{"id":35,"date":"2005-06-30T09:17:00","date_gmt":"2005-06-30T07:17:00","guid":{"rendered":"https:\/\/kids.esa.int\/what_is_gravity\/"},"modified":"2026-10-08T00:23:19","modified_gmt":"2026-10-07T22:23:19","slug":"what_is_gravity","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/fr\/what_is_gravity\/","title":{"rendered":"Qu'est-ce que la gravit\u00e9 ?"},"content":{"rendered":"
\n

Vous \u00eates-vous d\u00e9j\u00e0 demand\u00e9 pourquoi vous retombez toujours lourdement au sol, quelle que soit la hauteur de laquelle vous sautez ? On se posait d\u00e9j\u00e0 la m\u00eame question il y \u00e0 340 ans, jusqu'\u00e0 ce qu'un scientifique britannique, appel\u00e9 Isaac Newton, d\u00e9couvre la force de gravit\u00e9.<\/p>\n<\/div>\n

L'histoire raconte qu'Isaac \u00e9tait dans son jardin, quand une pomme lui est tomb\u00e9e sur la t\u00eate. Alors qu'il frottait sa bosse, il se demanda pourquoi la pomme \u00e9tait tomb\u00e9e sur lui au lieu d'\u00eatre partie en l'air.<\/p>\n

Newton a \u00e9mis l'hypoth\u00e8se qu'une force invisible devait attirer la pomme vers la Terre. Il a baptis\u00e9 cette force \u201c gravit\u00e9 \u201d, du mot latin \u201c gravitas \u201d, qui signifie \u201c poids \u201d.<\/p>\n

\"Newton's
Le canon de Newton<\/figcaption><\/figure>\n

Newton comprit que chaque objet de l'Univers attire n\u2019importe quel autre objet de l'Univers. M\u00eame une pomme applique une force d'attraction sur tout ce qui se trouve \u00e0 proximit\u00e9.<\/p>\n

C'est la gravit\u00e9 qui maintient la Lune sur orbite autour de la Terre et c'est encore elle qui permet au Soleil de s'accrocher \u00e0 sa famille de plan\u00e8tes. L'attraction du Soleil et de la Lune provoquent les mar\u00e9es des oc\u00e9ans sur Terre.<\/p>\n

Cependant, la force de la gravit\u00e9 d\u00e9pend de la taille et de la densit\u00e9 d'un objet \u2013 ce que les scientifiques appellent sa \u201cmasse\u201d. La gravit\u00e9 d'une minuscule pomme est trop faible pour r\u00e9sister \u00e0 l'\u00e9norme attraction de la Terre, c'est pourquoi elle tombe vers le centre de la plan\u00e8te.<\/p>\n

Plus la distance entre deux objets augmente, plus l'attraction de la gravit\u00e9 diminue. Un alpiniste en haut du Mont Everest p\u00e8se un peu moins que lorsqu'il se trouve au niveau de la mer. Si une fus\u00e9e s'\u00e9loigne suffisamment loin de la Terre, elle finira par sortir compl\u00e8tement de l'attraction terrestre.<\/p>","protected":false},"excerpt":{"rendered":"

Have you ever wondered why you always fall back to the ground with a bump, no matter how high you jump? People were asking the same question 340 years ago. […]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"esa_banner_image":"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2002\/01\/sir_isaac_newton_1642-17272\/17864713-3-eng-GB\/Sir_Isaac_Newton_1642-1727.jpg","esa_banner_description":"Sir Isaac Newton, 1642-1727","esa_banner_credit":"Isaac Newton Institute for Mathematical Studies","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2002\/01\/Sir_Isaac_Newton_1642-17272","esa_external_url":"","esa_external_new_window":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":true},"categories":[10,11,19],"tags":[2],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-35","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-story-of-the-universe","tag-background-article"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/35","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/comments?post=35"}],"version-history":[{"count":4,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/35\/revisions"}],"predecessor-version":[{"id":4271,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/posts\/35\/revisions\/4271"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/media?parent=35"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/categories?post=35"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/tags?post=35"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/panel?post=35"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/language?post=35"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/age?post=35"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/duration?post=35"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/resource_type?post=35"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/audience?post=35"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/fr\/wp-json\/wp\/v2\/wf_post_folders?post=35"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}