\u00f0ja \u00e1r eptir \u00feessa stj\u00f6rnu kom svo l\u00edti\u00f0 gras\u00e1r, a\u00f0 af \u00f6llum H\u00f3la t\u00fanum \u00ed Hrunamanna hrepp fengust ekki utan t\u00edutigi kaplar, me\u00f0 \u00fe\u00f3 l\u00edti\u00f0 band. Svo l\u00edti\u00f0 gras\u00e1r \u00fe\u00f3ttust f\u00e1ir muna.<em> [&#8230;]<\/em> \u00de\u00e1 var datum 1580.<\/p><\/blockquote>\n<p>\u00dear sem halastjarnan 1577 tengist fyrst og fremst nafni Danans <a href=\"https:\/\/en.wikipedia.org\/wiki\/Tycho_Brahe\">Tychos Brahe<\/a> (1546-1601) m\u00e1 til gamans geta \u00feess, a\u00f0 \u00feetta \u00e1r var fyrrum samst\u00fadent hans vi\u00f0 Hafnarh\u00e1sk\u00f3la, Gu\u00f0brandur \u00deorl\u00e1ksson, \u00feegar or\u00f0inn biskup \u00e1 H\u00f3lum.\u00a0 Gu\u00f0brandur hefur eflaust fylgst me\u00f0 stj\u00f6rnunni, \u00fe\u00f3tt engar heimildir s\u00e9u til um \u00fea\u00f0. Einnig er \u00e1st\u00e6\u00f0a til a\u00f0 nefna, a\u00f0 \u00fea\u00f0 er \u00e1 \u00feessum t\u00edma, sem \u00cdslendingar fara fyrir alv\u00f6ru a\u00f0 s\u00e6kja h\u00e1sk\u00f3lan\u00e1m til Kaupmannahafnar \u00fear sem \u00feeir l\u00e6r\u00f0u me\u00f0al annars stj\u00f6rnufr\u00e6\u00f0i og n\u00e1tt\u00faruspeki \u00ed grunnn\u00e1minu.<\/p>\n<ul>\n<li>Einar H. Gu\u00f0mundsson, 1996: <a href=\"http:\/\/timarit.is\/view_page_init.jsp?pageId=3312122\">Tycho Brahe og \u00cdslendingar.<\/a><\/li>\n<li>Einar H. Gu\u00f0mundsson, Eyj\u00f3lfur Kolbeins og \u00deorsteinn Vilhj\u00e1lmsson, 2006: <a href=\"https:\/\/notendur.hi.is\/~einar\/SAGA\/Kopernik.pdf\">Heimsmyndin \u00ed ritum l\u00e6r\u00f0ra \u00cdslendinga \u00e1 sautj\u00e1ndu og \u00e1tj\u00e1ndu \u00f6ld.<\/a><\/li>\n<li>Einar H. Gu\u00f0mundsson, 2010: <a href=\"https:\/\/notendur.hi.is\/~einar\/SAGA\/Heimildir.pdf\">Heimildir \u00cdslendinga um heimsmynd stjarnv\u00edsinda 1550-1750.<\/a><\/li>\n<li>\u00c1rni Hjartarson: <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522183939\/http:\/\/www.isor.is\/~ah\/comet\/hali8.htm\">Halastjarna Tycho Brahes og fleiri k\u00f3metur.<\/a><\/li>\n<\/ul>\n<p>Af \u00feeim fj\u00f6lda l\u00e6rd\u00f3msmanna, sem fylgdust vandlega me\u00f0 halastj\u00f6rnunni 1577, voru \u00feeir <a href=\"https:\/\/en.wikipedia.org\/wiki\/Michael_Maestlin\">M. M\u00e4stlin<\/a> (1550-1630) og Tycho Brahe fremstir \u00ed flokki. \u00deeim t\u00f3kst b\u00e1\u00f0um a\u00f0 s\u00fdna fram \u00e1 \u00fea\u00f0 me\u00f0 a\u00f0sto\u00f0 hli\u00f0runarm\u00e6linga, a\u00f0 stjarnan v\u00e6ri ofan tungls.<\/p>\n<p>M\u00e4stlin, sem s\u00ed\u00f0ar var\u00f0 pr\u00f3fessor vi\u00f0 h\u00e1sk\u00f3lann \u00ed T\u00fcbingen og kennari <a href=\"https:\/\/en.wikipedia.org\/wiki\/Johannes_Kepler\">Keplers<\/a>, var\u00f0 fyrri til a\u00f0 gefa \u00fat kver um ni\u00f0urst\u00f6\u00f0ur s\u00ednar, en m\u00e6lingar Brahes \u00e1 <a href=\"https:\/\/en.wikipedia.org\/wiki\/Uraniborg\">Hve\u00f0n<\/a> voru mun n\u00e1kv\u00e6mari og r\u00f6kstu\u00f0ningur hans fyrir fjarl\u00e6g\u00f0 halastj\u00f6rnunnar hnitmi\u00f0a\u00f0ri. Hann nota\u00f0i jafnframt m\u00e6lingar annarra l\u00e6rd\u00f3msmanna vi\u00f0 \u00fatreikningana, sem var\u00f0 til \u00feess a\u00f0 ni\u00f0urst\u00f6\u00f0ur hans ur\u00f0u mun \u00feekktari.<\/p>\n<p>Auk m\u00e6linga Brahes \u00e1 halastj\u00f6rnunni 1577 ber a\u00f0 hafa \u00ed huga, a\u00f0 fimm \u00e1rum \u00e1\u00f0ur haf\u00f0i hann s\u00fdnt fram \u00e1, a\u00f0 <a href=\"https:\/\/en.wikipedia.org\/wiki\/SN_1572\">n\u00fdstirni<\/a> sem hann uppg\u00f6tva\u00f0i og fylgdist n\u00e1i\u00f0 me\u00f0, var mun lengra \u00ed burtu en tungli\u00f0 og sennilega sta\u00f0sett me\u00f0al fastastjarnanna. \u00deessar m\u00e6lingar eru \u00e1st\u00e6\u00f0an fyrir \u00fev\u00ed, a\u00f0 \u00feegar afrek Brahes eru til umr\u00e6\u00f0u \u00ed kennslub\u00f3kum, f\u00e6r hanna r\u00e9ttilega hei\u00f0urinn af \u00fev\u00ed a\u00f0 hafa splundra\u00f0 kristalshvelum Arist\u00f3telesar.<\/p>\n<figure id=\"attachment_5517\" aria-describedby=\"caption-attachment-5517\" style=\"width: 612px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-5517\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/07\/Brahe2_1577-300x155.png\" alt=\"\" width=\"612\" height=\"316\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Brahe2_1577-300x155.png 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Brahe2_1577.png 618w\" sizes=\"auto, (max-width: 612px) 100vw, 612px\" \/><figcaption id=\"caption-attachment-5517\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Til vinstri eru teikningar \u00far vinnub\u00f3k Brahes af halastj\u00f6rnunni 1577 \u00e1 hvelfingunni. \u00dearna er h\u00fan \u00ed stj\u00f6rnumerkinu <a href=\"https:\/\/www.stjornufraedi.is\/stjornuskodun\/stjornumerkin\/bogmadurinn\/\">Bogmanninum<\/a>. Myndin til h\u00e6gri er \u00far b\u00f3k Brahes fr\u00e1 1588. Eina lei\u00f0in, sem hann s\u00e1 til \u00feess a\u00f0 koma halastj\u00f6rnunni fyrir \u00ed <a href=\"https:\/\/en.wikipedia.org\/wiki\/Tychonic_system\">s\u00ednu eigin jar\u00f0mi\u00f0jukerfi<\/a>, var a\u00f0 gera r\u00e1\u00f0 fyrir a\u00f0 braut hennar v\u00e6ri hringbogi me\u00f0 mi\u00f0ju \u00ed s\u00f3linni, ofan tungls og fyrir utan braut Venusar. M\u00e4stlin, sem a\u00f0hylltist <a href=\"https:\/\/en.wikipedia.org\/wiki\/Copernican_heliocentrism\">s\u00f3lmi\u00f0jukenningu K\u00f3pern\u00edkusar<\/a>, ger\u00f0i hins vegar r\u00e1\u00f0 fyrir \u00e1 halastjarnan v\u00e6ri \u00e1 braut um s\u00f3lina milli brauta jar\u00f0ar og Venusar og lengra fr\u00e1 j\u00f6r\u00f0inni en tungli\u00f0.<br \/><\/span><\/figcaption><\/figure>\n<p>Brahe var me\u00f0 s\u00ednar eigin hugmyndir um e\u00f0li halastjarna. Hann taldi \u00fe\u00e6r vera \u00far himnesku efni, en \u00f3l\u00edku\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Aether_(classical_element)\">eisunni<\/a> a\u00f0 \u00fev\u00ed leyti, a\u00f0 \u00fea\u00f0 v\u00e6ri ekki fullkomlega hreint og a\u00f0eins gagns\u00e6tt a\u00f0 hluta. H\u00f6fu\u00f0 stjarnanna v\u00e6ru \u00fev\u00ed gropin, sem ger\u00f0i \u00fea\u00f0 aftur a\u00f0 verkum a\u00f0 s\u00f3largeislarnir loku\u00f0ust inni og ger\u00f0u h\u00f6fu\u00f0in gl\u00f3andi. Hluti lj\u00f3ssins l\u00e6ki \u00fe\u00f3 \u00fat og mynda\u00f0i halana.<\/p>\n<ul>\n<li>J. R. Christianson, 1979: <a href=\"https:\/\/www.jstor.org\/stable\/230882?seq=1#page_scan_tab_contents\">Tycho Brahe&#8217;s German Treatise on the Comet of 1577: A Study in Science and Politics.<\/a> \u00cdtarlegur inngangur \u00e1samt enskri \u00fe\u00fd\u00f0ingu \u00e1 yfirliti Brahes fr\u00e1 1578, sem sennilega var \u00e6tla\u00f0 Fri\u00f0riki \u00f6\u00f0rum Danakonungi.<\/li>\n<li>T. Brahe, 1588: <a href=\"https:\/\/archive.org\/stream\/bub_gb_2f-EqKxRN34C#page\/n0\/mode\/2up\">De Mundi Aetherei Recentioribus Phaenomenis<\/a>. B\u00f3k Brahes um halastj\u00f6rnuna 1577 (\u00fatg\u00e1fa fr\u00e1 1610).<\/li>\n<li>M. M\u00e4stlin, 1578: <a href=\"https:\/\/books.google.is\/books?id=Z0xbAAAAcAAJ&amp;source=gbs_navlinks_s\">Observatio &amp; demonstratio cometae aetherei \u2026 anno 1577 et 1578.<\/a><\/li>\n<li><a href=\"https:\/\/de.wikipedia.org\/wiki\/Clarisse_Doris_Hellman\">C. Doris Hellman<\/a>, 1944: <a href=\"https:\/\/archive.org\/details\/TheCometOf1577\">The Comet of 1577.<\/a><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">Sautj\u00e1nda \u00f6ld<\/span><\/h3>\n<p><strong>\u25ca Halastjarnan 1607:<\/strong><\/p>\n<p>\u00dearna var <a href=\"https:\/\/en.wikipedia.org\/wiki\/Halley%27s_Comet\">halastjarna Halleys<\/a> enn \u00e1 fer\u00f0inni. \u00cd \u00feessari heims\u00f3kn s\u00e1st h\u00fan stuttlega \u00e1 \u00cdslandi eins og <span lang=\"IS\">G\u00edsli Oddsson getur um \u00ed <em>\u00cdslenskum ann\u00e1labrotum<\/em>: <\/span><\/p>\n<blockquote><p><span lang=\"IS\">15. og 16. desember, s\u00e1st \u00ed Sk\u00e1lholti \u00ed hei\u00f0sk\u00edru ve\u00f0ri halastjarna af annarri e\u00f0a \u00feri\u00f0ju st\u00e6r\u00f0 \u00e1 milli Drekans og St\u00f3rabjarnar; h\u00fan var ekki sk\u00e6rari en a\u00f0rar stj\u00f6rnur, en st\u00e6rri og fr\u00e1 henni st\u00f6fu\u00f0u geislar e\u00f0a stafur til su\u00f0ur\u00e1ttar. Rigningar sem gengu fyrir og eftir, skygg\u00f0u fyrir, svo a\u00f0 eigi var h\u00e6gt a\u00f0 sj\u00e1 hana. <\/span><\/p><\/blockquote>\n<p>\u00cd \u00fatl\u00f6ndum fylgdust margir me\u00f0 stj\u00f6rnunni, \u00fear \u00e1 me\u00f0al \u00feeir <a href=\"https:\/\/en.wikipedia.org\/wiki\/Johannes_Kepler\">Kepler<\/a> (1571-1630) og <a href=\"https:\/\/en.wikipedia.org\/wiki\/Christen_S%C3%B8rensen_Longomontanus\">Longomontanus<\/a> (1562-1647). S\u00e1 s\u00ed\u00f0arnefndi var fyrrverandi nemandi Brahes og Kepler haf\u00f0i a\u00f0sto\u00f0a\u00f0 hinn mikla stj\u00f6rnumeistara \u00e1 starfs\u00e1rum hans \u00ed Prag. B\u00e1\u00f0ir framkv\u00e6mdu einnig m\u00e6lingar \u00e1 halastj\u00f6rnunni miklu \u00e1ri\u00f0 1618, sem fjalla\u00f0 ver\u00f0ur um h\u00e9r \u00e1 eftir.<\/p>\n<figure id=\"attachment_7494\" aria-describedby=\"caption-attachment-7494\" style=\"width: 623px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-7494\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/08\/Kepler1607_2-300x130.png\" alt=\"\" width=\"623\" height=\"270\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Kepler1607_2-300x130.png 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Kepler1607_2.png 626w\" sizes=\"auto, (max-width: 623px) 100vw, 623px\" \/><figcaption id=\"caption-attachment-7494\" class=\"wp-caption-text\">Eina myndin \u00ed grein Keplers um halastj\u00f6rnuna 1607 s\u00fdnir sl\u00f3\u00f0 stj\u00f6rnunnar \u00e1 himinhvelinu.