{"id":37037,"date":"2022-10-20T00:00:00","date_gmt":"2022-10-20T00:00:00","guid":{"rendered":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/?post_type=purple_issue&p=37037"},"modified":"2023-03-30T09:02:31","modified_gmt":"2023-03-30T09:02:31","slug":"inside-the-sky-at-night-14","status":"publish","type":"post","link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/2022\/10\/20\/inside-the-sky-at-night-14\/","title":{"rendered":"Inside the Sky at Night"},"content":{"rendered":"\n

The Sky at Night <\/em>TV show, past, present and future<\/strong><\/p>\n\n

Inside The Sky at Night<\/em><\/span><\/h2>\n\n

October\u2019s Sky at Night <\/em>was a Q&A special. Panel member Nial Tanvir <\/strong>tells us five questions he\u2019s frequently asked about cosmic explosions<\/p>\n\n

\"\"
\u00de From left, Nial and other guests on the expert panel, Chris Lintott, Pete Lawrence, Maggie Aderin-Pocock and Suzie Imber, fielded viewers\u2019 questions asked by host Dallas Campbell, on everything from space junk to dark matter in the Q&A special <\/figcaption><\/figure>\n\n

My research mainly focuses on transient phenomena that come and go, particularly extremely powerful explosions known as gamma-ray bursts (GRBs). Some of these are produced by the deaths of massive stars, while others are from the mergers of binary neutron stars. The five questions I\u2019m always asked about my research are: <\/p>\n\n

Have astronomers looked for the place that the Big Bang occurred? <\/strong><\/h5>\n\n

The surprising thing we find, looking far across the Universe, is we essentially see a similar distribution of galaxies in every direction. There\u2019s no special place that could represent the centre of the Universe. In fact, this is built into the foundations of the Big Bang theory, which starts by assuming a symmetrical Universe. It also assumes it is infinite, meaning there is no centre and every point has essentially the same experience. The Big Bang isn\u2019t an explosion in space, but more an explosion of space. <\/p>\n\n

Aren\u2019t some galaxies moving away faster than the speed of light, in contradiction of the theory of relativity?<\/strong><\/h5>\n\n

It depends on how one defines distance and time. It is true that under certain ways of looking at distance, faraway galaxies are receding from us faster than the speed of light, breaking the cosmic speed limit. But if we regard that as the space between us and the distant galaxy expanding faster than the speed of light, then nothing is moving faster than the speed limit relative to other matter in its vicinity. <\/p>\n\n

How can we see GRBs from 13 billion years ago? Wouldn\u2019t their light have long passed us by now? <\/strong><\/h5>\n\n

It\u2019s a very good question and one of those aspects of the Big Bang theory that challenges our intuition. We already said the space between us and distant galaxies is expanding, so the light from them is continually playing catch-up in its journey from there to here. This means that some of the light is only just reaching us, and we see distant objects as they were in early times in the Universe. <\/p>\n\n

If the creation of black holes creates GRBs, why are they bright explosions? Shouldn\u2019t everything just fall in the black hole? <\/strong><\/h5>\n\n

When a large enough star collapses, it is initially just the central core that forms the black hole. The hole is only a few miles across (compared to millions of miles for the star). Gravity will cause material to fall into it, but the star\u2019s rotation will initially cause it to miss and be drawn into a disc around it. In the process, the potential energy of the matter gets transformed into heat, rotational velocity, magnetic energy, and so on. The surprising thing is that a fair fraction of this energy goes into powering very fast-moving jets or beams of outflowing plasma, and it is these that create gamma-ray bursts. Exactly how this occurs is still being researched, but it\u2019s probably the result of the star\u2019s magnetic field being wound up like a rubber band, throwing out matter when it unwinds. <\/p>\n\n

Could GRBs affect us on the Earth?<\/strong><\/h5>\n\n

GRBs are so powerful they could pose a threat to life on Earth if one occurred in the Milky Way. Fortunately they are very rare, even rarer in galaxies like ours. In practice they\u2019re not a great risk, but it\u2019s still important that we improve our understanding of them, to identify potentially threatening systems nearby. <\/p>\n\n

<\/div>
\n

Looking back: The Sky at Night <\/h4>\n\n\n\n

10 November 1986<\/h4>\n\n\n\n

In November 1986\u2019s episode of The <\/em>Sky <\/em>at <\/em>Night, <\/em>Patrick Moore took a look at one of the most bizarre stars ever observed: SS 433, 18,000 lightyears away in Cygnus. <\/p>\n\n\n\n

It first rose to prominence in 1978, when astronomers at the Anglo-Australian Observatory found a star that had a pair of emission lines, one of which was blueshifted, meaning it was coming towards us, and another that was redshifted as it moved away, leading it to be dubbed \u2018the star that\u2019s both coming and going\u2019.<\/span><\/p>\n\n\n\n

