Planetary astronomy renaissance rise (34 resultados)

- Tapa dura
Librería: A Book By Its Cover, Louisville, KY, Estados Unidos de AmericaA Book By Its Cover
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado - Muy bueno
EUR 46,11
Envío por EUR 3,81Se envía dentro de Estados Unidos de AmericaCantidad disponible: 1 disponible
Hardcover. Condición: Near Fine. Estado de la sobrecubierta: Near Fine. Lightest wear only. 274 pages + glossary and index.

- Tapa blanda
Librería: BooksRun, Philadelphia, PA, Estados Unidos de AmericaBooksRun
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado - Bueno
EUR 50,99
Gastos de envío gratisSe envía dentro de Estados Unidos de AmericaCantidad disponible: 1 disponible
Paperback. Condición: Very Good. 1. It's a well-cared-for item that has seen limited use. The item may show minor signs of wear. All the text is legible, with all pages included. It may have slight markings and/or highlighting.

- Tapa dura
Librería: Better World Books, Mishawaka, IN, Estados Unidos de AmericaBetter World Books
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado - Aceptable
EUR 57,99
Gastos de envío gratisSe envía dentro de Estados Unidos de AmericaCantidad disponible: 2 disponibles
Condición: Good. Former library copy. Pages intact with minimal writing/highlighting. The binding may be loose and creased. Dust jackets/supplements are not included. Includes library markings. Stock photo provided. Product includes identifying sticker. Better World Books: Buy Books. Do Good.

- Tapa blanda
Librería: Better World Books: West, Reno, NV, Estados Unidos de AmericaBetter World Books: West
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado - Bueno
EUR 59,10
Gastos de envío gratisSe envía dentro de Estados Unidos de AmericaCantidad disponible: 1 disponible
Condición: Very Good. Pages intact with possible writing/highlighting. Binding strong with minor wear. Dust jackets/supplements may not be included. Stock photo provided. Product includes identifying sticker. Better World Books: Buy Books. Do Good.
Más imágenesThe General History of Astronomy. Volume 2B. Planetary Astronomy from the Renaissance to the Rise of Astrophysics.
TATON, Rene (1915-2004), Alexandre Koyre Research Centre, Paris; Curtis WILSON, St John's College, Annapolis.
Idioma: Inglés
Editorial: Cambridge University Press, 1995., Cambridge:, 1995
- Tapa dura
Librería: Jeff Weber Rare Books, Neuchatel, NEUCH, SuizaJeff Weber Rare Books
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado
EUR 41,54
Envío por EUR 25,00Se envía de Suiza a Estados Unidos de AmericaCantidad disponible: 1 disponible
Royal 8vo. xiii, [1], 281, [1] pp. Illus., index. Black gilt-stamped cloth, dust-jacket. Near fine. ISBN: 0521351685 Hardcover issue. Part B of Planetary Astronomy from the Renaissance to the Rise of Astrophysics continues the history of celestial mechanics and observational discovery through the eighteenth and nineteenth centuries. It provides a synoptic view of the main developments and furnishes details about the lives, ideas, and interactions of the various astronomers involved. Twelve different authors have contributed their expertise to this book that begins with the reception of Newton's inverse-square law. In the remainder, a large place is given to the development of the mathematical theory of celestial mechanics from Clairaut and Euler to LeVerrier, Newcomb, Hill, and Poincare. This emphasis is balanced by other chapters on observational discoveries and the rapprochement of observation and theory (for instance, the discovery of Uranus and the asteroids, use of Venus transits to refine solar parallax, introduction of the method of least squares, and the development of planetary and satellite ephemerides). Lists of "Further Reading" provide entry to the literature of the several topics. This book will be of great interest to historians of science and astronomers." TABLE OF CONTENTS: Part V. Early Phases in the Reception of Newton's Theory: 14. The vortex theory in competition with Newtonian celestial dynamics Eric J. Aiton / 15. The shape of the Earth Seymour L. Chapin / 16. Clairaut and the motion of the lunar apse: The inverse-square law undergoes a test Craig B. Waff / 17. The precession of the equinoxes from Newton to d'Alembert and Euler Curtis Wilson / 18. The solar tables of Lacaille and the lunar tables of Mayer Eric G. Forbes and Curtis Wilson / 19. Predicting the mid-eighteenth-century return of Halley's Comet Craig B. Waff. Part VI. Celestial Mechanics During the Eighteenth Century: 20. The problem of perturbation analytically treated: Euler, Clairaut, d'Alembert Curtis Wilson / 21. The work of Lagrange in celestial mechanics Curtis Wilson / 22. Laplace Bruno Morando. Part VII. Observational Astronomy and the Application of Theory in the Late Eighteenth and Early Nineteenth Century: / 23. Measuring solar parallax: The Venus transits of 1761 and 1769 and their nineteenthâ"century sequels Albert Van Helden / 24. The discovery of Uranus, the Titius-Bode and the asteroids Michael Hoskin / 25. Eighteenthâ"and nineteenth century developments in the theory and practice of orbit determination Brian G. Marsden / 26. The introduction of statistical reasoning into astronomy: from Newton to Poincare Oscar Sheynin / 27. Astronomy and the theory of errors: from the method of averages to the method of least squares F. Schmeidler. Part VIII. The Development of Theory During the Nineteenth Century: / 28. The golden age of celestial mechanics Bruno Morando. Part IX. The Application of Celestial Mechanics to the Solar System to the End of the Nineteenth Century: / 29. Three centuries of lunar and planetary ephemerides and tables Bruno Morando / 30. Satellite ephemerides to 1900 Yoshihide Kozai.…