<\/figcaption><\/figure>\n<p>Tveimur \u00e1rum eftir a\u00f0 halastjarnan 1607 s\u00e1st \u00e1 stj\u00f6rnuhimninum, birti Kepler fyrstu tv\u00f6\u00a0 <a href=\"https:\/\/en.wikipedia.org\/wiki\/Kepler%27s_laws_of_planetary_motion\">l\u00f6gm\u00e1l s\u00edn um hreyfingar reikistjarna \u00ed s\u00f3lkerfinu<\/a>. \u00deri\u00f0ja l\u00f6gm\u00e1li\u00f0 birti hann svo 1619. \u00dea\u00f0 merkilega er, a\u00f0 \u00fea\u00f0 hvarla\u00f0i ekki a\u00f0 honum a\u00f0 beita \u00feessum l\u00f6gm\u00e1lum \u00e1 halastj\u00f6rnur. Hann vissi, a\u00f0 \u00fe\u00e6r voru lengra fr\u00e1 j\u00f6r\u00f0u en tungli\u00f0, en a\u00f0 \u00f6\u00f0ru leyti voru hugmyndir hans um halastj\u00f6rnur frekar forneskjulegar.<\/p>\n<p>Kepler taldi a\u00f0 halastj\u00f6rnur v\u00e6ru hverful fyrirb\u00e6ri og \u00fev\u00ed hlytu \u00fe\u00e6r a\u00f0 fer\u00f0ast eftir beinum l\u00ednum, \u00ed samr\u00e6mi vi\u00f0 hugmyndir Arist\u00f3telesar um hreyfingu hluta. \u00de\u00e6r v\u00e6ru sj\u00e1lfsprottnar \u00far \u201efitub\u00f3lum\u201c \u00ed eisunni (\u00e1 svipa\u00f0an h\u00e1tt og hvalir og s\u00e6skr\u00fdmsli myndu\u00f0st \u00far engu \u00ed hafinu). Samhli\u00f0a yr\u00f0u til einskonar lei\u00f0s\u00f6guandar, sem st\u00fdr\u00f0u stj\u00f6rnunum eftir beinum brautum \u00feeirra. Hluti lj\u00f3sgeislanna fr\u00e1 s\u00f3linni f\u00e6ri \u00ed gegnum h\u00f6fu\u00f0 hverrar halastj\u00f6rnu, dr\u00e6gi me\u00f0 s\u00e9r efni \u00feess og mynda\u00f0i \u00feannig halann, sem s\u00e6ist vegna endurkasts s\u00f3larlj\u00f3ss. \u00deegar h\u00f6fu\u00f0efni\u00f0 v\u00e6ri upp uri\u00f0, hyrfi stjarnan.<\/p>\n<ul>\n<li>J. Kepler, 1608: <em>Ausf\u00fchrlicher Bericht von dem Newlich im Monat Septembri vnd Octobri diss 1607. Jahrs erschienenen Haarstern oder Cometen vnd seinen Bedeutungen.<\/em> Bls. 23-41 \u00ed 7. bindi af\u00a0 <a href=\"https:\/\/archive.org\/details\/joanniskeplerias07kepl\">Joannis Kepleri astronomi opera omnia<\/a>.<\/li>\n<li>J. Kepler, 1619: <a href=\"https:\/\/archive.org\/details\/den-kbd-pil-130011021221-001\">De cometis libelli tres.<\/a> Um stj\u00f6rnurnar 1607 og 1618 og kenningu Keplers um halastj\u00f6rnur.<\/li>\n<li>Longomontanus, 1622: <a href=\"https:\/\/books.google.is\/books?id=f1I_AAAAcAAJ&amp;source=gbs_navlinks_s\">Astronomica Danica.<\/a> Fjalla\u00f0 er um halastj\u00f6rnurnar 1607 og 1618 \u00ed vi\u00f0auka.<\/li>\n<\/ul>\n<hr \/>\n<p><strong>\u25ca <a href=\"https:\/\/de.wikipedia.org\/wiki\/C\/1618_W1\">Halastjarnan mikla \u00e1ri\u00f0 1618:<\/a><\/strong><\/p>\n<p>\u00deetta \u00e1r s\u00e1ust \u00ferj\u00e1r halastj\u00f6rnur, en s\u00fa sem mesta athygli vakti var n\u00famer tv\u00f6 \u00ed r\u00f6\u00f0inni. J\u00f3n Ind\u00edafari mun hafa s\u00e9\u00f0 hana fr\u00e1 Kr\u00f3nborgarkastala \u00ed Danm\u00f6rku. \u00cd reisub\u00f3k sinni fr\u00e1 1661 l\u00fdsir hann me\u00f0al annars \u00fdmsum atbur\u00f0um, sem \u00e1 daga hans drifu \u00e1ri\u00f0 1618. \u00dear segir undir lokin:\u00a0 \u201e<em>\u00deetta ske\u00f0i \u00e1 \u00fev\u00ed \u00e1ri er v\u00f6ndur s\u00e1st \u00e1 lofti (e\u00f0a s\u00fa halastjarna)<\/em>.\u201c<\/p>\n<p><em>Skar\u00f0s\u00e1rann\u00e1ll<\/em> hefur \u00feetta a\u00f0 segja um stj\u00f6rnuna:<\/p>\n<blockquote><p>S\u00e1st ein cometa fyrir nor\u00f0an land um veturinn fyrir j\u00f3laf\u00f6stuinngang, n\u00e6r \u00ed m\u00e1nu\u00f0; h\u00fan haf\u00f0i ei svo e\u00f0lilegan gang sem a\u00f0rar stj\u00f6rnur. Undan henni gekk fyrst, \u00fe\u00e1 h\u00fan s\u00e1st, svo sem einn langur stafur, en \u00fe\u00e1 s\u00ed\u00f0ar, m\u00f3ti \u00fev\u00ed h\u00fan hvarf, kv\u00edsla\u00f0ist s\u00fa r\u00e1k og var a\u00f0 sj\u00e1 sem v\u00f6ndur. S\u00e1st ormurinn \u00ed Lagarflj\u00f3ti.<\/p><\/blockquote>\n<p>\u00cd hinni v\u00f6ndu\u00f0u hugvekju <a href=\"http:\/\/baekur.is\/bok\/000160591\/2\/57\/Kvoldvokurnar_Bindi_2_Bls_57\">um halastj\u00f6rnur<\/a> fr\u00e1 1797 segir Hannes Finnsson (bls. 53):<\/p>\n<blockquote><p>Hali stj\u00f6rnunnar, sem s\u00e1st 1618, og um hverja h\u00e9r \u00ed \u00cdslandi voru ortir nokkrir s\u00e1lmar, skein yfir meir en helming himinsins.<\/p><\/blockquote>\n<p>Me\u00f0al \u00edslenskra kv\u00e6\u00f0a, sem minnast \u00e1 \u00feessa stj\u00f6rnu, er <a href=\"http:\/\/baekur.is\/is\/bok\/000399674\/0\/564\/Tyrkjaranid_a_Islandi\">Harmavottur<\/a> J\u00f3ns J\u00f3nssonar prests, sem sennilega er ort 1628. \u00dear telur h\u00f6fundur me\u00f0al annars upp fyrirbo\u00f0a Tyrkjar\u00e1nsins \u00e1ri\u00f0 1627. \u00cd 40. erindi er fjalla\u00f0 um halastj\u00f6rnuna 1618:<\/p>\n<blockquote>\n<p style=\"padding-left: 150px\">\u00c1 lopti, himni, l\u00e1\u00f0i og sj\u00e1<br \/>\nlj\u00f3sleg teiknin hlj\u00f3ma.<br \/>\nhalastjarnan hermir fr\u00e1,<br \/>\na\u00f0 hirting fylgi eptir \u00e1;<br \/>\nskot \u00ed lopti sk\u00fdra hi\u00f0 sama og r\u00f3ma.<\/p>\n<\/blockquote>\n<p>\u00dearna mun or\u00f0i\u00f0 <em>halastjarna<\/em> koma fyrir \u00ed ritu\u00f0u m\u00e1li \u00ed fyrsta sinn.<\/p>\n<p>\u00cd kv\u00e6\u00f0i \u00d3lafs Einarssonar, <em>\u00c1rgalanum<\/em>, fr\u00e1 1757 er einnig minnst \u00e1 \u00feessa halastj\u00f6rnu \u00ed 13. erindi:<\/p>\n<blockquote>\n<p style=\"padding-left: 150px\">S\u00edna birtu s\u00f3lin kl\u00e1ra<br \/>\nsvo og tungli\u00f0 missa n\u00fa,<br \/>\nlofti\u00f0 sendir l\u00e6ki t\u00e1ra,<br \/>\nl\u00fdsir hr\u00edsi stjarna s\u00fa,<br \/>\ney\u00f0ing landi s\u00fdnir s\u00e1ra,<br \/>\ns\u00e9st hj\u00e1 flestum engin tr\u00fa.<\/p>\n<\/blockquote>\n<figure id=\"attachment_7503\" aria-describedby=\"caption-attachment-7503\" style=\"width: 614px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-7503\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/08\/C1618Augsburg-300x228.jpg\" alt=\"\" width=\"614\" height=\"467\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/C1618Augsburg-300x228.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/C1618Augsburg-768x584.jpg 768w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/C1618Augsburg.jpg 1020w\" sizes=\"auto, (max-width: 614px) 100vw, 614px\" \/><figcaption id=\"caption-attachment-7503\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Halastjarnan yfir Augsburg \u00ed n\u00f3vember 1618.<br \/><\/span><\/figcaption><\/figure>\n<p>\u00cd hinu mikla kv\u00e6\u00f0i\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Paradise_Lost\">Paradise Lost<\/a> eftir <a href=\"https:\/\/en.wikipedia.org\/wiki\/John_Milton\">John Milton<\/a> fr\u00e1 1667(?) eru margar tilv\u00edsanir \u00ed stj\u00f6rnufr\u00e6\u00f0i samt\u00edmans. \u00dear \u00e1 me\u00f0al er erindi, \u00fear sem myrkvah\u00f6f\u00f0ingjanum er l\u00edkt vi\u00f0 halastj\u00f6rnu, \u00feegar hann hittir Dau\u00f0ann vi\u00f0 hli\u00f0 helv\u00edtis. F\u00e6ra m\u00e1 sterk r\u00f6k fyrir \u00fev\u00ed, a\u00f0 \u00fearna s\u00e9 Milton a\u00f0 v\u00edsa til halastj\u00f6rnunnar 1618 (sumir segja halastj\u00f6rnunnar 1664, en \u00fea\u00f0 er \u00f3l\u00edklegra, \u00fear sem Milton var \u00fe\u00e1 or\u00f0inn blindur). Erindi\u00f0 er svona (B\u00f3k 2, l\u00ednur 706-711):<\/p>\n<blockquote>\n<p style=\"padding-left: 150px\">On th&#8217; other side,<br \/>\nIncensed with indignation, Satan stood<br \/>\nUnterrified, and like a comet burned,<br \/>\nThat fires the length of Ophiucus huge<br \/>\nIn th&#8217; arctic sky, and from his horrid hair<br \/>\nShakes pestilence and war.<\/p>\n<\/blockquote>\n<p>\u00cd <a href=\"http:\/\/timarit.is\/view_page_init.jsp?pageId=968280\">\u00fe\u00fd\u00f0ingu J\u00f3ns \u00deorl\u00e1kssonar<\/a>, sem birtist 1796, er erindi\u00f0 svona (bls. 294h-295v;\u00a0 sj\u00e1 einnig <a href=\"http:\/\/baekur.is\/bok\/000272009\/Paradisarmissir\">h\u00e9r<\/a>, bls. 45v):<\/p>\n<blockquote>\n<p style=\"padding-left: 150px\">St\u00f3\u00f0 samt Satan \u00e1<br \/>\ns\u00ednu m\u00e1li<br \/>\nhonum andsp\u00e6nis<br \/>\nhv\u00f6rgi smeikr.<br \/>\nLikr var hann logandi<br \/>\n\u00e1 lopti nor\u00f0rs,<br \/>\naf heipt heitt kyndtr,<br \/>\nhalastj\u00f6rnu,<br \/>\nsem b\u00e1last brei\u00f0um<br \/>\nbrautum eptir<br \/>\nOph\u00edocci*<br \/>\nat endilaungu,<br \/>\nok f\u00e1rsfullu \u00far<br \/>\nfaxi hristir<br \/>\n\u00f3kj\u00f6r, orrostur<br \/>\nok illa pest.<\/p>\n<\/blockquote>\n<p style=\"padding-left: 60px\">(* <em>Oph\u00edoccus, ein himinmynd fyri nor\u00f0an \u00feau 12 merki, hefir eigi, \u00feat ek veit, \u00edslenzkt heiti<\/em>.)<\/p>\n<p>Eins og fyrr sag\u00f0i fylgdust margir st\u00e6r\u00f0fr\u00e6\u00f0ilegir l\u00e6rd\u00f3msmenn me\u00f0 \u00feessari stj\u00f6rnu, \u00fear \u00e1 me\u00f0al b\u00e6\u00f0i Longomontanus og Kepler. \u00deetta mun jafnframt hafa veri\u00f0 fyrsta halastjarnan, sem sko\u00f0u\u00f0 var vandlega \u00ed sj\u00f3nauka.<\/p>\n<ul>\n<li>J. Kepler, 1619: <a href=\"https:\/\/archive.org\/details\/den-kbd-pil-130011021221-001\">De cometis libelli tres.<\/a>\u00a0 Um stj\u00f6rnurnar 1607 og 1618 og kenningu Keplers um halastj\u00f6rnur.<\/li>\n<li>Longomontanus, 1622: <a href=\"https:\/\/books.google.is\/books?id=f1I_AAAAcAAJ&amp;source=gbs_navlinks_s\">Astronomica Danica.<\/a> \u00a0Fjalla\u00f0 er um halastj\u00f6rnurnar 1607 og 1618 \u00ed vi\u00f0auka.<\/li>\n<li>T. H. Orchard, 1896: <a href=\"https:\/\/archive.org\/stream\/astronomyofmilto00orchuoft#page\/n9\">The Astronomy of Milton\u2019s Paradise Lost.<\/a><\/li>\n<li>\u00c1rni Hjartarson: <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522183902\/http:\/\/www.isor.is\/~ah\/comet\/hali10.htm\">Forbo\u00f0i Tyrkjar\u00e1ns.<\/a><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">\u00d3vissa um e\u00f0li og brautir halastjarna<\/span><\/h3>\n<p>N\u00fa \u00feegar hefur veri\u00f0 sagt fr\u00e1 hinum fj\u00f6lbreyttu og \u00f3l\u00edku kenningum spekinga eins og Arist\u00f3telesar, Apians, Brahes og Keplers um halastj\u00f6rnur. S\u00fa saga s\u00fdnir vel, hversu erfitt menn \u00e1ttu me\u00f0 a\u00f0 koma b\u00f6ndum \u00e1 \u00feetta fl\u00f3kna vi\u00f0fangsefni. \u00c1st\u00e6\u00f0an var a\u00f0 sj\u00e1lfs\u00f6g\u00f0u s\u00fa, a\u00f0 e\u00f0lisfr\u00e6\u00f0in, sem nau\u00f0synleg var til frekari skilnings, var ekki enn komin til s\u00f6gunnar.