\"\"
Corkscrewing jets fire from SS 433, one of the weirdest stars ever found <\/figcaption><\/figure><\/div>\n\n\n\n

The more astronomers observed the star, the stranger it got. The lines were soon found to be shifting back and forth in wavelength, crossing over each other and back again in a 160-day cycle. Soon a third, stationary line was also discovered, showing the lines were coming from hydrogen gas, but behaving very strangely.<\/span><\/p>\n\n\n\n

It turned out that the star was spinning like a top, while firing out two huge jets of gas at a quarter the speed of light. When a jet pointed at Earth, it was bluer; as it tipped away, it became redder. The relativistic speeds meant the light was also experiencing time-dilation effects, making it look even weirder. Those effects are usually only seen around black holes, leading to the discovery that SS 433 is actually a binary system, the larger star having collapsed in the stellar mass black hole. As it feeds off its orbiting companion, it throws off the huge jets.<\/p>\n<\/div><\/section>\n\n

<\/p>\n\n

\"\"<\/figure><\/div>\n\n

NOVEMBER <\/strong><\/h4>\n\n

In the Multiverse of Mystery<\/strong><\/p>\n\n

In this month\u2019s episode, Maggie and Chris delve into the biggest astronomical mysteries that are yet to be solved. Do multiple universes exist? Will interstellar travel ever be possible? Are white holes only a theoretical concept or are they a reality? Join the team as they explore these and other fantastical questions in the final Sky <\/em>at <\/em>Night <\/em>episode of 2022. <\/p>\n\n

BBC Four, 14 November, <\/strong>10pm (first repeat will be on Four, 16 November, <\/strong>time tbc) Check www.bbc.co.uk\/skyatnight<\/a> for more up-to-date information <\/strong><\/p>\n\n

\"\"
Could white holes really exist or are they science fiction? The Sky at Night <\/em>finds out <\/figcaption><\/figure><\/div>\n\n

<\/p>\n\n

\n\n
\"\"<\/figure><\/div>\n\n

Nial Tanvir is a professor in astronomy and physics at the University of Leicester<\/p>\n\n

<\/p>\n\n

Photos:BBC, NRAO, XUANYU HAN\/GETTY IMAGES <\/p>\n","protected":false},"excerpt":{"rendered":"

The Sky at Night TV show, past, present and future<\/p>\n","protected":false},"author":24,"featured_media":37035,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ub_ctt_via":"","purple_page_number":"18","purple_custom_meta_purple_page_number":"18","purple_seq_number":"1","purple_custom_meta_purple_seq_number":"1","purple_source_article":"article_18-1.xml","purple_custom_meta_purple_source_article":"article_18-1.xml","purple_source_issue":"November-2022","purple_custom_meta_purple_source_issue":"November-2022","purple_external_id":"November-2022-18-1","purple_custom_meta_purple_external_id":"November-2022-18-1","purple_issue_code":"|0000086558||","purple_custom_meta_purple_issue_code":"|0000086558||","purple_android_product":"com.im.skyatnight.210","purple_custom_meta_purple_android_product":"com.im.skyatnight.210","purple_ios_product":"com.im.skyatnight.210","purple_custom_meta_purple_ios_product":"com.im.skyatnight.210","purple_web_product":"","purple_custom_meta_purple_web_product":"","purple_publication_id":"075fab74-0a21-4201-866a-899d6c41c40c","purple_migrated":"","kt_blocks_editor_width":""},"categories":[18],"tags":[88,14],"featured_image_src":"https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/4828a134-ca36-4e47-bc47-0df037cb5b9d.jpg","author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/author\/importmanagerhubsprylab-com\/"},"acf":{"readingTimeMinutes":"6","apple_news_title":""},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/4828a134-ca36-4e47-bc47-0df037cb5b9d.jpg",2048,1223,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/4828a134-ca36-4e47-bc47-0df037cb5b9d-150x150.jpg",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/4828a134-ca36-4e47-bc47-0df037cb5b9d-300x179.jpg",300,179,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/4828a134-ca36-4e47-bc47-0df037cb5b9d-768x459.jpg",768,459,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/4828a134-ca36-4e47-bc47-0df037cb5b9d-1024x612.jpg",800,478,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/4828a134-ca36-4e47-bc47-0df037cb5b9d-1536x917.jpg",1536,917,true],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/77\/2022\/10\/4828a134-ca36-4e47-bc47-0df037cb5b9d.jpg",2048,1223,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":"The Sky at Night TV show, past, present and future","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/37037"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/users\/24"}],"replies":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/comments?post=37037"}],"version-history":[{"count":9,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/37037\/revisions"}],"predecessor-version":[{"id":38650,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/posts\/37037\/revisions\/38650"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media\/37035"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/media?parent=37037"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/categories?post=37037"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcskyatnight\/wp-json\/wp\/v2\/tags?post=37037"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}