- Tapa dura
Librería: -OnTimeBooks-, Phoenix, AZ, Estados Unidos de America-OnTimeBooks-
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado - Bueno
EUR 69,45
Gastos de envío gratisSe envía dentro de Estados Unidos de AmericaCantidad disponible: 1 disponible
Condición: very_good. Gently read. May have name of previous ownership, or ex-library edition. Binding tight; spine straight and smooth, with no creasing; covers clean and crisp. Minimal signs of handling or shelving. 100% GUARANTEE! Shipped with delivery confirmation, if you're not satisfied with purchase please return item! Ships USPS Media Mail.…

Idioma: Inglés
Editorial: Cambridge University Press (edition Illustrated), 2003
- Tapa blanda
Librería: BooksRun, Philadelphia, PA, Estados Unidos de AmericaBooksRun
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado - Bueno
EUR 80,19
Gastos de envío gratisSe envía dentro de Estados Unidos de AmericaCantidad disponible: 1 disponible
Paperback. Condición: Very Good. Illustrated. It's a well-cared-for item that has seen limited use. The item may show minor signs of wear. All the text is legible, with all pages included. It may have slight markings and/or highlighting.

- Tapa blanda
Librería: Rarewaves.com USA, London, LONDO, Reino UnidoRarewaves.com USA
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 88,90
Gastos de envío gratisSe envía de Reino Unido a Estados Unidos de AmericaCantidad disponible: Más de 20 disponibles
Paperback. Condición: New. Part B of Planetary Astronomy from the Renaissance to the Rise of Astrophysics is the sequel to Part A and continues the history of celestial mechanics and observational discovery through the eighteenth and nineteenth centuries. Twelve different authors have contributed their expertise in some eighteen chapters, each of them intended to be accessible to the interested layman. An initial section deals with stages in the reception of Newton's inverse square law as exact. In the remainder of the book a large place is given to the development of the mathematical theory of celestial mechanics from Clairaut and Euler to LeVerrier, Newcomb, Hill and Poincaré - a topic rarely treated, at once synoptically and in some detail. Lists of further reading provide entrée to the literature of these several topics.…