<\/p>\n<p>\u00deetta s\u00e9st jafnvel enn betur, \u00feegar liti\u00f0 er \u00e1 framlag eins af frumkv\u00f6\u00f0lum aflfr\u00e6\u00f0innar, <a href=\"https:\/\/en.wikipedia.org\/wiki\/Galileo_Galilei\">Gal\u00edle\u00f3s<\/a> (1564-1642), til halastj\u00f6rnufr\u00e6\u00f0a. Eins og \u00feekkt er, \u00e1tti \u00feessi mikli v\u00edsindama\u00f0ur \u00ed st\u00f6\u00f0ugum deilum vi\u00f0 jes\u00fa\u00edta og \u00feegar einn \u00feeirra <a href=\"https:\/\/en.wikipedia.org\/wiki\/Orazio_Grassi\">O. Grassi<\/a> (1583-1654) gaf \u00fat rit um halastj\u00f6rnuna 1618, \u00fear sem byggt var \u00e1 hugmyndum Brahes, br\u00e1st Gal\u00edle\u00f3 vi\u00f0 me\u00f0 \u00e1deiluriti. \u00dea\u00f0 var gefi\u00f0 \u00fat \u00e1ri\u00f0 1619 undir nafni nemanda hans, <a href=\"https:\/\/de.wikipedia.org\/wiki\/Mario_Guiducci\">M. Guiducci<\/a> (1585-1646), en allir vissu a\u00f0 innihaldi\u00f0 kom fr\u00e1 meistaranum.<\/p>\n<p>Riti\u00f0 fjallar me\u00f0al annars um n\u00fdja kenningu Gal\u00edle\u00f3s um halastj\u00f6rnur, en h\u00fan var s\u00fa, a\u00f0 halastj\u00f6rnur v\u00e6ru hra\u00f0fleyg gufusk\u00fd sem fer\u00f0u\u00f0ust eftir beinum l\u00ednum \u00ed andr\u00famslofti jar\u00f0ar og skin \u00feeirra v\u00e6ri endurkasta\u00f0 s\u00f3larlj\u00f3s. S\u00f6mu kenningu er a\u00f0 finna \u00ed ritinu <em>Il saggiatore<\/em> fr\u00e1 1623. \u00deannig var Gal\u00edle\u00f3 lengi hallur undir hugmyndir Arist\u00f3telesar um halastj\u00f6rnur, \u00fe\u00f3tt margir samt\u00edmamenn hans v\u00e6ru komnir \u00e1 \u00fe\u00e1 sko\u00f0un, a\u00f0 halastj\u00f6rnur v\u00e6ru handan tungls.<\/p>\n<ul>\n<li>O. Grassi, 1619: <a href=\"https:\/\/bibdig.museogalileo.it\/Teca\/Viewer;jsessionid=207B25D9E2FCEAA55D071FA34881DDFA?an=367735&amp;vis=D#page\/1\/mode\/2up\">De tribus cometis anni MDCXVIII disputatio astronomica.<\/a><\/li>\n<li>M. Guiducci, 1619: <a href=\"https:\/\/books.google.is\/books?id=_EtbAAAAcAAJ&amp;source=gbs_navlinks_s\">Discosro delle comete.<\/a> \u00a0 &#8211; \u00a0 Wikipedia: <a href=\"https:\/\/en.wikipedia.org\/wiki\/Discourse_on_Comets\">Discourse on Comets.<\/a><\/li>\n<li>G. Galileo, 1623: <a href=\"https:\/\/books.google.is\/books?id=6TUHnpEQ19EC&amp;dq=inauthor:%22Galileo,%22&amp;source=gbs_navlinks_s\">Il saggiatore.<\/a>\u00a0 &#8211;\u00a0 Wikipedia: <a href=\"https:\/\/en.wikipedia.org\/wiki\/The_Assayer\">The Assayer.<\/a><\/li>\n<\/ul>\n<p>Margir a\u00f0rir af fremstu st\u00e6r\u00f0fr\u00e6\u00f0ilegu l\u00e6rd\u00f3msm\u00f6nnum sautj\u00e1ndu aldar settu einnig fram s\u00ednar eigin kenningar um halastj\u00f6rnur. \u00dear m\u00e1 til d\u00e6mis nefna <a href=\"https:\/\/en.wikipedia.org\/wiki\/Pierre_Gassendi\">P. Gassendi<\/a>, <a href=\"https:\/\/en.wikipedia.org\/wiki\/Willebrord_Snellius\">W. Snel<\/a>, <a href=\"https:\/\/en.wikipedia.org\/wiki\/Giovanni_Alfonso_Borelli\">G. Borelli<\/a>,\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Giovanni_Domenico_Cassini\">G. D. Cassini<\/a>, <a href=\"https:\/\/en.wikipedia.org\/wiki\/Christiaan_Huygens\">C. Huygens<\/a> og <a href=\"https:\/\/en.wikipedia.org\/wiki\/Robert_Hooke\">R. Hooke<\/a>. Ekki er \u00e1st\u00e6\u00f0a til a\u00f0 fjalla um \u00feessar hugmyndir h\u00e9r, en \u00fe\u00f3 m\u00e1 minna \u00e1, a\u00f0 hva\u00f0 brautir var\u00f0ar skiptust menn a\u00f0allega \u00ed tvo h\u00f3pa. Annars vegar voru \u00feeir (t.d. Cassini og Borelli), sem t\u00f6ldu halastj\u00f6rnur eil\u00edfar og \u00fev\u00ed v\u00e6ru brautir \u00feeirra hringir. Hinir (t.d. Huygens) voru vissir um, a\u00f0 brautirnar v\u00e6ru beinar l\u00ednur, \u00fev\u00ed a\u00f0 halastj\u00f6rnurnar v\u00e6ru skamml\u00edf fyrirb\u00e6ri. \u00dearna m\u00e1 greinilega sj\u00e1 hin sterku \u00e1hrif Arist\u00f3telesar \u00e1 hugsunarh\u00e1tt manna \u00e1 sautj\u00e1ndu \u00f6ld.<\/p>\n<p>\u00de\u00f3tt h\u00fan hafi aldrei noti\u00f0 mikillar hylli, er r\u00e9tt a\u00f0 nefna h\u00e9r kenningu <a href=\"https:\/\/en.wikipedia.org\/wiki\/Ren%C3%A9_Descartes\">Descartes<\/a> (1596-1650) um halastj\u00f6rnur. Samkv\u00e6mt henni voru halastj\u00f6rnur dau\u00f0ar s\u00f3lir, sem megnu\u00f0u ekki a\u00f0 vi\u00f0halda s\u00ednum eigin hvirfli og hr\u00f6ktust \u00fev\u00ed eftir \u00fatj\u00f6\u00f0rum hvirfla annarra og enn virkra s\u00f3lna. H\u00f6fu\u00f0 stjarnanna endurk\u00f6stu\u00f0u s\u00f3larlj\u00f3sinu beint, en halarnir voru sj\u00f3nvilla. \u00dear var um a\u00f0 kenna s\u00e9rst\u00f6ku lj\u00f3sbroti \u00ed agnadreifingu \u00feyrlanna, \u00feannig a\u00f0 athugendum s\u00fdndust \u00feessar dau\u00f0u stj\u00f6rnur hafa hala.<\/p>\n<figure id=\"attachment_5844\" aria-describedby=\"caption-attachment-5844\" style=\"width: 578px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-5844\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/07\/GalileoDescartes-300x166.png\" alt=\"\" width=\"578\" height=\"320\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/GalileoDescartes-300x166.png 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/GalileoDescartes.png 585w\" sizes=\"auto, (max-width: 578px) 100vw, 578px\" \/><figcaption id=\"caption-attachment-5844\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Teikningin til vinstri \u00e1 a\u00f0 s\u00fdna braut halastj\u00f6rnu \u00ed andr\u00famslofti jar\u00f0arinnar skv. kenningu Gal\u00edle\u00f3s. D er jar\u00f0armi\u00f0ja, EF er braut halastj\u00f6rnunnar og A er athugunarsta\u00f0ur. AG er sj\u00f3ndeildarplani\u00f0 og a\u00f0 n\u00e6turlagi er s\u00f3lin ne\u00f0an \u00feess, undir G. \u00dar grein Guiduccis (og Gal\u00edle\u00f3s) fr\u00e1 1619.\u00a0 &#8211;\u00a0 Til h\u00e6gri er mynd af fer\u00f0alagi halastj\u00f6rnu (dau\u00f0ri stj\u00f6rnu) fr\u00e1 einum hvirfli til annars skv. kenningu Descartes. S er s\u00f3lin okkar og D, L, F, f, Y a\u00f0rar s\u00f3lir, hver \u00ed s\u00ednum hvirfli.\u00a0 Halastjarnan hefur f\u00f6r \u00ed N og hreyfist eftir bug\u00f0\u00f3ttri braut sem merkt er me\u00f0 t\u00f6lust\u00f6funum 2, 3, 4, 5 og 6. \u00dar <em>Princip\u00edum <\/em>Descartes fr\u00e11644, bls. 106.<\/span><\/figcaption><\/figure>\n<p>Eins og margir a\u00f0rir, var hinn \u00feekkti stj\u00f6rnufr\u00e6\u00f0ingur <a href=\"https:\/\/en.wikipedia.org\/wiki\/Johannes_Hevelius\">J. Hevel\u00edus<\/a> (1611-1687) me\u00f0 s\u00edna eigin kenningu um halastj\u00f6rnur. Samkv\u00e6mt henni myndu\u00f0st h\u00f6fu\u00f0 \u00feeirra vi\u00f0 \u00fatgufun \u00fargangsefna fr\u00e1 ystu reikistj\u00f6rnunum, J\u00fap\u00edter og Sat\u00farnusi. \u00de\u00e6r v\u00e6ru skamml\u00edfar og \u00fev\u00ed \u00e6ttu brautirnar a\u00f0 vera beinar, e\u00f0a svo haf\u00f0i Arist\u00f3teles sagt. Hevelius t\u00f3k \u00fe\u00f3 eftir \u00fev\u00ed, a\u00f0 \u00feetta var ekki \u00ed samr\u00e6mi vi\u00f0 athuganir hans sj\u00e1lfs, svo hann neyddist til a\u00f0 gera r\u00e1\u00f0 fyrir a\u00f0 brautirnar sveig\u00f0ust \u00f6rl\u00edti\u00f0 um s\u00f3lina. \u00c1st\u00e6\u00f0una taldi hann vera einskonar vi\u00f0n\u00e1m \u00ed eisunni.<\/p>\n<figure id=\"attachment_5481\" aria-describedby=\"caption-attachment-5481\" style=\"width: 415px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-5481\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/07\/Cometographia_3-181x300.jpg\" alt=\"\" width=\"415\" height=\"688\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Cometographia_3-181x300.jpg 181w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Cometographia_3.jpg 422w\" sizes=\"auto, (max-width: 415px) 100vw, 415px\" \/><figcaption id=\"caption-attachment-5481\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">\u00dearna m\u00e1 sj\u00e1 \u00ferj\u00e1 merka spekinga r\u00e6\u00f0a saman um halastj\u00f6rnur og brautir \u00feeirra. Til vinstri er Arist\u00f3teles me\u00f0 kort af lofthj\u00fapskenningu sinni. Hevel\u00edus er \u00ed mi\u00f0junni a\u00f0 \u00fatsk\u00fdra s\u00edna kenningu og til h\u00e6gri er Kepler me\u00f0 s\u00ednar beinu brautir. Yfir h\u00f6f\u00f0um \u00feeirra sv\u00edfur halastjarna, sem \u00e1hugasamir athugendur fylgjast vel me\u00f0 af sv\u00f6lunum til h\u00e6gri. Teikningin er \u00far <em>Cometographia<\/em> Hevel\u00edusar fr\u00e1 1668.<\/span><\/figcaption><\/figure>\n<ul>\n<li>R. Descartes, 1644: <a href=\"https:\/\/books.google.is\/books?id=nHBTAAAAcAAJ&amp;source=gbs_navlinks_s\">Principia philosophiae.<\/a><\/li>\n<li>J. Hevelius, 1668: <a href=\"https:\/\/books.google.is\/books?id=8UpZAAAAcAAJ&amp;source=gbs_navlinks_s\">Cometographia.<\/a><\/li>\n<li>J. A. Ruffner 1971: <a href=\"http:\/\/adsbit.harvard.edu\/\/full\/1971JHA.....2..178R\/0000178.000.html\">The Curved and the Straight: Cometary theory from Kepler to Hevelius.<\/a><\/li>\n<\/ul>\n<hr \/>\n<p><strong>\u25ca <a href=\"https:\/\/en.wikipedia.org\/wiki\/C\/1652_Y1\">Halastjarnan 1652:<\/a><\/strong><\/p>\n<p><a href=\"http:\/\/timarit.is\/view_page_init.jsp?gegnirId=000514418\">G\u00edsli Einarsson<\/a> sk\u00f3lameistari \u00ed Sk\u00e1lholti m\u00e6ldi st\u00f6\u00f0u \u00feessarar halastj\u00f6rnu \u00e1 hvelfingunni og \u00e1\u00e6tla\u00f0i hli\u00f0run hennar. Mun \u00fea\u00f0 vera \u00ed fyrsta sinn, sem sl\u00edkar m\u00e6lingar voru framkv\u00e6mdar h\u00e9r \u00e1 landi og markar \u00fea\u00f0 G\u00edsla og stj\u00f6rnunni s\u00e9rstakan sess \u00ed \u00edslenskri v\u00edsindas\u00f6gu.