…and extraordinary physics required to make it happen.<\/p>\n\n\n\n
According to General Relativity<\/strong>, the Earth\u2019s mass curves spacetime<\/em> around it. You, like everything else nearby, follow the straightest possible path through that curved geometry.<\/p>\n\n\n\n The mathematical machinery that describes this curvature is captured by the Riemann curvature tensor,<\/strong> which appears in Einstein\u2019s field equations as part of the relationship between matter, energy and the geometry of spacetime.<\/p>\n\n\n\n So gravity, in Einstein\u2019s picture, isn’t quite a force pulling you downward. Falling is what objects naturally do when they follow the geometry of curved spacetime. Two quantum-mechanical effects are largely responsible for the solidity of ordinary matter.<\/p>\n\n\n\n The first is electromagnetic repulsion<\/strong>. The electrons surrounding the atoms in your feet interact electromagnetically with the electrons surrounding the atoms in the floor. As the atoms are pushed closer together, these interactions resist further compression.<\/p>\n\n\n\n The second is the Pauli Exclusion Principle.<\/strong> And that stiffness is what you experience as the floor pushing back against your feet. The act of standing still is, in fact, you falling toward the centre of the Earth due to the curvature of spacetime, according to General Relativity \u2014 and not getting there because identical fermions cannot occupy the same quantum state, as dictated by Pauli\u2019s Exclusion Principle.<\/p>\n\n\n\n Stillness <\/em> …and extraordinary physics required to make it happen. Why are we falling toward the center of the Earth? According to General Relativity, the Earth\u2019s mass curves spacetime around it. You, like everything else nearby, follow the straightest possible path through that curved geometry. The mathematical machinery that describes this curvature is captured by the Riemann […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-165","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/gsama.cc\/index.php?rest_route=\/wp\/v2\/posts\/165","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gsama.cc\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gsama.cc\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gsama.cc\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gsama.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=165"}],"version-history":[{"count":5,"href":"https:\/\/gsama.cc\/index.php?rest_route=\/wp\/v2\/posts\/165\/revisions"}],"predecessor-version":[{"id":170,"href":"https:\/\/gsama.cc\/index.php?rest_route=\/wp\/v2\/posts\/165\/revisions\/170"}],"wp:attachment":[{"href":"https:\/\/gsama.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=165"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gsama.cc\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=165"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gsama.cc\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=165"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
<\/p>\n\n\n\nSo why don’t we fall all the way through?<\/h3>\n\n\n\n
Electrons are fermions, and identical fermions cannot occupy the same quantum state. As atoms are squeezed together, their electrons cannot all pile into the same low-energy states. The quantum rules governing matter resist that compression, contributing to the enormous stiffness of ordinary material.<\/p>\n\n\n\n
<\/p>\n\n\n\nShort Version<\/h3>\n\n\n\n
\n\n\n\n
is the quiet balance <\/em>
between forces <\/em>
forever asking us to move.<\/em><\/p>\n\n\n\n
\n","protected":false},"excerpt":{"rendered":"