- Tapa dura
Librería: Anybook.com, Lincoln, Reino UnidoAnybook.com
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado - Aceptable
EUR 76,27
Envío por EUR 15,86Se envía de Reino Unido a Estados Unidos de AmericaCantidad disponible: 1 disponible
Condición: Good. Volume 2. This is an ex-library book and may have the usual library/used-book markings inside.This book has hardback covers. In good all round condition. No dust jacket. Please note the Image in this listing is a stock photo and may not match the covers of the actual item,850grams, ISBN:0521242541. …

- Tapa blanda
Librería: Kennys Bookshop and Art Galleries Ltd., Galway, GY, IrlandaKennys Bookshop and Art Galleries Ltd.
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 84,34
Envío por EUR 9,50Se envía de Irlanda a Estados Unidos de AmericaCantidad disponible: Más de 20 disponibles
Condición: New. History of astronomy from Newton to Poincare. Editor(s): Taton, Rene; Wilson, Curtis. Series: General History of Astronomy. Num Pages: 296 pages, 26 line figures 25 tones 3 maps. BIC Classification: PDX; PG. Category: (P) Professional & Vocational; (U) Tertiary Education (US: College). Dimension: 246 x 189 x 16. Weight in Grams: 530. . 2009. Illustrated. paperback. . . . . …
Editorial: University Press, Cambridge, 1989
- Tapa dura
Librería: Jeremy Norman's historyofscience, Novato, CA, Estados Unidos de AmericaJeremy Norman's historyofscience
Contactar con el vendedorVendedor de 2 estrellasCondición: Usado
EUR 50,77
Envío por EUR 8,96Se envía dentro de Estados Unidos de AmericaCantidad disponible: 1 disponible
Añadir al carritoix, 274, [14]pp. Illustrated. Original cloth, dust-jacket. Fine.

- Tapa dura
Librería: Ammareal, Morangis, FranciaAmmareal
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado - Muy bueno
EUR 103,12
Envío por EUR 6,29Se envía de Francia a Estados Unidos de AmericaCantidad disponible: 1 disponible
No jacket. Condición: Bon. Ancien livre de bibliothèque avec équipements. Sans jaquette. Edition 1989. Tome 2. Ammareal reverse jusqu'à 15% du prix net de cet article à des organisations caritatives. ENGLISH DESCRIPTION Book Condition: Used, Good. Former library book. No dust jacket. Edition 1989. Volume 2. Ammareal gives back up to 15% of this item's net price to charity organizations. …

- Tapa blanda
Librería: Kennys Bookstore, Olney, MD, Estados Unidos de AmericaKennys Bookstore
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 108,00
Envío por EUR 9,41Se envía dentro de Estados Unidos de AmericaCantidad disponible: Más de 20 disponibles
Condición: New. History of astronomy from Newton to Poincare. Editor(s): Taton, Rene; Wilson, Curtis. Series: General History of Astronomy. Num Pages: 296 pages, 26 line figures 25 tones 3 maps. BIC Classification: PDX; PG. Category: (P) Professional & Vocational; (U) Tertiary Education (US: College). Dimension: 246 x 189 x 16. Weight in Grams: 530. . 2009. Illustrated. paperback. . . . . Books ship from the US and Ireland. …

Planetary Astronomy From the Renaissance to the Rise of Astrophysics: The Eighteenth and Nineteenth Centuries
Taton, Rene (Editor)/ Wilson, Curtis (Editor)/ Hoskin, Michael (Editor)
- Tapa blanda
Librería: Revaluation Books, Exeter, Reino UnidoRevaluation Books
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 121,46
Envío por EUR 15,00Se envía de Reino Unido a Estados Unidos de AmericaCantidad disponible: 2 disponibles
Paperback. Condición: Brand New. 1st edition. 295 pages. 9.50x7.50x0.50 inches. In Stock.