<\/p>\n<p>Ekki er vita\u00f0 hva\u00f0a t\u00e6kjum G\u00edsli beitti vi\u00f0 m\u00e6lingarnar, \u00fe\u00f3tt hugsanlegt s\u00e9, a\u00f0 \u00fear hafi hann notast vi\u00f0 gamlan kva\u00f0rant, sem G\u00edsli Oddson biskup (1593-1638) haf\u00f0i \u00e1 s\u00ednum t\u00edma fengi\u00f0 hj\u00e1 Longomontanusi, en ekki geta\u00f0 nota\u00f0 \u201evegna f\u00e1kunn\u00e1ttu\u201c.<\/p>\n<p>G\u00edsli ger\u00f0i grein fyrir athugunum s\u00ednum \u00ed br\u00e9fi til <a href=\"https:\/\/is.wikipedia.org\/wiki\/Henrik_Bjelke\">H. Bjelke<\/a>s (1615-83) \u00e1ri\u00f0 1653. Br\u00e9fi\u00f0 mun n\u00fa t\u00fdnt og tr\u00f6llum gefi\u00f0, en innihaldinu er l\u00fdst \u00ed \u00cdslandsl\u00fdsingu <a href=\"https:\/\/da.wikipedia.org\/wiki\/Peder_Hansen_Resen\">P. H. Resens<\/a> (1625-88), sem kom \u00ed \u00fe\u00fd\u00f0ingu Jakobs Benediktssonar \u00e1ri\u00f0 1991 (bls. 286-87):<\/p>\n<blockquote><p>10. desember \u00e1ri\u00f0 1652 s\u00e1st <em>[halastjarnan]<\/em> \u00e1 sunnanver\u00f0u \u00cdslandi \u00ed nautsmerki; 12. sama m\u00e1na\u00f0ar s\u00e1st h\u00fan \u00ed Sk\u00e1lholti undir auga Nautsins hj\u00e1 stj\u00f6rnu \u00ed vinstra l\u00e6ri og gekk undir sj\u00f3ndeildarhring samt\u00edmis henni og me\u00f0 s\u00f6mu hreyfingu. S\u00ed\u00f0ar s\u00fdndi h\u00fan sj\u00e1lfst\u00e6\u00f0a hreyfingu og gekk yfir \u00e1 nor\u00f0urhvel himins. Fr\u00e1 \u00fev\u00ed \u00e1 sj\u00f6ttu stund a\u00f0 kv\u00f6ldi hins 14. fram til n\u00edundu stundar um kv\u00f6ldi\u00f0 f\u00f3r h\u00fan fram hj\u00e1 austurhli\u00f0 sj\u00f6stj\u00f6rnunnar, og \u00e1 fj\u00f3r\u00f0u stundu a\u00f0 morgni hins 16. var h\u00fan komin a\u00f0 daufri stj\u00f6rnu \u00ed t\u00e1nni \u00e1 vinstra f\u00e6ti Perseus. \u00dev\u00ed n\u00e6st gekk h\u00fan \u00ed h\u00f6fu\u00f0 Med\u00fasu og sta\u00f0n\u00e6mdist \u00fear \u00ed tvo s\u00f3larhringa, en var \u00fe\u00e1 or\u00f0in dauf og \u00f3greinileg. En 25. desember s\u00e1st h\u00fan s\u00ed\u00f0ast um \u00fea\u00f0 bil \u00feremur gr\u00e1\u00f0um nor\u00f0an vi\u00f0 h\u00f6fu\u00f0 Med\u00fasu. H\u00fan s\u00e1st alla n\u00f3ttina yfir sj\u00f3ndeildarhring, og G\u00edsli segist hafa m\u00e6lt su\u00f0urh\u00e6\u00f0 hennar 68 gr\u00e1\u00f0ur en nor\u00f0urh\u00e6\u00f0 13 gr\u00e1\u00f0ur. Me\u00f0 \u00fev\u00ed a\u00f0 bera saman mismun \u00feessara talna vi\u00f0 breidd Sk\u00e1lholts, \u00fear sem athugunin var ger\u00f0, en h\u00fan er 64 gr\u00e1\u00f0ur og 14 m\u00edn\u00fatur, \u00fe\u00e1 hafi hli\u00f0runin reynst \u00ferj\u00e1r gr\u00e1\u00f0ur og 17 m\u00edn\u00fatur. Af \u00fev\u00ed lei\u00f0i a\u00f0 h\u00fan hafi veri\u00f0 undir tungli \u00e1 himni, og af \u00fev\u00ed \u00e1lyktar hann a\u00f0 h\u00fan hafi ekki veri\u00f0 lengra fr\u00e1 j\u00f6r\u00f0u en h\u00e1lft umm\u00e1l hennar.<\/p><\/blockquote>\n<figure id=\"attachment_7240\" aria-describedby=\"caption-attachment-7240\" style=\"width: 608px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-7240\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/08\/1652_newest-300x224.jpg\" alt=\"\" width=\"608\" height=\"454\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/1652_newest-300x224.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/1652_newest-1024x763.jpg 1024w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/1652_newest-768x572.jpg 768w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/1652_newest-1536x1145.jpg 1536w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/1652_newest.jpg 1905w\" sizes=\"auto, (max-width: 608px) 100vw, 608px\" \/><figcaption id=\"caption-attachment-7240\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">\u00deessi gamla erlenda teikning s\u00fdnir hluta af braut halastj\u00f6rnunnar 1652 \u00e1 hvelfingunni. \u00dearna er stjarnan \u00ed stj\u00f6rnumerkinu <a href=\"https:\/\/www.stjornufraedi.is\/stjornuskodun\/stjornumerkin\/perseifur\/\">Perseifi<\/a> \u00e1 lei\u00f0 fram hj\u00e1 h\u00f6f\u00f0i Med\u00fasu. R\u00e9tt er a\u00f0 taka fram a\u00f0 dagsetningarnar \u00e1 myndinni eru samkv\u00e6mt <a href=\"https:\/\/en.wikipedia.org\/wiki\/Gregorian_calendar\">n\u00fdja st\u00edl<\/a> en G\u00edsli Einarsson nota\u00f0i <a href=\"https:\/\/en.wikipedia.org\/wiki\/Julian_calendar\">gamla st\u00edl<\/a> \u00ed l\u00fdsingu sinni.<br \/><\/span><\/figcaption><\/figure>\n<p>Ef l\u00fdsing Resens \u00e1 ni\u00f0urst\u00f6\u00f0um G\u00edsla er r\u00e9tt, voru verulegir annmarkar \u00e1 m\u00e6lingum sk\u00f3lameistarans. Til d\u00e6mis benda \u00fe\u00e6r til \u00feess, a\u00f0 halastjarnan hafi veri\u00f0 ne\u00f0an tungls, sem er rangt. N\u00e1nri umfj\u00f6llun um \u00feetta efni er a\u00f0 finna \u00ed grein Einars H. Gu\u00f0mundssonar fr\u00e1 1998.<\/p>\n<p>Erlendis fylgdust margir me\u00f0 stj\u00f6rnunni, \u00fear \u00e1 me\u00f0al \u00feekktir stj\u00f6rnufr\u00e6\u00f0ingar eins og Hevel\u00edus og <a href=\"https:\/\/en.wikipedia.org\/wiki\/Giovanni_Domenico_Cassini\">Cassini<\/a> (1625-1712). B\u00e1\u00f0ir g\u00e1fu \u00feeir \u00fat \u00edtarlegar l\u00fdsingar \u00e1 athugunum s\u00ednum.<\/p>\n<ul>\n<li>Einar H. Gu\u00f0mundsson, 1998: <a href=\"http:\/\/timarit.is\/view_page_init.jsp?pageId=5280864\">Halastjarnan 1652<\/a> (kafli \u00ed greininni um G\u00edsla Einarsson sk\u00f3lameistara)<\/li>\n<li>G. D. Cassini, 1653: <a href=\"https:\/\/books.google.is\/books?id=CldRAAAAcAAJ&amp;source=gbs_navlinks_s\">De cometa anni 1652 et 1653<\/a>.\u00a0 &#8211;\u00a0 H\u00e9r eru <a href=\"http:\/\/www.atlascoelestis.com\/Cassini%201652.htm\">myndir \u00far greininni<\/a>.<\/li>\n<li>J. Hevelius, 1668: <a href=\"https:\/\/books.google.is\/books?id=8UpZAAAAcAAJ&amp;source=gbs_navlinks_s\">Cometographia.<\/a><\/li>\n<li>\u00c1rni Hjartarson: <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522183809\/http:\/\/www.isor.is\/~ah\/comet\/hali12.htm\">Halastjarnan 1652.<\/a><\/li>\n<\/ul>\n<hr \/>\n<p><strong>\u25ca <\/strong><a href=\"https:\/\/de.wikipedia.org\/wiki\/C\/1664_W1\"><strong>Halastjarnan mikla \u00e1ri\u00f0 1664:<\/strong><\/a><\/p>\n<p>S\u00f6gur herma, a\u00f0 \u00feessi stjarna hafi jafnvel veri\u00f0 enn gl\u00e6silegri en halastjarnan fr\u00e6ga \u00e1ri\u00f0 1618. H\u00fan s\u00e1st v\u00ed\u00f0a um l\u00f6nd, me\u00f0al annars h\u00e9r \u00e1 landi og er hennar geti\u00f0 \u00ed nokkrum \u00edslenskum ann\u00e1lum. \u00cd <em>Vallholtsann\u00e1l<\/em> segir:<\/p>\n<blockquote><p>24. Dec. s\u00e9n fyrst cometa \u00e1 lopti, vestur fr\u00e1 sj\u00f6stirni, me\u00f0 l\u00f6ngum hala sem v\u00f6ndur, s\u00e1st hvert kveld fram um j\u00f3l, horf\u00f0i til austurs. H\u00fan var svo:<\/p><\/blockquote>\n<figure id=\"attachment_7113\" aria-describedby=\"caption-attachment-7113\" style=\"width: 564px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-7113\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/08\/Halas1884-300x83.jpg\" alt=\"\" width=\"564\" height=\"156\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Halas1884-300x83.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Halas1884-1024x283.jpg 1024w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Halas1884-768x212.jpg 768w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Halas1884-1536x424.jpg 1536w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/Halas1884.jpg 1996w\" sizes=\"auto, (max-width: 564px) 100vw, 564px\" \/><figcaption id=\"caption-attachment-7113\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Teikningin af halastj\u00f6rnunni 1664 \u00ed handriti af <em>Vallholtsann\u00e1l<\/em> (Lbs. 158 4to). Sj\u00e1 til samanbur\u00f0ar mynd af stj\u00f6rnunni \u00e1 prentu\u00f0um <a href=\"http:\/\/www.gbv.de\/vd17-cms\/vd17_image_full_view?zuid=abe2988e-7100-499f-aa63-c4a15046c04a\">\u00fe\u00fdskum einbl\u00f6\u00f0ungi<\/a> fr\u00e1 \u00feessum t\u00edma.<\/span><\/figcaption><\/figure>\n<blockquote><p><em>[&#8230;]<\/em>\u00a0 Gott ve\u00f0ur \u00e1ttadag. Vetur g\u00f3\u00f0ur upp \u00fea\u00f0an. N\u00f3ttina n\u00e6stu eptir <em>[2. jan.]<\/em> s\u00e1st regnbogi gegnt tungli \u00ed har\u00f0a frosti, og \u00fear eptir rau\u00f0ur kross yfir og undir tunglinu og \u00ed kring um \u00fea\u00f0 allt. S\u00e9n v\u00edgabrandur fr\u00e1 vestri til austurs, rann \u00e1 oddinn og v\u00edgakn\u00f6ttur fr\u00e1 vestri til austurs. Enn s\u00e1st stjarna n\u00fd, er gekk um \u00fevert lopt til austurs mj\u00f6g hrapalega. \u00d6nnur stjarna s\u00e1st um kveld ne\u00f0arlega \u00e1 lopti \u00ed su\u00f0ri, gekk me\u00f0 hasti til vesturs, og svo undir. Enn s\u00e1st teikn miki\u00f0 \u00e1 lopti aflangt sem sk\u00fd. Upp fr\u00e1 19. Jan. s\u00e1st ekki cometan, sem fyrr var geti\u00f0.<\/p><\/blockquote>\n<p>Halastjarnan vakti verulega athygli b\u00e6\u00f0i \u00ed Evr\u00f3pu og Bandar\u00edkjunum og var miki\u00f0 um hana skrifa\u00f0, \u00fe\u00f3tt mest af \u00fev\u00ed hafi tengst sp\u00e1d\u00f3mum og vangaveltum um rei\u00f0i Gu\u00f0s. Til d\u00e6mis t\u00f6ldu margir, a\u00f0 h\u00fan hef\u00f0i veri\u00f0 forbo\u00f0i pl\u00e1gunnar miklu \u00ed London 1665-66 og brunans sem fylgdi \u00ed kj\u00f6lfari\u00f0.<\/p>\n<p>Newton fylgdist me\u00f0 stj\u00f6rnunni sem st\u00fadent \u00ed Cambridge og ef til vill hefur h\u00fan vaki\u00f0 hj\u00e1 honum \u00feann \u00e1huga \u00e1 halastj\u00f6rnum, sem s\u00ed\u00f0ar \u00e1tti eftir a\u00f0 skila s\u00e9r me\u00f0 eftirminnanlegum h\u00e6tti \u00ed tengslum vi\u00f0 stj\u00f6rnurnar miklu \u00e1rin 1680 og 1682.<\/p>\n<figure id=\"attachment_7739\" aria-describedby=\"caption-attachment-7739\" style=\"width: 556px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-7739\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/09\/Newton1664-300x158.jpg\" alt=\"\" width=\"556\" height=\"293\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/Newton1664-300x158.