{"id":4995,"date":"2015-07-03T07:27:01","date_gmt":"2015-07-03T07:27:01","guid":{"rendered":"http:\/\/revoscience.com\/en\/?p=4995"},"modified":"2015-07-03T07:29:55","modified_gmt":"2015-07-03T07:29:55","slug":"falling-in-to-a-blackhole","status":"publish","type":"post","link":"https:\/\/www.revoscience.com\/en\/falling-in-to-a-blackhole\/","title":{"rendered":"Falling In To a Blackhole"},"content":{"rendered":"

\"shutterstock_207984493\"<\/a>Many scientists believe that\u00a0anything sent into a black hole would probably be destroyed<\/span><\/a>. But a new study suggests that this might not be the case after all.<\/span><\/p>\n

The research says that, rather than being devoured, a person falling into a black hole would\u00a0actually be absorbed into a hologram<\/span><\/a>\u00a0\u2013 without even noticing. The paper challenges a rival theory stating that\u00a0anybody falling into a black hole hits a \u201cfirewall\u201d<\/span><\/a>\u00a0and is immediately destroyed.<\/span><\/p>\n

Hawking\u2019s Black Holes<\/strong><\/span><\/p>\n

Forty years ago Stephen Hawking shocked the scientific establishment with his discovery that\u00a0black holes aren\u2019t really black<\/span><\/a>. Classical physics implies that anything falling through the horizon of a black hole can never escape. But Hawking showed that black holes continually emit radiation once quantum effects are taken into account. Unfortunately, for typical astrophysical black holes, the temperature of this radiation is far lower than that of the\u00a0cosmic microwave background<\/span><\/a>, meaning detecting them is beyond current technology.<\/span><\/p>\n

Hawking\u2019s calculations are perplexing. If a black hole continually emits radiation, it will continually lose mass \u2013 eventually evaporating. Hawking realized that this implied a paradox: if a black hole can evaporate, the information about it will be lost forever. This means that even if we could measure the radiation from a black hole we could never figure out how it was originally formed. This violates an important rule of quantum mechanics that states\u00a0information cannot be lost or created<\/span><\/a>.<\/span><\/p>\n

Another way to look at this is that Hawking radiation poses a problem with determinism for black holes. Determinism implies that the state of the universe at any given time is uniquely determined from its state at any other time. This is how we can trace its evolution both astronomically and mathematically though quantum mechanics.<\/span><\/p>\n

Holograms in Space<\/span><\/h4>\n

This means that the loss of determinism would have to arise from\u00a0reconciling quantum mechanics with Einstein\u2019s theory of gravity<\/span><\/a>\u00a0\u2013 a notoriously hard problem and ultimate goal for many physicists. Black hole physics provides a test for any potential quantum gravity theory. Whatever your theory is, it must explain what happens to the information recording a black hole\u2019s history.<\/span><\/p>\n

It took two decades for scientists to\u00a0come up with a solution<\/span><\/a>. They suggested that the information stored in a black hole is proportional to its surface area (in two dimensions) rather than its volume (in three dimensions). This could be explained by quantum gravity, where the three dimensions of space could be reconstructed from a two-dimensional world without gravity \u2013 much like a hologram. Shortly afterwards, string theory, the most studied theory of quantum gravity,\u00a0was shown to be holographic<\/span><\/a>\u00a0in this way.<\/span><\/p>\n

Using holography we can describe the evaporation of the black hole in the two-dimensional world without gravity, for which the usual rules of quantum mechanics apply. This process is deterministic, with small imperfections in the radiation encoding the history of the black hole. So holography tells us that information is not lost in black holes, but tracking down the flaw in Hawking\u2019s original arguments has been surprisingly hard.<\/span><\/p>\n

Fuzzballs Versus Firewalls<\/span><\/h4>\n

But exactly what the black holes described by quantum theory look like is harder to work out. In 2003, Samir Mathur\u00a0proposed that black holes are in fact fuzzballs<\/span><\/a>, in which there is no sharp horizon. Quantum fluctuations around the horizon region record the information about the hole\u2019s history and thus Mathur\u2019s proposal resolves the information loss paradox. However the idea has been criticized since it implies that somebody falling into a fuzzball has a very different experience to somebody falling into a black hole descried by Einstein\u2019s theory of general relativity.<\/span><\/p>\n

The general relativity description of black holes suggests that once you go past the event horizon, the surface of a black hole, you can go deeper and deeper. As you do,\u00a0space and time become warped<\/span><\/a>\u00a0until they reach a point called the \u201csingularity\u201d at which point the laws of physics cease to exist. (Although in reality, you would be die pretty early on on this journey as you are\u00a0pulled apart by intense tidal forces<\/span><\/a>).<\/span><\/p>\n

In Mathur\u2019s universe, however, there is nothing beyond the fuzzy event horizon. Currently,\u00a0a rival theory in quantum gravity<\/span><\/a>\u00a0is that anybody falling into a black hole hits a \u201cfirewall\u201d and is immediately destroyed. The firewall proposal has been criticized since (like fuzzballs) firewalls have drastically different behavior at the horizon than general relativity black holes.<\/span><\/p>\n

But Mathur argues that to an outside observer, somebody falling into a fuzzball looks almost the same as somebody falling into an Einstein black hole, even though those falling in have very different experiences. Others working on firewalls and fuzzballs may well feel that these arguments rely on properties of the example he used. Mathur used an explicit description of a very special kind of fuzzball to make his arguments. Such special fuzzballs are probably very different to the fuzzballs needed to describe realistic astrophysical black holes.<\/span><\/p>\n

The debate about what actually happens when one falls into a black hole will probably continue for some time to come. The key question to understand is not whether the horizon region is reconstructed as a hologram \u2013 but exactly how this happens.<\/span><\/p>\n

\n

Source: discovermagazine<\/a>,\u00a0By\u00a0<\/span>Marika Taylor<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Many scientists believe that\u00a0anything sent into a black hole would probably be destroyed. But a new study suggests that this might not be the case after all. The research says that, rather than being devoured, a person falling into a black hole would\u00a0actually be absorbed into a hologram\u00a0\u2013 without even noticing. The paper challenges a […]<\/p>\n","protected":false},"author":6,"featured_media":4997,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-4995","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"featured_image_urls":{"full":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931-150x150.jpg",150,150,true],"medium":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931-300x168.jpg",300,168,true],"medium_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"1536x1536":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"2048x2048":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"ultp_layout_landscape_large":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"ultp_layout_landscape":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"ultp_layout_portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"ultp_layout_square":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"newspaper-x-single-post":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"newspaper-x-recent-post-big":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"newspaper-x-recent-post-list-image":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",95,53,false],"web-stories-poster-portrait":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",448,252,false],"web-stories-publisher-logo":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",96,54,false],"web-stories-thumbnail":["https:\/\/www.revoscience.com\/en\/wp-content\/uploads\/2015\/07\/shutterstock_2079844931.jpg",150,84,false]},"author_info":{"info":["Amrita Tuladhar"]},"category_info":"News<\/a>","tag_info":"News","comment_count":"0","_links":{"self":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/4995","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/comments?post=4995"}],"version-history":[{"count":0,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/posts\/4995\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media\/4997"}],"wp:attachment":[{"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/media?parent=4995"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/categories?post=4995"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.revoscience.com\/en\/wp-json\/wp\/v2\/tags?post=4995"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}