{"id":23667,"date":"2021-09-09T11:47:35","date_gmt":"2021-09-09T11:47:35","guid":{"rendered":"https:\/\/www.skyatnightmagazine.com\/?p=95773"},"modified":"2021-09-09T12:33:05","modified_gmt":"2021-09-09T12:33:05","slug":"what-is-hawking-radiation","status":"publish","type":"rss_feed","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/rss_feed\/what-is-hawking-radiation\/","title":{"rendered":"What is Hawking radiation?"},"content":{"rendered":"<p class=\"rssexcerpt\"><\/p><p class=\"rssauthor\">By Colin Stuart\n                \t\t<\/p><p class=\"rssbyline\">Published: Thursday, 09 September 2021 at 12:00 am<\/p><hr class=\"no-tts wp-block-separator\" \/>\n\n<p class=\"&quot;p1&quot;\">One of Professor Stephen Hawking\u2019s most famous ideas is known as Hawking radiation. By leaking particles back into space, a <a href=\"\/\/www.skyatnightmagazine.com\/podcasts\/what-is-a-black-hole\/&quot;\">black hole<\/a> can very slowly evaporate away.<\/p>\n<p>But what exactly is Hawking radiation, and how is it generated?<\/p>\n<p>Physicists know that on the smallest scales of the Universe pairs of particles pop into existence, suddenly appearing out of the vacuum only to rapidly recombine and disappear again.<\/p>\n<p>They are called \u2018virtual particles\u2019 and Stephen Hawking wondered what would happen if this process unfolded right on the event horizon of a black hole.<\/p>\n<p><em><strong>More about black holes:<\/strong><\/em><\/p>\n<ul><li><a href=\"\/\/www.skyatnightmagazine.com\/space-science\/m87-black-hole-photograph-how\/&quot;\"><em><strong>How to photograph a black hole<\/strong><\/em><\/a><\/li>\n<li><a href=\"\/\/www.skyatnightmagazine.com\/space-science\/where-is-nearest-black-hole\/&quot;\"><em><strong>Where is the nearest black hole to Earth?<\/strong><\/em><\/a><\/li>\n<li><a href=\"\/\/www.skyatnightmagazine.com\/space-science\/how-do-black-holes-form\/&quot;\"><em><strong>How do black holes form?<\/strong><\/em><\/a><\/li>\n<\/ul><div class=\"&quot;image-handler__container\" style=\"padding-bottom:\"> <img class=\"&quot;wp-image-99874\" align=\"\" data-src=\"&quot;https:\/\/images.immediate.co.uk\/production\/volatile\/sites\/25\/2021\/07\/Hawking-radiation-33a5ec1.jpg?quality=90&amp;resize=620%2C496&quot;\" width=\"&quot;1000&quot;\" height=\"&quot;800&quot;\" alt=\"&quot;An\" title=\"&quot;Hawking\" \/><\/div><div class=\"&quot;caption-hold&quot;\"><figcaption class=\"&quot;wp-caption-text&quot;\"><span class=\"&quot;caption-copy&quot;\"><i class=\"&quot;icon-arrow\" \/> An illustration showing what generates Hawking radiation. Credit: Getty Images<\/span><\/figcaption><span class=\"&quot;im-image-caption&quot;\" \/><\/div>\n<p>If one particle crosses the event horizon then it is forever separated from its companion and can never recombine with it.<\/p>\n<p>The particles that are left outside the event horizon are called \u2018Hawking radiation\u2019.<\/p>\n<p>However, the particles had to \u2018borrow\u2019 energy from empty space to appear in the first place.<\/p>\n<p>Normally this debt is repaid when they recombine, but as that can\u2019t happen in this case they effectively default on the loan.<\/p>\n<p>The repayment has to come from somewhere: the black hole.<\/p>\n<p>So over time a black hole slowly loses mass due to the constant need to cover these energy debts to empty space. It means that a black hole slowly evaporates over time.<\/p>\n<p>Although \u2018slowly\u2019 is a bit of an understatement. The number of years it would take a black hole with the same mass as the Sun to evaporate is one followed by 64 zeros \u2013 many times the current age of the Universe.<\/p>\n<hr class=\"no-tts wp-block-separator\" \/>","protected":false},"excerpt":{"rendered":"<p>By Colin Stuart Published: Thursday, 09 September 2021 at 12:00 am One of Professor Stephen Hawking\u2019s most famous ideas is known as Hawking radiation. By leaking particles back into space, a black hole can very slowly evaporate away. But what exactly is Hawking radiation, and how is it generated? Physicists know that on the smallest [&hellip;]<\/p>\n","protected":false},"author":24,"featured_media":0,"template":"","categories":[1],"acf":{"readingTimeMinutes":"2"},"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"By Colin Stuart Published: Thursday, 09 September 2021 at 12:00 am One of Professor Stephen Hawking\u2019s most famous ideas is known as Hawking radiation. By leaking particles back into space, a black hole can very slowly evaporate away. But what exactly is Hawking radiation, and how is it generated? Physicists know that on the smallest&hellip;","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed\/23667"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=23667"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=23667"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}