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/Newton1664.jpg 419w\" sizes=\"auto, (max-width: 556px) 100vw, 556px\" \/><figcaption id=\"caption-attachment-7739\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Ein af dagb\u00f3karf\u00e6rslum Newtons me\u00f0 sta\u00f0arm\u00e6lingum og teikningu af halastj\u00f6rnunni 1664. \u00dearna er h\u00fan \u00ed stj\u00f6rnumerkinu <a href=\"https:\/\/www.stjornufraedi.is\/stjornuskodun\/stjornumerkin\/hvalurinn\/\">Hvalnum<\/a>. Til vinstri m\u00e1 sj\u00e1 s\u00f3lstj\u00f6rnurnar <a href=\"https:\/\/en.wikipedia.org\/wiki\/Rigel\">R\u00edgel<\/a> \u00ed <a href=\"https:\/\/www.stjornufraedi.is\/stjornuskodun\/stjornumerkin\/orion\/\">\u00d3r\u00edon<\/a> og <a href=\"https:\/\/en.wikipedia.org\/wiki\/Aldebaran\">Aldebaran<\/a> \u00ed <a href=\"https:\/\/www.stjornufraedi.is\/stjornuskodun\/stjornumerkin\/nautid\/\">Nautinu<\/a> <br \/><\/span><\/figcaption><\/figure>\n<p>Me\u00f0al \u00feeirra l\u00e6rd\u00f3msmanna, sem fylgdust me\u00f0 halastj\u00f6rnunni og g\u00e1fu \u00fat rit um ni\u00f0urst\u00f6\u00f0ur s\u00ednar, voru \u00feeir Hevelius, Borelli og Cassini. S\u00e1 s\u00ed\u00f0astnefndi var \u00feeirrar sko\u00f0unar, a\u00f0 braut stj\u00f6rnunnar v\u00e6ri risast\u00f3r hringur me\u00f0 mi\u00f0ju \u00ed stefnu \u00e1 fastastj\u00f6rnuna S\u00edr\u00edus og jar\u00f0n\u00e1nd fyrir utan braut Sat\u00farnusar. Tilg\u00e1tan var bygg\u00f0 \u00e1 jar\u00f0mi\u00f0jukenningu Brahes.<\/p>\n<p>\u00cd Kaupmannah\u00f6fn ger\u00f0i <a href=\"https:\/\/da.wikipedia.org\/wiki\/Rasmus_Bartholin\">R. Bartholin<\/a> (1625-1698) n\u00e1kv\u00e6mar m\u00e6lingar \u00e1 stj\u00f6rnunni, b\u00e6\u00f0i fyrir og eftir j\u00f3l. Tali\u00f0 er fullv\u00edst, a\u00f0 \u00fear hafi hann noti\u00f0 a\u00f0sto\u00f0ar nemanda s\u00edns <a href=\"https:\/\/notendur.hi.is\/~einar\/SAGA\/Roemer.pdf\">O. R\u00f8mers<\/a> (1644-1710). Til gamans m\u00e1 benda \u00e1, a\u00f0 \u00ed lok greinar sinnar um stj\u00f6rnuna v\u00edkur Bartholin a\u00f0 halastj\u00f6rnunum 1222 og 1301 og vitnar \u00ed \u00fev\u00ed sambandi \u00ed \u00edslenska ann\u00e1la (sj\u00e1 einnig <a href=\"http:\/\/baekur.is\/bok\/000197461\/0\/62\/Islenzkir_annalar__sive_Bls_62\">h\u00e9r<\/a>).<\/p>\n<ul>\n<li>R. Bartholin, 1665: <a href=\"https:\/\/books.google.is\/books?id=AJsxSQAACAAJ&amp;source=gbs_navlinks_s\">De cometis anni MDCLXIV. &amp; MDCLXV. opusculum.<\/a><\/li>\n<li>G. D. Cassini, 1665: <a href=\"https:\/\/books.google.is\/books?id=9lZRAAAAcAAJ&amp;source=gbs_navlinks_s\">Theoriae motus cometae anni 1664.<\/a><\/li>\n<li>J. Hevelius, 1668: <a href=\"https:\/\/books.google.is\/books?id=8UpZAAAAcAAJ&amp;source=gbs_navlinks_s\">Cometographia.<\/a><\/li>\n<li>L.Boschiero, 2009: <a href=\"http:\/\/adsbit.harvard.edu\/\/full\/2009JHA....40...11B\/0000011.000.html\">Giovanni Borelli and the Comets of 1664-1665.<\/a><\/li>\n<li>\u00c1rni Hjartarson: <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522183847\/http:\/\/www.isor.is\/~ah\/comet\/hali13.htm\">Stj\u00f6rnurnar 1664, 1665 og 1668.<\/a><\/li>\n<\/ul>\n<p>Sj\u00e1 einnig <em>Vi\u00f0b\u00f3t 2<\/em> aftast \u00ed f\u00e6rslunni.<\/p>\n<hr \/>\n<p><strong>\u25ca <a href=\"https:\/\/de.wikipedia.org\/wiki\/C\/1665_F1\">Halastjarnan 1665:<\/a><\/strong><\/p>\n<p>A\u00f0eins nokkrum d\u00f6gum eftir a\u00f0 halastjarnan 1664 hvarf af sj\u00f3narsvi\u00f0inu \u00ed mars 1665, birtist n\u00fd stjarna \u00e1 himni. Flestir \u00feeirra l\u00e6rd\u00f3msmanna, sem fylgst h\u00f6f\u00f0u me\u00f0 fyrri stj\u00f6rnunni, voru flj\u00f3tir a\u00f0 hefja m\u00e6lingar \u00e1 hinum n\u00fdja gesti. Ni\u00f0urst\u00f6\u00f0ur sumra \u00feeirra er a\u00f0 finna \u00ed ritum, sem \u00e1\u00f0ur voru nefnd.<\/p>\n<figure id=\"attachment_6896\" aria-describedby=\"caption-attachment-6896\" style=\"width: 564px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-6896\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/08\/RBartholin1665-300x264.jpeg\" alt=\"\" width=\"564\" height=\"496\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/RBartholin1665-300x264.jpeg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/RBartholin1665-1024x899.jpeg 1024w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/RBartholin1665-768x675.jpeg 768w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/08\/RBartholin1665.jpeg 1118w\" sizes=\"auto, (max-width: 564px) 100vw, 564px\" \/><figcaption id=\"caption-attachment-6896\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Teikning af sl\u00f3\u00f0 halastj\u00f6rnunnar 1665 \u00e1 stj\u00f6rnuhimninum. \u00dar b\u00f3k Rasmusar Bartholin fr\u00e1 1665.<\/span><\/figcaption><\/figure>\n<p>\u00cdslenskir ann\u00e1lar nefna a\u00f0 h\u00e9r hafi s\u00e9st halastjarna \u00e1ri\u00f0 1665, en ekki er lj\u00f3st a\u00f0 \u00fear s\u00e9 um \u00feessa \u00e1kve\u00f0nu stj\u00f6rnu a\u00f0 r\u00e6\u00f0a.<\/p>\n<ul>\n<li>\u00c1rni Hjartarson: <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522183847\/http:\/\/www.isor.is\/~ah\/comet\/hali13.htm\">Stj\u00f6rnurnar 1664, 1665 og 1668.<\/a><\/li>\n<\/ul>\n<hr \/>\n<p><span style=\"font-size: 14pt\"><strong><span style=\"font-size: 12pt\">\u25ca H<a href=\"https:\/\/de.wikipedia.org\/wiki\/C\/1680_V1_(Gro%C3%9Fer_Komet_von_1680)\">alastjarnan mikla \u00e1ri\u00f0 1680:<\/a> <\/span><\/strong><br \/>\n<\/span><\/p>\n<p>Mikil og bj\u00f6rt halastjarna s\u00e1st v\u00ed\u00f0a um l\u00f6nd veturinn 1680. Reyndar t\u00f6ldu flestir, \u00fear \u00e1 me\u00f0al <a href=\"https:\/\/en.wikipedia.org\/wiki\/Isaac_Newton\">I. Newton<\/a> (1643-1727), a\u00f0 um tv\u00e6r stj\u00f6rnur v\u00e6ri a\u00f0 r\u00e6\u00f0a, sem b\u00e1\u00f0ar fer\u00f0u\u00f0ust eftir beinum l\u00ednum. \u00deetta var \u00ed samr\u00e6mi vi\u00f0 hugmyndir Keplers, en vi\u00f0 vitum n\u00fa, a\u00f0 \u201efyrri stjarnan\u201c, sem s\u00e1st \u00e1 austurhimni fyrir d\u00f6gun, var halastjarnan \u00e1 innlei\u00f0 og \u201ehin\u201c, sem s\u00e1st s\u00ed\u00f0ar og sem kv\u00f6ldstjarna \u00e1 vesturhimni, var halastjarnan \u00e1 \u00fatlei\u00f0.<\/p>\n<figure id=\"attachment_7708\" aria-describedby=\"caption-attachment-7708\" style=\"width: 550px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-7708\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/09\/Comet1680Rotterdam-300x239.jpg\" alt=\"\" width=\"550\" height=\"438\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/Comet1680Rotterdam-300x239.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/Comet1680Rotterdam.jpg 681w\" sizes=\"auto, (max-width: 550px) 100vw, 550px\" \/><figcaption id=\"caption-attachment-7708\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Halastjarnan 1680 yfir Rotterdam. M\u00e1lverk eftir L. Verschuier.<br \/><\/span><\/figcaption><\/figure>\n<p>Stjarnan s\u00e1st vel h\u00e9r \u00e1 landi oig er hennar geti\u00f0 \u00ed \u00edslenskum ann\u00e1lum. \u00cd <em>Kj\u00f3sarann\u00e1l<\/em> segir (dagsetningar skv. gamla st\u00edl):<\/p>\n<blockquote><p>Um hausti\u00f0 s\u00e1st v\u00edgabrandur. &#8211; 12. Decembris a\u00f0 \u00e1li\u00f0num degi, undir dagsetur, s\u00e1st teikn \u00e1 himnum \u00ed \u00fatsu\u00f0ri, gult a\u00f0 lit; a\u00f0 ne\u00f0anver\u00f0u var \u00fea\u00f0 bjartara en ofantil, og stundum meira en stundum minna. \u00dea\u00f0 h\u00e6kka\u00f0i alltaf \u00e1 himninum um 4 grader \u00e1 hverju kveldi; um s\u00ed\u00f0ir s\u00e1u menn, a\u00f0 stjarna var vi\u00f0 \u00fea\u00f0 a\u00f0 ne\u00f0anver\u00f0u og a\u00f0 \u00feetta teikn var ein cometa, \u00fe\u00f3 me\u00f0 annarlegum gangi vi\u00f0 a\u00f0rar stj\u00f6rnur; lengd halans meintist 42 gr\u00e1\u00f0ur, en elevatio 48 gr.; s\u00e1st sy\u00f0ra til 30. Januarii. Fyrir austan var sagt, einn ma\u00f0ur s\u00e9\u00f0 hef\u00f0i \u00e1 loptinu \u00fev\u00edl\u00edkt sem mannsh\u00f6nd, haldandi \u00e1 vendi, og v\u00ed\u00f0ar um landi\u00f0 s\u00e1ust teikn og fur\u00f0anlegar veifanir \u00e1 loptinu.<\/p><\/blockquote>\n<p>S\u00e9ra P\u00e1ll \u00ed Sel\u00e1rdal, sem almennt er talinn \u00ed h\u00f3pi merkustu l\u00e6rd\u00f3msmanna sinnar samt\u00ed\u00f0ar h\u00e9r \u00e1 landi, h\u00e9lt s\u00e9rstaka predikun \u00ed tilefni \u00feessarar heims\u00f3knar og var h\u00fan \u00e6tlu\u00f0 \u201e<em>Syndurum til gu\u00f0r\u00e6kilegrar kristilegrar Uppvakningar<\/em>\u201c.<\/p>\n<figure id=\"attachment_5884\" aria-describedby=\"caption-attachment-5884\" style=\"width: 592px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-5884\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/07\/PB_1680-300x151.jpg\" alt=\"\" width=\"592\" height=\"298\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/PB_1680-300x151.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/PB_1680.jpg 761w\" sizes=\"auto, (max-width: 592px) 100vw, 592px\" \/><figcaption id=\"caption-attachment-5884\" class=\"wp-caption-text\"><span style=\"font-size: 10pt\">Titillinn \u00e1 i\u00f0runarpredikun P\u00e1ls \u00ed Sel\u00e1rdal um halastj\u00f6rnuna 1680. <br \/><\/span><\/figcaption><\/figure>\n<p>\u00cd predikuninni uppl\u00fdsti s\u00e9ra P\u00e1ll s\u00f6fnu\u00f0inn me\u00f0al annars um e\u00f0li halastjarna:<\/p>\n<blockquote><p>Cometa kann ei vera \u00ed t\u00f6lu himinsins stjarna. <em>[\u2026]<\/em> Gu\u00f0 skapar cometurnar af \u00fev\u00ed bl\u00f3\u00f0i og bl\u00f3\u00f0ugum syndum, sem \u00e1 j\u00f6r\u00f0ina \u00fat hellast, og \u00e1 j\u00f6r\u00f0inni dr\u00fdgjast, hva\u00f0 allt upp st\u00edgur \u00ed h\u00e6\u00f0irnar. \u00deessi illska er s\u00e1 suddi og brennisteinn, sem b\u00e1last \u00ed \u00feessum cometueldi, svo sem Esajas segir (9. kap.): Rangl\u00e6ti\u00f0 brennir sem eldur. <em>[&#8230;]\u00a0 <\/em>Sj\u00e1i\u00f0, n\u00fa tekur a\u00f0 b\u00e1last s\u00fa arfas\u00e1tan vorrar synda sly\u00f0ru; s\u00e1 brennisteininum, sem er s\u00fa eitra\u00f0a \u00edstra holdlegra girnda, hefur sig dregi\u00f0 saman \u00e1 himnum, hverri v\u00e9r \u00ed vind sl\u00f3um. En s\u00e1 fort\u00e6randi eldur hefur kveikt \u00fear \u00ed einn v\u00edtaeld yfir oss og vor b\u00f6rn, h\u00fas og heimili. \u00c9g segi: \u00d3gnarligan cometen, l\u00edka sem gl\u00f3andi axarfaxi a\u00f0 oss s\u00e9 sn\u00fai\u00f0, og reitt Gu\u00f0s rei\u00f0fax.