- Tapa dura
- Primera edición
Librería: The Spoken Word, Oxfordshire, Reino UnidoThe Spoken Word
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado - Bueno
EUR 92,69
Envío por EUR 52,77Se envía de Reino Unido a Estados Unidos de AmericaCantidad disponible: 1 disponible
Hardcover. Condición: Very Good. Estado de la sobrecubierta: Near Fine. 1st Edition. Published by Cambridge University Press in 1989 and 1995 respectively, here are the first hardback printings of Planetary Astronomy from the Renaissance to the Rise of Astrophysics (The General History of Astronomy Series)complete in 2 volumes edited by Rene Taton and Curtis Wilson. Volume 1 Part 2A Tycho Brahe to Newton Published 1989. Black cloth binding, gilt spine lettering, 274 superbly illustrated pages plus a glossary of technical terms and an index the book is in very good plus condition with the merest hint of a spine slant. The dust jacket is in near fine condition. Volume 2: Part 2B The Eighteenth and Nineteenth Centuries. Published 195. Black cloth binding, gilt spine lettering, 269 superbly illustrated pages, sources plus an additional combined index for both volumes, the book is in very good condition with a spine slant to the top of the spine. The dust jacket is near fine. Both volumes together weigh in excess of 2 kgs when properly wrapped and therefore additional postage MUST be applied to areas OUTSIDE the UK as follows: Europe £5, Rest of the World £8. UK postage is as quoted.…

- Tapa blanda
Librería: AHA-BUCH GmbH, Einbeck, AlemaniaAHA-BUCH GmbH
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 113,63
Envío por EUR 35,00Se envía de Alemania a Estados Unidos de AmericaCantidad disponible: 1 disponible
Taschenbuch. Condición: Neu. Druck auf Anfrage Neuware - Printed after ordering - Part B of Planetary Astronomy from the Renaissance to the Rise of Astrophysics is the sequel to Part A and continues the history of celestial mechanics and observational discovery through the eighteenth and nineteenth centuries. Twelve different authors have contributed their expertise in some eighteen chapters, each of them intended to be accessible to the interested layman. An initial section deals with stages in the reception of Newton's inverse square law as exact. In the remainder of the book a large place is given to the development of the mathematical theory of celestial mechanics from Clairaut and Euler to LeVerrier, Newcomb, Hill and Poincaré - a topic rarely treated, at once synoptically and in some detail. Lists of further reading provide entrée to the literature of these several topics.…

- Tapa blanda
Librería: Books Puddle, Woodside, NY, Estados Unidos de AmericaBooks Puddle
Contactar con el vendedorVendedor de 4 estrellasCondición: Nuevo
EUR 157,82
Envío por EUR 3,58Se envía dentro de Estados Unidos de AmericaCantidad disponible: 4 disponibles
Condición: New. pp. 300.

- Tapa blanda
Librería: Rarewaves.com UK, London, Reino UnidoRarewaves.com UK
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 86,79
Envío por EUR 78,00Se envía de Reino Unido a Estados Unidos de AmericaCantidad disponible: Más de 20 disponibles
Paperback. Condición: New. Part B of Planetary Astronomy from the Renaissance to the Rise of Astrophysics is the sequel to Part A and continues the history of celestial mechanics and observational discovery through the eighteenth and nineteenth centuries. Twelve different authors have contributed their expertise in some eighteen chapters, each of them intended to be accessible to the interested layman. An initial section deals with stages in the reception of Newton's inverse square law as exact. In the remainder of the book a large place is given to the development of the mathematical theory of celestial mechanics from Clairaut and Euler to LeVerrier, Newcomb, Hill and Poincaré - a topic rarely treated, at once synoptically and in some detail. Lists of further reading provide entrée to the literature of these several topics.…

- Tapa blanda
Librería: BennettBooksLtd, Los Angeles, CA, Estados Unidos de AmericaBennettBooksLtd
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 189,67
Envío por EUR 6,23Se envía dentro de Estados Unidos de AmericaCantidad disponible: 1 disponible
paperback. Condición: New. In shrink wrap. Looks like an interesting title.

