{"id":62335,"date":"2025-12-22T18:44:17","date_gmt":"2025-12-22T13:14:17","guid":{"rendered":"https:\/\/www.nextias.com\/ca\/?p=62335"},"modified":"2025-12-23T17:19:20","modified_gmt":"2025-12-23T11:49:20","slug":"thorium-nuclear-clock-discovery","status":"publish","type":"post","link":"https:\/\/www.nextias.com\/ca\/current-affairs\/22-12-2025\/thorium-nuclear-clock-discovery","title":{"rendered":"Counting Electrons Reveals Thorium\u2019s Nuclear Tick in Solid Clock"},"content":{"rendered":"\n<p><strong>Syllabus: GS3\/Science and Technology<\/strong><\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Context<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Scientists have found a way to <strong>detect thorium-229\u2019s nuclear \u2018tick\u2019 <\/strong>in a solid, opening a path to<strong> miniaturised nuclear clocks.<\/strong><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>About<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Conventional atomic clocks<\/strong> count <strong>electron transitions,<\/strong> which are sensitive to external disturbances (electric\/magnetic fields).\n<ul class=\"wp-block-list\">\n<li><strong>Nuclear energy levels<\/strong> are far more shielded, promising more stable timekeeping.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Why Thorium-229 (\u00b2\u00b2\u2079Th)?<\/strong>\n<ul class=\"wp-block-list\">\n<li>It has a <strong>uniquely low-energy nuclear excited state <\/strong>which can be directly excited using vacuum-ultraviolet (VUV) lasers\u2014a rare and crucial property.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Main experimental challenge: <\/strong>In solid materials, the excited nucleus usually relaxes via internal conversion (energy transferred to an electron) instead of emitting a detectable photon, making direct detection difficult.<\/li>\n\n\n\n<li><strong>New breakthrough approach: <\/strong>Instead of avoiding internal conversion, researchers used it as the signal by embedding \u00b2\u00b2\u2079Th in thorium dioxide (ThO\u2082), exciting nuclei with VUV laser pulses and detecting the delayed electrons emitted during nuclear decay.<\/li>\n\n\n\n<li><strong>Key Results:<\/strong>\n<ul class=\"wp-block-list\">\n<li>Clear nuclear resonance detected at 2,020,407.5 GHz.<\/li>\n\n\n\n<li>Internal conversion lifetime measured at 12.3 \u03bcs.<\/li>\n\n\n\n<li>Implies a nuclear clock accuracy of 1 second error in ~15.8 billion years.<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Significance:\u00a0<\/strong>\n<ul class=\"wp-block-list\">\n<li>Opens <strong>new materials and designs<\/strong> for nuclear clocks.<\/li>\n\n\n\n<li><strong>Enables miniaturisation,<\/strong> since time can be read via electron current rather than complex optics.<\/li>\n\n\n\n<li>Potential applications in fundamental physics, precision sensing, and tests of physical constants.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Nuclear Clock<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A nuclear clock works by using <strong>ultraviolet light<\/strong> to excite the <strong>nucleus of a special atom, like thorium-229.\u00a0<\/strong><\/li>\n\n\n\n<li>When the light hits the nucleus at just the right frequency, it causes the <strong>nucleus to change its energy state, like flipping a tiny switch.\u00a0<\/strong><\/li>\n\n\n\n<li>By precisely measuring and counting these energy flips, <strong>scientists can create an extremely accurate timekeeping device.<\/strong><\/li>\n<\/ul>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img data-dominant-color=\"efedeb\" data-has-transparency=\"false\" loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"639\" src=\"https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/12\/image-121-1024x639.png\" alt=\"\" class=\"not-transparent wp-image-62336\" style=\"--dominant-color: #efedeb; aspect-ratio:1.6025277968223686;width:377px;height:auto\" srcset=\"https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/12\/image-121-1024x639.png 1024w, https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/12\/image-121-300x187.png 300w, https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/12\/image-121-768x479.png 768w, https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/12\/image-121-1536x958.png 1536w, https:\/\/wp-images.nextias.com\/cdn-cgi\/image\/format=auto\/ca\/uploads\/2025\/12\/image-121.png 1600w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n<\/div>\n\n\n<h2 class=\"wp-block-heading\"><strong>Difference Between Atomic Clock and Nuclear Clock<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-background has-fixed-layout\" style=\"background-color:#fff2cc\"><tbody><tr><td><strong>Aspect<\/strong><\/td><td><strong>Atomic Clocks<\/strong><\/td><td><strong>Nuclear Clocks<\/strong><\/td><\/tr><tr><td><strong>Reference System<\/strong><\/td><td>Electron orbital transitions.<\/td><td>Nuclear energy transitions.<\/td><\/tr><tr><td><strong>Oscillation Frequency<\/strong><\/td><td>Microwave to optical (MHz-THz range).<\/td><td>Higher frequencies (ultraviolet).<\/td><\/tr><tr><td><strong>Precision &amp; stability<\/strong><\/td><td>Very high (defines 1 second).<\/td><td>Potentially much higher than atomic clocks.<\/td><\/tr><tr><td><strong>Applications<\/strong><\/td><td>GPS, telecom, internet, satellites.<\/td><td>Future deep-space navigation, fundamental physics.<\/td><\/tr><tr><td><strong>Current status<\/strong><\/td><td>Fully operational, widely used.<\/td><td>Experimental \/ research stage.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Key Advantages of Nuclear Clock over Atomic Clock<\/strong><\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Much greater accuracy and stability.<\/li>\n\n\n\n<li>Better for testing fundamental constants.<\/li>\n\n\n\n<li>Less environmental interference.<\/li>\n\n\n\n<li>Higher sensitivity to gravitational time dilation.<\/li>\n<\/ul>\n\n\n\n<p><strong>Source: <\/strong><a href=\"https:\/\/www.thehindu.com\/sci-tech\/science\/thorium-nuclear-clock-mossbauer-spectroscopy\/article70402209.ece\" target=\"_blank\" rel=\"noopener\"><strong>TH<\/strong><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p><strong>Context<\/strong><\/p>\n<li class=\"ms-5\">Scientists have found a way to detect thorium-229\u2019s nuclear \u2018tick\u2019 in a solid, opening a path to miniaturised nuclear clocks.<\/li>\n<p><\/p>\n<p><strong>About<\/strong><\/p>\n<li class=\"ms-5\">Conventional atomic clocks count electron transitions, which are sensitive to external disturbances (electric\/magnetic fields).<\/li>\n<li class=\"ms-5\">Nuclear energy levels are far more shielded, promising more stable timekeeping.<\/li>\n<li class=\"ms-5\">Why Thorium-229 (\u00b2\u00b2\u2079Th)?<\/li>\n<p><a href=\"https:\/\/www.nextias.com\/ca\/current-affairs\/22-12-2025\/thorium-nuclear-clock-discovery\" class=\"btn btn-primary btn-sm float-end\">Read\u00a0More<\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[21],"tags":[],"class_list":["post-62335","post","type-post","status-publish","format-standard","hentry","category-current-affairs"],"acf":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/62335","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/comments?post=62335"}],"version-history":[{"count":3,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/62335\/revisions"}],"predecessor-version":[{"id":62339,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/posts\/62335\/revisions\/62339"}],"wp:attachment":[{"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/media?parent=62335"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/categories?post=62335"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nextias.com\/ca\/wp-json\/wp\/v2\/tags?post=62335"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}