<\/p><\/blockquote>\n<p>R\u00e9tt er a\u00f0 hafa \u00ed huga, a\u00f0 \u00e1 sautj\u00e1ndu \u00f6ld voru samskonar predikanir fluttar v\u00ed\u00f0a erlendis, \u00feegar bjartar halastj\u00f6rnur birtust \u00e1 himni. Einnig m\u00e1 minna \u00e1, a\u00f0 \u00e1 \u00feessum t\u00edmum voru prenta\u00f0ir erlendir b\u00e6klingar, me\u00f0 svipu\u00f0u innihaldi sem og sp\u00e1d\u00f3mum, margfalt fleiri en \u00feau rit, sem fj\u00f6llu\u00f0u um m\u00e6lingar \u00e1 halastj\u00f6rnum og n\u00e1tt\u00faruspekilegar vangaveltur um e\u00f0li \u00feeirra.<\/p>\n<ul>\n<li>\u00c1rni Hjartarson: <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522183657\/http:\/\/www.isor.is\/~ah\/comet\/hali14.htm\">Halastjarna Newtons 1680.<\/a><\/li>\n<li>Kolbeinn \u00deorleifsson (vi\u00f0tal), 1985: <a href=\"http:\/\/timarit.is\/view_page_init.jsp?pageId=2901667\">A\u00f0 flj\u00faga me\u00f0 h\u00f6ndunum og \u00e6\u00f0a me\u00f0 f\u00f3tunum.<\/a><\/li>\n<\/ul>\n<p>Stjarnan mikla \u00e1ri\u00f0 1680 mun vera fyrsta halastjarnan, sem uppg\u00f6tvu\u00f0 var \u00ed gegnum sj\u00f3nauka. \u00de\u00fdski stj\u00f6rnufr\u00e6\u00f0ingurinn <a href=\"https:\/\/en.wikipedia.org\/wiki\/Gottfried_Kirch\">G. Kirch<\/a> (1639-1710) s\u00e1 hana fyrstur og er stjarnan stundum vi\u00f0 hann kennd. Einn \u00feeirra m\u00f6rgu, sem fylgdust me\u00f0 halastj\u00f6rnunni, var l\u00e6rd\u00f3msma\u00f0urinn <a href=\"https:\/\/de.wikipedia.org\/wiki\/Georg_Samuel_D%C3%B6rffel\">G. S. D\u00f6rffel<\/a> (1643-1688) sem benti \u00e1, a\u00f0 sennilega v\u00e6ri braut hennar fleygbogi (parab\u00f3la) me\u00f0 s\u00f3lina \u00ed brennipunkti. \u00dear sem enginn fr\u00e6\u00f0ilegur r\u00f6kstu\u00f0ningur fylgdi ni\u00f0urst\u00f6\u00f0unni, t\u00f3ku f\u00e1ir mark \u00e1 henni.<\/p>\n<p>Hinn konunglegi enski stj\u00f6rnufr\u00e6\u00f0ingur <a href=\"https:\/\/en.wikipedia.org\/wiki\/John_Flamsteed\">J. Flamsteed<\/a> (1646-1719) taldi einnig, a\u00f0 a\u00f0eins v\u00e6ri um eina halastj\u00f6rnu a\u00f0 r\u00e6\u00f0a, en ekki tv\u00e6r, eins og Newton og flestir a\u00f0rir h\u00e9ldu fram. Hugmynd Flamsteeds var s\u00fa, a\u00f0 \u00ed s\u00f3ln\u00e1nd hef\u00f0i halastjarnan endurkastast fr\u00e1 s\u00f3linni vegna einskonar \u201efr\u00e1hrindandi segulkrafts\u201c.<\/p>\n<p>Newton fylgdist vel me\u00f0 stj\u00f6rnunni og ger\u00f0i \u00e1 henni margar sta\u00f0arm\u00e6lingar \u00ed \u00fev\u00ed skyni a\u00f0 finna braut hennar. Hann var n\u00e6rs\u00fdnn og \u00ed byrjun nota\u00f0ist hann \u00fev\u00ed vi\u00f0 einglyrni. \u00deegar \u00e1hugi hans j\u00f3kst, keypti hann s\u00e9r linsusj\u00f3nauka, fyrst einn \u00feriggja feta og s\u00ed\u00f0an annan sj\u00f6 feta me\u00f0 m\u00edkr\u00f3m\u00e6li. Hann \u00e1tti einnig \u00ed br\u00e9faskiptum vi\u00f0 Flamsteed og f\u00e9kk hj\u00e1 honum m\u00e6lini\u00f0urst\u00f6\u00f0ur, jafnframt \u00fev\u00ed sem hann safna\u00f0i g\u00f6gnum fr\u00e1 \u00f6\u00f0rum stj\u00f6rnufr\u00e6\u00f0ingum.<\/p>\n<p>En allt kom fyrir ekki; \u00fer\u00e1tt fyrir talsver\u00f0a reikninga t\u00f3kst Newton ekki a\u00f0 \u00e1kva\u00f0a brautina me\u00f0 \u00feeirri n\u00e1kv\u00e6mni sem hann vildi. Hann missti \u00fev\u00ed \u00e1hugann \u00ed bili. Nokkrum \u00e1rum s\u00ed\u00f0ar komu m\u00e6lini\u00f0urst\u00f6\u00f0urnar \u00fe\u00f3 a\u00f0 g\u00f3\u00f0um notum. A\u00f0 auki t\u00f3k Newton til vi\u00f0 a\u00f0 endurb\u00e6ta spegilsj\u00f3nauka sinn og ger\u00f0i vi\u00f0 \u00fea\u00f0 n\u00fdjar uppg\u00f6tvanir um liti, sem hann gat birt \u00ed <a href=\"https:\/\/en.wikipedia.org\/wiki\/Opticks\">Lj\u00f3sfr\u00e6\u00f0inni<\/a> \u00e1ri\u00f0 1704.<\/p>\n<ul>\n<li>G. S. D\u00f6rffel, 1681:\u00a0 <a href=\"http:\/\/digitale.bibliothek.uni-halle.de\/vd17\/content\/titleinfo\/662176\">Astronomische Betrachtung des Grossen Cometen.<\/a><\/li>\n<li>D. W. Hughes, 1988: <a href=\"https:\/\/www.jstor.org\/stable\/531369?seq=1#page_scan_tab_contents\">The Principia and Comets.<\/a><\/li>\n<li>J. A. Ruffner, 2010: <a href=\"http:\/\/www.iub.edu\/~hpscdept\/news\/ruffner.pdf\">Isaac newton&#8217;s historia cometarum and the quest for elliptical orbits.<\/a><\/li>\n<\/ul>\n<p>Sj\u00e1 einnig <em>Vi\u00f0b\u00f3t 1<\/em> aftast \u00ed f\u00e6rslunni.<\/p>\n<hr \/>\n<p><span style=\"font-size: 14pt\"><strong><span style=\"font-size: 12pt\">\u25ca Halastjarnan 1682:<\/span><\/strong><br \/>\n<\/span><\/p>\n<p>Margir, \u00fear \u00e1 me\u00f0al\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Edmond_Halley\">E. Halley<\/a> (1656-1742), fylgdust n\u00e1i\u00f0 me\u00f0 bjartri <a href=\"https:\/\/en.wikipedia.org\/wiki\/Halley%27s_Comet\">halastj\u00f6rnu<\/a>, sem s\u00e1st vel \u00e1 hvelfingunni hausti\u00f0 1682. \u00de\u00f3tt stjarnan hafi b\u00e6\u00f0i veri\u00f0 bj\u00f6rt og f\u00f6gur, er h\u00fan \u00fe\u00f3 fyrst og fremst \u00feekkt \u00ed s\u00f6gu stj\u00f6rnufr\u00e6\u00f0innar vegna \u00feess, a\u00f0 \u00e1ri\u00f0 1705 s\u00fdndi Halley fram \u00e1, a\u00f0 h\u00fan hef\u00f0i \u00e1\u00f0ur komi\u00f0 \u00ed heims\u00f3kn. Jafnframt sp\u00e1\u00f0i hann \u00fev\u00ed, a\u00f0 h\u00fan myndi birtast aftur \u00e1ri\u00f0 1758. \u00dea\u00f0 gekk eftir og hefur stjarnan s\u00ed\u00f0an bori\u00f0 nafn \u00feessa merka l\u00e6rd\u00f3msmanns.<\/p>\n<figure id=\"attachment_7709\" aria-describedby=\"caption-attachment-7709\" style=\"width: 546px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-7709\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/09\/halley1682_Augsburg-300x179.jpg\" alt=\"\" width=\"546\" height=\"326\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/halley1682_Augsburg-300x179.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/halley1682_Augsburg-768x459.jpg 768w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/halley1682_Augsburg.jpg 900w\" sizes=\"auto, (max-width: 546px) 100vw, 546px\" \/><figcaption id=\"caption-attachment-7709\" class=\"wp-caption-text\">\u00cdb\u00faar borgarinnar Augsburg fylgjast me\u00f0 halastj\u00f6rnunni 1682 vi\u00f0 hli\u00f0 minnkandi tungls.<\/figcaption><\/figure>\n<ul>\n<li>D. W. Hughes og A. Drummond, 1984: <a href=\"http:\/\/adsbit.harvard.edu\/\/full\/1984JHA....15..189H\/0000189.000.html\">Edmond Halley&#8217;s Observations of Halley&#8217;s Comet.<\/a><\/li>\n<li>I. Ridpath, 1985: <a href=\"http:\/\/www.ianridpath.com\/halley\/halley4.htm\">A Brief History of Halley\u2019s Comet.<\/a><\/li>\n<\/ul>\n<p><span lang=\"IS\">Ekki er a\u00f0 fullu lj\u00f3st, hvort halastjarnan 1682 hefur s\u00e9st h\u00e9r \u00e1 landi. \u00de\u00f3 er r\u00e9tt a\u00f0 vitna \u00ed <em>Eyrarann\u00e1l<\/em>, \u00fear sem eftirfarandi kemur fram: <\/span><\/p>\n<blockquote><p><span lang=\"IS\">S\u00e1st halastjarna \u00ed h\u00e1lfan m\u00e1nu\u00f0, og \u00fe\u00e1 dreymdi Sigur\u00f0 Sigur\u00f0sson \u00e1 L\u00e1gagn\u00fapi, a\u00f0 hann s\u00e1 3 s\u00f3lir, en s\u00fa \u00ed mi\u00f0i\u00f0 var \u00f6llum fegri, og var\u00f0 a\u00f0 manns \u00e1sj\u00f3nu og sag\u00f0i vi\u00f0 Sigur\u00f0: Hva\u00f0 heldur f\u00f3lki\u00f0, a\u00f0 stjarnan hafi a\u00f0 \u00fe\u00fd\u00f0a, sem h\u00e9r s\u00e1st n\u00fdlega? Sigur\u00f0ur svara\u00f0i: \u00dea\u00f0 vita menn ei af. Andliti\u00f0 svara\u00f0i: \u00c9g vil segja \u00fe\u00e9r \u00fea\u00f0; h\u00fan merkir \u00fea\u00f0, a\u00f0 h\u00e9r eigi a\u00f0 koma r\u00e6ningjar <em>[&#8230;]<\/em> haltu \u00feetta fyrir enga draum\u00f3ra, sem \u00e9g segi \u00fe\u00e9r, \u00fev\u00ed \u00fea\u00f0 er satt. Og vakna\u00f0i Sigur\u00f0ur. &#8211; Item 3 vikum seinna dreymdi Sigur\u00f0 gamlan mann, gr\u00e1h\u00e6r\u00f0an, og sag\u00f0i vi\u00f0 Sigur\u00f0: Satt er \u00fea\u00f0 sem s\u00f3lin sag\u00f0i \u00fe\u00e9r um stj\u00f6rnuna og r\u00e6ningjana. <\/span><\/p><\/blockquote>\n<p>Ekki er til \u00feess vita\u00f0, a\u00f0 hinir undarlegu draumar Sigur\u00f0ar hafi r\u00e6st.<\/p>\n<ul>\n<li>\u00c1rni Hjartarson: <a href=\"http:\/\/wayback.vefsafn.is\/wayback\/20060522183720\/http:\/\/www.isor.is\/~ah\/comet\/hali15.htm\">Stjarna Halleys 1682<\/a>.<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">Newton leysir brautar\u00ferautina<\/span><\/h3>\n<p>\u00cd \u00e1g\u00fast \u00e1ri\u00f0 1684 f\u00f3r Halley \u00ed fr\u00e6ga heims\u00f3kn til Newtons \u00ed Cambridge og spur\u00f0i meistarann, hvort hann vissi hver yr\u00f0i l\u00f6gun reikistj\u00f6rnubrauta, ef a\u00f0dr\u00e1ttarkrafturinn \u00e1 \u00fe\u00e6r fr\u00e1 s\u00f3linni v\u00e6ri \u00ed \u00f6fugu hlutfalli vi\u00f0 anna\u00f0 veldi fjarl\u00e6g\u00f0arinnar.\u00a0 <a href=\"http:\/\/www.mathpages.com\/home\/kmath658\/kmath658.htm\"> Newton mun hafa svara\u00f0 a\u00f0 brag\u00f0i<\/a>, a\u00f0 samkv\u00e6mt s\u00ednum reikningum v\u00e6ru brautirnar sporbaugar. Honum t\u00f3kst \u00fe\u00f3 ekki a\u00f0 finna \u00fatreikningana til a\u00f0 s\u00fdna Halley, en lofa\u00f0i a\u00f0 senda \u00fe\u00e1 til hans seinna.<\/p>\n<p>\u00cd n\u00f3vember sama \u00e1r f\u00e9kk Halley loks dr\u00f6g a\u00f0 grein fr\u00e1 Newton undir nafninu\u00a0 <a href=\"https:\/\/en.wikipedia.org\/wiki\/De_motu_corporum_in_gyrum\">Um hreyfingu hluta eftir himinbrautum<\/a>. \u00cd dr\u00f6gunum s\u00fdndi Newton fram \u00e1, a\u00f0 ef a\u00f0dr\u00e1ttarkrafturinn hef\u00f0i \u00feau einkenni sem \u00e1\u00f0ur var l\u00fdst, v\u00e6ru brautirnar <a href=\"https:\/\/en.wikipedia.org\/wiki\/Conic_section\">keilusni\u00f0<\/a>, \u00fea\u00f0 er sporbaugar (ellipsur), fleygbogar (parab\u00f3lur) e\u00f0a glei\u00f0bogar (h\u00fdperb\u00f3lur), me\u00f0 s\u00f3lina \u00ed brennipunkti. Newton benti \u00e1, a\u00f0 brautir reikistjarnanna v\u00e6ru auglj\u00f3slega sporbaugar og jafnframt m\u00e6tti nota ni\u00f0urst\u00f6\u00f0una til a\u00f0 finna brautir halastjarna, \u00fe\u00f3tt \u00fea\u00f0 v\u00e6ri ekki au\u00f0velt verk.