- Tapa blanda
Librería: AHA-BUCH GmbH, Einbeck, AlemaniaAHA-BUCH GmbH
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 155,85
Envío por EUR 35,00Se envía de Alemania a Estados Unidos de AmericaCantidad disponible: 2 disponibles
Taschenbuch. Condición: Neu. Druck auf Anfrage Neuware - Printed after ordering - The International Astronomical Union and the International Union for the History and Philosophy of Science have sponsored a major work on the history of astronomy, which the Press publishs are in four volumes, three of which will be divided into two parts. Publication commenced with volume 4, part A. The history of astronomy has never been tackled on this scale and depth and this major synthesis breaks wholly new ground. The individual chapters of each volume have been prepared by leading experts in every field of the history of astronomy.…

- Tapa blanda
Librería: Kennys Bookstore, Olney, MD, Estados Unidos de AmericaKennys Bookstore
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 201,13
Envío por EUR 9,41Se envía dentro de Estados Unidos de AmericaCantidad disponible: Más de 20 disponibles
Condición: New. The history of astronomy has never been tackled on this scale and depth and this major synthesis breaks wholly new ground. Editor(s): Taton, Rene; Wilson, Curtis. Series: General History of Astronomy. Num Pages: 300 pages, black & white illustrations. BIC Classification: PDX; PG. Category: (G) General (US: Trade). Dimension: 240 x 188 x 18. Weight in Grams: 562. . 2003. 1st Edition. Paperback. . . . . Books ship from the US and Ireland. …

- Tapa blanda
- Primera edición
Librería: Kennys Bookshop and Art Galleries Ltd., Galway, GY, IrlandaKennys Bookshop and Art Galleries Ltd.
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 223,74
Envío por EUR 9,50Se envía de Irlanda a Estados Unidos de AmericaCantidad disponible: Más de 20 disponibles
Condición: New. The history of astronomy has never been tackled on this scale and depth and this major synthesis breaks wholly new ground. Editor(s): Taton, Rene; Wilson, Curtis. Series: General History of Astronomy. Num Pages: 300 pages, black & white illustrations. BIC Classification: PDX; PG. Category: (G) General (US: Trade). Dimension: 240 x 188 x 18. Weight in Grams: 562. . 2003. 1st Edition. Paperback. . . . . …
Editorial: Cambridge Univ. Press, Cambridge, 1995
- Tapa dura
Librería: Jeremy Norman's historyofscience, Novato, CA, Estados Unidos de AmericaJeremy Norman's historyofscience
Contactar con el vendedorVendedor de 2 estrellasCondición: Usado
EUR 64,57
Envío por EUR 8,96Se envía dentro de Estados Unidos de AmericaCantidad disponible: 1 disponible
Añadir al carritoGeneral History of Astronomy, Vol. 2. xiii, 281pp. Illustrated. Original cloth, dust-jacket. Fine.

- Tapa dura
Librería: BUCHSERVICE / ANTIQUARIAT Lars Lutzer, Wahlstedt, AlemaniaBUCHSERVICE / ANTIQUARIAT Lars Lutzer
Contactar con el vendedorVendedor de 5 estrellasCondición: Usado - Bueno
EUR 299,90
Envío por EUR 39,95Se envía de Alemania a Estados Unidos de AmericaCantidad disponible: 1 disponible
Condición: gut. Planetary Astronomy from the Renaissance to the Rise of Astrophysics, Part A, Tycho Brahe to Newton (General History of Astronomy) In englischer Sprache. pages.
Editorial: Cambridge University Press, Cambridge, 1989
- Tapa dura
- Primera edición
Librería: Webbooks, Wigtown, Wigtown, Reino UnidoWebbooks, Wigtown
Contactar con el vendedorVendedor de 5 estrellasMiembro de asociación: PBFA
Condición: Usado - Aceptable
EUR 59,33
Envío por EUR 36,00Se envía de Reino Unido a Estados Unidos de AmericaCantidad disponible: 1 disponible
Añadir al carritoHard Cover. Condición: Good. No Jacket. 1st Edition. From an academic library with the usual stamps etc. This item is heavy and may attract postal surcharges.

