Determining longitude: the first broadcast search<\/h3>\n
“And I have told you oftener then once that it [the longitude] is not be found by clock-work alone. [\u2026] Nothing but Astronomy is sufficient for this purpose. But if you are unwilling to meddle with Astronomy, I am unwilling to meddle with any other methods then the right one.” The problem was thought to be so difficult and so important to solve that the British Parliament created the Longitude Board in 1714 and offered a Prize of \u00a320 000 (representing more than \u20ac3.5 million in today\u2019s terms) to whoever would find a method to determine longitude to within 30 nautical miles (56 km). Indeed, England was not the only country interested in finding the solution: the French Acad\u00e9mie Royale des Sciences, founded by Louis XIV, also offered a prize to improve navigation (1715) and Philippe II did the same in Spain (1567), etc.<\/p>\n The Longitude Prize is probably the first, and if not then at least the most famous, scientific challenge solved by broadcast search. The principle of broadcast search is to open a problem (a challenge) to anybody, irrespective of its background, culture, expertise, etc. To interest people, some form of incentive has to be provided by the organizers of the competition: the incentive can be money, but it can be many other things, such as fame.<\/p>\n Since the Earth rotates at a steady rate, there is a direct relationship between time and longitude. If you know the local time at the position of your boat (this is possible for example by observing the passage of the Sun through its zenith) and if you know the local time at some reference point (for example Greenwich Mean Time), then, by difference, you can calculate the longitude of your boat. This was known. The problem that scientists had to face was that there was no way to keep an accurate time reference on a boat. At the time, most high accuracy clocks used pendulums that were severely disturbed by the rolling, pitching and yawing of the boat so that time was rapidly lost. It was therefore believed by leading scientists that the reference time could only be given by looking at particular astronomical movements (such as Jupiter\u2019s moons), despite the difficulty of making such measurements accurately on a moving boat. Nonetheless, due to the preconceptions, or perhaps the fancies, of leading scientists, most research efforts where channeled in this direction.<\/p>\n He started in 1730 to build several chronometers to finally reach the accuracy required in 1761. Instead of looking for the solution where everybody else was already looking, Harrison plumbed his own specific set of talents to look somewhere else. He looked in an unexpected direction and found the Solution. Unfortunately for Harrison, Newton’s dogma was so deeply anchored in the scientific community, and the Longitude Board, that it took 40 years of effort and a special favor by King George III for Harrison to be declared the winner of the Longitude prize in 1773.<\/p>\n The goal of this article was not to provide a detailed historical account Harrison\u2019s solution to the measurement of longitude (for more details, see references below), but rather to demonstrate the power of broadcast search. By opening a problem (i.e. by broadcasting a challenge) to a large community and by finding the right incentives to get people involved (such as offering a prize), it is possible to gather a large and variegated group of people, from various horizons and fields of expertise to think about a solution. The story of the measurement of Longitude demonstrates that solutions to difficult scientific problems can emerge from unexpected areas if they are broadcast to a diverse solver population.<\/p>\n In the case of Longitude, whilst the Longitude board, filled with eminent scientists, launched their prize assuming the solution would be based on astronomy (because this is what they knew), the solution was found by a humble clockmaker who was able to apply and transpose his own specific knowledge to solve an important maritime problem. Promoting and supporting broadcast search, crowdsourcing, finding Solutions in Diversity to solve today\u2019s pressing technical issues, this is PRESANS mission.<\/p>\n [\/et_pb_text][et_pb_cta admin_label=”CFE Appel d’action” _builder_version=”3.14″ title=”Calls for Expertise & Innovation Contests” button_text=”GET STARTED” button_url=”https:\/\/presans.com\/contact\/” background_image=”\/wp-content\/uploads\/2018\/06\/cfe-1.jpg” body_font=”|800|||||||” custom_button=”on” button_bg_color=”#ffffff” button_icon=”%%40%%” button_font=”|800||on|||||” header_font=”|700||on|||||” header_font_size=”25″ button_text_color=”#182954″ button_border_color=”#ffffff” button_text_size=”17″ custom_padding=”|60px||60px” saved_tabs=”all” global_module=”7257″]<\/p>\n Inject on-demand expertise into industrial innovation projects to accelerate decision making and overcome technical and scientific obstacles<\/p>\n [\/et_pb_cta][\/et_pb_column][\/et_pb_row][\/et_pb_section]<\/p>","protected":false},"excerpt":{"rendered":" Behind this provocative title lies the seminal article of a series to be published on Open Your Innovation<\/em>, a blog on Open Innovation by people working on Open Innovation<\/span><\/strong>.