<\/p>\n<p>Halley var\u00f0 himinlifandi vi\u00f0 fr\u00e9ttirnar og m\u00e1nu\u00f0i seinna h\u00e9lt hann erindi \u00ed <a href=\"https:\/\/royalsociety.org\/about-us\/history\/\">Konunglega breska v\u00edsindaf\u00e9laginu<\/a> um \u00feessa t\u00edmam\u00f3tani\u00f0urst\u00f6\u00f0u Newtons. \u00dea\u00f0 t\u00f3k Newton hins vegar r\u00fam tv\u00f6 \u00e1r til vi\u00f0b\u00f3tar a\u00f0 ganga fr\u00e1 fyrstu \u00fatg\u00e1funni af meistaraverki s\u00ednu, <a href=\"https:\/\/en.wikipedia.org\/wiki\/Philosophi%C3%A6_Naturalis_Principia_Mathematica\">Principia<\/a>, \u00fear sem \u00feessar ni\u00f0urst\u00f6\u00f0ur og margar a\u00f0rar voru kynntar. H\u00e9r ver\u00f0ur ekki r\u00e6tt frekar um mikilv\u00e6gi \u00feessa st\u00f3rbrotna verks (sj\u00e1 \u00fe\u00f3\u00a0<a href=\"https:\/\/plato.stanford.edu\/entries\/newton-principia\/\">h\u00e9r<\/a>) og \u00feess a\u00f0eins geti\u00f0, a\u00f0 \u00fev\u00ed l\u00fdkur me\u00f0 \u00edtarlegri umfj\u00f6llun um halastj\u00f6rnur (fr\u00e1 og me\u00f0 lemmu 4 \u00ed \u00feri\u00f0ju b\u00f3k) og hvernig frumreikna m\u00e1 brautir \u00feeirra \u00ed fleygbogan\u00e1lgun \u00fat fr\u00e1 \u00feremur sta\u00f0arm\u00e6lingum. \u00deessa a\u00f0fer\u00f0 nota\u00f0i Newton svo \u00ed b\u00f3kinni til finna braut halastj\u00f6rnunnar 1680 (sj\u00e1 \u00edtarlegri umfj\u00f6llun um brautarreikninga \u00ed upphafi n\u00e6stu f\u00e6rslu).<\/p>\n<figure id=\"attachment_5843\" aria-describedby=\"caption-attachment-5843\" style=\"width: 598px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-5843\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/07\/Principia_Comet-300x155.png\" alt=\"\" width=\"598\" height=\"309\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Principia_Comet-300x155.png 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/07\/Principia_Comet.png 600w\" sizes=\"auto, (max-width: 598px) 100vw, 598px\" \/><figcaption id=\"caption-attachment-5843\" class=\"wp-caption-text\">Braut halastj\u00f6rnunnar 1680 \u00ed fleygbogan\u00e1lgun. Myndin er \u00far halastj\u00f6rnuhluta Princip\u00edu.<\/figcaption><\/figure>\n<p>\u00deegar h\u00e9r var komi\u00f0 s\u00f6gu var Newton or\u00f0inn \u00feess fullviss, a\u00f0 halastj\u00f6rnur v\u00e6ru ekki jafn fr\u00e1brug\u00f0nar reikistj\u00f6rnum og \u00e1\u00f0ur var tali\u00f0. \u00de\u00e6r v\u00e6ru \u00fev\u00ed eil\u00edfar eins og a\u00f0rir himinhnettir og kjarni \u00feeirra e\u00f0a h\u00f6fu\u00f0 v\u00e6ru \u00far f\u00f6stu sam\u00fej\u00f6ppu\u00f0u efni. \u00de\u00e6r fengju lj\u00f3s sitt fr\u00e1 s\u00f3linni og s\u00f3larhitinn framkalla\u00f0i jafnframt yfirbor\u00f0sgufur, sem myndu\u00f0u hj\u00fap stj\u00f6rnunnar. Hluti agnanna \u00ed hj\u00fapnum b\u00e6rist svo me\u00f0 upphita\u00f0ri eisu \u00ed \u00e1tt fr\u00e1 s\u00f3linni, l\u00edkt og reykur berst fr\u00e1 reykh\u00e1fi me\u00f0 heitu lofti.<\/p>\n<p>Til gamans m\u00e1 geta \u00feess, a\u00f0 hinn einl\u00e6gi a\u00f0d\u00e1andi Newtons, <a href=\"https:\/\/en.wikipedia.org\/wiki\/Voltaire\">Voltaire<\/a> (1694-1778), var ekki s\u00e1ttur vi\u00f0 \u00feessa sk\u00fdringu meistarans. A\u00f0 hans mati voru halarnir raunverulegur reykur fr\u00e1 brennandi efnum \u00e1 yfirbor\u00f0i stj\u00f6rnunnar.\u00a0 \u00ddmis \u00f6nnur tilbrig\u00f0i vi\u00f0 kenningu Newtons um e\u00f0li halastjarna komu fram \u00e1 n\u00e6stu \u00e1rum, \u00e1ratugum og \u00f6ldum. Vandam\u00e1li\u00f0 var \u00fe\u00f3 ekki a\u00f0 fullu leyst fyrr en vel var li\u00f0i\u00f0 \u00e1 tuttugustu \u00f6ldina.<\/p>\n<p>Fyrsti \u00cdslendingurinn sem kynnti s\u00e9r aflfr\u00e6\u00f0i Newtons var\u00a0<a href=\"http:\/\/uni.hi.is\/einar\/2017\/10\/18\/aflfraedi-i-verkum-stefans-bjornssonar\/\">Stef\u00e1n Bj\u00f6rnsson<\/a> reiknimeistari. \u00cd disp\u00fatat\u00edu fr\u00e1 1758 fjallar hann um halastj\u00f6rnur og \u00feyngdarl\u00f6gm\u00e1li\u00f0, eins og n\u00e1nar er sagt fr\u00e1 \u00ed n\u00e6stu f\u00e6rslu. \u00c1 einum sta\u00f0 f\u00e6rir hann fram r\u00f6k fyrir \u00fev\u00ed, a\u00f0<\/p>\n<blockquote><p>g\u00f3\u00f0f\u00fas Gu\u00f0 <em>[hafi]<\/em> af \u00f3endanlegri visku sinni r\u00e9ttilega fengi\u00f0 halastj\u00f6rnunum sta\u00f0 utan d\u00fdrahringsins, einmitt \u00ed \u00feeim tilgangi a\u00f0 komast hj\u00e1 of miklum truflunum \u00e1 gangi og brautum reikistjarnanna, sem annars yr\u00f0u \u00f3hj\u00e1kv\u00e6milegar.<\/p><\/blockquote>\n<p>\u00dearna notar Stef\u00e1n <a href=\"https:\/\/en.wikipedia.org\/wiki\/Teleological_argument\">markhyggjur\u00f6k<\/a> til a\u00f0 \u00fatsk\u00fdra, hvers vegna brautir halastjarna eru ekki bundnar vi\u00f0 s\u00f3lkerfisplani\u00f0 (d\u00fdrahringinn) heldur komi inn \u00ed reikistj\u00f6rnukerfi\u00f0 \u00far \u00f6llum \u00e1ttum. \u00deessa hugmynd hefur Stef\u00e1n s\u00f3tt \u00ed eftirm\u00e1la Princip\u00edu, n\u00e1tt\u00faruspekilega hugvekju, sem Newton gaf nafni\u00f0 <a href=\"https:\/\/isaac-newton.org\/general-scholium\/\">General scholium<\/a> og einkennist a\u00f0 hluta af markhyggju og <a href=\"https:\/\/en.wikipedia.org\/wiki\/Natural_theology\">n\u00e1tt\u00farugu\u00f0fr\u00e6\u00f0i<\/a>. \u00cd framhaldi af fyrri or\u00f0um \u00ed disp\u00fatat\u00edunni vitnar Stef\u00e1n \u00ed 6. kafla \u00ed \u00feri\u00f0ju efnisgreinina \u00ed hugvekju Newtons og segir:<\/p>\n<blockquote><p>\u00d6nnur markhyggjur\u00f6k fyrir \u00fev\u00ed a\u00f0 halastj\u00f6rnur s\u00e9u fjarri d\u00fdrahringnum f\u00e6rir snillingurinn Newton \u00ed Princip\u00edu, \u00feri\u00f0ju b\u00f3k <em>[&#8230;]<\/em>:\u00a0\u00a0 \u201eAf \u00feessu gefur a\u00f0 skilja hvers vegna halastj\u00f6rnurnar eru ekki \u00ed d\u00fdrahringnum eins og reikistj\u00f6rnur, en flakka \u00fea\u00f0an og berast \u00e1 \u00fdmsa vegu um geiminn. Au\u00f0vita\u00f0 \u00ed \u00feeim tilgangi a\u00f0 \u00ed s\u00f3lfir\u00f0 sinni, \u00feegar \u00fe\u00e6r hreyfast h\u00e6gast, s\u00e9u \u00fe\u00e6r sem fj\u00e6rst hver annarri og togi sem minnst gagnkv\u00e6mt hver \u00ed a\u00f0ra.\u201c\u00a0\u00a0 Og \u00feessi tvennu markhyggjur\u00f6k reynist fulln\u00e6gjandi, hlutl\u00e6g, frumspekileg r\u00f6ksemd sem orka\u00f0i \u00e1 Gu\u00f0, svo hann setti halastj\u00f6rnurnar v\u00ed\u00f0sfjarri d\u00fdrahringnum.<\/p><\/blockquote>\n<ul>\n<li>I. Newton, 1684 (handrit): <a href=\"http:\/\/www.newtonproject.ox.ac.uk\/catalogue\/record\/NATP00089\">De motu corporum in gyrum<\/a> (ftrst prenta\u00f0 1838).<\/li>\n<li>I. Newton, 1726: <a href=\"https:\/\/books.google.is\/books?id=WeZ09rjv-1kC&amp;source=gbs_navlinks_s\">Philosophiae naturalis principia mathematica<\/a> (\u00feri\u00f0ja \u00fatg\u00e1fa). Ensk \u00fe\u00fd\u00f0ing F. Cajoris fr\u00e1 1934: <a href=\"https:\/\/books.google.is\/books?id=dXpXtAEACAAJ&amp;source=gbs_navlinks_s\">The mathematical principles of natural philosophy.<\/a><\/li>\n<li>Voltaire, 1738:<i><span lang=\"fr\"> <a href=\"https:\/\/books.google.is\/books?id=7DEHAAAAQAAJ&amp;source=gbs_navlinks_s\">\u00c9l\u00e9mens de la philosophie de Neuton.<\/a><\/span><\/i><\/li>\n<li>Stef\u00e1n Bj\u00f6rnsson, 1758: <a href=\"https:\/\/notendur.hi.is\/einar\/SAGA\/SB_cometae_1758.pdf\">De effectu cometarum descendentium in systema nostrum planetarium<\/a>.<\/li>\n<li>A. N. Kriloff, 1925: <a href=\"http:\/\/adsbit.harvard.edu\/\/full\/1925MNRAS..85..640K\/0000640.000.html\">On Sir Isaac Newton&#8217;s method of determining the parabolic orbit of a comet.<\/a><\/li>\n<li>D. W. Hughes, 1988: <a href=\"https:\/\/www.jstor.org\/stable\/531369?seq=1#page_scan_tab_contents\">The Principia and Comets.<\/a><\/li>\n<li>J. A. Ruffner, 2010: <a href=\"http:\/\/www.iub.edu\/~hpscdept\/news\/ruffner.pdf\">Isaac newton&#8217;s historia cometarum and the quest for elliptical orbits.<\/a><\/li>\n<li>T. Heidarzadeh, 2006: <a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/abs\/10.1111\/j.1600-0498.2006.00036.x\">The Reception of Newton\u00b4s Theory of Cometary Tail Formation.<\/a><\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h3 style=\"text-align: center\"><span style=\"font-size: 14pt\">Halastj\u00f6rnurit Halleys 1705<\/span><\/h3>\n<p>Reiknia\u00f0fer\u00f0in, sem Newton kynnti til s\u00f6gunnar \u00ed lok Prnicip\u00edu \u00e1ri\u00f0 1687 og nota\u00f0i til a\u00f0 finna braut halastj\u00f6rnunnar 1680, var b\u00e6\u00f0i erfi\u00f0 og t\u00edmafrek. Halley, sem las pr\u00f3f\u00f6rk af Princip\u00edu og a\u00f0sto\u00f0a\u00f0i Newton vi\u00f0 a\u00f0 b\u00faa verki\u00f0 undir prentun, var \u00ed s\u00e9rstakri a\u00f0st\u00f6\u00f0u til a\u00f0 tileinka s\u00e9r a\u00f0fer\u00f0ina og beita henni \u00e1 fleiri halastj\u00f6rnur. Vegna \u00feess hversu fl\u00f3knir reikningarnir voru, li\u00f0u hartn\u00e6r tveir \u00e1ratugir \u00fear til a\u00f0rir stj\u00f6rnufr\u00e6\u00f0ingar t\u00f3ku a\u00f0 nota \u00fe\u00e1 til \u00e1kvar\u00f0ana \u00e1 brautum halastjarna. Halley f\u00f3r s\u00e9r \u00fev\u00ed a\u00f0 engu \u00f3\u00f0slega, enda upptekinn vi\u00f0 \u00f6nnur st\u00f6rf \u00e1 \u00feessu t\u00edmabili.<\/p>\n<p>\u00dea\u00f0 var fyrst einum \u00e1tta \u00e1rum eftir \u00fatkomu Princip\u00edu, sem Halley var fari\u00f0 a\u00f0 gruna, a\u00f0 brautarreikningar hans g\u00e6fu til kynna a\u00f0 halastj\u00f6rnurnar fr\u00e6gu, \u00e1rin 1531, 1607 og 1682, v\u00e6ru \u00ed raun ein og sama stjarnan. H\u00fan v\u00e6ri \u00e1 sporbaug um s\u00f3lina og f\u00e6ri eina umfer\u00f0 \u00e1 um \u00fea\u00f0 bil 76 \u00e1rum.