- Tapa blanda
- Impresión bajo demanda
Librería: Chiron Media, Wallingford, Reino UnidoChiron Media
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 77,18
Envío por EUR 7,79Se envía de Reino Unido a Estados Unidos de AmericaCantidad disponible: 20 disponibles
PF. Condición: New. This item is printed on demand. Brand new book, sourced directly from publisher. Dispatch time is 6-7 days from our warehouse. Book will be sent in robust, secure packaging to ensure it reaches you securely.

- Tapa blanda
- Impresión bajo demanda
Librería: Chiron Media, Wallingford, Reino UnidoChiron Media
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 109,50
Envío por EUR 7,79Se envía de Reino Unido a Estados Unidos de AmericaCantidad disponible: 20 disponibles
PF. Condición: New. This item is printed on demand. Brand new book, sourced directly from publisher. Dispatch time is 6-7 days from our warehouse. Book will be sent in robust, secure packaging to ensure it reaches you securely.

- Tapa blanda
- Impresión bajo demanda
Librería: CitiRetail, Stevenage, Reino UnidoCitiRetail
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 87,74
Envío por EUR 44,40Se envía de Reino Unido a Estados Unidos de AmericaCantidad disponible: 1 disponible
Paperback. Condición: new. Paperback. Part B of Planetary Astronomy from the Renaissance to the Rise of Astrophysics is the sequel to Part A and continues the history of celestial mechanics and observational discovery through the eighteenth and nineteenth centuries. Twelve different authors have contributed their expertise in some eighteen chapters, each of them intended to be accessible to the interested layman. An initial section deals with stages in the reception of Newton's inverse square law as exact. In the remainder of the book a large place is given to the development of the mathematical theory of celestial mechanics from Clairaut and Euler to LeVerrier, Newcomb, Hill and Poincare a topic rarely treated, at once synoptically and in some detail. Lists of further reading provide entree to the literature of these several topics. Part B covers the history of planetary astronomy in the eighteenth and nineteenth centuries. It provides a synoptic view of the main developments and at the same time furnishes much detail about the lives, ideas, mathematical techniques and interactions of the various astronomers involved. This item is printed on demand. Shipping may be from our UK warehouse or from our Australian or US warehouses, depending on stock availability.…
Más imágenes- Tapa blanda
- Impresión bajo demanda
Librería: preigu, Osnabrück, Alemaniapreigu
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 87,20
Envío por EUR 70,00Se envía de Alemania a Estados Unidos de AmericaCantidad disponible: 5 disponibles
Taschenbuch. Condición: Neu. The General History of Astronomy | Volume 2, Planetary Astronomy from the Renaissance to the Rise of Astrophysics | Rene Taton (u. a.) | Taschenbuch | Kartoniert / Broschiert | Englisch | 2009 | Cambridge University Press | EAN 9780521120098 | Verantwortliche Person für die EU: Libri GmbH, Europaallee 1, 36244 Bad Hersfeld, gpsr[at]libri[dot]de | Anbieter: preigu Print on Demand.…

- Tapa blanda
- Impresión bajo demanda
Librería: CitiRetail, Stevenage, Reino UnidoCitiRetail
Contactar con el vendedorVendedor de 5 estrellasCondición: Nuevo
EUR 121,11
Envío por EUR 44,40Se envía de Reino Unido a Estados Unidos de AmericaCantidad disponible: 1 disponible
Paperback. Condición: new. Paperback. The International Astronomical Union and the International Union for the History and Philosophy of Science have sponsored a major work on the history of astronomy, which the Press publishs are in four volumes, three of which will be divided into two parts. Publication commenced with volume 4, part A. The history of astronomy has never been tackled on this scale and depth and this major synthesis breaks wholly new ground. The individual chapters of each volume have been prepared by leading experts in every field of the history of astronomy. The history of astronomy has never been tackled on this scale and depth and this major synthesis breaks wholly new ground. The individual chapters of each volume have been prepared by leading experts in every field of the history of astronomy. This item is printed on demand. Shipping may be from our UK warehouse or from our Australian or US warehouses, depending on stock availability. …