<\/p>\n","protected":false},"author":2,"featured_media":24,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"on","_et_pb_old_content":" Derri\u00e8re ce titre provocateur se trouve l'article fondateur d'une s\u00e9rie qui sera publi\u00e9e sur Open Your Innovation<\/em><\/strong>.<\/p> Pourquoi avons-nous choisi ce titre un peu trompeur: en effet le sujet principal de cet article n'est pas Newton mais la recherche par broadcast<\/em>. L'Open Innovation a pas mal \u00e0 voir avec la recherche par broadcast<\/em> (enfin, pas uniquement avec \u00e7a). Qu'est ce que la recherche de solution par broadcast <\/em>? Pourquoi est elle si puissante ? Depuis quand cela existe-t-il ? Dans le pr\u00e9sent article quelques r\u00e9ponses \u00e0 travers l'histoire du Prix de la Longitude.<\/p> Voici l'histoire de John Harrison (1693-1776).<\/p> Harrison, charpentier et horloger, fut aussi le g\u00e9nie qui a invent\u00e9 ce qu'on appelle le chronom\u00e8tre de marine, appareil pratique et pr\u00e9cis pour calculer la longitude d'un bateau sur n'importe quel point du Globe. L'invention d'Harrison \u00e9tait r\u00e9voltionnaire car elle a permis de s\u00e9curiser les voyages maritimes \u00e0 longue distance.<\/p> La d\u00e9termination de la longitude \u00e9tait consid\u00e9r\u00e9e comme le plus grand d\u00e9fi scientifique entre le 16e et le 18e si\u00e8cles. Bien que les m\u00e9thodes pour mesurer avec pr\u00e9cision la latitude soient connues, aucune m\u00e9thode n'\u00e9tait suffisamment pr\u00e9cise pour calculer la longitude, ce qui a transform\u00e9 de nombreux voyages maritimes en trag\u00e9die.<\/p> Un certain nombre de scientifiques c\u00e9l\u00e8bres ont propos\u00e9 des m\u00e9thodes th\u00e9oriques, et m\u00eame si certaines d'entre elles pouvaient \u00eatre exactes, elles n'\u00e9taient pas acceptables pour la navigation:<\/p> Le probl\u00e8me \u00e9tait si difficile et si important \u00e0 r\u00e9soudre que le Parlement britannique a cr\u00e9\u00e9 le Conseil de la longitude en 1714 et a d\u00e9cid\u00e9 d'offrir une prime de \u00a3 20 000 (repr\u00e9sentant plus de 3,5 millions \u20ac) \u00e0 qui trouverait une m\u00e9thode pour obtenir la longitude \u00e0 30 miles nautiques pr\u00e8s (56 km). L'Angleterre n'\u00e9tait pas le seul pays int\u00e9ress\u00e9: l'Acad\u00e9mie Royale des Sciences, fond\u00e9e en France par Louis XIX, a \u00e9galement offert une prime pour am\u00e9liorer la navigation (1715). Philippe II avait fait de m\u00eame en Espagne (1567), etc.<\/p> Le Prix de la longitude n'est pas le premier d\u00e9fi scientifique, mais il est certainement le plus c\u00e9l\u00e8bre r\u00e9solu gr\u00e2ce \u00e0 la recherche par broadcast<\/em>. Le principe de la recherche par\u00a0broadcast <\/em>est de poser un probl\u00e8me (un d\u00e9fi) \u00e0 quiconque, ind\u00e9pendamment de ses ant\u00e9c\u00e9dents, de sa culture; pour int\u00e9resser les gens, une certaine forme d'incitation doit \u00eatre fourni par les organisateurs de la comp\u00e9tition: l'incitation peut \u00eatre l'argent, mais il peut \u00eatre beaucoup d'autres choses, telle que la c\u00e9l\u00e9brit\u00e9.<\/p> Comme la Terre tourne sur elle-m\u00eame, il existe une relation directe entre le temps et la longitude. Si vous connaissez l'heure locale sur votre bateau (ce qui est possible par exemple en regardant le soleil) et si vous connaissez l'heure locale \u00e0 un certain point de r\u00e9f\u00e9rence (par exemple, Greenwich Mean Time), par diff\u00e9rence, vous pouvez calculer la longitude de votre bateau. Cela \u00e9tait connu. Le probl\u00e8me auquel les scientifiques ont d\u00fb faire face est qu'il n'y avait aucun moyen de conserver une r\u00e9f\u00e9rence de temps sur un bateau. En effet, les horloges les plus pr\u00e9cises \u00e9taient fortement perturb\u00e9es par le roulis. Tangage et roulis mettaient rapidement hors d'usage toutes les horloges du bateau. On croyait donc que le temps de r\u00e9f\u00e9rence ne pouvait \u00eatre donn\u00e9 qu'en examinant notamment les mouvements astronomiques (tels que les lunes de Jupiter).<\/p>
\nSir Isaac Newton, 1725 (Andrewes 1996)<\/em><\/p>\nThe solution: time is money<\/span> longitude<\/h3>\n
Transposition of a solution<\/h3>\n
![\"Harrison's](\"http:\/\/open-organization.com\/wp-content\/uploads\/2010\/03\/Harrisons_Chronometer_H5_JPG.jpeg\" "\\"Harrison's")
<\/a>While famous and influent scientists of the Longitude Board, including Newton, were convinced that the solution could only be found in Astronomy, Harrison spent most of his life working on a very different approach to solve the challenge: chronometers.<\/p>\nConclusion<\/h3>\n
References and Links<\/h3>\n
\n
Introduction<\/h3>
Trouver la longitude: le plus grand d\u00e9fi depuis des si\u00e8cles.<\/h3>
Trouver la longitude: la recherche de premi\u00e8re diffusion<\/h3>
La solution: le temps est de la longitude de l'argent<\/h3>
Transposition d'une solution<\/h3>