<\/p>\n<p>Eftir a\u00f0 hafa r\u00e6tt m\u00e1lin vi\u00f0 Newton, kynnti Halley \u00feessa hugmynd \u00ed Konunglega breska v\u00edsindaf\u00e9laginu \u00e1ri\u00f0 1696. \u00dea\u00f0 var \u00fe\u00f3 ekki fyrr en 1705, sem hann l\u00e9t prenta ni\u00f0urst\u00f6\u00f0ur reikninga sinna \u00e1 brautum 23 halastjarna \u00ed handh\u00e6gri t\u00f6flu (ni\u00f0urst\u00f6\u00f0ur Newtons fyrir stj\u00f6rnuna 1680 eru einnig me\u00f0 \u00ed t\u00f6flunni):<\/p>\n<figure id=\"attachment_7718\" aria-describedby=\"caption-attachment-7718\" style=\"width: 600px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\" wp-image-7718\" src=\"http:\/\/uni.hi.is\/einar\/files\/2018\/09\/HalleyTable1705-300x196.jpg\" alt=\"\" width=\"600\" height=\"392\" srcset=\"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/HalleyTable1705-300x196.jpg 300w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/HalleyTable1705-1024x669.jpg 1024w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/HalleyTable1705-768x502.jpg 768w, https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/wp-content\/uploads\/2018\/09\/HalleyTable1705.jpg 1420w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><figcaption id=\"caption-attachment-7718\" class=\"wp-caption-text\">Hin merka tafla Halleys fr\u00e1 1705 \u00fear sem sj\u00e1 m\u00e1 l\u00edkindin me\u00f0 halastj\u00f6rnunum \u00e1rin 1531, 1607 og 1682. T\u00f6lulegar uppl\u00fdsingar um \u00feessar \u00ferj\u00e1r stj\u00f6rnur eru undirstrika\u00f0ar me\u00f0 appels\u00ednugulum lit.<\/figcaption><\/figure>\n<p>\u00cd \u00feessari s\u00f6mu grein setti Halley fram hina fr\u00e6gu tilg\u00e1tu a\u00f0 halastjarnan, sem \u00e1\u00f0ur haf\u00f0i s\u00e9st 1531, 1607 og 1682, myndi birtast \u00e1 n\u00fdjan leik \u00e1ri\u00f0 1758:<\/p>\n<blockquote><p>Whenever a new comet shall appear, we may be able to know, by comparing together the elements, whether it be any of those which has appeared before, and consequently to determine its period, and the axis of its orbit, and to foretell its return. And, indeed, there are many things which make me believe that the comet which <em>Apian<\/em> observed in the year 1531 was the same with which <em>Kepler<\/em> and <em>Longomontanus<\/em> took notice of and described in the year 1607, and which I my self have seen return, and observd in the year 1682. All the elements agree, and nothing seems to contradict this my opinion. <em>[\u2026]<\/em>\u00a0 Hence I dare venture to foretell, that it will return again in the year 1758.<\/p><\/blockquote>\n<p>\u00cd n\u00e6stu f\u00e6rslu (nr. 2) ver\u00f0ur r\u00e6tt n\u00e1nar um endurkomu halastj\u00f6rnu Halleys \u00e1ri\u00f0 1758.<\/p>\n<ul>\n<li>Halley, 1705: <a href=\"https:\/\/archive.org\/details\/synopsisofastron00hall\">A synopsis of the astronomy of comets.<\/a> Ensk \u00fe\u00fd\u00f0ing \u00e1 latnesku frum\u00fatg\u00e1funni, <a href=\"https:\/\/archive.org\/details\/jstor-102980\">Astronomiae Cometicae Synopsis.<\/a><\/li>\n<li>R. E. Wilson, 1910: <a href=\"http:\/\/adsabs.harvard.edu\/full\/1910PA.....18..357W\">The Story of Halley and His Comet.<\/a><\/li>\n<li>R. L. Newburn og D. K. Yeomans, 1982: <a href=\"http:\/\/adsbit.harvard.edu\/\/full\/1982AREPS..10..297N\/0000297.000.html\">Halley\u2019s comet.<\/a><\/li>\n<li>P. Broughton, 1985: <a href=\"http:\/\/adsabs.harvard.edu\/full\/1985JHA....16..123B\"> The First Predicted Return of Comet Halley.<\/a><\/li>\n<li>R. J. M. Olson og J. M. Pasachoff, 1987: <a href=\"http:\/\/adsbit.harvard.edu\/\/full\/1987A%26A...187....1O\/0000001.000.html\">New Information on Comet p\/Halley as Depicted by Giotto DI Bondone and Other Western Artists.<\/a><\/li>\n<li>R. M. Jenkins, 2004: <a href=\"https:\/\/www.staff.science.uu.nl\/~gent0113\/hovo\/downloads\/text1_10b.pdf\">The Star of Bethlehem and the comet of AD 66.<\/a><\/li>\n<li>\u00c1rni Hjartarson, 1985: <a href=\"https:\/\/notendur.hi.is\/~einar\/AH1985.pdf\">Halastjarnan Halley \u00ed \u00edslenskum heimildum.<\/a><\/li>\n<\/ul>\n<hr \/>\n<h3 style=\"text-align: center\">Framhaldsf\u00e6rslur:<\/h3>\n<ul>\n<li>Halastj\u00f6rnur fyrr og n\u00fa &#8211; 2. \u00c1tj\u00e1nda og n\u00edtj\u00e1nda \u00f6ld.<\/li>\n<li>Halastj\u00f6rnur\u00a0fyrr og n\u00fa &#8211; 3. Tuttugasta \u00f6ld.<\/li>\n<li>Halastj\u00f6rnur\u00a0fyrr og n\u00fa &#8211; 4. Upphaf tuttugustu og fyrstu aldar (me\u00f0 lista yfir \u00fdmsar a\u00f0rar gagnlegar vefs\u00ed\u00f0ur og ritsm\u00ed\u00f0ar).<\/li>\n<\/ul>\n<hr \/>\n<hr \/>\n<p><span style=\"font-size: 10pt\"><strong>Vi\u00f0b\u00f3t 1<\/strong> (20. sept. 2018):\u00a0 \u00c9g var ekki fyrr b\u00fainn a\u00f0 birta f\u00e6rsluna en <a href=\"https:\/\/aeon.co\/ideas\/how-a-huguenot-philosopher-realised-that-atheists-could-be-virtuous\">\u00feessi skemmtilega grein<\/a>\u00a0 um <a href=\"https:\/\/en.wikipedia.org\/wiki\/Pierre_Bayle\">Pierre Bayle<\/a>\u00a0 (1647-1706) birtist \u00ed vefritinu AEON. \u00dear er minnt \u00e1, a\u00f0 Bayle nota\u00f0i heims\u00f3kn halastj\u00f6rnunnar miklu \u00e1ri\u00f0 1680 til a\u00f0 f\u00e6ra r\u00f6k fyrir \u00fev\u00ed, a\u00f0 gu\u00f0leysingjar (atheists) g\u00e6tu veri\u00f0 dygg\u00f0ugir einstaklingar:\u00a0 <a href=\"https:\/\/books.google.is\/books?id=UueopQAmgzUC&amp;source=gbs_navlinks_s\">Various Thoughts on the Occasion of a Comet<\/a>.\u00a0 \u00de\u00f3tt \u00ed dag s\u00e9 \u00feetta fulllj\u00f3st \u00f6llum \u00f6\u00f0rum en ofst\u00e6kism\u00f6nnum, var ekki svo \u00ed lok sautj\u00e1ndu aldar.<\/span><\/p>\n<hr \/>\n<p><span style=\"font-size: 10pt\"><strong>Vi\u00f0b\u00f3t 2<\/strong> (24. sept. 2018):\u00a0 Sama \u00e1r og Rasmus Bartholin gaf \u00fat verki\u00f0 um ranns\u00f3knir s\u00ednar \u00e1 halastj\u00f6rnunum 1664 og 1665, kom \u00fat \u00f6\u00f0ruv\u00edsi b\u00f3k um halastj\u00f6rnur \u00ed Kaupmannah\u00f6fn. H\u00f6fundurinn var <a href=\"https:\/\/en.wikipedia.org\/wiki\/Thomas_Bartholin\">Thomas Bartholin<\/a>\u00a0 (1616-1680), br\u00f3\u00f0ir Rasmusar og fr\u00e6gur l\u00e6knapr\u00f3fessor vi\u00f0 Hafnarh\u00e1sk\u00f3la. Hans er n\u00fa einkum minnst fyrir a\u00f0 hafa veri\u00f0 me\u00f0al hinna fyrstu til a\u00f0 l\u00fdsa sog\u00e6\u00f0akerfi l\u00edkamans.<\/span><\/p>\n<ul>\n<li><span style=\"font-size: 10pt\">Th. Bartholin, 1665:\u00a0 <a href=\"https:\/\/books.google.is\/books?id=U7HToQEACAAJ&amp;source=gbs_navlinks_s\">De Cometa, Consilium Medicum, cum Monstrorum Nuper in Dania narorum Historia.<\/a><\/span><\/li>\n<\/ul>\n<p><span style=\"font-size: 10pt\">\u00cd verki s\u00ednu\u00a0 <em>L\u00e6kningar, Curationes, s\u00e9ra \u00deorkels Arngr\u00edmssonar<\/em>\u00a0 fr\u00e1 1949 segir Vilmundur J\u00f3nsson \u00feetta um Thomas (bls. 154):<\/span><\/p>\n<blockquote><p><span style=\"font-size: 10pt\">T\u00f3mas Barthol\u00edn <em>[\u2026]<\/em> var yfirleitt engin betrungur \u00d3la Worms um t\u00f6k s\u00edn \u00e1 veruleikanum, og er hann tilvali\u00f0 d\u00e6mi \u00feeirra t\u00edmaskiptamanna, sem n\u00e1\u00f0 h\u00f6f\u00f0u haldi \u00e1 litlum sk\u00e6kli reynsluv\u00edsindanna og voru a\u00f0 v\u00edsu sta\u00f0reyndum h\u00e1\u00f0ir \u00e1 \u00fev\u00ed \u00fer\u00f6nga svi\u00f0i en utan \u00feess enn allir \u00e1 bandi hinna hugl\u00e6gu v\u00edsinda og sta\u00f0lausu hugmyndaflugi \u00feeirra \u00fear engin takm\u00f6rk sett.<\/span><\/p><\/blockquote>\n<p><span style=\"font-size: 10pt\">\u00cd verkinu um halastj\u00f6rnur er hinn fr\u00e6gi pr\u00f3fessor fullkomlega \u00e1 valdi hj\u00e1tr\u00faar og hindurvitna. Almennt telur hann, a\u00f0 fyrirb\u00e6ri \u00e1 himni, svo sem sta\u00f0a s\u00f3lar, fasar tunglsins og s\u00f3lblettir hafi mikil \u00e1hrif \u00e1 l\u00edf og heilsu manna. \u00deetta \u00e1 ekki s\u00edst vi\u00f0 um hinar hverfulu halastj\u00f6rnur. Allt fr\u00e1 d\u00f6gum Jerem\u00edasar sp\u00e1manns hafi \u00fe\u00e6r reynst forbo\u00f0ar um slys og pl\u00e1gur. Enda ekki fur\u00f0a, \u00fev\u00ed halastj\u00f6rnur ver\u00f0i til \u00far \u00fatbl\u00e6stri fr\u00e1 j\u00f6r\u00f0u og endursendi svo botnfalli\u00f0 til okkar sem \u00fargang og saur. Gott d\u00e6mi um sl\u00edkar sendingar eru vansk\u00f6pu\u00f0 b\u00f6rn, sem f\u00e6\u00f0ist vegna illsku syndugra manna.<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Inngangur \u00deessi f\u00e6rsla er s\u00fa fyrsta af fj\u00f3rum um halastj\u00f6rnur. Hinar eru: Halastj\u00f6rnur fyrr og n\u00fa &#8211; 2. \u00c1tj\u00e1nda og n\u00edtj\u00e1nda \u00f6ld. Halastj\u00f6rnur\u00a0fyrr og n\u00fa &#8211; 3. Tuttugasta \u00f6ld. Halastj\u00f6rnur\u00a0fyrr og n\u00fa &#8211; 4. Upphaf tuttugustu og fyrstu aldar. A\u00f0 stofni til er h\u00e9r um a\u00f0 r\u00e6\u00f0a heimildaskr\u00e1 og safn minnispunkta h\u00f6fundar. Inn \u00e1 milli [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,7,12,13,14,15],"tags":[],"class_list":["post-6398","post","type-post","status-publish","format-standard","hentry","category-edlisfraedi","category-midaldir","category-sautjanda-oldin","category-sextanda-oldin","category-staerdfraedi","category-stjornufraedi"],"_links":{"self":[{"href":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/index.php?rest_route=\/wp\/v2\/posts\/6398","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=6398"}],"version-history":[{"count":0,"href":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/index.php?rest_route=\/wp\/v2\/posts\/6398\/revisions"}],"wp:attachment":[{"href":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=6398"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=6398"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wizardly-antonelli.176-10-35-210.plesk.page\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=6398"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}